Category 6™

IPCC: Climate Change Increasing Risk of Hunger, Thirst, Disease, Refugees, and War

By: JeffMasters, 11:42 AM GMT on March 31, 2014

Climate change is already having "widespread impacts", and has the potential to worsen global hunger, water availability, disease, drought, flooding, refugees, and war in the coming decades if we do nothing to reduce it, said the Intergovernmental Panel on Climate Change (IPCC) today, in the latest installment of their once-every-seven-year report on the climate. Today's report on climate change impacts and how we can adapt to them warned that "throughout the 21st century, climate-change impacts are projected to slow down economic growth, make poverty reduction more difficult, further erode food security, and prolong existing and create new poverty traps." Today's report by the Nobel-prize winning group of scientists was the second of four parts. Part 1, released in September 2013, covered the physical science behind climate change. Part 3 (due out in mid-April, 2014) will discuss how we can mitigate (reduce) climate change impacts. Part 4 (due out in early November, 2014) will present a grand summary of Parts 1, 2, and 3. Some key themes from today's report:

Food supplies will tighten. To me, the most important finding of the report is the climate change's threat to reduce global food supplies, which have already been negatively impacted, and are at risk to get much worse: “Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive impacts. Climate change has negatively affected wheat and maize (corn) yields for many regions and in the global aggregate." For the future, the report acknowledges that some areas will likely see increases in food production, due to increased CO2 in the air and more favorable precipitation, but the overall global trend in food supplies will likely be downward (Figure 1.) This downward trend in yields will occur in the face of rapidly increasing demand, as the population grows by 2 billion, resulting in "increased likelihood of under-nutrition resulting from diminished food production in poor regions."

Figure 1. Summary of projected changes in crop yields, due to climate change over the 21st century. The figure includes projections for different emission scenarios, for tropical and temperate regions, and for adaptation and no-adaptation cases combined. Over the period 2010 - 2029, about as many scenarios predict an increase in global crop yields as predict a decrease. However, beyond 2030, more than twice as many scenarios predict a decrease versus an increase. Relatively few studies have considered impacts on cropping systems for scenarios where global mean temperatures increase by 4°C or more. For five time frames in the near-term and long-term, data (n=1090) are plotted in the 20-year period on the horizontal axis that includes the midpoint of each future projection period. Changes in crop yields are relative to late-20th-century levels. Data for each time frame sum to 100%. Image credit: IPCC.

Water availability to people will decrease, as wet areas get wetter and dry areas get drier. Not only does climate change pose huge risks to our food supply, it also threatens water availability. “The fraction of global population experiencing water scarcity and the fraction affected by major river floods increase with the level of warming in the 21st century.”

We're not adapting fast enough to avoid serious damage. The report talks about "adaptation deficits", as demonstrated by our relatively poor ability to respond to impacts from from recent extreme climatic events. "Climate-change-related risks from extreme events, such as heat waves, extreme precipitation, and coastal flooding, are already moderate (high confidence) and high with 1°C additional warming (medium confidence)." IPCC author and Princeton Professor Michael Oppenheimer put it more succinctly to the Associated Press: “We’re all sitting ducks.”

Poor people are most at risk from climate change. Climate-related hazards constitute an additional burden to people living in poverty, acting as a threat multiplier.

Climate change increases the risk of violence. For the first time, the IPCC lays out the case that climate change can add a destabilizing factor that can make violence more likely in countries with social and economic inequalities. "Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence by amplifying well-documented drivers of these conflicts such as poverty and economic shocks."

Climate change increases the risk of more refugees. "Displacement risk increases when populations that lack the resources for planned migration experience higher exposure to extreme weather events."

Climate change will be costly. Though the uncertainties are high, the costs for an additional 2°C rise in temperature are thought to be between 0.2 and 2.0% of global GDP. "Losses are more likely than not to be greater, rather than smaller, than this range, since it is difficult to account for catastrophic changes, tipping points, and many other factors."

Human health will suffer. "Throughout the 21st century, climate change is expected to lead to increases in ill-health in many regions and especially in developing countries with low income…the magnitude and severity of negative impacts are projected to increasingly outweigh positive impacts. Examples include greater likelihood of injury, disease, and death due to more intense heat waves and fires; increased likelihood of under-nutrition resulting from diminished food production in poor regions; risks from lost work capacity and reduced labor productivity in vulnerable populations; and increased risks from food- and water-borne diseases and vector-borne diseases" (like malaria.)

We can take action to reduce these substantial risks. "Mitigation is considered essential for managing the risks of climate change." Mitigation refers to human actions to reduce climate change. Burning fewer fossil fuels and thus putting less CO2 in the air is essential to mitigating climate change. We should view the next few decades as the era of ‘climate responsibility’, when we can make a huge difference to keep our future climate livable. The report emphasizes that if greenhouse gases continue to rise, the world can expect an additional 6 - 7°F (3.5 - 4°C) of warming by 2100, instead of the international goal of keeping this rise less than 2°F (1.2°C). Princeton's Dr. Oppenheimer compared these two choices as "the difference between driving on an icy road at 30 mph versus 90 mph. It's risky at 30, but deadly at 90." Uncertainty is not a reason to delay climate action, and it is cheaper to act now on climate change than to delay. The International Energy Agency said in 2013 that in order to keep global warming less than 2°C above pre-industrial levels, "Delaying stronger climate action until 2020 would avoid $1.5 trillion in low-carbon investments up to that point, but an additional $5 trillion would then need to be invested through to 2035 to get back on track." The latest IPCC findings will be a key discussion topic for world leaders at a September 23, 2014 Climate Summit in New York City, hosted by UN Secretary-General Ban Ki-moon. The summit aims to mobilize political will to pave the way for an ambitious global legal climate agreement to be signed at the critical December 2015 Conference of Parties (COP) negotiations in Paris.

Associated Press coverage of the IPCC Part 2 report.

New Blockbuster IPCC Climate Report: Comprehensive, Authoritative, Conservative, my September 2013 post on who the IPCC is, and how they write their reports.

Landmark 2013 IPCC Report: 95% Chance Most of Global Warming is Human-Caused, my September 2013 post on Part I of the 2013 - 2014 IPCC report.

Video 1. The IPCC released this video to accompany today's release of their 2014 Impacts and Adaptation report.

Jeff Masters

Climate Change

Dangerous Category 4 Hellen Nears Madagascar

By: JeffMasters, 9:14 PM GMT on March 30, 2014

Extremely dangerous Category 4 Tropical Cyclone Hellen is bearing down on Madagascar after an extraordinary burst of rapid intensification brought the cyclone from a 60 mph tropical storm to a high-end Category 4 storm with 150 mph winds in just 24 hours. That 90 mph increase in winds in 24 hours is not far below the record intensification rate of Hurricane Wilma in 2005, which was 110 mph in 24 hours. Official bulletins from La Réunion indicate the central pressure dropped 61 mb in 24 hrs, from 986mb at 1800 UTC Saturday to 925mb at 1800 UTC Sunday. They warn in their 18 UTC Sunday advisory:


Figure 1. True-color MODIS satellite image of Tropical Cyclone Hellen nearing Madagascar at 12 UTC March 29, 2014. At the time, Hellen was a Category 4 storm with 150 mph winds. Image credit: NASA.

Jeff Masters


Can Cloud Seeding Help Ease California's Drought?

By: JeffMasters, 3:37 PM GMT on March 28, 2014

The California rainy season is bringing one final blast of moisture to the drought-parched state over the coming week. Strong low pressure systems will bring mountain snows and valley rains to most of the northern half of the state on Saturday and again on Monday, and widespread precipitation amounts of 4+ inches are likely. A Winter Storm Watch is posted for the Sierras, where snowfall amounts of 1 - 2 feet are expected over the weekend. Monday's storm will likely dump another 1 - 2 feet, providing a critical boost to a drought-depleted snowpack that the state desperately needs to provide water during the hot, dry summer months. Rain-bearing low pressure systems typically stop bringing heavy rains to the state by mid-April, as the jet stream shifts to the north in its usual springtime migration. The 16-day GFS forecast is showing one more decent shot of moisture is possible on April 4, then a shift to a drier pattern will occur. The March 25, 2014 Drought Monitor is showing that 99.8% of California is in drought, with 95% of the state in Severe, Extreme, or Exceptional drought, a 2% rise from the previous week.

