Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 12. maaliskuuta 2010 klo 15:26 (GMT)
The U.S. just experienced its coldest winter in 25 years, according to the National Climatic Data Center. The winter period December - February was the 18th coldest winter in the contiguous U.S. over the past 115 years, and the coldest since 1984 - 1985. It was also a wet winter, ranking 19th wettest. The states experiencing the coldest winters, relative to average, were Texas and Louisiana, which had their 5th coldest winters on record. Mississippi, Georgia, Alabama, Oklahoma, Arkansas, Florida, and South Carolina also had a top-ten coldest winter. The only state much above average was Maine, which had its 3rd warmest winter. As I discussed earlier this week, this winter's cold weather over the U.S. is largely due to the Arctic Oscillation/North Atlantic Oscillation, which assumed its most extreme negative configuration since record keeping began in 1950. El Niño helped keep things cool from Texas to the Southeastern U.S., as well.
Figure 1. Winter temperatures for the winter of 2009 - 2010. Image credit: National Climatic Data Center.
A cold February in the U.S.
February temperatures were 2.2°F below average across the contiguous U.S., making it the 29th coldest February in the 115-year record. For the second month in a row, Florida was the coldest state, relative to average. Florida had its 4th coldest February on record. Seven other states had February temperatures between 5th and 8th coldest on record: Louisiana, Texas, Alabama, Mississippi, Arkansas, Georgia, and South Carolina. Maine had its 3rd warmest February, New Hampshire its 5th, and Washington its 6th. Precipitation across the U.S. was near average in February.
Warmest and driest winter on record in Canada
Canada had its warmest winter on record, 4.0°C (7.2°F) above average, according to Environment Canada. The previous record was 3.9°C above average, set in 2005-2006. Canada also experienced its driest winter on record this year, with precipitation 22.0% below normal. The previous driest winter was 1977-1978 (20.1% below normal). Canadian weather records go back 63 years, to 1948. David Phillips, a senior climatologist with Environment Canada, warned of potential "horrific" water shortages, insect infestations, and wildfires this summer due to the warm, dry winter. Phillips blamed the warm winter weather on El Niño and the severe loss of arctic sea ice last fall. The winter season in Canada has warmed, on average, by 2.5°C (4.5°F) over the past 63 years.
Figure 2. Departure of temperature from average in Canada for the winter of 2009 - 2010. Image credit: Environment Canada.
Brazilian tropical/subtropical storm named "Anita"
The South Atlantic tropical/subtropical storm we've been tracking this week has moved over colder waters and has now transitioned to a regular extratropical storm. Earlier this week, the storm became just the 7th tropical or subtropical cyclone on record in the South Atlantic. According to a statement put out by MetSul Meteorologia, a Brazilian weather company, this storm is now named "Tropical Storm Anita:"
The regional weather centers and the private weather enterprises of both Rio Grande do Sul and Santa Catarina, southernmost Brazilian states, in a joint decision, named Anita the rare tropical storm of March 9th and 10th in the coastal areas of the region. The name was chosen considering a historic figure of Rio Grande do Sul and Santa Catarina, both states affected by the tropical cyclone. Anita Garibaldi (1821-1849) was a heroine of the Farroupilha Revolution (1835-1845), one of the most important events in the Brazilian history that took place in the Southern part of the country. Anita was used in the past to designate tropical cyclones in other basins: North Atlantic, the Pacific and the Indian Ocean.
Next week, we need to keep an eye on northeastern Australia, where Tropical Cyclone 20 may pay a visit. The storm is under light shear and warm waters, and is forecast to increase to Category 4 strength by Monday. Also of concern is Tropical Cyclone 19, which is expected to hit Fiji as a Category 2 storm early next week.
First tornado death of the year for the U.S
A tornado that hit Cleburne, Arkansas on Wednesday caused three serious injuries and the tornado season's first fatality, a 79-year old man sheltering in his single story wood-frame home. Yesterday, a suspected tornado ripped through Haines City, Florida destroying four condos and damaging fifteen others. One person was injured. Two other tornadoes caused minor damage in central Florida. The severe weather outbreak continues today, as NOAA's Storm Prediction Center is forecasting a "slight" chance of severe weather over portions of Florida, Georgia, Alabama, Kentucky, Indiana, and Ohio. After today, the severe weather action should diminish for at least five days over the U.S. The major U.S. weather story this weekend will be flooding in the Mid-Atlantic, where heavy rains of up to four inches are expected. Soils are already saturated and the heavy snows from this winter's major snowstorms will also melt, likely creating moderate flooding problems over much of the Mid-Atlantic.
Links to follow:
Interactive tornado map
Severe weather page
Figure 3. Severe weather forecast for today from the NOAA Storm Prediction Center.
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