Category 6™

August hurricane outlook

By: JeffMasters, 3:02 PM GMT on July 31, 2009

The Atlantic remains quiet today, with no threat areas to discuss and no models calling for tropical storm formation over the seven days. Not much has changed in the Atlantic since my mid-July Atlantic hurricane outlook posted two weeks ago. However, we are now at the cusp of when hurricane activity begins a steep rise (Figure 1). Early August is typically when wind shear begins a major decline, sea surface temperatures continue to rise, African dust and dry air outbreaks diminish, and the African Monsoon and Intertropical Convergence Zone (ITCZ) become quite active, spawning frequent and powerful tropical waves. These tropical waves serve as the instigators of about 85% of all major hurricanes.

Since the current active hurricane period began in 1995, ten out of fourteen years (71%) have had a named storm form during the first half of August, with an average of 1.4 named storms per year. The last nine years in a row have had a named storm form during the first half of August, but the previous four year stretch (1996 - 1999), did not have any storms form.


Figure 1. The seasonal distribution of Atlantic hurricane activity shows a steep rise at the beginning of August. Image credit: NHC.

Sea Surface Temperatures
Eighty-five percent of all major hurricanes form in the Main Development Region (MDR) of the Atlantic, from the coast of Africa to the coast of Central America, between 10° and 20° latitude. This region also spawns 60% of all weaker hurricanes and tropical storms. Sea Surface Temperature (SST) anomalies in the MDR have slowly but steadily risen during July, and now stand at a respectable 0.5°C (0.9°F) above average (Figure 2). SSTs are well below the record levels observed in 2005 and 2006, when they were up to 2°C above average over large portions of the Main Development Region. Still, there is plenty of heat energy available for strong hurricanes to form this year. The strength of the Azores-Bermuda high has been below average over the past month, driving below average trade winds. Weaker trade winds don't mix up as much cold water from the depths, and cause less evaporative cooling. The latest 2-week run of the GFS model predicts continued slightly below average-strength trade winds through mid-August, so SST anomalies should continue to warm during this period.


Figure 2. Sea Surface Temperature (SST) departure from average for July 30, 2009. SSTs were about 0.5°C (0.9°F) above average over the tropical Atlantic's Main Development region for hurricanes, from Africa to Central America between 10° and 20° North Latitude. Note the large region of above average SSTs along the Equatorial Pacific off the coast of South America, the hallmark of an El Niño episode. Image credit: NOAA/NESDIS

El Niño
El Niño conditions have remained steady over the tropical Eastern Pacific over the past month. Ocean temperatures in the area 5°N - 5°S, 120°W - 170°W, also called the "Niño 3.4 region", remain at 0.8°C above average, which is 0.3°C above the threshold for a weak El Niño, according to the Australian Bureau of Meteorology (Figure 3). An increase of another 0.2°C would push the current El Niño into the "moderate" category. NOAA's Climate Prediction Center issued an El Niño Advisory earlier this month, and predicts that El Niño conditions will intensify over the next few months, and last through the coming winter. The latest set of mid-July runs of the El Niño computer models are almost universally calling for El Niño conditions to remain well-established for the peak months of hurricane season, August - October. It is likely that Atlantic hurricane activity will be suppressed in 2009 due to the strong upper-level winds and resulting wind shear an El Niño event usually brings to the tropical Atlantic. The NOAA CFS model is calling for continued above-average wind shear over most of the tropical Atlantic for the August-September-October peak part of hurricane season.


Figure 3. Sea Surface Temperature (SST) departure from average for the the equatorial Eastern Pacific (the area 5°N - 5°S, 120°W - 170°W, also called the "Niño 3.4 region"). El Niño conditions exist when the SST in this region rises 0.5°C above average. As of July 31, 2009, SSTs in the Niño 3.4 region had risen to 0.83°C above average. To be considered an "El Niño episode", El Niño conditions must occur for five consecutive months, using 3-month averages. Image credit: Australian Bureau of Meteorology.

Wind shear
Wind shear is usually defined as the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude). In most circumstances, wind shear above 20 knots will act to inhibit tropical storm formation. Wind shear below 12 knots is very conducive for tropical storm formation. High wind shear acts to tear a storm apart. The jet stream's band of strong high-altitude winds is the main source of wind shear in July over the Atlantic hurricane breeding grounds, but in August the jet stream retreats to the north, and wind shear typically falls.

Wind shear over the past month (Figure 4) has mostly been above average over the tropical Atlantic, particularly over the Caribbean. The presence of El Niño conditions over the tropical Eastern Pacific may be primarily responsible for this enhanced shear. However, wind shear has been slowly falling over the southern portion of the Caribbean and southern MDR over the past week, and is forecast by the GFS model to fall to near-average levels by mid-August. This should present a more favorable environment for hurricanes to form in by mid-month.


Figure 4. Departure of wind shear from average in m/s for the 1-month period ending July 27, 2009. Higher than average wind shear (blue colors) was observed over the Caribbean. The El Niño conditions over the tropical Eastern Pacific may be primarily responsible for this enhanced shear. Image credit: NOAA Climate Prediction Center.

Dry air and African dust
June and July are the peak months for dust coming off the coast of Africa, and the Saharan dust storms have been quite active over the past month. Expect dust from Africa to diminish in the coming month, allowing a greater chance for African tropical waves to develop.

Steering currents
The steering current pattern has remained virtually the same all summer. A persistent trough of low pressure has remained entrenched over the Eastern U.S., bringing cool and relatively moist weather to the northeastern portion of the country. This trough is strong enough to recurve any tropical storms or hurricanes that might penetrate north of the Caribbean Sea. Steering current patterns are predictable only about 3 - 5 days in the future, although we can make very general forecasts about the pattern as much as two weeks in advance. At present, it appears that the coming two weeks will maintain the strong trough over the Eastern U.S., which decreases the hurricane risk to the U.S. Gulf Coast. It is often difficult to break a months-long steering current pattern like the current one, and it's reasonable to forecast that the current steering pattern will continue to dominate into September.

Summary
Recent history suggests a 71% chance of a named storm occurring in the first half of August. However, this is not a typical year. The ITCZ has been remarkably inactive, and there have been an unusually low number of tropical waves coming off the coast of Africa. Although SST anomalies should continue to rise and wind shear should slowly fall over the next few weeks, the computer models suggest no significant changes to the current inactive weather pattern. I'll go with a 30% chance of a named storm forming in the first half of August.

I'll have a new post on Monday.

Jeff Masters

Hurricane

Late-starting hurricane seasons

By: JeffMasters, 2:01 PM GMT on July 29, 2009

Late-starting hurricane seasons--ones where the first named storm of the year doesn't occur until August--have happened in eleven of the fifty years between 1960 - 2009 (a 22% occurrence.) Only two of these eleven seasons ended up with more hurricanes than average (seven or greater). The record for the latest starting hurricane season since 1851 was set in 1914, when the only storm of the season formed on September 15. The year 1941 was also late starting, with the season's first storm arriving on September 11. Of course, we didn't have satellites back then, so it's a good bet there were storms earlier in these seasons that got missed. However, there's a good possibility that 1914 really did have only one storm. A re-analysis of the hurricane activity in the decade 1911-1920 (Landsea et al., 2008) found 1.3 missing tropical cyclones per year, thanks to the inclusion of a new database of ship weather reports called COADS. However, 1914 was not one of those years. Various authors have estimated that we missed an average of between one and three tropical cyclones per year during that time period, so it is quite possible 1914 had only one storm.


Figure 1. The hurricane season of 1914 featured only one tropical storm, and was the latest-starting hurricane season on record (September 15).

The latest dates for the first named storm of the season in the recent past, followed by the number of named storms, hurricanes, and intense hurricanes that year are:

2009 (August 15) 9,3,2
2004 (August 1) 15,9,6
2000 (August 4) 15,8,3
1988 (August 7) 12,6,3
1987 (August 9) 7,3,1
1984 (August 18) 13,5,1
1983 (August 15) 4,2,1
1977 (August 30) 6,5,1
1967 (August 30) 8,6,2
1963 (August 2) 9,6,2
1962 (August 22) 5,3,1

We can also add 1992 to the list if we ignore the unnamed subtropical storm that formed in April of that year. That year had the notorious Hurricane Andrew as its first named storm. Andrew formed on August 17 of that year, and was the only major hurricane in a year that had only seven named storms and four hurricanes. For comparison, an average Atlantic hurricane season has 10 named storms, 6 hurricanes, and 2 intense hurricanes. So, it is a good bet that 2009 will be a below-average season.

References
Landsea, C. W. , D. A. Glenn, W. Bredemeyer, M. Chenoweth, R. Ellis J. Gamache, L. Hufstetler, C. Mock, R. Perez, R. Prieto, J. Sanchez-Sesma, D. Thomas, and L. Woolcock, 2008, A Reanalysis of the 1911-20 Atlantic Hurricane Database", Journal of Climate, 21, p.2138-2168.

Jeff Masters

Hurricane

Bill Gates takes on hurricanes

By: JeffMasters, 2:49 PM GMT on July 27, 2009

Bill Gates thinks big. His charitable foundation has poured $1 billion into the fight against that great scourge of humankind, malaria, resulting in the creation of a new vaccine that is 100% effective in mice, and is now headed towards trials in humans. If successful, Gates' efforts have the potential to save millions of lives. Gates has also turned his attention to another great scourge of humankind, the hurricane. In a 2008 patent filing that recently came to light, Bill Gates and his friends presented a scheme for reducing the strength of hurricanes by cooling sea surface temperatures, using a fleet of ships that bring up cold water from the depths. Can Gates really pull this off? I don't think so. The obstacles are fourfold: technical, financial, environmental, and legal.