Figure 1. Predicted precipitation for the 7-day period ending on Friday, April 4, 2014. Much needed rains and snows are expected to fall in California in the coming week. Image credit: NOAA/HPC.

Cloud Seeding Can Help Ease California's Drought
Extra moisture can be wrung out of clouds passing over mountain areas to increase the winter snowpack using cloud seeding. Such efforts have been made since the 1960s in the Sierras by the Desert Research Institute (DRI) of Reno, Nevada. During the winter of 2013 - 2014, DRI used six ground-based cloud-seeding generators in the Tahoe-Truckee Sierras of California and Nevada, for a total of 150 hours, to burn a solution of silver iodide, sodium iodide, salt and acetone. These generators were remotely operated by telephone, radio, or wireless communication, and released microscopic silver iodide particles which created ice crystals, then snow, in winter clouds. Six ground-based generators and a cloud seeding aircraft performed an additional 59 hours of cloud seeding farther to the south, in the Walker Basin Sierras. According to a Desert Research Institute cloud seeding fact sheet, wintertime cloud seeding does not diminish snowfall in areas downwind of the seeded area. DRI sums up the benefits of cloud seeding this way: "Research results have documented precipitation rate increases of a few hundredths to about 2 millimeters per hour due to ground-based seeding during the proper weather conditions. Based on the rate increases, estimates of augmented snow water from the DRI seeding program have varied from 20,000 to 80,000 acre-feet annually over the past 15 years of operation. Seasonal percentage increase estimates have varied from 2% to 10%. The cost of augmented water, based on the annual cost of the program, has ranged from $7 to about $18 per acre-foot." The DRI cloud seeding project is state-funded. Future plans include the development of uncrewed drone aircraft for cloud seeding, which could be operational by the winter of 2014 - 2015. The U.S. Bureau of Reclamation projects that cloud seeding could supply the Colorado River watershed with up to 700,000 acre-feet of water per year by 2035, and 1.7 million AF by the year 2060, at a very low cost of $30 - $60 per acre-foot. By comparison, the Colorado River, which is a primary source of water to Southern California, typically supplies 15 million acre-feet of water each year to the U.S. (an acre-foot is the amount of water needed to cover an acre of land to a depth of one foot.)

Figure 2. A cloud seeding generator run by the Desert Research Institute (DRI) in Reno, Nevada.

I’ll discuss several other ways California can get more water in future blogs posts in the coming weeks. Have a great weekend, everyone!

Jeff Masters


Mighty 955 mb Nor'easter Pounds Canadian Maritime Provinces

By: JeffMasters, 12:50 PM GMT on March 27, 2014

The strongest Nor'easter of 2014 blasted Prince Edward Island, New Brunswick and Nova Scotia on Wednesday with wind gusts over 100 mph and up to a half meter (19.5") of snow, bringing travel to a standstill and causing power outages that affected about 17,000 customers in Nova Scotia. The mighty storm intensified rapidly on Wednesday afternoon, "bombing" to a central pressure by 2pm EDT of 955 mb--similar to the central pressure of a Category 3 hurricane. The storm's pressure fall of 45 mb in 24 hours is among the greatest on record for a Nor'easter (for comparison, the 1978 Cleveland Superbomb had a pressure drop of 43 millibars in 24 hours, also to 955 mb.) The La Have Bank buoy south of Halifax, Nova Scotia measured a pressure of 957 mb as the center of the storm passed nearby, along with significant wave heights of 29 feet. A wind gust of 129 mph was measured on Wednesday at the Bay of Fundy, and sustained winds of 89 mph with a gust to 115 mph was recorded between 6:30 - 7:30 pm EDT in Wreckhouse, Newfoundland, beating the previous strongest gust of 112 mph set in 2007 (Wreckhouse is named for the terrain-enhanced winds that often cause destruction.) Grand Étangon the Gulf of St Lawrence side of Cape Breton in Nova Scotia recorded top sustained winds of 70 mph, gusting to 102 mph. This location is susceptible to strong "Les Suêtes" winds in this type of setup--"Suêtes" is a dialectal corruption of French "sud-est," or "southeast". These southeasterly winds travel up over Cape Breton and a funneling effect intensifies them as they blow downslope toward the Gulf of St Lawrence. As a result, these gusts are not truly representative of the storm, but rather the storm plus local terrain effects. Environment Canada has a special "Les Suêtes Wind Warning", and issued it for Wednesday's storm.

Figure 1. True-color MODIS satellite image taken at approximately 2pm EDT Wednesday March 26, 2014, of the powerful Nor'easter affecting Canda's Maritime provinces. At the time, the storm had a central pressure of 955 mb, and was generating winds over the water of Category 1 hurricane strength (at least 74 mph.) Image credit: NASA.

Thanks go to TWC's Nick Wiltgen, Stu Ostro, Mike Seidel, and Matt Crowther for some of the stats on this storm.

Jeff Masters

Winter Weather

Washington Landslide Death Toll Grows to 14

By: JeffMasters, 2:03 PM GMT on March 25, 2014

The death toll has grown to fourteen from Saturday's massive landslide near Oso, Washington, located about 50 miles north-northeast of Seattle. At least seven were injured, and 176 are listed as missing, though this total is likely to decrease dramatically as missing people check in. The landslide was triggered by unusually heavy rains over the past 30 days in the region. A personal weather station located about ten miles west of the slide recorded 13.81" of precipitation in the 30 days prior to the slide, including 5.17" in the ten days just before. Precipitation imagery from NOAA's Advanced Hydrological Precipitation Service (Figure 2) shows that the 30-day precipitation amounts in the region were more than 8" above average--about double the usual amount of rain for this time of year.

Figure 1. The Oso, Washington area before the March 22, 2014 landslide as seen on Google Earth (top) and after the landslide, as photographed by the Washington Department of Transportation (bottom.) The landslide blocked the North Fork of the Stillaguamish River and Highway 530.

Figure 2. Precipitation for the 30-day period ending March 24, 2014, was 150% - 200% of average in Oso, Washington--about 8" above average. Image credit: NOAA/AHPS.

Figure 3. Predicted precipitation for the 7-day period ending on Tuesday, April 1, 2014. The landslide area to the northwest of Seattle is expected to receive 2 - 4" of precipitation, which will slow recovery efforts from the landslide. However, the rains over Northern California will be welcome, helping to fill drought-depleted reservoirs as that state's dry season approaches. Image credit: NOAA/HPC.

A re-activation of an old landslide
According to Dave Petley, Professor of Hazard and Risk in the Department of Geography at Durham University in the United Kingdom, it is clear that major landslides have occurred here on many previous occasions, so much so that the landslide is known as either the Hazel landslide or the Steelhead landslide. In his excellent Landslide Blog, my go-to source of information for any landslide, he writes: "The landslide has been widely reported as a mudslide. In terms of the lower portion, which did the damage, this is correct, although in places it might have been more of a mudflow than a mudslide. However, the upper portion is a rotational landslide–the rotated block with the fallen trees is very clear. A working hypothesis would be that this block failed catastrophically, transferring load onto the block below, which in turn generated very high pore water pressures, causing fluidisation and a very rapid mudflow that struck the settlements across the river." He writes that the last event on a similar scale he knows of was the 25th December 2003 debris flow in San Bernadino County, California, which killed sixteen people. Weather historian Christopher C. Burt has a post about the worst landslides in U.S. history, which puts this week's landslide in context.

The Yakima Herald has a very nice article that details the chronology of events on the Oso landslide. This includes:
• 1949: A large landslide (1000 feet long and 2600 feet wide) affected the river bank
• 1951: Another large failure of the slope; the river was partially blocked
• 1967: Seattle Times published an article that referred to this site as “Slide Hill”
• 1997 report, by Daniel Miller, for the Washington Department of Ecology and the Tualialip Tribes
• 1999: US Army Corps of Engineers report by Daniel and Lynne Rodgers Miller that warned of “the potential for a large catastrophic failure”
• 25 January 2006: large movement of the Steelhead landslide blocked the river

When Will Spring Come For REAL? Join Me at 5:30pm EDT Tuesday for a Google Hangout Discussion
Spring has officially begun for those of us in the Northern Hemisphere, but it's still more like winter in the Midwest and Northeast U.S. In celebration of the new season, I'll host a 15-minute Google Hangout on Tuesday, March 25th at 5:30pm EDT to review where on Earth the most severe winter weather is occurring, and forecast when those of us still experiencing winter can expect to see Spring--for real! I'll focus on the forecast for four cities: Detroit, Boston, Seattle, and Moscow, and discuss some of the remarkable weather events those cities have seen this month. You can watch the hangout by visiting our Weather Underground Spring Forecast page.

