Earth Has Its 4th Warmest March on Record; Weekend Severe Weather Outbreak Coming

March 2014 was the globe's 4th warmest March since records began in 1880, according to NOAA's National Climatic Data Center (NCDC) and NASA. March 2014 global land temperatures were the 5th warmest on record, and global ocean temperatures were also the 5th warmest on record. The year-to-date January - March period has been the 7th warmest on record for the globe. Global satellite-measured temperatures in March 2013 for the lowest 8 km of the atmosphere were 11th or 9th warmest in the 36-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively. Northern Hemisphere snow cover during March was the 6th lowest in the 48-year record. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of March 2014 in his March 2014 Global Weather Extremes Summary.


Figure 1. Departure of temperature from average for March 2014, the 4th warmest March for the globe since record keeping began in 1880. Much of Europe had a top-five warmest March, including Austria (2nd), Norway (3rd), Denmark (4th), Germany (3rd), Latvia (3rd), the Netherlands (3rd), and Slovakia (1st.) In the U.S., Vermont had its coldest March on record, and Michigan, New York, Maine, and New Hampshire all had top-five coldest Marches on record. Image credit: National Climatic Data Center (NCDC) .



One billion-dollar weather disaster in March 2014: Drought in Brazil
One billion-dollar weather-related disaster hit the Earth during March 2014: Southeastern Brazil's worst drought in 50 years, which has cost at least $4.3 billion so far this year, according to the March 2014 Catastrophe Report from insurance broker Aon Benfield. This is the third most expensive natural disaster in Brazil's history, and the second consecutive year of disastrous drought in the country. Drought in Northeast Brazil during the first five months of 2013 caused an estimated $8 billion in damage--Brazil's second most expensive natural disaster in recorded history. According to the international disaster database EM-DAT, Brazil's costliest natural disaster was the drought of 1978 ($2.3 billion in 1978 dollars, or $8.3 billion 2014 dollars.)


Disaster 1. Cattle in a drought-parched filed in Quixada, Ceara state, Brazil on January 2, 2014. Small farmers in Ceara state have not able to harvest corn to feed cattle, and have been selling them at a loss. Aurelien Francisco Barros/AFP/Getty Images.


Figure 2. The deadliest U.S. weather disaster of March 2014 was the tragic landslide at Oso, Washington that killed 41 people and did $10 million in damage. The landslide was triggered by record March rains that saturated the soils. The nearby Seattle airport measured 9.44” (240 mm) of precipitation in March, a new record for the month. Photo by Washington State Patrol.

An El Niño Watch continues
March 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 greater than 50% chance that an El Niño event will occur by the summer. The April 10 El Niño discussion from NOAA's Climate Prediction Center noted that "there remains considerable uncertainty as to when El Niño will develop and how strong it may become. This uncertainty is amplified by the inherently lower forecast skill of the models for forecasts made in the spring." None of the El Niño models (updated in mid-April 2014) predict La Niña conditions for peak hurricane season, August-September-October 2014, and 16 of 20 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 +0.2°C from average as of April 21. 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 is currently a Westerly Wind Burst (WWB) over the equatorial Pacific Ocean that is helping push warm water eastwards towards South America. If this Westerly Wind Burst persists and expands eastwards through early May, the odds of an El Niño event will increase.

Arctic sea ice falls to 5th lowest March extent on record
Arctic sea ice extent during March was 5th lowest in the 36-year satellite record, according to the National Snow and Ice Data Center (NSIDC). The winter maximum extent of Arctic sea ice came on March 21, and was the 5th lowest such peak on record. Temperatures in the Arctic were 2 - 6°C (4 -11°F) above average during the last half of the month, but a late-season surge in ice extent came as the Arctic Oscillation turned strongly positive the second week of March, with unusually low sea level pressure in the eastern Arctic and the northern North Atlantic. The associated pattern of surface winds helped to spread out the ice pack, keeping ice extent greater than it would have been. There was a modest increase in thick, multi-year ice over the winter, and the Arctic is in better shape to resist a record summer melt season this year than it was in 2013.


Figure 2. Regions most at risk of severe weather for the period Saturday, April 26 - Monday, April 28, 2014, as predicted by NOAA's Storm Prediction Center at 4:15 am EDT Wednesday, April 23, 2014.

Weekend tornado and severe weather outbreak coming for the Plains
A significant multi-day severe weather event is expected Saturday, Sunday, and Monday across the Central U.S. A strong low pressure system will trundle slowly across the region, spawning supercell thunderstorms capable of generating large hail, damaging winds, and a few strong tornadoes. The action will begin Saturday afternoon along a swath from Central Texas northwards into Oklahoma and Kansas, then gradually shift eastwards on Sunday and Monday. Recent runs of the GFS and European model have been very consistent in showing moderate to extreme instability in the warm air ahead of the storm's cold front Saturday through Monday, and this weekend's severe weather outbreak has the potential to be the most dangerous one of this relatively quiet 2014. This year has yet to spawn a killer tornado, setting a new record for latest date of the year's first killer tornado. The previous record belonged to 2002, when the year's first killer tornado struck April 21 (an F-3 that killed a man in a mobile home in a rural area of Wayne County, Illinois.) The relatively cool and dry weather across Tornado Alley so far this year has led to no EF-3 or stronger tornadoes as of April 23, and that's also a record-long wait since modern tornado records began in 1950. According to tornado historian Tom Grazulis' book, Significant Tornadoes 1680-1991, "serious efforts" to document all tornadoes began in 1953, which was the first full year of tornado watches issued by the U.S. Weather Bureau, now the National Weather Service.

I'll have a new post on Friday.

Jeff Masters