Figure 1. A diagram from a 2008 Bill Gates patent filing, depicting an array of hurricane-control vessels in the Gulf of Mexico. Image credit: techflash.com.

Technical issues
While modification of hurricanes is theoretically possible, the scale of the undertaking is truly enormous. A fleet of dozens or hundreds of ships spanning a huge swath of ocean would be required, and these ships would have to be able to withstand the 50-foot waves and 160 mph winds a major Category 5 hurricane could deliver. As I discussed when a similar scheme was proposed in 2006 by Atmocean, Inc., it is not clear how long the cold water pumped to the surface will stay there--the cold water pumped to the surface is more dense than the water beneath it, and so will tend to sink, allowing warmer water beneath to replace it and warm the surface waters again. Modeling studies and field studies are needed to determine if the cold water can stay at the surface long enough to significantly affect a hurricane. Furthermore, simply cooling the ocean may have no effect on a hurricane, if the storm is in a favorable upper-atmospheric environment with low wind shear.

Financial issues
Any hurricane modification effort is going to be tremendously expensive. The cost of the array of cooling pumps proposed by Atmocean in 2006 for the Gulf of Mexico was pegged at $2.4 billion. Gates' scheme would have a similar cost. He proposes paying for it through government funding and the sale of insurance policies in hurricane-prone areas.

Environmental issues
A large change to the ocean temperatures over a wide area of ocean is bound to have significant--and unknown--impacts on fisheries and wildlife. Regional weather patterns may also be affected, intensifying droughts or bringing heavy rains and flooding.

Legal issues
Hurricanes naturally make sudden unpredictable course shifts, and the hurricane modification efforts are also capable of causing track shifts in a storm. Residents on the coast hit by the modified storm will want to sue, and there will be many lawyers more than happy to take their case. Gates would have to get special legislation passed to protect his company from lawsuits, such Congress passed for the gun industry in 2006.

Summary
In summary, we simply don't know enough about hurricanes yet to safely engage in modifying them. A lot more research is needed before we should spend the huge sums needed to attempt hurricane modification. The Department of Homeland Security has a $1 million research effort going that will attempt to answer some of these questions, called HURRMIT (The Identification and Testing of Hurricane Mitigation Hypotheses). The HURRMIT program is evaluating the potential of a number of hurricane modification techniques, including:

Seeding with tiny hygroscopic aerosols to suppress warm rain (Rosenfeld et al. 2007 and Cotton et al., 2007)

Seeding with radiation-absorbing aerosols (i.e., carbon black) at the storm periphery (Gray et al., 1976)

Seeding with radiation-absorbing aerosols (i.e., carbon black) at storm top (Alamaro et al., 2006)

Pumping cool water from the depths to the ocean surface in front of the hurricane (Ginis and Kithil, 2008)

Frankly, I'm dubious that the money being spent on HURRMIT is worth it, given the four huge obstacles to hurricane modification I presented above. However, the research may provide some new insights into hurricane intensification that we don't have now.

For more insight on this issue, read the Washington Post article published on this subject earlier this year.

In closing, I'll present the proposal one reader of an New Orleans online newspaper had:

"[Bill Gates] should just have one of his employees write an ActiveX Script for Google maps so we can just highlight the hurricane, right click on it, then select delete. Or maybe just cut and paste it farther out into the Atlantic Ocean."

Controlling hurricanes, Hollywood style
Hollywood's latest attempt to create a weather disaster epic is itself a disaster, as many of you who suffered through last night's installment of "The Storm" miniseries on NBC will agree. The uninspired plot involves government/military bad guys and a noble scientist who heroically tries to save the world, with a good measure of made-for-TV chase scenes, murders, and special effects thrown in. The hero scientist Dr. Jonathan Kirk (James Van Der Beek) has a scheme whereby one can control the weather by bouncing crackling streams of energy from a ground-based array of dishes off of satellites and into the ionosphere, which then gets "peeled away like an onion". Dr. Kirk then uses the energy to bring life-giving rains to the Sudan, and to steer a hurricane away from Florida. The trouble is, he doesn't quite have things figured out. Unintended side effects occur, such as the Mojave Desert getting 8 inches of snow the day after 112°F temperatures. More problematically, the hurricane heading for Florida strengthens instead of weakening. In one scene, a radar animation of the hurricane off the coast of Florida shows the powerful storm spinning clockwise instead of counter-clockwise, defying the laws of physics. Hmm, that's some pretty powerful weather control technology! The scientific basis for the weather control scheme is preposterous--ground-based energy streams beamed into the ionosphere would not appreciably affect the weather. The weather is made in the troposphere, the layer of atmosphere closest to the ground. Furthermore, the amount of energy needed to cause the kind of disturbances portrayed in the movie are enormous, similar in scale to the entire electrical output of the world. A small array of ground-based dishes could only channel perhaps a trillionth of the amount of energy required. The movie's special effects are cheesy, the acting average, the plot weak, and the science behind the the story completely implausible, making this weather disaster movie as disastrous as the equally rotten Day After Tomorrow movie. The movie's main redeeming grace is as a cautionary tale--weather modification on a large scale will certainly have unintended side effects, and we should not engage in such efforts until we have a much greater understanding of how the weather and climate work.

Scientific American has an interesting article that talks about the proposed Bill Gates hurricane modification idea in more detail.
Jeff Masters

Hurricane

The 6 lost Hurricane Hunter missions, Part V: Typhoon Ophelia, 1958

By: JeffMasters, 2:55 PM GMT on July 24, 2009

There are no threat areas in the Atlantic to discuss, and no models are calling for tropical storm development in the next seven days, so it's time to continue my 6-part series on the hurricane/typhoon hunter missions that never returned. On January 15, 1958, an Air Force WB-50 (49-295) assigned to the 54th Weather Reconnaissance Squadron on Guam was lost in Category 4 Typhoon Ophelia, 500 miles west of Guam. From the New York Times article, "Typhoon Survey Plane Missing With 10 Aboard", 16 Jan 1958 58:7, "The Air Force said the plane last reported its position at 11:30pm January 15 (9:30am EST) at a point near the eye of storm and its 145 mph winds. A plane from the 79th Air Rescue Squadron flew to the area today, but its crew reported that the winds could not be penetrated. The search plane remained in the vicinity for four hours, trying vainly for a radio contact with the reconnaissance plane." Here is the text of the official Air Force Casualty summary for the accident (thanks to Bernie Barris of the Air Reconnaissance Weather Association for providing this!):

CASUALTY SUMMARY

On 15 January 1958, WB-50 #49-0295 departed Guam on the twelfth mission to be flown by the 54th Weather Reconnaissance Squadron on Typhoon Ophelia. This aircraft was to obtain data on the typhoon including latest position and then return to Guam.

Radio contact was last made at l330Z, 15 January when they reported their position at 13-03 North Latitude and 135-20 East Longitude in the vicinity of the typhoon. No further contact was made with the aircraft.

Two hours after receipt of the last message 79th Air Rescue Squadron on Guam was alerted. A rescue aircraft departed at 1715Z for search and possible interception. Shortly thereafter, an intensive search was begun which during its course covered more than 500,000 square miles with areas or greatest probability searched numerous times and as thoroughly as possible.

Aircraft from 79th ARS, 54th WRS,and numerous other sources completed nearly one hundred sorties accomplishing over 1200 flying hours in the effort. This is believed to be the largest Search and Rescue operation of its type ever conducted. The joint Air Force and Navy search mission was suspended on 23 January 1958. However, special weather reconnaissance missions were flown until l5 February. These flights included investigation of possible emergency landing areas, i.e. islands, reefs, and atolls within possible range of the missing aircraft. Watch was also maintained on emergency radio frequencies. 79th ARS also continued modified search operations for a period after 23 January.

After all survival possibilities had been checked with negative results the status of the missing crew members was changed from "missing" to "dead" on 20 February 1958. The following is a list of crew members lost aboard WB-5O #49-0295 :

Aircraft Commander- Captain Albert J Lauer
AO 2095765

Pilot- Captain Clyde W Tefertiller
AO 751488

Weathar Observer- Captain Marcus G Miller
AO 751488

Navigator- First Lieutenant Courtland Beeler III
AO 2210728

Navigator- First Lieutenant Paul J Buerkle Jr
AO3053321

F1ight Engineer- Technical Sergeant De1ivan L Gordon
AF 57625218

Flight Engineer- Staff Sergeant Kenneth L Tetzloff
AFl7336278

Radio Operator- Staff Sergeant Kenneth L Houseman
AF 17319484

Radio Operator- Airman First Class Randolph C Watts
AF 14382160

Weather Technician- Airman First Class Bernard G Tullgren


I spoke with Hank Woollard, whose father, Slaton Woolard, flew into Typhoon Ophelia on the hunter flight just prior to the lost flight. Mr. Woolard said his plane was so beat up by the turbulence when they penetrated the typhoon, he practically begged the flight operations control not to not let the following plane penetrate the storm. His plane was grounded for repairs for several months due to the damage it sustained. He theorized that the crash may have been related to lack of an engine air intake conversion done to most of the WB-50's when they adapted them from the very high altitude SAC service to weather reconnaisance. The conversion was to keep water out of the air intakes. Without the conversion, in certain wet weather circumstances, the engines could "drown out". One of the other WB-50 aircraft in the squadron almost went down for this reason.