Jeff Masters


Meteorological Bomb Brewing for Canada on Wednesday

By: JeffMasters, 2:25 PM GMT on March 24, 2014

The most powerful Nor'easter of the year will gather strength over the waters offshore of Virginia on Tuesday, then head northeast and bring damaging winds, heavy rain and snow, and a substantial storm surge to Nova Scotia and Newfoundland Canada on Wednesday. The storm will brush Cape Cod, Nantucket, and Martha's Vineyard, Massachusetts on Tuesday night and Wednesday morning, bringing at least six inches of snow and wind gusts of up to 60 mph. A Blizzard Watch and Coastal Flood Watch are posted for Cape Cod and Nantucket Island, where a NOAA storm surge model run using the winds from the 00Z run of the GFS model predicted almost a 2 foot surge could occur on Wednesday morning. A surge of this magnitude is capable of causing minor to moderate flooding.

Figure 1. Wind forecast for 5pm EDT Wednesday March 26, 2014, made from the 2am EDT Monday, March 24, 2014 run of the GFS model. Winds in excess of 50 knots (57.5 mph, pink colors) are predicted along the coasts of Nova Scotia and Newfoundland, Canada.

A Meteorological Bomb
As the storm pulls away from the Mid-Atlantic coast on Tuesday evening, it will undergo explosive deepening, meeting the criteria of a "meteorological bomb"--a storm that deepens by at least 24 mb in 24 hours. In fact, the Monday morning 00Z run of the European model shows the pressure falling by more than double that pace--deepening by an extraordinary 40 mb in just eighteen hours, ending at 2 pm EDT Wednesday. When the Nor'easter hits Nova Scotia and Newfoundland on Wednesday evening, the central pressure of the storm is expected to be between 956 - 960 mb, similar to the central pressure of a strong Category 2 hurricane. However, Nor'easters do not form eyewalls with intense winds concentrated over a small area, and this Nor'easter's strong winds will be spread out over a large area. I doubt we'll see sustained hurricane-force winds of 74 mph or greater at any land stations, but sustained winds of 60 - 70 mph are likely in some locations, which will be capable of causing widespread power outages and considerable tree damage. A storm surge of 2 - 4 feet may also cause coastal damage and moderate flooding, if the surge arrives at high tide.

Jeff Masters

Winter Weather

U.S. Spring Flood Forecast: No Widespread Major Flooding Expected

By: JeffMasters, 3:11 PM GMT on March 21, 2014

Though the calendar says it's spring, the latest 10-day forecast from the GFS model calls for winter-like weather over the snow-covered northern tier of states in the U.S. through March 26, followed by a slow warm-up. No heavy rainfall events capable of triggering widespread major flooding are predicted through the end of March. A shift to a less winter-like pattern is in the offing for the first week of April, when the flood risk will rise. This weather pattern will put rivers in approximately half of the continental United States at risk of minor or moderate flooding this spring, NOAA said on Thursday in their annual spring flood risk forecast. The highest flood threat is in the southern Great Lakes region, due to above-average snow pack and a deep layer of frozen ground. The unusually long and severe winter in the northern tier of the U.S. from Montana eastward to northern New England has resulted in much more ice formation on rivers than usual, and there is a greater than usual chance of ice jam flooding, caused when a rise in river levels due to melt water run-off or rain causes a sudden break-up of river ice. Fortunately, no widespread major flooding is expected in the U.S., though a deep layer of frozen ground and significant river ice throughout the northern tier of states may cause localized major flooding. The flood risk is highly dependent on the amount and timing of future rainfall, and the rate of snow melt this spring. There are a number of areas at risk of moderate flooding:

Mississippi River between Davenport, Iowa and Burlington, Iowa
Illinois River between Beardstown, Illinois and Henry, Illinois
Red River of the North between eastern North Dakota and northwest Minnesota
Souris River in North Dakota
Western South Dakota
Southern Wisconsin
Southern Lower Michigan

Figure 1. The NOAA spring flood forecast shows a large portion of the country is at risk of minor to moderate flooding, but there are no areas at high risk of major flooding. Image credit: NOAA Spring Flood Forecast.

Flood categories are defined by NOAA as follows:

Minor Flooding: Minimal or no property damage, but possibly some public threat (e.g., inundation of roads).

Moderate Flooding: Some inundation of structures and roads near streams. Some evacuations of people and/or transfer of property to higher elevations.

Major Flooding: Extensive inundation of structures and roads. Significant evacuations of people and/or transfer of property to higher elevations.

Video 1. On March 20, 2014, NOAA's National Weather Service issued its Spring Outlook, covering flooding, drought, temperature, and precipitation through June.

Have a great weekend, everyone!

Jeff Masters


February 2014: Earth's 21st Warmest February on Record

By: JeffMasters, 3:36 PM GMT on March 20, 2014

February 2014 was the globe's 21st warmest February since records began in 1880, according to NOAA's National Climatic Data Center (NCDC), and 17th warmest, according to NASA. Relative to average, February 2014 was Earth's coolest month in two years. February 2014 global land temperatures were the 44th warmest on record, and global ocean temperatures were the 7th warmest on record. Global satellite-measured temperatures in February 2013 for the lowest 8 km of the atmosphere were 13th or 9th warmest in the 36-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of February 2014 in his February 2014 Global Weather Extremes Summary.

Figure 1. Departure of temperature from average for February 2014, the 21st warmest February for the globe since record keeping began in 1880. The majority of the world's land surfaces experienced warmer-than-average monthly temperatures, with record warmth over Far East Russia, Southern Mexico, and Southern Europe. The Midwest U.S. had the largest area of much cooler than average temperatures for any place on the globe. The Northern Hemisphere land was 0.17°C (0.31°F) above average, the 53rd warmest February on record, and coolest February in the past two decades. Image credit: National Climatic Data Center (NCDC) .

The two billion-dollar weather disasters of February 2014
Two billion-dollar weather-related disasters hit the Earth during February 2014: Winter Storm Tini in the U.K., which killed 1 and did $1.0 billion in damage, and winter weather and heavy snows in Japan that killed 37 and did $1.2 billion in damage. These two disasters bring the world-wide tally of billion-dollar weather disasters in 2014 to three, according to the February 2014 Catastrophe Report from insurance broker Aon Benfield.

Disaster 1. Winter Storm Tini brought extreme winds gusting above 160 kph (100 mph) and flooding to Western Europe February 11 - 13, 2014, killing at least one person and causing $1 billion in damage. The worst damage was in Ireland, Wales and England as hurricane-force winds ripped off portions of roofs, blew down trees, and knocked out power to over 400,000 customers. In this photo, a car sits in flood water besides agricultural buildings on the Somerset Levels near Burrowbridge on February 14, 2014 in Somerset, England. (Photo by Matt Cardy/Getty Images)

Disaster 2. Pedestrians cross a street in the snow in Tokyo on February 15, 2014. The heaviest snow in decades fell across portions of Japan February 8 - 16, 2014, killing 37 and injuring 2,750, mostly in traffic accidents. Tokyo's 27 centimeters (10.6 inches) of snow was the most snow in 45 years. The heavy snow caused widespread residential and commercial damage while also severely disrupting transportation and causing production delays. Total economic losses were expected to approach $1.2 billion. Photo credit: KAZUHIRO NOGI/AFP/Getty Images.

