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 , 8. helmikuuta 2012 klo 14:25 (GMT)
It wasn't the warmest January in U.S. history, but it sure didn't seem like winter last month--the contiguous U.S. experienced its fourth warmest January on record, and the winter period December 2011 - January 2012 was also the fourth warmest in the 117-year record, reported NOAA's National Climatic Data Center yesterday. The percent area of the U.S. experiencing extremes in warm maximum temperatures was 56 percent--the second highest value on record. Twelve of the 550 major U.S. cities with automated airport weather stations broke or tied all-time records for their hottest January temperature:
Craig, CO 82°F
Bakersfield, CA 82°F
Duluth, MN 48°F
Minot, ND 61°F
Mitchell, SD 68°F
Fargo, ND 55°F
Jamestown, ND 56°F
Huron, SD 65°F
Aberdeen, SD 63°F
Iron Mountain, MI 52°F
Alma, GA 83°F
Omaha, NE 69°F
However, extremely cold air settled in over Alaska in January, and several cities in Alaska had their coldest average January temperatures on record: Nome (-16.6 degrees F), Bethel (-17.3 degrees F), McGrath (-28.5 degrees F), and Bettles (-35.6 degrees F).
Figure 1. State-by-state rankings of temperatures for January 2012. Nine states had top-ten warmest Januarys on record, while no states had below-average temperatures in January. Records go back to 1895. Image credit: NOAA's National Climatic Data Center.
28th driest January for the contiguous U.S.
The first week of January was almost precipitation-free across the entire contiguous U.S., but a series of storms over Texas, the Ohio Valley, and the Pacific Northwest later in the month boosted precipitation totals enough to make January 2012 the 28th driest in the 118-year period of record. Remarkably, Texas had its 30th wettest January on record, and was the 2nd wettest state during the month. Texas also had a very wet December, their 19th wettest December. It is very rare for Texas to receive so much precipitation during a La Niña winter. Texas had not experienced two consecutive months with above-average precipitation since January - February 2010, during the last El Niño event.
Figure 2. State-by-state rankings of precipitation for January 2012. Three states had top-ten driest Januarys on record, while no states had a top-ten wettest January. Records go back to 1895. Image credit: NOAA's National Climatic Data Center.
3rd least-snowy January
According to the Rutgers Global Snow Lab, the average U.S. snow extent during January was the 3rd smallest January snow cover extent in the 46-year period of record. The National Weather Service sends out a daily "Weather and Almanac" product for several hundred major U.S. cities that we make available on underground. The February 6 statistics for those cities that reported measurable snow this winter show that only fifteen cities in the lower 48 states reported above-average snowfall as of February 6, and 155 had received below-average snowfall.
Figure 3. The new "Blue Marble" image of Earth on January 4, 2012, as seen by the VIIRS instrument on the new Suomi NPP satellite. The U.S. and Canada are virtually snow-free and cloud-free, which is extremely rare for a January day. The lack of snow in the mountains of the Western U.S. is particularly unusual. I doubt one could find a January day this cloud-free with so little snow on the ground throughout the entire satellite record, going back to the early 1960s. NOAA's Advanced Hydrologic Prediction Service shows that only one state--Washington--had areas where precipitation accumulated more than 0.25" on January 4, 2012, which is an extraordinary occurrence for a January day. Image credit: NASA.
Drought expands in January
According to the U.S. Drought Monitor, as of January 31st, 2012, about 3.3 percent of the contiguous U.S. was experiencing the worst category of drought--called D4 or exceptional drought--about the same as the beginning of the month. However, the percent area of the U.S. experiencing drought of any severity increased from 32 percent at the beginning of January to 38 percent at the end of the month. Most of the drought expansion occurred across the Upper Midwest and the western states.
2nd most January tornadoes on record
With 95 preliminary tornado reports, January 2012 is likely to end up with the 2nd most January tornadoes since 1950 (the record is 218, set in January 1999.)
I'll have a new post on Friday.
Comments will take a few seconds to appear.