Figure 1. A Popular Mechanics cover story from 1950 dramatized the dangers that the early typhoon hunters faced. From the article: "It is impossible for me to describe accurately or exaggerate the severity of the turbulence we encountered. To some it may sound utterly fantastic, but to me it was a flight for life. I have flown many weather missions in my 30 months with the 514th Reconnaissance Squadron. I have flown night combat missions in rough weather out of England, and I have instructed instrument flying in the States, but never have I dreamed of such turbulence as we encountered in Typhoon Beverly. It is amazing to me the ship held together as it did."

Previous posts in this series:
October 1, 1945 typhoon
Typhoon Wilma, 1952
Typhoon Doris, 1953
Hurricane Janet, 1955

Jeff Masters

Invest 98L or a nor'easter?

By: JeffMasters, 1:52 AM GMT on July 24, 2009

Hi, it's Dr. Rob Carver, filling in for Dr. Masters today.

Take a look at the satellite image below:


Fig. 1 GOES IR composite at 2120 EDT, July 23 2009

What do you see? (This is like a Rorschach test for meteorologists) Well, it's got a comma head with what looks like a front extending southward. It must be a nor'easter with some pretty good precipitation bands from NY into New England. There are also plenty of coastal flood advisories out to make it seem like fall/winter. Right?


Fig. 1 Plot of severe weather advisories made at 2120 EDT, July 23 2009

Well, that's not quite the right answer. For 4 hours earlier today, this low was known as INVEST98L. I have to admit that this designation caught me by surprise. Looking at the QUIKSCAT passes and SSMI data in the dark hours of the morning (I work in the SF office), I saw an elongated cyclone that looked it had a front extending southward. That meant the feature was maybe subtropical at best, and more than likely extratropical given the model analyses available. So, color me surprised when I found out about INVEST98L and even more surprised about it's short lifespan.

Moving on and taking at look at the tropical Atlantic, there's not much in the way of tropical waves to look at on satellite except for the fresh cluster that just moved off the coast. We'll have to wait and see how that wave will develop.

Rob

Hurricane

Quiet in the Atlantic; total eclipse darkens Asia

By: JeffMasters, 1:42 PM GMT on July 22, 2009

The strong tropical wave (97L) we've been tracking all week has now moved over the Bahamas, and remains disorganized, thanks to 30 knots of wind shear and a traumatic encounter with the island of Hispaniola. This wave should remain disorganized for at least the next two days, thanks to high wind shear.

The new tropical disturbance north of the central Bahama Islands is lifting northwards towards the Outer Banks of North Carolina. This morning's QuikSCAT pass showed winds of 30 - 35 mph, but no evidence of a closed circulation. This region is under about 20 - 25 knots of wind shear, and has the potential for some slow development over the next few days as it moves northwards, parallel to the coast. This low probably does not have enough time over warm water to reach tropical depression status. None of the computer models are showing any tropical development over the next seven days, though the tropical disturbance north of the central Bahamas may develop into an extratropical storm capable of dumping heavy rain on the Canadian Maritime provinces late this week.

I won't be making a post Thursday, since I'll be traveling. Wunderground's severe storms expert, Dr. Rob Carver, will make a post if a new Invest pops up. Dr. Carver has started his own blog--check out his cool satellite loops of this morning's total eclipse in Asia.

Jeff Masters

Hurricane

97L fizzles; new Bahamas disturbance develops

By: JeffMasters, 2:17 PM GMT on July 21, 2009

A strong tropical wave (97L), now located just south of Puerto Rico, has grown disorganized today. Sustained winds as high as 26 mph were observed on Barbados, and 35 mph winds were observed on St. Lucia yesterday when 97L passed through the Lesser Antilles Islands. Wind gusts to 45 mph and heavy rain can be expected in the Dominican Republic and Puerto Rico this afternoon, and in Haiti and the southeastern Bahama Islands on Wednesday. However, 97L is under too much wind shear to develop, and shear will remain in the high 25 - 35 knot range over the disturbance over the next two days.


Figure 1. Today's disturbances to watch.

A new tropical disturbance has formed north of the central Bahama Islands, about 600 miles east of Miami. The thunderstorm activity is not yet very intense, but does cover a moderately large area. This morning's QuikSCAT pass showed winds of 20 - 25 mph, and no evidence of a circulation trying to form. This region is under about 20 - 25 knots of wind shear, and has the potential for some slow development over the next few days as it moves slowly northwards. The GFS and ECMWF models hint at the possibility that this system may attempt to organize into a tropical depression by Friday, off the coast of North Carolina.

I'll have an update Wednesday.

Jeff Masters

Hurricane

High wind shear ripping into 97L

By: JeffMasters, 1:49 PM GMT on July 20, 2009

A strong tropical wave (97L) a few hundred miles east of Barbados in the Lesser Antilles Islands has grown less organized today as it tracks west at 15 - 20 mph. The wave is moving underneath an upper-level trough of low pressure, which is bringing 30 knots of wind shear to 97L. While there is a respectable amount of heavy thunderstorm activity associated with 97L, there is no longer any low-level spiral banding or rotation of the cloud pattern. This morning's QuikSCAT pass at 5:35 am EDT showed sustained winds of 35 mph a few hundred miles east of Barbados, but there was no surface circulation evident. The islands of Barbados, St. Vincent and the Grenadines, St. Lucia, and Martinique can expect heavy rain and wind gusts to 50 mph as 97L moves through the Lesser Antilles Islands this afternoon and tonight, but 97L will not become a tropical depression.

Wind shear along the path of 97L is forecast to remain in the high 25 - 35 knot range for at least the next three days. This should prevent further development of 97L, and I expect the disturbance will be gradually torn apart during the next few days. The National Hurricane Center gives 97L a low (less than 30% chance) of developing into a tropical depression in the next 48 hours. None of the computer models are forecasting any tropical storm development over the next seven days.


Figure 1. Current satellite image of African wave 97L.

I'll have an update Tuesday morning. As 97L moves through the islands, you may want to follow local observations there using our wundermap for the region.

Jeff Masters

Hurricane

97L growing more organized, will bring heavy rain to the Lesser Antilles

By: JeffMasters, 3:55 PM GMT on July 19, 2009

The tropical wave near 12N 52W, about 600 miles east of the Lesser Antilles Islands (97 L), has grown more organized this morning as it tracks west at about 20 mph. This wave is surrounded by an area of very dry air from the Sahara Desert, but 97L has been able to steadily moisten a large region of the atmosphere over the past day, insulating itself from the dry air. This moistening process has been aided by sea surface temperatures (SSTs) that have steadily increased from 26.5°C to 27.5°C, plus the presence of only 10 knots of wind shear. The system now has a small area of intense thunderstorms near its center, with some rotation of the cloud pattern evident at mid-levels of the atmosphere. An upper-level outflow channel has opened to the north, and there is evidence that surface spiral bands are beginning to form. This morning's QuikSCAT pass missed 97L, so we don't know what is happening at the surface.

Wind shear is a modest 10 knots over the disturbance, and is forecast to remain in the moderate 10 - 15 knot range through Monday morning. This should allow further development to occur today, and 97L could be approaching tropical depression strength on Monday as it moves through the central Lesser Antilles Islands. Monday night, shear is expected to rise to 20 - 30 knots, thanks to the presence of a trough of low pressure at upper levels of the atmosphere over the eastern Caribbean. Since 97L is a relatively small system, it is very vulnerable to wind shear. This shear may be able to drive some of the dry air west of 97L deep into its interior, significantly disrupting the disturbance. Shear will remain high along 97L's path through Thursday, when the storm should be in the western Caribbean near Cuba. If there is anything left of 97L by then, some development is possible. The National Hurricane Center gave 97L a low (less than 30% chance) of developing into a tropical depression in the next 48 hours in their 8am Tropical Weather Outlook. However, I'd say the odds are now in the medium range (30 - 50%).

None of the computer models are forecasting tropical storm development over the next seven days.


Figure 1. Current satellite image of African wave 97L.

I'll have an update Monday morning. As 97L approaches the islands, you may want to follow local observations there using our wundermap for 97L.

Jeff Masters

Hurricane

Two African waves worth mentioning

By: JeffMasters, 3:51 PM GMT on July 18, 2009

There are two African tropical waves worth mentioning today, though neither looks particularly threatening. A tropical wave near 12N 45W, about 1200 miles east of the Lesser Antilles Islands (97 L), is moving west at 15 - 20 mph. This wave is now surrounded by an area of very dry air from the Sahara Desert. The dry air has disrupted most of the wave's heavy thunderstorm activity, and will continue to make it difficult for this system to develop over the next 2 - 3 days. Wind shear is a modest 10 knots over the disturbance, and should remain in the moderate 10 - 15 knot range over the next 2 - 3 days. Thereafter, shear is expected to rise to 20 - 30 knots. This morning's QuikSCAT pass showed no evidence of a surface circulation, and only a modest wind shift associated with 97L. The National Hurricane Center is giving this system a low (less than 30% chance) of developing into a tropical depression in the next 48 hours.

A second tropical wave now approaching the northern Lesser Antilles Islands is under 30 knots of wind shear, and has little prospect of development due to the high shear. However, the wave will bring heavy rain to the islands over the next two days.

None of the computer models are forecasting tropical storm development over the next seven days, and I don't expect either of the two African waves mentioned today to develop over at least the next three days.


Figure 1. Current satellite image of African wave 97L, 1200 miles east of the Lesser Antilles Islands.