Neutral El Niño conditions continue in the equatorial Pacific
February 2014 featured neutral El Niño conditions in the equatorial Eastern Pacific, but NOAA has issued an El Niño Watch for the summer and fall of 2014, giving a 50% chance that an El Niño event will occur this year. The March 6 El Niño discussion from NOAA's Climate Prediction Center noted that "While all models predict warming in the tropical Pacific, there is considerable uncertainty as to whether El Niño will develop during the summer or fall. If westerly winds continue to emerge in the western equatorial Pacific, the development of El Niño would become more likely. However, the lower forecast skill during the spring and overall propensity for cooler conditions over the last decade still justify significant probabilities for ENSO-neutral. The consensus forecast is for ENSO-neutral to continue through the Northern Hemisphere spring 2014, with about a 50% chance of El Niño developing during the summer or fall." None of the El Niño models (updated in mid-February 2014) predict La Niña conditions for peak hurricane season, August-September-October 2014, and 8 of 18 predict El Niño conditions. Temperatures in the equatorial Eastern Pacific need to be 0.5°C above average or warmer for three consecutive months for an El Niño episode to be declared; sea surface temperatures were -0.4°C from average as of March 17, and have been +0.1 to -0.7°C from average since April 1, 2013. El Niño conditions tend to make quieter than average Atlantic hurricane seasons, due to an increase in upper-level winds that create strong wind shear over the Tropical Atlantic. There have been two major Westerly Wind Bursts over the equatorial Pacific Ocean over the past two months that have helped pushed warm water eastwards towards South America. The most recent of these bursts has now diminished, and there will likely need to be at least one more Westerly Wind Burst in order for a full-fledged El Niño to develop.

Arctic sea ice falls to 4th lowest February extent on record
Arctic sea ice extent during February was 4th lowest in the 36-year satellite record, according to the National Snow and Ice Data Center (NSIDC). Temperatures in the Arctic were 4 - 8°C (7 - 14°F) above average for the month. Northern Hemisphere snow cover during February was the 17th largest in the 48-year record.

Figure 2. One of the most astonishing weather disasters of February 2014 was the February 3 ice storm in Slovenia, as seen in this wunderphoto of an ice storm-devastated forest made on February 4, 2014. The tree damage is incredible. Image credit: wunderphotographer domcek.

Jeff Masters

Climate Summaries

California's Rainy Season Almost Over

By: JeffMasters, 3:12 PM GMT on March 18, 2014

The California rainy season is close to its end. Rain-bearing low pressure systems typically stop bringing heavy rains to the state by mid-April, as the jet stream shifts to the north in its usual springtime migration. With no rain in the forecast for the next seven days, and the 16-day GFS forecast showing mostly light rains affecting the northern portion of the state 8 - 16 days from now, California has likely seen at least 90% of the precipitation that it’s going to get this anemic rainy season. That’s a huge concern for a state suffering through its worst winter drought conditions in recorded history, and Sierra snow pack and reservoir levels near record lows. This year’s drought could well be a harbinger of the future, as climate change is expected to cause increased water availability problems in California. The state is going to have to find new sources of water in the future to support its growing population. Where can California find more water?

Figure 1. Predicted precipitation for the 7-day period ending on Tuesday, March 25, 2014. No rain is expected to fall in California in the coming week. Image credit: NOAA/HPC.

The most feasible way for California and the thirsty Southwest U.S. to get more water is through conservation. Irrigated agriculture currently consumes more than 70% of the water supply within the Colorado River basin, and is the obvious first place to look to implement water-saving conservation measures. A 2013 publication by the Pacific Institute, "Water to Supply the Land: Irrigated Agriculture in the Colorado River Basin", offers a number of common-sense ways agriculture could use Colorado River water more efficiently. The river's annual flow is about 15 million acre-feet (an acre-foot is the amount of water needed to cover an acre of land to a depth of one foot.) One-third of the Colorado River's annual flow, about 5 million acre-feet, is devoted to irrigating pasture, alfalfa (hay), and other forage crops used to feed cattle and horses. Alfalfa, planted extensively from Wyoming to the delta in Mexico, covers more than a quarter of the total irrigated acreage in the basin. Almost 7% of the river's flow (1 million acre-feet) might be saved by irrigating alfalfa less often (a practice known as “regulated deficit irrigation”). This process reduces crop yields by about 25%, and thus this process costs approximately $81 per acre-foot of water saved. According to Dr. Peter Gleick, President of the Pacific Institute, farmers in Southern California's Imperial Irrigation District are charged as little as $22 per acre-foot of Colorado River water, so some incentives would have to be offered to farmers to get them to implement this water savings plan. (The $22/acre-foot price is an amazingly good deal for a commodity so precious. For comparison, water pumped from rivers in Northern California to Southern California is priced at over $1500 per acre-foot.)

Figure 2. A 2013 publication by the Pacific Institute, "Water to Supply the Land: Irrigated Agriculture in the Colorado River Basin", offers a number of common-sense ways agriculture could use Colorado River water more efficiently.

Shifting to less water-intensive crops can also yield impressive water savings. For example, replacing about 10% of the basin’s irrigated alfalfa acreage with cotton and wheat could save about 1.5% of the river's flow (250,000 acre-feet), at an estimated cost of about $36 per acre-foot of water saved. Other industrial and municipal water conservation efforts could save up to 600,000 acre-feet per year at a cost of about $700/acre-foot before the year 2035, according to the U.S. Bureau of Reclamation.

I’ll discuss four other ways California can get more water in future blogs posts in the coming week.

Jeff Masters


WeatherSTEM: Innovative Software for Personal Weather Stations in Schools

By: JeffMasters, 2:32 PM GMT on March 17, 2014

Today’s guest post is by Edward Mansouri of, who has written some excellent software to integrate data collected by Weather Underground-connected Davis Personal Weather Stations (PWSs) with curriculum in schools. It’s cool how the software lets you easily put the data from your PWS into social media platforms like Twitter, Facebook, and Twilio.

- Jeff Masters

Figure 1. Students and teachers at the 2014 American Meteorological Society Weatherfest in Atlanta check out the WeatherSTEM curriculum and a Davis Personal Weather Station.

More than ever in our history, schools across the United States face the challenge of better preparing students to enter careers where competency in STEM-related subject areas (Science, Technology, Engineering, and Mathematics) is a requirement.

There are numerous educational standards being implemented at the federal and state level that seek to insure all students who earn a high school degree demonstrate increased STEM competency. Most of these standards promote integration of topics from different disciplines into lessons and activities.

Weather provides an excellent foundation for STEM education. It also provides myriad opportunities for exposing students to topics from a plethora of disciplines in the scope of a single activity. Any weather situation, from the most benign scenario where a few cumulus humilus clouds dot the sky to the most intense Category 5 hurricane, can turn into a discussion covering everything from algebra to zoology. (If you are not sold on zoology and weather being related, consider the impact of weather on the flight paths of migratory birds.)

WeatherSTEM is a platform being developed by e-learning software-maker, Ucompass. It motivates teachers to create STEM lessons, activities, and assessments from real-world weather. WeatherSTEM is currently being piloted in several Florida school districts.

Ucompass’ primary product, Educator, is a learning management system (LMS). An LMS is (typically) a web-based software system, bringing educational content delivery, communication, and evaluation together into one interface. Colleges, universities, and K-12 environments use an LMS to manage online instruction and increasingly, to augment classroom instruction.

I authored Educator back in 1998, while I was teaching General Meteorology to undergraduate students at Florida State University. Working on my Masters degree, I became enamored by the exploding possibilities for leveraging the World Wide Web to enhance learning and teaching. After finishing my Master’s degree, I left school to start Ucompass. My focus became marketing and the further development of Educator. The Educator program has since been used by millions of students across North America in K-12 and higher education. WeatherSTEM represents a union between my 16-year career creating online education software, and my lifelong passion for weather.

The WeatherSTEM platform is implemented across the domain of a school district. In Florida, where we are piloting the product, each of the state’s 67 counties represents an individual school district. Many of these school districts cover relatively large geographic areas. For example, the Miami-Dade County district covers an area nearly 2,500 square miles and serves almost 400,000 students.

Figure 2. WeatherSTEM allows one to easily put data from a Davis Personal Weather Station into Twitter, as shown here.

How WeatherSTEM works
We install full-service weather stations at schools across the client school district. If money were no object, we’d install a weather station at every school. However, in public K-12 education, dollars are always stretched thin, and there is great pressure to provide as much service and value at the absolute minimum cost possible.

WeatherSTEM has features and resources for the entire community. There are engaging student activities such as online forecasting competitions. Teachers have tools that enable them to integrate weather data into their Lesson Plans and align them with relevant educational standards including the Common Core. Each weather station broadcasts live weather data online, so everyone in the community can benefit from hyper-local information. Schools can sell advertising space to local businesses with 100% of the generated revenue being turned over to the school for use in furthering their STEM education efforts. A school in one of our pilot districts recently used funds generated by WeatherSTEM to purchase kits for students to build their own windmills.

