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 , 17. joulukuuta 2009 klo 15:46 (GMT)
The globe recorded its fourth warmest November since record keeping began in 1880, according to NOAA's National Climatic Data Center. NASA's Goddard Institute for Space Studies rated November 2009 as the warmest November on record, beating the 2001 record by 0.02°C. NOAA classified the year-to-date period, January - November 2009, as the fifth warmest such period on record. The November satellite-measured temperatures for the lowest 8 km of the atmosphere were the warmest on record according to the University of Alabama Huntsville data set, or fifth warmest, according to the RSS data set.
Figure 1. Departure of temperature from average for November 2009. Image credit: National Climatic Data Center.
Warmest November on record for Southern Hemisphere land areas
Southern Hemisphere land areas had their warmest November on record including Australia, according to the Australian Bureau of Meteorology. November was 1.87°C (3.4°F) above average in Australia, and several statewide records were broken, with New South Wales, Victoria, and Tasmania, surpassing the previous largest maximum temperature anomaly recorded for an Australian state. The highest minimum temperature record for the continent was also broken, with an anomaly of 1.61°C (2.90°F) above average.
Third warmest November on record for the U.S.
For the contiguous U.S., the average November temperature was 4.0°F above average, making it the 3rd warmest November in the 115-year record, according to the National Climatic Data Center. That's a pretty remarkable swing from October, which was the third coldest October on record. Delaware experienced its warmest November on record, Wisconsin and New Jersey their second warmest, and five states had their third warmest November (Maine, New Hampshire, Massachusetts, Iowa, and North Dakota). Eighteen other states had an average temperature that ranked in the top ten. No states had below normal temperatures for the month.
Unusually low tornado activity in November
November was a quiet month for tornadoes in the U.S., with only 4 preliminary reports. November 2009 was the slowest November since 1980, which had 3 tornadoes, and tied for 3rd quietest since extensive records began in 1950. The autumn as a whole was also calm with only 80 tornadoes reported in the U.S., compared to the 2006-2008 year average of 164.
At the end of November, 9% of the contiguous United States was in moderate-to-exceptional drought. This is the smallest November drought footprint since 2005. Drought expanded across Arizona, southern California, and southern Nevada, but improved over drought-stricken Texas. For the first time in many years, the U.S. Drought Monitor shows no areas in the highest classification of drought--exceptional drought. The second highest category of drought, extreme drought, covers only a small region of northeast Arizona.
U.S. fire activity
November, like September and October, saw below-normal U.S. fire activity in all respects.
Strong El Niño conditions continue
Strong El Niño conditions continue over the tropical Eastern Pacific. Ocean temperatures in the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region", were at 1.6°C above average on December 15, just above the 1.5°C threshold for a strong El Niño, according to the Australian Bureau of Meteorology. The strength of El Niño was roughly constant for the 5 weeks ending December 15. NOAA's Climate Prediction Center is maintaining an El Niño Advisory. Current conditions and model forecasts favor continued El Niño conditions lasting through the Northern Hemisphere spring of 2010.
November sea ice extent in the Arctic 3rd lowest on record
November 2009 Northern Hemisphere sea ice extent was the 3rd lowest since satellite measurements began in 1979, according to the National Snow and Ice Data Center (NSIDC). Only 2006 and 2007 saw lower arctic sea ice extent. During 10-day period in the first half of November, arctic ice extent decreased below the 2007 record minimum, but rose above record minimum levels by the middle of the month.
Ricky Rood in Copenhagen
Our Climate Change expert, Dr. Ricky Rood, is in Copenhagen for the COP15 climate change treaty negotiations. His latest post, called Have you no sense of decency, sir, at long last? makes for very interesting reading on how the U.S. is "wasting its intellect and time on disruptions designed to play to people at home".
I'll have another post late Friday.
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