I'll have an update Sunday afternoon.
Jeff Masters

Hurricane

An African wave worth watching; 2nd warmest June on record

By: JeffMasters, 1:51 PM GMT on July 17, 2009

There's finally a African tropical wave worth mentioning, in what has been a very inactive June/July period for African waves with a potential to develop. A tropical wave near 12N 36W, about 1200 miles west of the coast of Africa, is triggering some modest heavy thunderstorm activity over the open ocean as the storm moves west at 10 - 15 mph. NHC designated this wave 97 L at noon today. Wind shear is a modest 15 knots over the disturbance, which is low enough to allow some slow development over the next few days. As long as the disturbance stays south of Puerto Rico's latitude (18°N), wind shear should remain low enough to allow development. However, there is a substantial amount of African dust and dry air surrounding the system on its west and north sides. This dry air will retard development, and may be able to completely disrupt the disturbance at some point over the next 3 - 4 days. None of the computer models develop the disturbance. The National Hurricane Center is giving this system a low (less than 30% chance) of developing into a tropical depression in the next 48 hours.


Figure 1. The first African wave of 2009 worth watching.

Second warmest June on record
The globe recorded its second warmest June on record, 0.02°C short of the record set in 2005, according to the National Climatic Data Center. The period January - June was the fifth warmest such period on record. Global temperature records go back to 1880. The most notable warmer-than-average temperatures were recorded across parts of Africa and most of Eurasia, where temperatures were 3°C (5°F) or more above average. The global ocean Sea Surface Temperature (SST) for June 2009 was the warmest on record, 0.59°C (1.06°F) above the 20th century average. This broke the previous June record set in 2005. The record June SSTs were due in part to the development of El Niño conditions in the Eastern Pacific. If El Niño conditions continue to strengthen during the coming months, we will probably set one or more global warmest-month-on-record marks later this year. The last time Earth experienced a second warmest month on record was in October 2008.


Figure 1. Departure of temperature from average for June 2009. Image credit: National Climatic Data Center.

June sea ice extent in the Arctic 4th lowest on record
June 2009 Northern Hemisphere sea ice extent was the 4th lowest since 1979, according to the National Snow and Ice Data Center. The record June low was set in 2006. This summer's melt is lagging behind the melting in the summer of 2007, which set the record for the lowest amount of summer sea ice in the Arctic. Forecasts of summer Arctic sea ice melt made in early June by two teams of German scientists put the odds of a new record sea ice minimum this year between 7% and 28%. With the amount of sunlight in the Arctic now on the wane, it appears unlikely that we will set a new record sea ice minimum in 2009. This year will probably have the 2nd or 3rd least sea ice extent on record come September, when the melting season ends. The ice-free seas that nearly surround Greenland now have contributed to temperatures of 2 - 3°C above average over the island over the past ten days. With clear skies and above-average temperatures likely over most of the island for at least the next week, we can expect near-record July melting over portions of the Greenland Ice Sheet this month.

Northwest Passage likely to open for the third consecutive year
The fabled Northwest Passage is more than half clear now, and has a good chance of melting free for the third consecutive year--and third time in recorded history. The first recorded attempt to find and sail the Northwest Passage was in 1497, and ended in failure. The thick ice choking the waterways thwarted all attempts at passage for the next four centuries. Finally, in 1905, Roald Amundsen completed the first successful navigation of the Northwest Passage. It took his ship two-and-a-half years to navigate through narrow passages of open water, and his ship spent two cold, dark winters locked in the ice during the feat.

We can be sure the Northwest Passage was never open from 1900 on, as we have detailed ice edge records from ships (Walsh and Chapman, 2001). It is very unlikely the Passage was open between 1497 and 1900, since this spanned a cold period in the northern latitudes known as "The Little Ice Age". Ships periodically attempted the Passage and were foiled during this time. The Northwest passage may have been open at some period during the Medieval Warm Period, between 1000 and 1300 AD.


Figure 3. Ice extent as measured by an AMSR-E microwave satellite sensor on July 15, 2009. Most of the famed Northwest Passage (red lines) has melted out. Image credit: University of Bremen.

References
Walsh, J.E and W.L.Chapman, 2001, "Twentieth-century sea ice variations from observational data", Annals of Glaciology, 33, Number 1, January 2001 , pp. 444-448.

I'll have an update on the African tropical wave at least once this weekend if the system doesn't fall apart.

Jeff Masters

Climate Summaries Hurricane

Remainder of July hurricane outlook

By: JeffMasters, 2:31 PM GMT on July 15, 2009

Not much has changed in the Atlantic since my early July Atlantic hurricane outlook posted two weeks ago. Tropical cyclone activity typically picks up a bit during the last half of July, but we are still a month away from when hurricane season really gets going. Since the current active hurricane period began in 1995, nine of 14 years (63%) have had a named storm form during the last half of July. We had two last-half-of-July named storms last year--Christobal and Dolly. As seen in Figure 1, most of the late July activity occurs in the Gulf of Mexico, Western Caribbean, and Carolina waters. However, a few long-track "Cape Verdes" hurricanes begin to occur. These are spawned by tropical waves that come off the coast of Africa. Tropical waves serve as the instigators of about 85% of all major hurricanes.


Figure 1. Tracks of all tropical storms and hurricanes 1851 - 2006 that formed July 16 - 31.The Gulf of Mexico coast is the preferred strike location. There are still very few major Cape Verdes-type hurricanes forming in the last half of July.

Sea Surface Temperatures
Sea Surface Temperature (SST) anomalies have warmed slightly over the past two weeks, and are about 0.3°C (0.5°F) above average over the tropical Atlantic between Africa and Central America (Figure 2). These are some of the coolest SST anomalies for this time of year that we've seen since 1994. The strength of the Azores-Bermuda high has been near or slightly below average over the past two weeks, driving slightly below average trade winds. Weaker trade winds don't mix up as much cold water from the depths, and cause less evaporative cooling. The latest 2-week run of the GFS model predicts continued near-average or slightly below average-strength trade winds through the end of July, so SSTs should remain slightly above average during this period.


Figure 2. Sea Surface Temperature (SST) departure from average for July 13, 2009. SSTs were about 0.3°C (0.5°F) average over the tropical Atlantic's Main Development region for hurricanes, from Africa to Central America between 10° and 20° North Latitude. Note the large region of above average SSTs along the Equatorial Pacific off the coast of South America, the hallmark of a developing El Niño episode. Image credit: NOAA/NESDIS

El Niño
El Niño conditions continue to amplify over the tropical Eastern Pacific. Ocean temperatures in the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region", are now 0.4°C above the threshold for a weak El Niño, according to the Australian Bureau of Meteorology (Figure 3). An increase of another 0.1°C will push the current El Niño into the "moderate" category. NOAA's Climate Prediction Center issued an El Niño Advisory earlier this month. The latest set of mid-June runs of the El Niño computer models are almost universally calling for El Niño conditions to become well-established for the peak months of hurricane season, August - October. It is likely that Atlantic hurricane activity will be suppressed in 2009 due to the strong upper-level winds and resulting wind shear an El Niño event usually brings to the tropical Atlantic.


Figure 3. Sea Surface Temperature (SST) departure from average for the the equatorial Eastern Pacific (the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region"). El Niño conditions exist when the SST in this region rises 0.5°C above average. As of July 8, 2009, SSTs in the Niño 3.4 region had risen to 0.9°C above average. To be considered an "El Niño episode", El Niño conditions must occur for five consecutive months, using 3-month averages. Image credit: Australian Bureau of Meteorology.

Wind shear
Wind shear is usually defined as the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude). In most circumstances, wind shear above 20 knots will act to inhibit tropical storm formation. Wind shear below 12 knots is very conducive for tropical storm formation. High wind shear acts to tear a storm apart. The jet stream's band of strong high-altitude winds is the main source of wind shear in July over the Atlantic hurricane breeding grounds, since the jet is very active and located quite far south this time of year.

The jet stream over the past three months has been locked into a pattern where a southern branch (the subtropical jet stream) brings high wind shear over the Caribbean, and a northern branch (the polar jet stream) brings high wind shear offshore of New England.

The jet stream is forecast to maintain this two-branch pattern for the next week. However, during the final week of July, the subtropical jet is forecast to weaken. This will leave regions of low wind shear over the Caribbean and Gulf of Mexico for the final week of July (Figure 4), increasing the chances of hurricane development.


Figure 4. Wind shear in m/s between 200 mb and 850 mb on July 31, 2009, as forecast by the 00Z July 15, 2009 run of the GFS model. The subtropical jet is forecast to weaken by this time, leaving regions of low wind shear over the Caribbean and Gulf of Mexico for the final week of July. Wind speeds are given in m/s; multiply by two to get a rough conversion to knots. Thus, the red regions of low shear range from 0 - 16 knots.

Dry air and African dust
June and July are the peak months for dust coming off the coast of Africa, and the Saharan dust storms have been quite active over the past month. Expect dust from Africa to be a major deterrent to any storms that try to form between Africa and the Lesser Antilles Islands in July. Several well-developed African waves have been done in by dry air from Africa over the past few weeks.

Steering currents
The steering current pattern over the past few weeks has not changed much. A persistent trough of low pressure has remained entrenched over the Eastern U.S. all summer, bringing cool and relatively moist weather to the eastern half of the country. This trough is strong enough to recurve any tropical storms or hurricanes that might penetrate north of the Caribbean Sea. Steering current patterns are predictable only about 3 - 5 days in the future, although we can make very general forecasts about the pattern as much as two weeks in advance. At present, it appears that the coming two weeks will maintain the strong trough over the Eastern U.S., which decreases the hurricane risk to the U.S. Gulf Coast. There is no telling what might happen to the steering current pattern during the peak months of August, September, and October, but it is often difficult to break a months-long steering current pattern like the current one.