Each station is easily integrated into social media platforms like Twitter, Facebook, Twilio, and Weather Underground.

The standard station installation is based on the Davis Instruments Wireless Vantage Pro 2 Plus with fan-aspirated radiation shield. This system measures temperature, barometric pressure, humidity, wind speed and direction, rainfall and rainfall rate, solar radiation, and ultraviolet radiation. Our decision to standardize around the Davis Instruments product was based on multiple factors, including affordability, reliability, and my own great experiences with the company, its support, and its products. The weather station connects to the school’s LAN and data is continuously transmitted to WeatherSTEM in one-minute intervals.

Most stations are also equipped with a cloud camera that is mounted atop the school and transmits pictures of the skies overhead in one-minute intervals to WeatherSTEM. An upgrade we plan to make soon will even allow users to pan, tilt, and zoom the camera themselves to focus on particularly interesting aspects of the sky.

For any schools that have gardens, we install Davis Instruments’ Wireless Leaf/Soil Moisture stations to measure soil conditions. The “STEM” in the name of our product refers both to Science, Technology, Engineering, and Mathematics in addition to the “stem” part of a plant. We intend to make agriculture an equally integral part of the platform as weather.

Forecast data, satellite and radar imagery, and almanac data are incorporated into the WeatherSTEM platform. All of this information is obtained from Weather Underground’s innovative commercial API. We are also in discussions with several publishers who will augment the curriculum overlaying the historical, present, and forecast data.

Each weather station additionally provides an API (Application Program Interface) where students can access data using basic libraries such as JQuery. Students taking courses where development of web content is part of the curriculum can use the API to augment their web content with weather data from a school in their district. This will expose them to a variety of topics including JavaScript, JSON, and CSS to name a few.

Each weather station also has a data extraction tool. Our vision is to introduce students to concepts of “Big Data” at the earliest grade levels possible. This would enable a science teacher to tell her students, “Go to our school’s weather station, and extract the last 2 weeks’ worth of temperature, humidity, wind speed, and soil moisture data at 5-minute intervals. You will need this for our afternoon laboratory activity.”

Our business model for WeatherSTEM is to partner with client school districts to identify potential grant funding to which they may have access, and/or to seek potential sponsorships from gardening centers and nurseries within the geographic domain of a district. Our goal is to deploy the project at the minimum possible cost to the school district. Any grant or sponsorship funds generated will be used to offset the cost of the weather stations, cameras, and associated infrastructure, as well as the installation costs.

Maintenance activities are supported by students and fashioned into STEM lessons and activities. We’re even exploring how teacher’s can earn CEU (Continuing Education Units) credit for helping to support the WeatherSTEM equipment.

Our global society is evolving into one where we need to encourage bright young minds to enter into STEM-related careers. Hopefully, WeatherSTEM can make a small contribution to that overall objective.

Edward Mansouri

Atmospheric Phenomena

Winter of 2013 - 2014: Top-10 Coldest in Midwest; Warmest on Record in California

By: JeffMasters, 12:19 PM GMT on March 14, 2014

The winter of 2013 - 2014 will go down in the history books in the Midwest U.S. as a top-ten coldest winter on record, but ranked as the warmest winter on record in California. Temperatures averaged over December 2013 - February 2014 in the contiguous U.S. made it our 34th coolest winter since records began in 1895, said NOAA's National Climatic Data Center (NCDC) in their latest State of the Climate report. The last winter that was colder was 2009 - 2010, which ranked 15th coolest. For comparison, the winter of 2012 - 2013 was the 20th warmest, and the "non-winter" of 2011 - 2012 was the 4th warmest. Seven states had a top-ten coldest winter on record in 2013 - 2014: Wisconsin, Minnesota, Iowa, Missouri, Illinois, Indiana, and Michigan. Three states had a top-ten warmest winter on record: California, Arizona, and Alaska. The Southwest had an unusually dry winter, with California, Arizona, New Mexico, and Texas all recording top-ten dryness. For the nation as a whole, it was the 9th driest winter on record. The winter average snow cover extent for the contiguous U.S. was the 10th largest since record keeping began in 1966.

Figure 1. Perhaps the most iconic image of the U.S. winter of 2013 - 2014: Traffic gridlock in Atlanta on Tuesday afternoon, January 28, 2014 after Winter Storm Leon brought 2.6" of snow, shutting down the city. Image credit: @beercontrol/twitter.

25th most extreme U.S. winter since 1910
The U.S. winter of 2013 - 2014 had the 25th highest level of extremes observed since 1910, thanks primarily to the spatial extent of cold maximum and minimum temperatures and days with precipitation, according to NOAA's U.S. Climate Extremes Index (CEI). The index tracks the percentage area of the contiguous U.S. experiencing top-10% and bottom-10% extremes in temperature, precipitation, and drought. For the Western U.S. (California and Nevada), it was the most extreme winter on record, primarily because 84% of the region experienced top-10% dryness.

Figure 2. Historical temperature ranking for the U.S. for the winter of 2013 - 2014. Seven Midwest states had a top-ten coldest winter on record, but it was the warmest winter on record in California. Image credit: National Climatic Data Center (NCDC).

Figure 3. Historical precipitation ranking for the U.S. for the winter of 2013 - 2014. California, Arizona, New Mexico, and Texas all had top-ten driest winters on record; no states had a top-ten wettest winter. Image credit: National Climatic Data Center (NCDC).

Figure 4. Despite cool winters in 2013 - 2014 and 2009 - 2010, wintertime (December, January, February) temperatures in the contiguous U.S. have increased by about 2°F over the past 100 years. Image credit: NOAA/NCDC.

Figure 5. Palmer Drought Severity Index (PDSI) for California for the winter period December, January, and February. The winter of 2013 - 2014 had the most severe drought conditions since record keeping began in 1895. January and February 2014 also set records for most severe drought conditions ever recorded in those months. Image credit: NOAA/NCDC.

February 2013: 37th coolest February for the U.S.
February 2013 was cooler than average in the contiguous U.S, ranking as the 37th coolest February since 1895, said NOAA's National Climatic Data Center (NCDC) in their latest State of the Climate report. Illinois, Iowa, and Wisconsin each had a top-ten cold February, and Arizona, California, and Utah each had a top-ten warmest February. There were 1.75 times as many record cold daily highs (2,205) and lows (1,276), compared to record warm daily highs (945) and lows (1,043.)

Have a great weekend, everyone!

Jeff Masters

Climate Summaries

Snowiest Winter on Record in Portions of Michigan and Ohio

By: JeffMasters, 1:40 PM GMT on March 13, 2014

The relentless winter of 2013 - 2014 continues to add to its extraordinary resume over the Eastern U.S., where yet another near-record cold blast is underway. Temperatures on Thursday will be 10 - 25° below normal over the eastern 1/3 of the country, and it will be a serious case of weather whiplash in places like New York City, where the temperature peaked at 65°F at JFK Airport on Tuesday, a record high for the date. Temperatures will struggle to reach the upper-20s on Thursday--a spectacular 40° swing, and one of the coldest high temperatures so late in the year. The weather pattern that brought this winter's persistent cold to the Midwest and Eastern U.S., and record warmth and drought to the West Coast, is going to remain in place through most of the remainder of March. The latest 16-day forecast from the GFS model predicts a continuation of the dominant ridge over the Western U.S. and trough over the Midwest and Eastern U.S. that we've all grown very, very, very tired of (said Dr. Masters, after shoveling the latest installment of 6.5" of concrete-like snow of this winter's 90.7 inches that have fallen in the Detroit area--second only to the 93.6" that fell in the winter of 1880 - 1881.) Detroit has now had over 1" of snow on the ground for 72 consecutive days, and will easily break the record of 74 straight days, set during the notorious winter of 1978. Just to the south, in Toledo, Ohio, and Fort Wayne, Indiana, Wednesday's dumping of 6.7 - 7" of snow from Winter Storm Vulcan made the winter of 2013 - 2014 the snowiest on record at both cities. Chicago's 3.2" brought the winter total to 79.1", making it the Windy City's 3rd snowiest winter (the record: 89.7" in 1978 - 1979.) Some major cities that have had a top-five snowiest winters on record during 2013 - 2014:

