Category 6™

New blog organization effort

By: JeffMasters, 2:00 PM GMT on March 28, 2008

Well, today's blog marks my 921st blog since I began blogging in April of 2005. At long last, I've found time to organize my blogs by subject so we can easily find an old blog. This is now a permanent link at the right of my blog page under the "Previous Entries for 2008" section titled, "Complete Archive by Subject--new!" I've broken out my blogs on individual hurricanes and tropical storms for a particular year into their own index page; my busiest year was (duh!) 2005, when I wrote 251 blogs on the individual storms that occurred. My record for most blogs in a month is 68, set in September of 2005.

Greatest hits
I'm not sure how how each blog ranks in terms of number of readers, but below is a list of five blogs I spent the most time working on. These aren't necessarily the blogs I am proudest of. I am still trying to find the right balance between providing unbiased scientific facts and my personal opinions. For the most part, I feel my blogs are most valuable when I allow readers to draw their own conclusions based on the facts presented. For example, I say little on what efforts should be made to slow down global warming. I am not an expert in policy or economics. However, I do get very upset when I hear politicians and scientists lying or distorting the facts, and feel a strong need to speak up when that occurs. Many of the below blogs reflect that passion:

Climate Change: An analysis of Dr. Richard Lindzen's Wall Street Journal op-ed accusing climate scientists of alarmism: Climate of Fear.

Hurricanes: The appalling failure of our elected leaders to prevent the Katrina disaster: Katrina: an unnatural disaster.

Politics: The numbers former National Hurricane Center chief Bill Proenza used to justify replacement of the aging QuikSCAT satellite just didn't add up: Challenging Bill Proenza's QuikSCAT numbers.

Air Pollution: Which is worse--a Category 5 hurricane, or a major air pollution episode? Pick your poison.

Aviation: A flight I took into a hurricane strength 'Noreaster in 1989: Flying into a record 'Noreaster.

Humor: Well, the image of George W. Bush at the National Hurricane Center that appears as the image header for the humor section is from a blog I haven't posted yet. Tune in on Tuesday, April 1, to see a hurricane humor piece I put a rather ridiculous amount of effort into!

Thanks go to all of you who've contributed to the value of this blog by posting intelligent comments, and those who share their weather knowledge and experiences through their own blogs. I also want to thank the many Personal Weather Station owners who upload their data, and the wunderphotographers that share their pictures. I've linked a few of my favorites from past blogs below. I look forward to many more years of blogging!

Jeff Masters

Connecticut-sized ice shelf disintegrating in Antarctica

By: JeffMasters, 10:48 PM GMT on March 25, 2008

A large ice sheet on the Antarctic Peninsula has begun to disintegrate in spectacular fashion over the past four weeks, according to a press release today from the National Snow and Ice Data Center. They attribute the event to strong warming due to climate change. The victim is the Connecticut-sized Wilkins Ice Shelf (5,200 square miles), located about 1,000 miles south of the southern tip of South America. The nearby Larsen B Ice Shelf, which was about three times smaller than the Wilkins Ice Shelf, disintegrated in just three days in 2002. The Larsen B Ice Shelf was several thousand years old, and the Wilkins Ice Shelf is at least several hundred years old. It began disintegrating on February 28, and has just a narrow 6 km wide strip of ice holding it together.


Figure 1. Disintegrating ice from the Wilkins Ice Shelf forms huge blocks in the Bellingshausen Sea by the Antarctic Peninsula. Satellite image from March 8, 2008, courtesy of the National Snow and Ice Data Center.

Sea level rise due to antarctic melting
The disintegration of the Wilkins Ice Shelf will not significantly alter global sea level, since the ice is already floating in the ocean. Some Antarctic ice shelves are important because of their ability to insulate and buttress glaciers along the coast, and their loss allows more rapid melting of the glaciers they hold back. However, this is not the case for the Wilkins Ice Shelf. Its disintegration is of note because the shelf had been around hundreds of years, and is a spectacular sign that the climate is changing.

Melting of ice in the Antarctic Peninsula and along the ocean edges of the West Antarctic Ice Sheet is contributing to about 0.5 mm/year of sea level rise to the world's oceans, according to a NASA study published in February 2008. This is up from the 0.3 mm/year of sea level rise Antarctica contributed in 1996. Melting from the Greenland Ice Sheet also contributes about 0.5 mm/year to global sea level rise. Melting ice from Greenland and Antarctica each contribute about 10-15% of the observed 3-4 mm/year of global sea level rise.

Antarctic temperatures
While most of Antarctica cooled during the period 1981-2004, the Antarctic Peninsula where the Wilkins Ice Shelf lies warmed by about 1° C. Sea Surface Temperatures (SSTs) also warmed by about 1° C near the Antarctic Peninsula, and these warmer waters may be primarily responsible for the disintegration of the shelf. In the period 2005-2007, almost all of Antarctica warmed, canceling out much of cooling observed during 1981-2004 (Figure 2). I explained in detail in a November 2007 blog why most of Antarctica cooled up until the past few years.