Summary
Recent history suggests a 63% chance of a named storm occurring in the last half of July. Given that none of the computer models are forecasting tropical storm formation in the coming seven days, and SST and wind shear patterns look pretty average, I'll go with a 30% chance of a named storm forming this month. Such a storm would most likely form near the end of the month, when wind shear is expected to decline due to a weakening of the subtropical jet stream. The last time we went this long in the season without a named storm forming was in 2004, when the first storm (Alex) formed on August 1.

I'll have a new post on Friday.

Jeff Masters

Hurricane

How much will global sea level rise this century?

By: JeffMasters, 2:49 PM GMT on July 13, 2009

How much will global sea level rise this century? Well, global sea level rise began in the late 1700s, and accelerated to 1.2 inches (3 cm) per decade over the past 25 years (see my post, Sea level rise: what has happened so far). If the conditions that led to this acceleration continue, we can expect sea level will rise an additional 1.1 ft (0.34 m) by 2100 (Jevrejeva et al., 2008). At a minimum, sea level rise during the 21st century should equal that of the 20th century, about seven inches (0.6 ft, 0.18 meters). This is the lower bound given by the IPCC in its 2007 assessment, which projected sea level rise of 0.6 - 1.9 ft (0.18 - 0.59 m) by 2100. However, they cautioned in their report that due to the lack of knowledge about how melting glaciers behave, the actual sea level rise might be higher. There is a growing consensus that the 2007 IPCC sea level rise estimates are much too low.


Figure 1. Observed global sea level from tide gauges (red line, pink color is the uncertainty range) and satellite measurements (green line), with forecasts for the future. The blue colors show the range of projections for three different forecasts (the forecasts overlap, but this overlap is not shown). Image modified from U.S. EPA.

The 2007 IPCC report: too conservative?
Three major sea level rise studies published since the 2007 IPCC report have argued that the IPCC's projections of sea level rise are too conservative. A paper published in 2008 in Science by Pfeffer et al. (2008) concluded that the "most likely" range of sea level rise by 2100 is 2.6 - 6.6 ft (0.8 - 2.0 meters). Their estimates came from a detailed analysis of the processes the IPCC said were understood too poorly to model--the ice flow dynamics of glaciers in Greenland and Antarctica. For example, increased glacial flow may result when water draining from melt water lakes on the surface of the glacier to the base of the glacier, where it acts as a lubricant. The authors cautioned that "substantial uncertainties" exist in their estimates, and that the cost of building higher levees to protect against sea level rise is not trivial.

Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany looked at the observed relationship between changes in sea level and global temperatures since 1900 (Rahmstorf, 2007). Rahmstorf showed that that there has been a direct relationship between sea level rise and global average temperature: 0.1 - 0.3 meters of sea level rise occurs per °C increase in global temperature. Using this relationship, Rahmstorf predicted 1.6 - 4.6 ft (0.5 - 1.4 m) of sea level rise by 2100, since the IPCC predicts that global temperatures will rise 1.4° to 5.8°C. Rahmstorf concluded, "very low sea-level rise values as reported in the 2007 IPCC report now appear rather implausible in the light of the observational data".

A similar approach was taken by Grinsted et al. (2009), but they extended the relationship between sea level and global average temperature all the way back to 200 A.D. using proxy records. They concluded that ice sheets respond more quickly to temperature changes than the computer models used in the 2007 IPCC assessment. The authors estimated that "IPCC projections of sea level rise 2090 - 2099 are underestimated by roughly a factor of three". The authors predicted that global sea level will be rising 11 mm/year by 2050--four times faster than the 20th century rise. By the last decade of this century, they forecasted that sea level will rise 3.0 - 4.3 feet (0.9 - 1.3 meters), using the IPCC's A1B "business as usual" scenario.

The long-range forecast: using paleohistory to forecast sea level rise
We can also look at times in Earth's past that had similar climate to what we expect by the year 2100. The best time to look at is probably just before the most recent ice age--the Eemian. This interglacial period 130,000 - 114,000 years ago featured temperatures near the poles that were 2°C warmer than present-day temperatures. Tree line lay about 500 miles farther north in the Canadian Arctic, and the hippopotamus ranged as far north as the Thames River in England. A similar climate is expected under some of the more moderate global warming scenarios envisioned by the IPCC. Sea level is believed to have been 4 - 6 meters (13 - 20 feet) higher than at present during the Eemian, but there is at least one unpublished study that presents evidence that global sea level was 6 - 9 meters (20 - 30 feet) higher. If the climate does warm to levels seen in the Eemian, it is widely believed that we would again see sea levels at least 4 - 6 meters higher than the present-day levels. Clearly, sea level rises of this magnitude would be ruinous to society. However, most climate change scientists believe that it would take many centuries for enough ice to melt from the Greenland and West Antarctic ice sheets to create sea level rises of 4 - 6 meters.

However, the scientist who is arguably the most visible and authoritative climate scientist in the world, Dr. James Hansen of NASA, stated (Hansen, 2007) "I find it almost inconceivable that business-as-usual climate change would not yield a sea level change of the order of meters on the century timescale" (IPCC business-as-usual (BAU) scenarios assume that emissions of CO2 and other greenhouse gases will continue to increase year after year). Hansen gave a hypothetical but potentially realistic scenario where the sea level rise due to ice sheet disintegration doubles every decade, leading to a 16 foot (5 meter) sea level increase by 2100. He noted that during the Plio-Pleistocene period 2 - 3 million years ago, CO2 levels were similar to today (350 - 450 ppm), and global temperatures were 2 - 3°C warmer, similar to what we expect by the end of the century. Yet, this Plio-Pleistocene world was "a dramatically different planet, without Arctic sea ice in the warm seasons and with a sea level 25 ± 10 m higher."

Summary
To summarize, here are some predictions of how high global sea level might rise by 2100:

0.6 ft (0.18 m): Constant linear rise, equal to 20th century rise
1.1 ft (0.34 m): Constant acceleration model (Jevrejeva et al., 2008)
0.6 - 1.9 ft (0.18 - 0.59 m): Primitive models of ice sheets (IPCC, 2007)
1.6 - 4.6 ft (0.5 - 1.4 m): Relationship between temperature and sea level rise since 1900 (Rahmstorf, 2007)
3.0 - 4.3 feet (0.9 - 1.3 m): Relationship between temperature and sea level rise since 200 A.D. (Grinsted et al., 2009)
2.6 - 6.6 ft (0.8 - 2.0 meters): Considering glacier ice flow dynamics not included by the IPCC (Pfeffer et al., 2008)

In a 2009 interview with New Scientist magazine, sea level expert Stephan Rahmstorf said, "I sense that now a majority of sea level experts would agree with me that the IPCC projections are much too low." This sentiment was echoed by glaciologist Robert Bindschadler of the NASA Goddard Space Flight Center in Greenbelt, Maryland, who commented, "most of my community is comfortable expecting at least a metre by the end of this century."

In forthcoming posts in this series, I'll explore how a meter (3.28 feet) of sea level rise will affect the U.S. coast, the Caribbean, and other vulnerable locations world-wide. It would be wise to begin preparing now for a potential rise in sea level of a meter this century. In particular, development near the coasts should be severely restricted in low-elevation zones. It will be very expensive to protect or move infrastructure away from rising seas later this century. However, even if the rate of sea level rise doubles every decade, those of us who are over the age of 50 will not live to see sea level rise cause a significant disruption to society. There is time for society to prepare for the rising sea.

References
Jevrejeva, S., J.C. Moore, A. Grinsted,, and P.L. Woodworth, 2008, "Recent global sea level acceleration started over 200 years ago?", Geophysical Research Letters, 35, L08715, doi:10.1029/2008GL033611, 2008.

Grinsted, A., J.C. Moore, and S. Jevrejeva, 2009, "Reconstructing sea level from paleo and projected temperatures 200 to 2100 AD", Climate Dynamics, DOI 10.1007/s00382-008-0507-2, 06 January 2009.

Hansen, J., 2007, "Scientific reticence and sea level rise",, Environ. Res. Lett. 2 (April-June 2007) 024002 doi:10.1088/1748-9326/2/2/024002.

IPCC (Intergovernmental Panel on Climate Change), 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, UK, and New York, 996 pp.

Pfeffer, W.T., J.T. Harper, and S. O'Neel, 2008, "Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise", Science 321 no. 5894, pp. 1340-1343, 5 September 2008. DOI: 10.1126/science.1159099

Rahmstorf, Stefan. "Sea-Level Rise: A Semi-Empirical Approach to Projecting Future." Science 315 (2007): 368–370.

Other posts in this series
Sea level rise: what has happened so far
U.S. vulnerability to sea level rise

Wednesday, I'll take a look at the Atlantic hurricane forecast for the remainder of July. There's currently nothing out there worth discussing--will it stay that way?

Dr. Ricky Rood has some interesting commentary on the new climate change legislation that passed the House last month, and will go to the Senate in September.