Ann Arbor, MI: 1st snowiest, 92.1" (previous record: 89.8", 2007 - 2008)
Toledo, OH: 1st snowiest, 84.8" (previous record: 73.1" in 1977 - 1978)
Ft. Wayne, IN: 2nd snowiest, 72.2" (previous record: 81.2", 1981-82)
Detroit, MI: 2nd snowiest, 90.7" (record: 93.6" 1880 - 1881)
Flint, MI: 2nd snowiest, 81.8" (record: 82.9", 1974 - 1975)
Grand Rapids, MI, 2nd snowiest, 112.6" (record: 132.2", 1951 - 1952)
Billings, MT: 2nd snowiest, 95.2" (record: 98.7", 1996 - 1997)
Chicago, IL: 3rd snowiest, 79.1" (record: 89.7", 1978 - 1979)
Philadelphia, PA: 3rd snowiest, 62.9" (record: 78.7", 2009 - 2010)
Indianapolis, IN: 3rd snowiest, 54.7" (record: 58.2", 1981 - 1982)
Cincinnati, OH: 4th snowiest, 45.8" (record: 53.9", 1977 - 1978)

Figure 1. Predicted temperatures for March 20 - 26, 2014, from NOAA's Climate Prediction Center show a continuation of much colder than average temperatures over the Midwest and Northeast U.S.

Figure 2. Daniel Davis is covered in snow and ice while clearing a sidewalk during a snow storm in Detroit Wednesday, March 12, 2014. The storm moved Detroit into 2nd place for its snowiest winter on record, behind the winter of 1880 - 1881. (AP Photo/Paul Sancya)

Jeff Masters

Winter Weather

Save the Keeling Curve!

By: JeffMasters, 2:13 PM GMT on March 11, 2014

Climate change's most iconic research project is in danger--a victim of budget cuts in an era of increased government belt-tightening. The Keeling Curve is a measurement of the concentration of carbon dioxide in the atmosphere made atop Hawaii’s Mauna Loa, begun in 1958 by Dr. Charles Keeling. It is the longest-running such measurement in the world. The curve was instrumental in showing how human emissions of carbon dioxide were steadily accumulating in Earth's atmosphere, and raised awareness that human-caused climate change was an ever-increasing threat to the stability of our climate. After Keeling's death in 2005, the measurements were continued by his son, Ralph F. Keeling. Support from NSF, NOAA and NASA is being diminished or withdrawn, and Keeling has turned to crowd-funding to help raise funds to continue these important measurements. I hope you can join me in making a donation.

Figure 1. The Keeling Curve: climate change's most iconic image. The curve's steady year-by-year increase in CO2 due to burning of coal, oil, and natural gas has wriggles on top of it, due to the natural seasonal cycle in CO2--plants suck in CO2 during the Northern Hemisphere growing season, then release it during the winter. Image credit: Scripps Institution of Oceanography, USCD.

Figure 2. Dr. Charles Keeling posing at the entrance to the Charles Keeling Building at Mauna Loa, Hawaii. Image credit: NOAA/ESRL.

CO2 Levels Hit 401 ppm
The latest data from the Keeling curve website shows that atmospheric carbon dioxide levels are surging upwards in their usual late winter push, as plants return CO2 to the atmosphere before the Northern Hemisphere spring growing season hits. CO2 levels reached 401 ppm (parts per million) last week on top of Mauna Loa, setting a new record. CO2 levels were at 280 ppm in 1870, increased less than 1 ppm per year in the 1960s, then accelerated to 2 ppm per year during the 2000s. Less than 1% of the increase since 1870 has been due to natural sources, such as volcanoes. The last time carbon dioxide levels reached 400 ppm—between 2.5 and 5 million years ago during the Pliocene Era—the Earth was 3.5 to 9° F warmer (2 to 5° C), and sea levels were 65 to 80 feet higher.

There is a hashtag #savetheKeelingCurve
Eli Rabett's post, Shaking the Cup for Science
What Does 400 ppm Look Like? December 2013 blog post by Robert Monroe of the Scripps Institution of Oceanography.

Senate holds all-nighter on climate change
A group of 31 U.S. Senators pulled an all-nighter last night on the floor of the U.S. Senate, taking turns from 9 pm Monday night until 9 am Tuesday morning to promote policy actions on climate change. Many of the Senators involved issued tweets using the hashtag #Up4Climate. The all-nighter was another indication that politicians are becoming increasingly bold about speaking up on climate change.

Latest Version of our WunderMap App Now Includes WunderPhotos
Weather Underground has released today a new version of our WunderMap app for iPhone and iPad. The main new feature that we'd like to highlight is the WunderPhotos layer--now users can view, share, and submit photos all from within the app. Here are a few of the features of the new version of the WunderMap app:

◦ Improved Weather Station display, and both station size and station spacing are now adjustable (Weather Stations Layer ⇒ Settings).
◦ New WunderPhotos layer! View, share, and submit beautiful weather photos.
◦ Fixed incorrect elevation for some Personal Weather Stations.
◦ Swipe-to-delete search history items.
◦ "Terrain/Satellite” and other map options made more prominent.
◦ Bug fixes (crashes, visual glitches, and usability enhancements).
◦ Optimized performance across all devices.

The latest version is available to download for iPhone and iPad at

Jeff Masters

Climate Change

Great Lakes Ice Cover Peaks at 2nd Highest Level on Record

By: JeffMasters, 2:35 PM GMT on March 10, 2014

This winter's severe cold over the Great Lakes--Superior, Michigan, Huron, Erie, and Ontario--froze a near-record amount of ice this year. Ice coverage peaked at 92.2% on March 6, the 2nd highest ice cover on record, according to NOAA's Great Lakes Environmental Research Laboratory (GLERL). Dating back to 1977, only February 1979 (94.7% peak) had a greater ice coverage. Warmer temperatures this past weekend caused Great Lakes ice cover to dip to 91% as of Sunday, March 9, and temperatures in the 40s and 50s on Monday and Tuesday this week will further erode the ice cover. It is unlikely that the renewed cold blast expected later this week will be able to refreeze the lakes enough to break the 1979 Great Lakes ice cover record. On March 8th, the ice concentration on Lake Michigan reached a record high of 93.3%. The previous record was 93.1%, set in 1977, with records dating back to 1973. 

Figure 1. True-color MODIS satellite image of the Great Lakes on March 6, 2014. Two day later, on March 8, Great Lake ice cover peaked at 92.2%, the second highest coverage since record keeping began in 1977. Only Lake Ontario had large areas of ice-free water. Image credit: NASA.

Figure 2. Ice coverage on Lake Michigan peaked at 93.3% on March 8, 2014, setting a new record for the lake. The previous record was 93.1%, set in 1977, with records dating back to 1973. Image credit: NOAA's Great Lake Environmental Research Laboratory (GLERL).

Long-term trend: Great Lakes ice cover down 71% from 1973 - 2010
This year's near-record ice cover on the Great Lakes is a major departure from what happened in 2012, when the lakes' 5% coverage was the second lowest on record (the record low was set in 2002.) The long-term trend in recent decades is sharply downward; Great Lakes ice cover declined 71% between 1973 - 2010. A 2012 study published in the Journal of Climate by researchers at NOAA's Great Lakes Environmental Research Laboratory found that the biggest loser of ice during the 1973 - 2010 time period was Lake Ontario, which saw an 88% decline in ice cover. During the same time period, Superior lost 79% of its ice, Michigan lost 77%, Huron lost 62%, and Erie lost 50%. The loss of ice is due to warming of the lake waters. Winter air temperatures over the lower Great Lake increased by about 2.7°F (1.5°C) from 1973 - 2010, and by 4 - 5°F (2.3 - 2.7°C) over the northern Lakes, including Lake Superior. Lake Superior's summer surface water temperature warmed 4.5°F (2.5°C) over the period 1979 - 2006 (Austin and Colman 2007). During the same period, Lake Michigan warmed by about 3.3°F (1.7°C), Lake Huron by 4.3°F (2.4°C), and Lake Erie showed almost no warming. The amount of warming of the waters in Lakes Superior, Huron, and Michigan is higher than one might expect, because of a process called the ice-albedo feedback: when ice melts, it exposes darker water, which absorbs more sunlight, warming the water, forcing even more ice to melt. This sort of vicious cycle is also responsible for the recent extreme loss of Arctic sea ice. The increase in temperature of the lakes could be due to a combination of global warming and natural cycles, the researchers said. They noted a pronounced 4-year and 8-year oscillation in ice coverage, which could be caused by the El Niño/La Niña and Arctic Oscillation (AO), respectively.