Figure 2. Antarctic surface temperatures as observed via AHVRR satellite measurements between 1981 and 2007. Note that the Antarctic Peninsula where the Wilkins Ice Shelf lies has seen the strongest warming. Image credit: NASA

Jeff Masters

Spring flooding hits Midwest; Southeast drought eases

By: JeffMasters, 7:04 PM GMT on March 20, 2008

This year's annual spring flooding season is upon us, and it's been a worse flood year than usual across much of the Midwestern U.S. At least 13 people have been killed due to the flooding this week, with another three persons missing. A slow moving storm system brought rains in excess of ten inches to the region (Figure 1). These rains, combined with melting from unusually heavy snows this winter, have led to the floods.


Figure 1. Heavy rains exceeding 10 inches have fallen in some portions of the Midwest over the past week. Image credit: NOAA.

According to NOAA, 224 cities are experiencing flooding today, with major flooding reported in 13 cities in Missouri, Arkansas, Oklahoma, Texas, Indiana, Ohio, Kentucky, and Illinois. As snow continues to melt and runoff from the recent rains continues to increase the flooding, an additional 13 cities are expected to observe major flooding in the next 48 hours. Fortunately, no heavy rain is expected in the next three days, so a long duration flooding event is not likely.


Figure 2. The NOAA flood outlook calls for significant river flooding across much of the Midwest through Monday. Image credit: NOAA.

Flooding outlook for this Spring
According to NOAA, Above-normal flood potential is expected this Spring in much of the Mississippi River basin, the Ohio River basin, the lower Missouri River basin, Pennsylvania, New Jersey, most of New York, all of New England, and portions of the West, including Colorado and Idaho. Snow depths up to a foot above usual in upstate New York and much of New England could cause flooding in the Connecticut River Valley; locations in the mountains of Colorado and Idaho have 150 to 200 percent of average water contained in the snow pack, leading to a higher than normal flood potential there; and Wisconsin and northern Illinois have had heavy snows this winter that could cause continued flooding concerns this Spring.

Southeast drought continues to improve
On the plus side, the area of the Southeast U.S. covered by the severest form of drought--exceptional drought--has shrunk to a small spot over southern Tennessee/northern Alabama, and Georgia is free of exceptional drought for the first time since July. The drought is expected to continue to improve between now and June over the Southeast U.S.

Jeff Masters

Flood

Atlanta tornado one the most damaging on record

By: JeffMasters, 2:24 PM GMT on March 17, 2008

The strong EF2 tornado that smashed through downtown Atlanta at 9:40 pm Friday night is a reminder that the U.S. is potentially vulnerable to a very high death toll from a violent tornado hitting a major city. Friday's tornado, with a width of 200 yards, path length of 6 miles, and winds up to 130 mph, was strong enough to cause an estimated $150-$200 million in damage to downtown Atlanta. Only 16 tornadoes during the 20th century caused inflation-adjusted damage more than $200 million (Brooks and Doswell, 2000), so the Atlanta tornado is one of the most damaging of all time. Fortunately, no one was killed, although at least 27 people were injured, one seriously.

As unlucky as Atlanta was to have its first tornado ever to hit the downtown area, the city was extremely fortunate that the tornado was not not stronger. What would have happened if a clone of the strongest tornado on record--the May 3, 1999 Bridgecreek-Moore F5 tornado--had hit Atlanta? According to tornado researcher Josh Wurman of the Center for Severe Weather Research in Boulder and three co-authors in a paper published in the January 2007 issue of the Bulletin of the American Meteorological Society, the toll would have been staggering--14,900 deaths and tens of billions in damage. I discussed their findings in an April 2007 blog.

However, three tornado researchers, led by Harold Brooks of the National Severe Storms Laboratory, challenged these numbers in a January 2008 article in the Bulletin of the American Meteorological Society. They argued that Wurman et al. overestimated the potential deaths from such a storm by a factor of 100, and a death toll nearer to 150 would be more reasonable. They stated:

Given that the highest death toll in a tornado in U.S. history is 695 in the Tri-State tornado of 1925, and that the last death toll of greater than 100 was in 1953, the validity of these estimates is of some concern.

The authors conceded that a violent tornado traveling the length of a rush hour-packed freeway or hitting a sports stadium filled with spectators could generate much higher death tolls. Wurman et al. responded to the criticism by defending their death toll estimates:

We acknowledge that historical tornadoes have not caused the level of fatalities estimated in our paper. However, considering that tornadoes are relatively rare and that dense population in urban and suburban neighborhoods in the United States is a relatively recent but growing phenomenon, the historical record is too short to indicate the range of possible events.