Jeff Masters

Climate Change Sea level rise

The 6 lost Hurricane Hunter missions, Part IV: Hurricane Janet, 1955

By: JeffMasters, 1:07 PM GMT on July 10, 2009

The only Atlantic Hurricane Hunter flight to go down occurred on September 26, 1955. Snowcloud Five, a U.S. Navy P2V Neptune weather reconnaissance airplane flying out of Guantanamo, Cuba, was lost in Hurricane Janet, 300 miles southwest of Jamaica. Snowcloud Five was part of the Airborne Early Warning Squadron Four (VW-4), based at the Jacksonville, Florida Naval Air Station. Carrying a crew of nine and two reporters from the Toronto Daily Star, Snowcloud Five took off at 0630 local time, and performed its initial penetration into Janet at an altitude of 700 feet. At the time of the crash, Janet was a Category 4 hurricane with 145 mph winds. The aircraft sent back this transmission, then was never heard from again:

NAVY RECONNAISSANCE FLIGHT 5U93, OBSERVATION NUMBER FIVE, AT 1330 GMT (8:30AM EST), MONDAY, LOCATED AT LATITUDE 15.4 DEGREES N, LONGITUDE 78.2 DEGREES W. OBLIQUE AND HORIZONTAL VISIBILITY 3-10 MILES, ALTITUDE 700 FEET, FLIGHT WIND 050 DEGREES (NE) 45 KNOTS (52 MPH). PRESENT WEATHER LIGHT INTERMITTENT SHOWERS, PAST WEATHER SAME, OVERCAST AND SOME SCUD BELOW, SURFACE PRESSURE 1,003 MILLIBARS (29.62 INCHES), SURFACE WINDS 050 DEGREES (NE), 45 KNOTS (52 MPH). BEGINNING PENETRATION.


Figure 1. Snowcloud Five, the U.S. Navy P2V Neptune weather reconnaissance airplane that went down in Hurricane Janet of 1955. Image credit: navyhurricanehunters.com

An intensive air and sea search operation combed a 300 by 200 mile region of the Caribbean for the airplane over the next five days. In all, sixty aircraft, seven ships, and three thousand personnel were involved. No trace of Snowcloud Five was ever found. A book called Stormchasers (David Toomey, 2002) provides a detailed story of the flight into Hurricane Janet and offers some insight as to what may have gone wrong. Dr. Hugh Willoughby, former director of NOAA's Hurricane Research Division, speculated on the fate of Snowcloud Five in a review of Stormchasers that appeared in the February, 2003 issue of the Bulletin of the American Meteorological Society: "The enlisted aerographer's mate was left behind that day in order to accommodate the Toronto Daily Star reporter. This key crew member was normally responsible for keeping the pilots aware of altitude by calling out readings from the only radar altimeter on board, located at the aerologist's station. Without him, the aerologist, Lt. (jg) William Buck, had to do two demanding jobs: He had to simultaneously read the bouncing, flickering altimeter and peer down from his Plexiglas bubble in the nose to discern the wind from streaks of foam on the sea. It is easy to imagine how he might have lost control of the situation as he struggled to keep the airplane safely above the waves and flying perpendicular to the wind towards the eye."

The crew members lost on the mission were:

Lt. Cmdr. Grover B. Windham Jr. of Jacksonville, FL, Plane Commander
LTjg Thomas R. Morgan of Orange Park, FL, Navigator
LTjg George W. Herlong of Yukon, FL, Co-Pilot
Aviation Electronics Technician Second Class Julius J. Mann, 22, of Canton, Ohio
LTjg Thomas L. Greaney, 26, of Jacksonville, FL, Navigator
Aviation Mechanic First Class J. P. Windham, Jr., 32 of Jacksonville, FL
Airman Kenneth L. Klegg, 22, of Cranston, RI
Aviation Electronics Man First Class Joseph F. Combs of Forest Park, NY
Aerologist William A. Buck, of Jacksonville, FL
Toronto Daily Star Reporter Alfred O. Tate
Toronto Daily Star Photographer Douglas Cronk

Robert Ballard, or other experts in finding sunken ships--I challenge you to find the wreckage of Snowcloud Five, and help bring to light the final fate of the only Atlantic Hurricane Hunter plane to go down in the line of duty!


Figure 2. Damage to the town of Corozal, Belize, after Hurricane Janet in 1955. Janet intensified to a Category 5 hurricane the day after Snowcloud Five went down, and hit the Yucatan Peninsula near the Belize/Mexico border with 175 mph winds, killing more than 500 people. Image credit: corozal.com.

Sources: The book, Stormchasers (David Toomey, 2002) provides a detailed story of the flight into Hurricane Janet, and is a good read. Other sources: The Florida Times-Union Jacksonville, Wednesday, September 28, 1955: "Navy Plane Missing With 11 Local Men".

Previous posts in this series:
October 1, 1945 typhoon
Typhoon Wilma, 1952
Typhoon Doris, 1953

The tropics remain quiet, with no threat areas and no models forecasting Atlantic tropical development over the next seven days. I'll have a new post on Monday.

Jeff Masters

Modiki El Niños and Atlantic hurricane activity

By: JeffMasters, 1:48 PM GMT on July 08, 2009

It's an El Niño year, which typically means that Atlantic hurricane activity will be reduced. But not all El Niño events are created equal when it comes to their impact on Atlantic hurricane activity. Over the past 150 years, hurricane damage has averaged $800 million/year in El Niño years and double that during La Niña years. The abnormal warming of the equatorial Eastern Pacific ocean waters in most El Niño events creates an atmospheric circulation pattern that brings strong upper-level winds over the Atlantic, creating high wind shear conditions unfavorable for hurricanes. Yet some El Niño years, like 2004, don't fit this pattern. Residents of Florida and the Gulf Coast will not soon forget the four major hurricanes that pounded them in 2004--Ivan, Frances, Jeanne, and Charley. Overall, the 15 named storms, 9 hurricanes, and 6 intense hurricanes of the hyperactive hurricane season of 2004 killed over 3000 people--mostly in Haiti, thanks to Hurricane Jeanne--and did $40 billion in damage.

A new paper published in Science last Friday attempts to explain why some El Niño years see high Atlantic hurricane activity. "Impact of Shifting Patterns of Pacific Ocean Warming on North Atlantic Tropical Cyclones", by Georgia Tech researchers Hye-Mi Kim, Peter Webster, and Judith Curry, theorizes that Atlantic hurricane activity is sensitive to exactly where in the Pacific Ocean El Niño warming occurs. If the warming occurs primarily in the Eastern Pacific, near the coast of South America, the resulting atmospheric circulation pattern creates very high wind shear over the tropical Atlantic, resulting in fewer hurricanes. This pattern, called the Eastern Pacific Warming (EPW) pattern, occurred most recently during the El Niño years of 1997, 1987, and 1982 (Figure 1). In contrast, more warming occurred in the Central Pacific during the El Niño years of 2004, 2002, 1994, and 1991. The scientists showed that these Central Pacific Warming (CPW) years had lower wind shear over the Atlantic, and thus featured higher hurricane activity than is typical for an El Niño year. One of the paper's authors, Professor Peter J. Webster, said the variant Central Pacific Warming (CPW) El Niño pattern was discovered in the 1980s by Japanese and Korean researchers, who dubbed it modiki El Niño. Modiki is the Japanese word for "similar, but different".


Figure 1. Difference of Sea Surface Temperature (SST) from average during the peak of hurricane season, August-September-October, for seven years that had El Niño events (except for 2009, when the SST anomaly for July 1 - 3 is plotted). On the left side are years when the El Niño warming primarily occurred in the Eastern Pacific (EPW years). On the right are years when the warming primarily occurred in the Central Pacific (CPW years). Shown on the top of each plot is the number of named storms (NS), hurricanes (H), and intense hurricanes (IH) that occurred in the Atlantic each year. Atlantic hurricane activity tends to be more prevalent in CPW years than EPW years. An average hurricane season has 10 named storms, 6 hurricanes, and 2 intense hurricanes. Image credit: NOAA/ESRL.

What, then, can we expect the current developing El Niño event to do to 2009 hurricane activity? Kim et al. note that in recent decades, the incidence of modiki CPW El Niño years has been increasing, relative to EPW years. However, the preliminary pattern of SST anomalies in the Pacific observed so far in July (lower left image in Figure 1) shows an EPW pattern--more warming in the Eastern Pacific than the Central Pacific. If Kim et al.'s theory holds true, this EPW pattern should lead to an Atlantic hurricane season with activity lower than the average 10 named storms, 6 hurricanes, and 2 intense hurricanes. There is still a possibility that the observed warming pattern could shift to the Central Pacific during the peak portion of hurricane season, however. We are still in the early stages of this El Niño, and it is unclear how it will evolve.

Jeff Masters

Island in a Storm: a book review

By: JeffMasters, 2:19 PM GMT on July 06, 2009

Island in a Storm tells the riveting story of one of America's greatest hurricane disasters--the ravaging of Louisiana's Isle Derniere by the notorious Last Island Hurricane of 1856. If you haven't heard of Isle Derniere, there's a good reason why--the 13 - 18 foot storm surge of the Category 4 Last Island Hurricane completely submerged the 24-mile long, 5 to 6 foot high barrier island, which lay 5 miles off the central Louisiana coast. The resulting erosion by the pounding waves and wind-driven currents stripped away huge amounts of the island's sand, cutting a new channel through the 1/2-mile wide island. The author tells us, "During the 1856 hurricane, Isle Derniere was pushed beyond a tipping point from which it could not recover". Continued erosion during the 150 years since the 1856 hurricane has reduced the land area of Isle Derniere to less than 22% of what it once was (Figure 2).