Figure 3. A tale of two winters: Lake Superior was choked with ice at the end of the winter of 2013 - 2014 (top), but was virtually ice-free at the end of the winter of 2011 - 2012 (bottom.) Image credit: NASA.

Great Lakes water levels recover from record lows
The near-record ice levels are good news for Great Lakes water levels, which have suffered from record or near-record lows in recent years. In February 2013, Lake Michigan and Lake Huron set an all-time low water record, 29 inches below the long-term mean. This record was due, in large part, to the steadily declining winter ice coverage on the lake, which allows much more water to evaporate in winter. The latest U.S. Army Corps of Engineers water level forecast for the Great Lakes shows that Lake Michigan and Lake Huron water levels have recovered to be about 13" below the long-term March mean, and are forecast to rise another 3" over the coming month.

Lower water levels have had a significant impact on the Great Lakes economy. Over 200 million tons of cargo are shipped every year through the Great Lakes. Since 1998, when water levels took a severe drop, commercial ships were forced to light-load their vessels. For every inch of clearance that these oceangoing vessels lost because of low water levels, $11,000 - $22,000 in profits were lost per day. Hydropower plants have also been affected by low water levels; several New York and Michigan plants were run at reduced capacity, forcing them to buy higher priced energy from other sources, and passing on the higher costs to consumers. Ice loss is also likely to accelerate shoreline erosion because of the increase in open water, and promote more algal blooms. It is uncertain if the Great Lake water levels will continue to fall as the climate warms, since the region is expected to see an increase in precipitation over the coming decades. In Michigan, annual precipitation increased by about 10% between 1895 - 2013, according to the National Climatic Data Center.

Austin, J. A., and S. Colman, 2007, "Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback," Geophys. Res. Lett., 34, L06604, doi:10.1029/2006GL029021.

Wang, J., X. Bai, H. Hu, A.H. Clites, M.C. Colton, and B.M. Lofgren, 2012, "Temporal and spatial variability of Great Lakes ice cover, 1973-2010," Journal of Climate 25(4):1318-1329 (DOI:10.1175/2011JCLI4066.1)

Jeff Masters

Winter Weather

NOAA Issues El Niño Watch

By: JeffMasters, 2:58 PM GMT on March 06, 2014

NOAA has issued an El Niño Watch for the summer and fall of 2014, giving a 50% chance that an El Niño event will occur. The March 6 El Niño discussion from NOAA's Climate Prediction Center noted that "While all models predict warming in the tropical Pacific, there is considerable uncertainty as to whether El Niño will develop during the summer or fall. If westerly winds continue to emerge in the western equatorial Pacific, the development of El Niño would become more likely. However, the lower forecast skill during the spring and overall propensity for cooler conditions over the last decade still justify significant probabilities for ENSO-neutral. The consensus forecast is for ENSO-neutral to continue through the Northern Hemisphere spring 2014, with about a 50% chance of El Niño developing during the summer or fall."

None of the El Niño models predict La Niña conditions for peak hurricane season, August-September-October 2014, and 8 of 18 predict El Niño conditions. Temperatures in the equatorial Eastern Pacific need to be 0.5°C above average or warmer for three consecutive months for an El Niño episode to be declared; sea surface temperatures were -0.6°C from average as of March 3, and have been +0.1 to -0.7°C from average since April 1, 2013. El Niño conditions tend to make quieter than average Atlantic hurricane seasons, due to an increase in upper-level winds that create strong wind shear over the Tropical Atlantic.

Figure 1. Depth-longitude section of the departure of ocean temperature from average over the equatorial Pacific upper ocean between 0 - 300 meters between 5°S and 5°N during the period February 25 - March 1, 2014. Averages are taken from a 1981 - 2010 base period. While surface temperatures in the Eastern Pacific were near average to cooler than average, a strong eastwards-propagating Kelvin wave with temperatures up to 6°C (11°F) above average at a depth of about 160 meters was headed towards the Eastern Pacific. If unusually strong westerly winds continue over the equatorial Western Pacific during March and April, this Kelvin wave has the potential to trigger a strong El Ninño event over the Eastern Pacific later this year. Image credit: NOAA/CPC.

An impressive westerly wind burst over the Equatorial Pacific
The potential El Niño event has been made more likely over the past month due to the intensification of a strong "Westerly Wind Burst" (WWB) along the equatorial Pacific west of the Date Line. As of March 6, 2014, westerly winds that were more than 10 m/s (22 mph) stronger than average had developed between 140 - 150°E, just north of New Guinea. These unusually strong westerly winds were acting to push warm water piled up to the east of the Philippines eastwards towards South America. The "Westerly Wind Burst" was due, in part, to the counter-clockwise circulation of wind around Typhoon Faxai, which became a tropical storm on February 28 near 9°N, 149°E, and later intensified into a Category 1 typhoon. The Madden Julian Oscillation (MJO), a pattern of increased thunderstorm activity near the Equator that moves around the globe in 30 - 60 days, was also likely involved in amplifying the WWB. In order to keep the momentum of this WWB going and trigger a full-fledged El Niño event, some additional west-to-east push of winds is likely needed during March and April. Some extra push may come from a tropical disturbance (96P) that has developed this week south of the Equator near 13°S 153°E, to the northeast of Australia. The clockwise circulation of air around this storm is bringing increased westerly winds to the Equator in the region of the WWB, and the Joint Typhoon Warning Center is giving this disturbance a "medium" chance of developing into a tropical depression or tropical storm by Friday. The GFS and European models predict that this storm will move southwards and bring heavy rain to the Queensland province of Australia over the weekend.

Figure 2. Departure of the 5-day average west-to-east blowing wind (the "zonal" wind) from average, averaged along the Equator, between 2°S and 2°N. A strong "Westerly Wind Burst" (WWB) formed in January 2014 near 140°E, and has intensified and propagated eastwards along the Equator. As of March 6, 2014, westerly winds that were more than 10 m/s (22 mph) stronger than average had developed. Image credit: NOAA/PMEL.

Additional links
An El Niño Coming in 2014? Guest blog post by Dr. Michael Ventrice on February 21, 2014.
All eyes on the tropical Pacific: March 5, 2014 blog post by Georgia Tech climate scientist Kim Cobb.

Jeff Masters

Hurricane Atmospheric Phenomena

Record Cold in a Warming World

By: JeffMasters, 2:58 PM GMT on March 04, 2014

An impressive blast of Arctic air has toppled more records for all-time March cold over the Eastern U.S., in the wake of the major snowstorm that brought 4 - 8" of snow from Missouri to Maryland. Fresh snow is very efficient at radiating heat to space, and the 3.8" of snow that fell in Baltimore on Monday helped drive the temperature down to 5°F on Monday night, tying the city's all-time March low temperature record set on March 4, 1873. The temperature eventually dipped down to 4°F Tuesday morning, breaking the March record. Atlantic City, NJ, which got 5.5" of snow on Monday, also set a new all-time cold record for the month of March on Monday night, when the temperature fell to 2°F. The previous all-time low for the month of March was 3°F set on March 4, 2009. Official records for the Atlantic City area date back to 1874.

At least five other cities have set or tied all-time March cold temperature records during the current cold wave:

Charlottesville, Virginia set an all-time March low of 1°F Tuesday morning (previous record: 7°F on March 4, 1943.)

Billings, Montana set an all-time March low of -21° on March 2, 2014 (previous record: -19°.)

Pierre, South Dakota set an all-time March low on both March 1 and March 2, dipping to -20° (previous record: -19°F on March 11, 1998.)

Flint, Michigan set an all-time March low of -16° on March 3 (previous record: -12°.)

Rockford, Illinois tied its all-time March record low of -11° on March 3.

At least five U.S. cities have set records for their coldest winter on record, as detailed by wunderground's weather historian Christopher C. Burt in his latest blog post. He has not yet compiled a list of cities that have set a record for their warmest winter on record during 2013 - 2014, but I know of at least two: Las Vegas, Nevada, and Tucson, Arizona.

Figure 1. Departure of surface temperature from average as diagnosed by the GFS model at 00 UTC March 4, 2014. A negative phase of the Arctic Oscillation (AO) allowed cold air to spill southwards out of the Arctic over the Eastern U.S., bringing temperatures up to 36°F (20°C) below average. Compensating warm air flowed northwards into the Arctic underneath a ridge of high pressure over Europe. Data/image obtained using Climate Reanalyzer™ (, Climate Change Institute, University of Maine, Orono, Maine.

How can a planet that is warming experience record cold?
This week's impressive cold blast brings up the question: How can a planet undergoing "global warming" experience record cold? Well, it's a big planet, and the weather has naturally crazy extremes. We expect to see many locations experience all-time daily and monthly cold records each month. It's just that the number of these cold records will be outnumbered by all-time heat records, when averaged over the globe, and over decades. It is called Global Warming for good reason! A 2009 study led by Dr. Jerry Meehl of the National Center for Atmospheric Research in Boulder, CO found that in the U.S., the ratio of the number of record daily highs to lows was near 1:1 in the 1960s and 1970s, but had increased to more than 2:1 during the decade of the 2000s, due to our warming climate. The ratio for the 2010’s was approximately 2.4-to-1 for daily records, for the four years 2010 - 2013, as explained in detail at Guy Walton's wunderblog. If "business as usual" emissions of heat-trapping gases like carbon dioxide continue this century, this ratio of record highs to record lows is expected to increase to 20:1 by the year 2050, and 50:1 by 2100. So, even on planet experiencing extreme global warming, we will still see a few record low temperatures in the 22nd Century.

Figure 2. Ratio of record daily highs to record daily lows observed at about 1,800 weather stations in the 48 contiguous United States from January 1950 through September 2009. Each bar shows the proportion of record highs (red) to record lows (blue) for each decade. The 1960s and 1970s saw slightly more record daily lows than highs, but in the last 30 years record highs have increasingly predominated, with the ratio now about two-to-one for the 48 states as a whole. ©UCAR, graphic by Mike Shibao; data from a 2009 study led by Dr. Jerry Meehl of the National Center for Atmospheric Research in Boulder, CO.

Two Years Ago: Summer in March
When we do break all-time heat records in the current warming climate, we should expect that some of these new records will crush the old records in phenomenal ways. That was the case during the astonishing U.S. record-breaking "Summer in March" heat wave just two years ago, in 2012. It was the warmest March on record for the contiguous U.S., 8.6°F above the 20th century average for March, and 0.5°F warmer than the previous warmest March in 1910. Of the more than 1,400 months that have passed since the U.S. record began in 1895, only one month, January 2006, had a larger departure from its average temperature than March 2012. Every state in the nation experienced a record warm daily temperature during March, and 25 states east of the Rockies had their warmest March on record. An additional 15 states had monthly temperatures ranking among their ten warmest. All-time March records were broken at 290 stations, with some stations breaking their all-time March record four times. There were 21 instances of the nighttime temperatures being as warm, or warmer, than the existing record daytime temperature for a given date. Four stations broke daily records by 30°F or more.

Figure 3. "This is the kind of sunset that you can expect to see in July, not in March. 77°F when I took this," said the caption on this wunderphoto taken on March 17, 2012 in Windom, Minnesota by wunderphotographer sally.

Jeff Masters

Winter Weather Climate Change

March Like a Lion: Record Cold in Midwest, Heavy Snow in Mid-Atlantic

By: JeffMasters, 4:01 PM GMT on March 03, 2014

March is roaring in like a lion over most of the U.S., where a sprawling winter storm has brought significant snows and freezing rain to over 100 million people over past two days, from Texas to New Jersey. Snows of 4 - 8" are expected Monday along a swath from Washington DC through Baltimore and into Southern New Jersey, with a few 8+" totals likely just south of DC. Behind the storm is a renewed blast of Arctic air, which on Monday morning brought the coldest temperatures ever measured so late in the year to Flint, Michigan (-16°F) and Rockford, Illinois (-11°F). The forecast low of 10°F in Washington D.C. for Tuesday morning would come close to that city's coldest March day on record of 4°F, and the low of 7°F predicted for Philadelphia, Pennsylvania would come close to the all-time coldest March temperature of 5° set in 1872. Some peak snowfall amounts from the storm, "Winter Storm Titan", as of 10 am EST Monday, from the latest NOAA Storm Report:

Indiana: 10.3" in Porter
West Virginia: 10.0", Bruceton Mills
Missouri: 8.5", Anderson
Illinois: 7.0", Mendota
New Mexico: 7.0", Arroyo Seco
Maryland: 6.5", New Market
Arkansas: 6.5", Pea Ridge
Oklahoma: 6.1", Hunter
Pennsylvania: 6.0", Mount Pleasant
New Jersey" 6.0", Woodbine
Tennessee: 6.0", Clarksville (fell as sleet)
Michigan: 5.5", Hillsdale
Kentucky: 5.3", Clover Bottom
Iowa: 5.2", E Solon
Kansas: 5.0", Newton
Ohio: 4.5", Wauseon
Virginia: 4.2", Stephens City
Washington DC: 2.0", American University
Delaware: 2.0", Newark

Figure 1. Workers clear the tarmac of snow so that flights can resume at Washington's Ronald Reagan National Airport on March 3, 2014. Image credit: AP/Cliff Owen.

Wild weather Ends in California
Winter Storm Titan battered California Friday and Saturday with high winds, heavy rains, and mountain snows. Downtown Los Angeles received 3.41" of rain February 28 - March 2, making it the city's heaviest rain event since March 19 - 27, 2011 (3.80"). A few California notable events from Winter Storm Titan:

Snow Reports

• Near Kirkwood Ski Area: 40"
• Near Donner Peak: 30"
• Soda Springs: 18"

Rain Reports
• Mining Ridge (Monterey Co.): 11.81"
• Matilija Canyon (Ventura Co.): 11.79"
• Cogswell Dam (L.A. Co.): 8.19"
• Santa Barbara: 1.83". Santa Barbara has received 5.20" of rain since July 1st, which is 7.97" below average.
• Downtown San Francisco: 1.53". San Francisco has received only 7.96" of rain since July 1st, which is 10.11" below average.
• Downtown Sacramento: 1.49". Sacramento has received only 6.19" of rain since July 1st, which is 7.54" below average.

Wind Reports
• 102 mph peak wind gust measured at Big Bear Resort on Friday (east of Los Angeles)
• 91 mph peak wind gust measured at Chilao on Friday (northeast of Los Angeles)
• 89 mph peak wind gust measured at Grapevine Peak on Friday

Flood Reports
• Debris flows reported at Big Sur Village and other locations in Monterey County, California on Friday
• Reported water rescue from the Los Angeles River in Cypress Park on Friday
• Report of five inches of water running down the street in the northern San Bernardino neighborhood
• Report of roadway flooding in San Jose on I-280 Northbound and SR17 South connector. In addition, several inches of standing water reported across all lanes near I-280 and Highway 87.
• Report of firefighters rescuing a man from the waters of Coyote Creek near the San Jose Municipal Golf Course.
• Flooding on the off-ramp of I-280 at Saratoga.
• Flash flooding caused a car to get trapped in Lake View Terrace, near Foothill Boulevard and Gladstone Avenue. A lady was rescued; no injuries reported.

Severe Weather Reports
• A plane was moved three feet and a jet bridge was damaged by a likely microburst at John Wayne Airport in Santa Ana Friday.
• One man was injured by a lightning strike in an oil field near Fresno Friday.
• One inch hail in Walnut early Saturday morning from a severe thunderstorm.
• At 6:24pm PT Friday, an EF0 tornado touched down 9 miles south of Karnak, Calif. No damage was reported for the 5 minute-long tornado.

Phoenix got its first rain of 2014 on March 1 (Saturday), ending a 70-day period without precipitation. This year was just the third year since 1896 the city had gone without precipitation during January and February. Las Vegas received its first rainfall of 2014 on Friday (0.30"), its first rain since December 4, ending the city's longest winter dry streak on record. This winter has been the warmest winter on record in Las Vegas.

Video 1. A huge wave from Winter Storm Titan crashes through a window at a Santa Barbara, California restaurant on March 1, 2014. The "time to go" comment is precious.

Jeff Masters

Winter Weather

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™


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