Considering that Friday's Atlanta tornado hit the Georgia Dome stadium when it was packed with 16,000 people watching an SEC tournament basketball game, I think that both groups of researchers would agree that a death toll in the thousands was quite possible had the Atlanta tornado been an EF5.


Figure 1. Doppler winds image of the March 14, 2008, Atlanta, Georgia EF2 tornado. Note the region just northwest of the city showing blues and reds right next to each other, denoting strong winds moving both towards and away from the radar in a tight circulation. This is the signature associated with a mesocyclone--a rotating thunderstorm that commonly spawns a tornado.

More severe weather expected this week
Severe weather is expected over much of the Midwest and Southern U.S. over the next three days, in association with a strong cold front that will traverse the region. The Storm Prediction Center has placed portions of Texas, Oklahoma, Kansas, Missouri, and Arkansas under its lowest classification of potential severe weather today, "Slight Risk". The Weather Underground Severe Weather page and Tornado page are good places to go to follow this week's severe weather.

Good tornado book
For those of you interested in reading about the most violent and most damaging tornado on record, the famed 1999 Bridgecreek-Moore tornado, I recommend a reading of Nancy Mathis' book Storm Warning, which is now out in paperback. I reviewed the book in a blog last year.

Annual WeatherDance contest ready for registration!
Armchair forecasters, now's your chance to shine! WeatherDance, based on teams in the men's and women's NCAA basketball tournaments, allows players to predict which team's city will be hotter or colder on game day in each round of the Big Dance. Beginning today, players can make their forecasts at the Weather Dance Web site at: www.weatherdance.org. The site will be updated with cities promptly after NCAA seeding announcements. First round Weather Dance selections must be entered by 11:59 p.m. EST Wednesday, March 19.

"Officially, Weather Dance began as a class project to get students involved in weather forecasting, but we kept it around because it got popular. People think they can do better forecasting than the meteorologists. Well, here's their shot!" said Perry Samson, WeatherDance creator, co-founder of the The Weather Underground, Inc., and Professor in the Department of Atmospheric, Oceanic and Space Sciences at the University of Michigan.

This is the third year for the game. Last year more than 2,000 people played. Most play merely for the thrill, but many science teachers involve their classes as part of meteorology units. The winning teacher will receive an invitation and $500 to join the Texas Tech/University of Michigan Storm Chasing team this spring for a day of tornado chasing. Other winners will receive a Weather Underground umbrella or a copy of the book "Extreme Weather," by Christopher C. Burt.

Jeff Masters

Tornado

Destructive thunderstorm rips Atlanta

By: JeffMasters, 2:40 PM GMT on March 15, 2008

A violent thunderstorm roared through downtown Atlanta at 9:40 pm Friday night, bringing tornado-force winds that injured 27 people and caused millions in damage. It is uncertain whether the wind damage was due to a tornado or a strong thunderstorm microburst. If it was a tornado, it was the only one for the day, since the Storm Prediction Center did not receive any other reports for tornadoes Friday. However, 96 reports of hail and 23 reports of damaging wind were received. Examination of the radar reflectivity loop shows the classic hook echo commonly accompanying tornadoes was present in the storm before and after it hit Atlanta, but not while it was over the city. The Doppler velocity loop shows that there was rotation associated with the thunderstorm that hit the city, and this rotation increased as the thunderstorm moved over the city. It is certainly possible that this thunderstorm spawned a tornado.


Figure 1. Radar reflectivity image of the March, 14, 2008 Atlanta, Georgia thunderstorm. No "hook" echo is evident in the image as the storm swept through Atlanta.


Figure 2. Doppler winds image of the March 14, 2008, Atlanta, Georgia thunderstorm. Note the region just northwest of the city showing blues and reds right next to each other, denoting strong winds moving both towards and away from the radar in a tight circulation. This is the signature associated with a mesocyclone--a rotating thunderstorm that commonly spawns tornadoes.

Severe weather is not done with the region yet--the Storm Prediction Center has placed northern Georgia and much of South Carolina under their "Moderate Risk" category for severe weather today, one level below the their highest level of risk. The Weather Underground Severe Weather page and Tornado page are good places to go to follow today's severe weather.

Jeff Masters

Tornado

If global warming is occurring, why was the winter of 2007-2008 so cold and snowy?

By: JeffMasters, 1:38 PM GMT on March 14, 2008

The planet was much snowier and warmer than usual during the winter of 2007-2008, according to statistics released today by the National Climatic Data Center. Snow cover extent over the Northern Hemisphere during the period December 2007 - February 2008 was the fourth greatest on record, and was the greatest on record for January. Satellite-derived snow cover records extend back to 1967. Some regions of the Middle East, such as Baghdad, Iraq saw their first snow in living memory, and seasonal snowfall records were broken in Wisconsin and a few places in the Northeastern U.S. Surprisingly, the winter also ranked much above average in temperature--it was the 16th warmest December through February period in the 128-year global record. This puts the winter of 2007-2008 in the warmest 13% of all winters. Temperatures this winter were a bit cooler than recent winters because of an ongoing strong La Niña event in the Eastern Pacific Ocean, which has dramatically cooled the ocean surface waters. By one measure (the surface pressure difference between Darwin and Tahiti), February 2008 was the strongest February La Niña event on record. The last time we had a winter this cool was during 2000-2001, which also happened to be the last time we had a major winter La Niña event.


Figure 1. Departure of temperature from average for the winter of 2007-2008. Image credit: National Climatic Data Center.

A normal winter for the U.S.
December 2007 through February 2008 was about average in the contiguous U.S.--the 54th coolest winter on record in the 113 year period of record. The average temperature was 33.2°F (0.6°C), which was 0.2°F (0.1°C) above the 20th Century mean. It was the 18th wettest December-February in the 1895-2008 record. New York experienced its wettest winter on record, and the states of Colorado, Connecticut, Pennsylvania, and Vermont experienced their second-wettest winter on record. Only the South received below normal levels of precipitation, mostly due to a dry winter in Texas.

All time winter snowfall records have already been set in some portions of the Northeast U.S. and Wisconsin. As of March 12, Madison, WI had accumulated 92 inches of snow, smashing the previous seasonal snowfall record of 76.1 inches (193.3 cm) of snow in the winter of 1978-1979. Two locations in the Northeast have set new winter snowfall records, and more records will fall if an average amount of snow falls in March. By the end of February, new snowfall records for the season-to-date were also set in both Telluride and Aspen, Colorado.

An exceptionally warm winter in Northern Europe and Asia, cold in Central Asia
Northern Asia and northern Europe experienced an exceptionally warm winter, with Sweden and Finland recording their warmest winters ever, and Norway, its second warmest. Conversely, Tajikistan recorded its coldest winter in 30 years, and heavy snows in Kazakhstan caused severe flooding when they melted. Snow storms and cold weather in China this winter killed 129 people and did over $21 billion in damage.

Why did we see a cool winter, if global warming is occurring?
It is important to understand the difference between weather and climate. Climate is what you expect; weather is what you get. What we experience in one particular season or year is "weather". Weather has a large variation from year to year, with cool seasons and years mixed in with warms ones. "Climate" is the weather measured on scales of tens of years or longer. One cool winter or year is not an indication that the climate is cooling back to normal. The climate is warming, and unless we see a series of several years of cool conditions, this year's cool winter merely represents a normal fluctuation of the weather. Relatively cool weather is to be expected globally during a strong La Niña event in the Eastern Pacific Ocean, and relatively warm weather is expected during an El Niño event. We shouldn't expect to see record warmth for the globe unless an El Niño event is occurring.

Why did we see record snows this winter, if global warming is occurring?
Beware of global warming skeptics trumpeting record snowfalls this winter as an excuse to doubt that global warming is occurring. One should primarily look at global temperatures on a scale of decades to judge the validity of global warming. Dr. Ricky Rood, who writes our Climate Change blog, put it this way in his current blog, Creeping Onset of Spring and in an earlier blog, Water, water, water:

This year has been very snowy in the northern hemisphere. That it is snowy does not suggest that it is colder. If it gets warmer, it does not mean that we no longer see freezing temperatures in places like Michigan. If it gets warmer there is more water in the atmosphere, and when there is precipitation there will be more precipitation, and if it is below freezing, then that precipitation will be ice and snow. The high mountains near the coast, like the Cascades and the Sierra Nevada would expect more snow. This is also true for the high altitudes parts of Greenland and Antarctica. From a climate point of view it is more important to look at snow cover in the late winter and early spring. Is the snow melting earlier?


Figure 2. Average February arctic sea ice coverage as observed by satellites between 1979 and 2008. Image credit: National Snow and Ice Data Center

Arctic sea ice recovers a bit
It will be interesting to see if this year's heavy Northern Hemisphere snow cover melts earlier than usual, as this will have a big impact on the annual Arctic sea ice melt. We're starting off with more ice surface area in the Arctic than in the past four years--February 2008 Northern Hemisphere sea ice extent was greater than each of the previous four years, thanks to cooler than usual temperatures over much of the Canadian Arctic. However, this was still the fifth lowest ice extent on record for the month of February, and 8% below its extent in 1979 when satellite measurements began, according to the National Snow and Ice Data Center. February was the third straight month that a new monthly minimum Arctic sea ice record was not set, following a string of five months in a row where monthly records were set. The extra sea ice extent will help to reduce the amount of melting this summer, but this effect will probably be overshadowed by the fact that natural wind patterns have forced a large amount of thick, multi-year ice out of the Arctic this winter. This has left much of the sea ice very thin, making it very vulnerable to melting. For the first time on record, the edge of thin first-year ice has pushed beyond the North Pole. IF we get another relatively warm and sunny summer in the Arctic in 2008, we will likely see Arctic sea ice loss surpassing last year's astounding collapse.

Annual WeatherDance contest ready for registration!
Armchair forecasters, now's your chance to shine! WeatherDance, based on teams in the men's and women's NCAA basketball tournaments, allows players to predict which team's city will be hotter or colder on game day in each round of the Big Dance. Beginning March 17, players can make their forecasts at the Weather Dance Web site at: www.weatherdance.org. The site will be updated with cities promptly after NCAA seeding announcements. Team selection occurs March 16 for men and March 17 for women. First round Weather Dance selections must be entered by 11:59 p.m. EST March 19. Players can register now and receive periodic reminders as the game progresses.

"Officially, Weather Dance began as a class project to get students involved in weather forecasting, but we kept it around because it got popular. People think they can do better forecasting than the meteorologists. Well, here's their shot!" said Perry Samson, WeatherDance creator, co-founder of the The Weather Underground, Inc., and Professor in the Department of Atmospheric, Oceanic and Space Sciences at the University of Michigan.

This is the third year for the game. Last year more than 2,000 people played. Most play merely for the thrill, but many science teachers involve their classes as part of meteorology units. The winning teacher will receive an invitation and $500 to join the Texas Tech/University of Michigan Storm Chasing team this spring for a day of tornado chasing. Other winners will receive a Weather Underground umbrella or a copy of the book "Extreme Weather," by Christopher C. Burt.

Jeff Masters

Climate Change Climate Summaries

Big money for hurricane research for 2009?

By: JeffMasters, 9:50 PM GMT on March 11, 2008

The National Oceanic and Atmospheric Administration (NOAA), the parent organization of the National Weather Service (NWS) and National Hurricane Center (NHC), has just released the President's proposed Fiscal year 2009 (FY 2009) budget. The new $4.1 billion budget is 5.2% larger than the budget enacted for this year, and proposes major new funding for hurricane-related research and operations. If approved by Congress and sustained for the next ten years, the new hurricane research funding offers some real hope that we will finally make headway in improving hurricane intensity forecasts.

$5.3 million in new funding for improving hurricane intensity and track forecasts
The big news in this year's proposed budget is the increased funding for improving hurricane intensity (and track) forecasts. Forecasts of hurricane tracks improved by about 50% in the past 20 years, but intensity forecasts improved very little during that period. In fact, the intensity forecasts issued by NHC in 2007 were poorer than average, thanks to twice as many rapid intensification episodes as usual (recall Felix, Humberto, and Lorenzo). To have any hope of solving the hurricane intensification problem, a major investment in hurricane research is required. In May 2007, the NOAA Executive Council (NEC) established the NOAA Hurricane Forecast Improvement Project (HFIP), a 10-year NOAA effort to accelerate improvements in one to five day forecasts for hurricane track, intensity, storm surge and to reduce forecast uncertainty, with an emphasis on rapid intensity change. The proposed FY 2009 budget allocates $1.04 million to fund this effort, plus another $3.2 million for improving hurricane models such as the new HWRF model (which debuted operationally in 2008). An additional $1 million is proposed for the Numerical Prediction Developmental Testbed Center (DTC), to transfer improvements in hurricane forecast models done in a research setting into operational use by the NHC as quickly as possible.

This proposed $5.3 million in new funding for hurricane research would allow us to increase the resolution of today's current computer hurricane forecast models--currently no better than 9 km--down to 1 km, a scale that can resolve the fine-scale processes that are critical to hurricane intensification. This sort of improvement gives us real hope of being able to solve the hurricane intensity forecast problem. The cost of such an effort could be made up in savings from the reduced evacuation costs from just one major hurricane. For example, the evacuation effort for Hurricane Rita cost over 100 lives and $2 billion. Quoting from the proposed FY 2009 budget document (p. 386):

A case study of Hurricane Rita demonstrates the economic benefits derived from improved forecasting. Typically, a household decision to evacuate is based on the issuance of a hurricane warning and the anticipated storm strength. On early morning of September 22, 2005, a hurricane warning was issued from Port Mansfield, Texas to Cameron, Louisiana. At that time, Hurricane Rita was a Category 4 storm having just been downgraded from a Category 5. Under this scenario, the estimated economic impact of the evacuation was $2.344 billion. Without the initiative, NWS expects a reduction of forecast track and wind speed errors by 10% resulting in 159,000 people remaining home and saving the economy $68.9 million dollars. With the initiative however, NWS could improve forecast track and wind speed errors by 50% and 30% respectively, resulting in 4 million remaining home and saving the economy $1.99 billion dollars. This includes 100 that would have been saved during the evacuation of Houston."

References:
1. Cost of Hurricane Evacuation by Kevin Smith, University of Eastern Carolina, 1999; Opportunity Costs of Hurricane Evacuation by John Whitehead, University of Eastern Carolina, 1999; and Structure of a Hurricane Evacuation by Mike Lindell, Texas A&M University, 2005.

2. Based on 2002 Current Population Estimate and 2002 County Business Patterns from the Bureau of the Census. Probability of Evacuation and average cost from Cost of Hurricane Evacuation by Kevin Smith, University of Eastern Carolina, 1999. The average household will spend $149 during an evacuation and the average business will lose $20,599 in 2006 dollars.


Figure 1. Hurricane Rita approaches the Texas/Louisiana coast on September 23, 2005. Image credit: NASA.

New funding for the Hurricane Hunters
The new budget proposes $4 million in new money for NOAA's weather research aircraft, including the two NOAA P-3 Orion hurricane hunter aircraft. Flight hours would increase by about a factor of two, from 1365 to 2845, and a third NOAA P-3 aircraft would be added for hurricane hunting. The new P-3 is expected to be operational for the coming 2008 hurricane season.

Not all of the money for the NOAA weather research aircraft would go for hurricane-related operations; there would be increased flight hours for winter storms surveillance (125 hours), airborne snow surveys to improve water resource forecasts and improve snow melt flood forecasts (330 hours), and coastal mapping to improve and maintain nautical charts and to improve tsunami inundation modeling (330 hours).

$3 million for Unmanned Aircraft Systems (UAS)
The new budget proposes $3 million to fund the use of remote controlled aircraft--Unmanned Aircraft Systems (UAS)--for weather research. Some of this money would go to fund hurricane research. The UAS platforms would also be used for climate change work and studies of Pacific storms that impact the U.S. West Coast. These UAS platforms can go where the Hurricane Hunters cannot--at low altitude in hurricanes--and provide a crucial set of data that can help with forecasts of rapid hurricane intensification.

$3 million for buoys
Another major increase in hurricane-related funding is an additional $3 million to operate the network of 15 open ocean "Hurricane Supplemental data buoys" that provide important measurements of wind speeds, pressure, and wave heights. These buoys had only $1.4 million in funding last year. Real time data from these stations will assist the National Hurricane Center to more accurately determine hurricane formation or dissipation; the extent of tropical hurricane wind circulation; the location and center of hurricanes; direction, height, and distribution of ocean waves generated by hurricanes; the maximum hurricane intensity; and the quality of measurements and estimates obtained from remote-sensing reconnaissance aircraft and satellites. Although this is not as big a deal as the proposed hurricane intensity research funding, it is still a great boost for hurricane forecasters.

Is this too much money for hurricane research and operations?
The President's proposed budget will be modified by both the House and Senate before it becomes law in October. It is possible that some or all of the increased hurricane-related funding could be stripped from the budget. However, it is more likely that additional funding would be added, since Congress has always passed a NOAA budget larger than asked for by President Bush. According to the National Science Board, government funding for hurricane research averaged $20 million between 2001 and 2006, so the proposed addition of another $10 million or so in the FY 2009 budget would represent a huge boost. Is this too much money to spend? Well, considering that the National Science Board advocated creation of a National Hurricane Research Initiative funded at $300 million per year, an extra $10 million per year for hurricane research is not very much.

To do a thorough job of reducing our vulnerability to hurricanes, $300 million per year is a reasonable amount to spend. However, the U.S. faces a number of threats that also require large outlays of dollars, such as bioterrorism, a flu pandemic, and earthquakes. Getting a $300 million per year project funded in a time of "increasingly small non-defense discretionary budgets" is difficult. To put this number in perspective, the annual amount spent in the U.S. on meteorology operations and supporting research is $3 billion. About $900 million per year of this goes to run the National Weather Service. The federal budget request for FY 2009 for flu pandemic emergency preparedness is $820 million--about the same amount of money that is spent for the entire National Weather Service! What's really startling is the amount of money spent on bioterrorism emergency preparedness--between $3 and $6 billion per year since 2002, with $4.3 billion requested for 2009. That's over 200 times what we spend on hurricane research, and over ten times the $300 million for hurricane research proposed by the National Science Board. A catastrophic bioterrorism attack on the U.S. may never occur, but catastrophic hurricane strikes are guaranteed. These strikes will occur with increasing frequency in the future, as more people move to the coast and the population increases. A major increase in hurricane research funding will reduce the costs of these future disasters, and is very much in order.

Jeff Masters

Lufthansa jet narrowly avoids crashing in German windstorm

By: JeffMasters, 6:39 PM GMT on March 05, 2008

A Lufthansa Airbus A320 with 137 people on board nearly crashed at the Hamburg, Germany airport on Saturday, March 1, as the pilot struggled to land the airplane during high winds kicked up by winter storm "Emma". If you don't have a fear of flying, take at look at the remarkable video an amateur photographer captured of the landing. It's been uploaded to LiveLeak.com and YouTube. As seen in the still images captured from the video (Figure 1), the pilot attempted to land the aircraft with a strong crosswind blowing from right to left. The crosswind is so strong that the drift angle of the aircraft (the difference between where the nose is pointed and the actual track of the airplane along the runway) is about 20 degrees. As the pilot touches the wheels down, he kicks the rudder to straighten the airplane out, and at that moment, a strong gust of wind lifts up the right wing, pushing the left wingtip of the aircraft into the runway. The pilot is skillful and lucky enough to avoid having the airplane cartwheel down the runway and explode, and aborts the landing attempt. You can see the blast of the engines kick up a cloud of dust on the left side of the runway as he goes to full throttle for a "go around" (thanks to Jeff Weber of UNIDATA for making the correct analysis of this dust cloud). The plane landed safely on its second attempt. Do you think the passengers were praying during that second landing? I do! Only minor damage was done to the left wingtip, and the plane was back in service by the next day.


Figure 1. Still photo of the Lufthansa jet (left) as it approached the runway. Note sharp angle between the direction the airplane's nose is pointed, and the track it is taking along the length of the runway. Strong winds of 40 mph gusting to 63 mph were observed at the airport that afternoon. Right photo: the left wingtip of the jet scrapes the runway as a big gust of wind hits. Image credit: LiveLeak.com.

The weather that led to the near disaster
The initial press reports indicated that a wind gust of 155 mph hit the aircraft as it tried to land. That sounded rather dubious to me, so I took a closer look at the weather conditions that day. The only way a wind gust of that magnitude could have been generated would be from a powerful microburst flowing out from the base of a severe thunderstorm. The world record strongest thunderstorm microburst occurred on August 1, 1983, when winds of 149.5 mph were clocked at Andrews Air Force Base near Washington D.C., just five minutes after President Reagan landed there aboard Air Force 1. So, a 155 mph wind gust is possible, but it would be a new world record.


Figure 2. Visible satellite image from 10:20 GMT Saturday March 1 2008. Winter storm "Emma", a 960 mb low pressure centered north of Hamburg over Norway, has pushed a cold front through Germany. A strong northwest to west-northwest flow of air coming off the North Sea (red arrows) brought sustained winds of 36 mph, gusting to 56 mph, to Hamburg, Germany. Image credit: University of Bern, Switzerland.

Were there severe thunderstorms near Hamburg on March 1 that could have generated such a wind gust? A powerful low pressure system (Emma) with a central pressure of 960 mb passed to the north of Hamburg, Germany that morning, dragging a strong cold front through in the late morning (Figure 2). After cold frontal passage, the wunderground history page for Hamburg at 12:50 GMT, five minutes before the time of the incident, shows sustained winds of 35 mph, gusting to 56 mph. A temporary wind reading of 40 mph, gusting to 63 mph, also occurred. The temperature was about 45°F, with occasional rain. This is classic post-cold front weather, and is not the sort of environment where severe thunderstorms with strong microbursts occur. Later press reports corrected the 155 mph wind gust, reducing it to 56 mph. Apparently, the aircraft's landing speed was 155 mph. In any case, the plane was operating very near to the maximum crosswinds an Airbus A320 is permitted to land in--38 mph, gusting to 44 mph. There are questions whether air traffic control should have used that runway for landings, and whether or not the pilot should have attempted a landing in those conditions. There is an interesting discussion at the LiveATC.net discussion forum where some pilots weight in on the near-disaster.

Winter storm Emma did considerable damage across Germany. Six people died in weather-related automobile accidents, power was cut to 150,000 homes, and high winds ripped the roof off of a school in Hesse. In neighboring countries, 260 buildings lost their roofs in Poland, flooding collapsed a bridge in Romania, and in the Czech Republic, 92,000 people (about 10 percent of the population) lost power.

Jeff Masters

Aviation

Severe weather outbreak expected today across the Southeast U.S.

By: JeffMasters, 2:28 PM GMT on March 04, 2008

Two tornadoes touched down in Mississippi yesterday, and the record early season onslaught of tornadoes in the U.S. is expected to continue today. An unconfirmed tornado hit Camp Shelby, a Joint Forces Training Center 75 miles northwest of Mobil, Alabama at 11:25 pm CST Monday, injuring 14 National Guardsmen. A second tornado briefly touched down near Cary, Mississippi, and golf ball sized hail and damaging thunderstorm winds were plentiful across Mississippi, Louisiana, and Arkansas yesterday.

Another volley of tornadoes is possible over the eastern portion of North Carolina, South Carolina, and Virginia this afternoon. The Storm Prediction Center has placed this region under its "Moderate Risk" target today--one level below the maximum "High Risk" threat level. A powerful low pressure system will pass north of these states, dragging a strong cold front through. Strong EF2 and EF3 tornadoes are possible along this front, and the action may move into Maryland and Delaware late tonight. Tornado watches have already been posted for portions of Georgia, Florida, Alabama, and Tennessee this morning. The tornado page is a good place to track the tornadoes as they occur today, along with our severe weather page.

2008 sets early tornado season records
The year 2008 smashed the record for most January and February tornadoes, with 368. The previous record was set in 1999, with 235 January/February tornadoes. Reliable records extend back to 1950. The 232 tornadoes reported in February of 2008 was a record for the month of February. Second place goes to 1971, with a relatively paltry 83 tornadoes. Each of the past three years has seen an unusually early start to tornado season (Figure 1). One would expect to see a shift in tornado activity earlier in the year in a warming climate, along with an earlier than usual drop off in activity in late spring. We can see that in both 2005 and 2006 that tornado activity dropped off much earlier than usual, and it will be interesting to see if 2008 follows a similar pattern. Note that there is a very high natural variability in tornado numbers, and the record for fewest ever January and February tornadoes was set just five years ago in 2002, when only four twisters occurred. It will be at least ten more years before we can say with any confidence that a warming climate is leading to an earlier peak in tornado season.

La Niña to blame?
There does seem to be a tendency for more early season tornadoes during La Niña years--four of the five years that had January/February tornado counts above 75 were all La Niña years (1971, 1975, 1999, and 2008). The only exception was 1998, which was an El Niño year, and had 118 January/February tornadoes. However, connection between La Niña and enhanced tornado activity is a controversial area of active research, and we don't know enough about the matter to blame this season's early tornado activity on La Niña.


Figure 1. Tornado reports so far this year have totaled 368 for the months of January and February, by far the greatest number of tornadoes observed so early in the year. Image credit: NOAA Storm Prediction Center.

Jeff Masters

Record early tornado season set to add more to its tally today

By: JeffMasters, 4:17 PM GMT on March 03, 2008

March will roar in like a lion today over the Southern U.S., with another volley of strong EF2 and EF3 tornadoes possible over portions of Louisiana, Arkansas, and Mississippi. The Storm Prediction Center has placed this region under its "Moderate Risk" target today--one level below the maximum "High Risk" threat level. The powerful low pressure system responsible for today's severe weather developed over Texas and Oklahoma on Sunday, spawning at least two tornadoes and hail up to 4.25" in diameter. The huge hail was reported in Buffalo, near the Kansas border.

The intensifying low pressure system will move through Louisiana, Arkansas, and Mississippi today, dragging a cold front through those states. This front has already spawned severe thunderstorms across eastern Texas and southern Arkansas this morning, with many reports of damaging thunderstorm winds. The tornado page is a good place to track the tornadoes as they occur today, along with our severe weather page.

2008 sets early tornado season records
The year 2008 smashed the record for most January and February tornadoes, with 368. The previous record was set in 1999, with 235 January/February tornadoes. Reliable tornado records extend back to 1950. The 232 tornadoes reported in February of 2008 was a record for the month of February. Second place goes to 1971, with a relatively paltry 83 tornadoes. Each of the past three years has seen an unusually early start to tornado season (Figure 1). One would expect to see a shift in tornado activity earlier in the year in a warming climate, along with an earlier than usual drop off in activity in late spring. We can see that in both 2005 and 2006 that tornado activity dropped off much earlier than usual, and it will be interesting to see if 2008 follows a similar pattern. Note that there is a very high natural variability in tornado numbers, and the record for fewest ever January and February tornadoes was set just six years ago in 2002, when only four twisters occurred. It will be at least ten more years before we can say with any confidence that a warming climate is leading to an earlier peak in tornado season. There does seem to be a tendency for more early season tornadoes during La Niña years--four of the five years that had January/February tornado counts 75 or above were all La Niña years (1971, 1975, 1999, and 2008). The only exception was 1998, which was an El Niño year, and had 118 January/February tornadoes.


Figure 1. Tornado reports so far this year have totaled 368 for the months of January and February, by far the greatest number of tornadoes observed so early in the year. Image credit: NOAA Storm Prediction Center.

Potential South Atlantic subtropical storm fizzles
Last Friday, I mentioned the possibility of a rare subtropical storm forming the South Atlantic off the coast of Brazil. It turned out that the candidate low pressure system wrapped a lot of dry air into its center, killing any chance it had to become a subtropical storm. There is still some vigorous tropical-looking thunderstorms firing up off the coast of Brazil this morning, and it is worth continuing to watch this region for formation of a subtropical storm. A separate low pressure system in southern Brazil has brought a wide variety of severe weather to Brazil, Argentina, and Uruguay over the past few days, as documented in the metsul.com weather blog (for those of you who read Portugese). For those of you who don't, try the web page translator at http://babelfish.altavista.com/babelfish/tr.

Jeff Masters

Tornado


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™

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