The author
The book's author is Dr. Abby Sallenger, who heads the U.S. Geological Survey's Storm Impact research group, which investigates how the coast changes after extreme storms. The book is very clearly the work of a methodically-minded scientist, as the book quotes heavily from a broad range of historical sources throughout the text. Sallenger includes 50 pages of detailed notes and references at the end of the book. I found that the quotes were well-chosen and illuminating, and added a 19th-century feel to the book.


Figure 1. Track of the Last Island Hurricane.

A history book
Island in a Storm starts out as a history book, as we are introduced to the various people who will eventually be caught in the great hurricane. Sallenger spends six of the book's sixteen chapters setting the stage for the great disaster, and this portion of the story may drag on too long for readers who are disinterested in the history of Louisiana in the mid-1800s. I found it fascinating to read about the Yellow Fever epidemic that hit the region during 1856, which drove many of New Orleans' wealthy residents to seek sanctuary on the seemingly safe ocean front retreat of Isle Derniere for the summer. We are introduced to about six sets of characters during this initial portion of the book, and it does take a bit of effort to keep everyone straight as the book progresses into the storm's fury. The introductory chapters also devote a few pages to the meteorology of how hurricanes work, and the competing theories of the time. These pages do a good job giving the necessary background to understand what happened to Isle Derniere.

A survival and adventure tale
When we reach the main portion of the book, Sallenger presents a fast-paced and riveting description of some remarkable survival tales from this great disaster. We hear the story of how the hurricane's winds gradually tore apart all the homes and hotels on Isle Derniere, leaving the hundreds of people at the mercy of the storm surge. Many were swept away, but some survived harrowing voyages on pieces of debris during a dark and terrifying night. One group of survivors on the island managed to live by hanging on to a children's carousel, whose central post had been driven deep into the sand to anchor it. As the wind and water surged the around them, the desperate survivors hung onto the whirligig as it spun around. "The twirling and twisting, the dashing and splashing, the heeling and toeing, the flapping and floundering which ensued, would at any other time have produced a first-class comedy", one of the survivors relates. We also hear the remarkable tale of several ships caught in the storm. The crew of one ship driven aground by the storm leaped off their ship into the roiling storm surge in an attempt to seek shelter on the submerged barrier island. On another ship, "Captain Thompson could now view his cargo of livestock crowded onto the forward half of the main deck. The cows and horses and mules slid astern as the waves lifted and over-topped the bow. White water streamed through their hooves. The animals stumbled forward as the bow fell into holes and side to side as the vessel rolled".

A cautionary tale
The book ends with several chapters devoted to the aftermath of the hurricane. The survivors on the storm-ravaged island were not visited at first by relief ships, but by pirates eager to prey on the dead and the living. Relief eventually reached the 200 or so survivors on the island, and a romance leading to marriage is one happy outcome of the storm's wake.

Barrier islands are terrible places to build human settlements, and "the lesson of the flood was not forgotten," according to one of the survivors. The resorts on Isles Dernieres were never rebuilt. Sallenger notes that "such lessons are forgotten or ignored. In the last century and a half, the Village of Isle Derniere was one of only a few seafront communities that were destroyed or severely damaged in a storm and never rebuilt. The common practice is not only to rebuild structures on devastated coasts but also to make them bigger and more elaborate...We continue in the United States to develop extremely hazardous coastal locations, like the low-lying areas on the Bolivar Peninsula east of Galveston, Texas, that were wiped out in 2008 by Hurricane Ike. The extreme vulnerability of such locations today will only increase as the world's seas rise."


Figure 2. Graphic from Island in a Storm, showing the long-term deterioration of Isle Derniere into multiple islands, now called Isles Dernieres. The island lost 78% of its land area between 1888 and 1988, and the remains of the island migrated 2/3 of a mile northwards. Further destruction of the islands has been arrested by a large-scale dredging project that adds mud and shells from the nearby sea bottom. Image credit: Coasts in Crisis, USGS Circular 1075, 1990.

Summary
Sallenger's first-class story-telling of the remarkable tales of survival during the Last Island Hurricane make this a book well worth reading. My only gripe is that the book could have benefited from better graphics than the few black-and-white figures that are of mediocre quality. Nevertheless, Island in a Storm rates 3 1/2 stars (out of four). It's $16.47 from Amazon.com.

I'll have a new post Tuesday afternoon or Wednesday morning, when I plan to discuss why some El Niño episodes in recent years have had high Atlantic hurricane activity associated with them. As you may have guessed, there is no Atlantic tropical activity worth mentioning, and no models are predicting tropical storm formation over the next seven days.

Jeff Masters

July hurricane outlook

By: JeffMasters, 7:26 PM GMT on July 02, 2009

Atlantic tropical cyclone activity typically picks up a bit during the first half of July. Since the current active hurricane period began in 1995, seven of 14 years (50%) have had a named storm form during the first half of July. The busiest first half of July occurred in 2005, when three hurricanes formed. These included Hurricane Dennis and Hurricane Emily--the strongest hurricanes ever observed so early in the season. As seen in Figure 1, most of the early July activity occurs in the Gulf of Mexico, Western Caribbean, and Carolina waters. However, a few long-track "Cape Verdes" hurricanes begin to occur. These are spawned by tropical waves that come off the coast of Africa. Tropical waves serve as the instigators of about 85% of all major hurricanes. Last year's Hurricane Bertha was one such rare early July Cape Verdes hurricane. Bertha's 120 mph winds made it the sixth strongest early-season Atlantic hurricane on record. Bertha also set the record for farthest east formation as a tropical storm, hurricane, and major hurricane, so early in the season.


Figure 1. Tracks of all tropical storms and hurricanes 1851 - 2006 that formed July 1-15. North Carolina and the Gulf of Mexico coast from the Florida Panhandle to Texas are the preferred strike locations. Oddly, the Florida Peninsula has been struck by only two storms that formed in the first half of July.

Sea Surface Temperatures
Sea Surface Temperatures (SST) anomalies have warmed slightly over the past two weeks, but are close to average over the tropical Atlantic between Africa and Central America (Figure 2). These are the are the coolest SST anomalies we've seen since 1994. The strength of the Azores-Bermuda high has been near average over the past two weeks, driving near-average trade winds. Stronger-than-average trade winds were observed through most of the period November 2008 - May 2009, which helped cool the tropical Atlantic substantially. Strong winds mix up colder water from the depths and cause greater evaporative cooling. The latest 2-week run of the GFS model predicts continued average-strength trade winds through mid-July, so SSTs should remain near average during this period.

Typically, July tropical storms form over the Gulf of Mexico, Western Caribbean, and Gulf Stream waters just offshore Florida. SSTs are about 1.0°C above average for this time of year in the Gulf of Mexico, but near average elsewhere. July storms typically form when a cold front moves off the U.S. coast and stalls out, with the old frontal boundary serving as a focal point for development of a tropical disturbance. There will be one or two fronts moving off the U.S. coast over the next two weeks, and we will need to watch these for development. Wind shear is too high and SSTs are usually too cold in July to allow African tropical waves to develop into tropical storms. African tropical waves serve as the instigators of about 85% of all major hurricanes,

Figure 2. Sea Surface Temperature (SST) departure from average for July 2, 2009. SSTs were near average over the tropical Atlantic's Main Development region for hurricanes, from Africa to Central America between 10° and 20° North Latitude. Note the large region of above average SSTs along the Equatorial Pacific off the coast of South America, the hallmark of a developing El Niño episode. Image credit: NOAA/NESDIS

El Niño
El Niño conditions continue to amplify over the tropical Eastern Pacific. Ocean temperatures there rose 0.5°C over the past two weeks, and are now 0.45°C above the threshold for El Niño, according to the Australian Bureau of Meteorology (Figure 3). NOAA's Climate Prediction Center issued an El Niño Watch in early June, saying "that conditions are favorable for a transition from neutral to El Niño conditions during June - August 2009". The pattern of changes in surface winds, upper-level winds, sea surface temperatures, and deeper water heat content are all consistent with what has been observed during previous developing El Niños, and latest set of mid-June runs of the El Niño computer models are almost universally calling for El Niño conditions to become well-established for the peak months of hurricane season, August - October. It is likely that Atlantic hurricane activity will be suppressed in 2009 due to the strong upper-level winds and resulting wind shear an El Niño event usually brings to the tropical Atlantic.


Figure 3. Sea Surface Temperature (SST) departure from average for the the equatorial Eastern Pacific (the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region"). El Niño conditions exist when the SST in this region rises 0.5°C above average. As of June 28, 2009, SSTs in the Niño 3.4 region had risen to 0.95°C above average. To be considered an "El Niño episode", El Niño conditions must occur for five consecutive months, using 3-month averages. Image credit: Australian Bureau of Meteorology.

Wind shear
Wind shear is usually defined as the difference in wind between 200 mb (roughly 40,000 foot altitude) and 850 mb (roughly 5,000 foot altitude). In most circumstances, wind shear above 20 knots will act to inhibit tropical storm formation. Wind shear below 12 knots is very conducive for tropical storm formation. High wind shear acts to tear a storm apart. The jet stream's band of strong high-altitude winds is the main source of wind shear in July over the Atlantic hurricane breeding grounds, since the jet is very active and located quite far south this time of year.

The jet stream over the past two months has been locked into a pattern where a southern branch (the subtropical jet stream) brings high wind shear over the Caribbean, and a northern branch (the polar jet stream) brings high wind shear offshore of New England. This often leaves a "hole" of low shear between the two branches off the coast of North Carolina, which is where Tropical Depression One formed at the end of May.

The jet stream is forecast (Figure 4) to maintain this two-branch pattern over the coming two weeks. This means that the waters offshore of the Carolinas are the most likely place for a tropical storm to form during this period.


Figure 4. Wind shear in m/s between 200 mb and 850 mb, as forecast by the 06Z July 02, 2009 run of the GFS model. The position and strength of the subtropical jet stream is forecast to change little over the next two weeks, and this jet will bring high wind shear to the Caribbean and Gulf of Mexico into mid-July. There will at times be a region of low shear between the polar jet (northern set of arrows on the plots) and the subtropical jet, allowing for possible tropical development off the coast of North Carolina. Wind speeds are given in m/s; multiply by two to get a rough conversion to knots. Thus, the red regions of low shear range from 0 - 16 knots.

Dry air and African dust
June and July are the peak months for dust coming off the coast of Africa, and the Saharan dust storms have been quite active over the past month. Expect dust from Africa to be a major deterrent to any storms that try to form between Africa and the Lesser Antilles Islands in July.

Steering currents
The steering current pattern over the past few weeks has not changed much, and is typical for June and July. We have an active jet stream bringing many troughs of low pressure off the East Coast of the U.S. These troughs are frequent enough and strong enough to recurve any tropical storms or hurricanes that might penetrate north of the Caribbean Sea. Steering current patterns are predictable only about 3 - 5 days in the future, although we can make very general forecasts about the pattern as much as two weeks in advance. At present, it appears that the coming two weeks will maintain the typical July pattern, bringing many troughs of low pressure off the East Coast capable of recurving any July storms that might form. There is no telling what might happen during the peak months of August, September, and October--we might be in for a repeat of the favorable 2006 steering current pattern that recurved every storm out to sea--or the unfavorable 2008 pattern, that steered Ike and Gustav into the Gulf of Mexico.

Summary
Recent history suggests a 50% chance of a named storm occurring in the first half of July. Given that none of the computer models are forecasting tropical storm formation in the coming seven days, and SST and wind shear patterns look pretty average, I'll go with a 20% chance of a named storm forming during the first half of July.

Vote for Mike Theiss as an Antarctica blogger
Extreme weather photographer Mike Theiss, who wrote our Ultimate Chase photography blog for two years until a new job took him to South America, wants your help. He's entering a Quark Expeditions competition to receive an expense-paid 2-week trip to Antarctica, where he will do some intensive photography and blogging. In order to go, he needs the votes to show that he's a popular blogger. So, if you liked his posts while he was blogging for wunderground, and want to see him blog for wunderground during this potential Antarctica voyage, go to http://www.blogyourwaytoantarctica.com/blogs/view /220 and cast a vote. It takes about 3 minutes navigate through the registration and voting process. Mike will be back chasing hurricanes this August, and has promised to post his excellent storm photos on wunderground should we help him secure the Antarctica gig.

Have a great holiday weekend, and I'll be back Monday with a new post.

Jeff Masters

Hurricane

New $50 million hurricane research center: a bad idea

By: JeffMasters, 1:28 PM GMT on July 01, 2009

Hurricane track forecasts have improved by about 50% over the past twenty years, which has undoubtedly saved many lives and billions of dollars. These forecast improvements have primarily resulted from the investment made in hurricane research, which has been funded at approximately $50 million per year over that period. To me, it is unfathomable that our nation spends so little on scientific research that provides such an incredible value. The President's National Science Board, which makes budget recommendations for the National Science Foundation (NSF), agrees, and recommended a six-fold increase in hurricane research spending to $300 million per year in a 2007 report. But exactly how much "bang for the buck" are we getting from hurricane research? The answer is murky, making it difficult to excite the kind of attention and political appeal needed to give hurricane research funding the big shot in the arm it deserves. However, recent moves by the Obama administration show that they are taking notice of the need to spend more money on hurricane research. But, a recent proposal by Rep. Alan Grayson, D-Florida, to build a new $50 million hurricane research center in Orlando, is the wrong way to boost hurricane research.


Figure 1. A science team led by NOAA's Hurricane Research Division (HRD) prepares for a mission into Hurricane Gustav in 2008. Image credit: NOAA/HRD.

How current hurricane research is funded
In 2008, about $50 million was spent by the U.S. government on hurricane research, with about 25% of this total going to maintain the facilities that do the research. The $50 million funded 228 person-years of research. About 35% of this was provided by the National Oceanic and Atmospheric Administration (NOAA), with the rest of the money coming from the National Science Foundation (NSF), Office of Naval Research (ONR), and NASA. An additional $4 million was earmarked by Congress in 2008 to fund NOAA's promising new effort to improve hurricane intensity forecasts--the Hurricane Forecast Improvement Project (HFIP).

Where future funding increases should go: HFIP and JHT
The President's proposed FY 2010 budget continues the roughly $50 million dollars the hurricane research community traditionally gets, but adds $13 million in funding for the HFIP effort. To me, this is a great way to channel new hurricane research funding, as the HFIP effort is heavily focused on improving hurricane intensity forecasts, which have not improved at all over the past twenty years. Specific advancements outlined in the HFIP plan include:

1) Improving hurricane track forecast accuracy by 50% out to 5 days by 2018.
2) Improving hurricane intensity forecast accuracy by 50% out to 5 days by 2018.
3) Extending the lead time for hurricane forecasts out to 7 days.
4) Reducing the false alarm rate for rapid intensity forecasts.
5) Increasing the probability of detection of rapid intensification.

Another great way to boost hurricane research funding would be to put more money into NOAA's Joint Hurricane Testbed (JHT) project. This $1 million per year program has funded 50 separate hurricane research efforts over since 2001, 30 of which have been adopted operationally by the National Hurricane Center. Examples of successful JHT projects include the successful integration of the Stepped Frequency Microwave Radiometer (SFMR) surface wind measurement instrument into NHC operations; improvements to the GFDL and HWRF computer models; and improving techniques to make a "consensus" forecast based on the output of our four best computer models. However, no new money for JHT has been proposed in the FY 2010 budget, though some of the money earmarked for HFIP may flow into JHT.

A new $50 million hurricane research center proposed
Instead, a new proposal for hurricane research funding has been championed by Representative Alan Grayson, D-Florida. According to an article in the Orlando Sentinel, Grayson is pushing for a new $50 million hurricane research center to be built in Orlando. He demanded that such a hurricane research center be built in exchange for his vote for the controversial climate change bill passed Friday by the U.S. House, the American Clean Energy and Security Act of 2009. There is no language in the actual bill authorizing funds for such a center--Grayson merely has the word of democratic lawmakers, including President Obama, that such a center would be built. "I think it's a very worthwhile project. I look forward to working on it and making it a priority as the legislative process moves along," said U.S. Rep. Henry Waxman, the California Democrat who sponsored the bill, in the Orlando Sentinel article. The center could be constructed with funds aimed at helping states "study and adapt to climate change," money that would not be available until 2012 at the earliest. The hurricane center is "among the type of activities that would be eligible to receive funding," Waxman said. "We've never had anything [like this] come into this district before, ever," said Grayson, a freshman lawmaker. "This will be the world-leading facility for hurricane research. This will draw people from all over the world."

Well, I have championed efforts to give more funding to hurricane research over the years, and I think the $300 million per year in funding for the National Hurricane Research Initiative proposed in 2007 by the President's National Science Board is what is needed. However, I think Grayson's proposed new hurricane center is a bad idea. Florida already has a world-leading facility for hurricane research, NOAA's Hurricane Research Division on Virginia Key, and does not need another. The U.S. hurricane research community has an infrastructure in place that works, and the best way to foster hurricane research is to pump money into this existing infrastructure. I talked with a number of senior hurricane research scientists about the idea of a new hurricane research center, and none of them supported it. It's great that Rep. Grayson's wants to put new much-needed funding into hurricane research, but he didn't consult with the experts to see if a new research center was a good way to do this. It isn't. Where are all of the scientists needed to staff such a center going to come from? Presumably, they will be drawn from existing successful research teams, leading to the disruption of these proven research efforts. Adding a new national research center with a new bureaucracy with new management needing on-the-job training will dilute and distract from current hurricane research efforts, and is not a good way to spend $50 million. Several senior hurricane research scientists are going to be reaching out to Rep. Grayson over the next few months to make him more aware of the abilities and needs of the hurricane research community. Hopefully, these efforts will result in a more productive way for the Congressman to boost hurricane research. If you live in Rep. Grayson's district, I recommend you contact him to express your desire to see him champion a more effective way to boost hurricane research than with his proposed $50 million hurricane research center. Putting the $50 million into the National Hurricane Research Initiative (HFIP) effort would be a better use of the funds. To his credit, Rep. Grayson is a co-sponsor of the National Hurricane Research Initiative of 2009 (H.R. 327), a bill introduced into the House of Representatives on January 8, 2009. This bill is a lesser ($150 million per year) version of the $300 million per year National Hurricane Research Initiative proposed in 2007 by the President's National Science Board.

Good links for HFIP information are at:

http://www.nrc.noaa.gov/HFIPDraftPlan.html
http://www.dtcenter.org/plots/hrh_test/workshop20 09/presentations/1_Gall_HRH%20HFIP%20presentation. pdf

Some summaries of recent HFIP activities in the last year are at:

http://www.dtcenter.org/plots/hrh_test/index.php
http://rammb.cira.colostate.edu/research/tropical _cyclones/hfip/workshop_2009/

My next post will be Friday, when I'll have the first half of July hurricane outlook.

Jeff Masters

Politics


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Category 6™

About

Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather