5th warmest winter on record

The winter of 2005-2006 (December, January and February) was the 5th warmest on record in the U.S., according to the National Climatic Data Center. February temperatures were near average for the U.S., with no states much warmer or much cooler than their long-term means. February 2006 was the 45th warmest on record since 1895. However, the record warm January over most of the U.S. helped push the temperatures for the winter as a whole sharply upwards. The global numbers are not tabulated yet, but it is likely that the winter will rank in the top 15 warmest winters globally, since December was the 9th warmest December on record, and January was the 13th warmest. The very cold temperatures seen in Asia during January 2006, plus the emergence of La Ni�a, will keep the global winter from setting any records for warmth.


Figure 1. Global temperatures in January 2006 were the 13th warmest on record, and the warmest on record in the U.S. Note the cool blue dots along the Equator off the Pacific coast of Central America, indicating the presence of La Ni�a cooling of the ocean surface. It is unprecedented in the historical record for a La Ni�a of this intensity to develop so early in the year.

Precipitation for the winter of 2005-2006
Precipitation was much below average in February for much of the U.S., making this February 2006 the 9th driest on record. December-February precipitation was near normal for the U.S. as a whole, but portions of the south-central U.S. and southwest U.S. suffered acute drought conditions. However, the Southwest is poised to receive its biggest storm of the season Saturday, when a half-inch of rain is expected in Phoenix, bringing its amazing string of 143 straight days without rain to an end. Up to foot of snow is expected in the mountains near Phoenix. Not much precipitation is likely for the upcoming months, though, as the persistent La Ni�a pattern should act to keep the jet stream and major storm systems well north of the Southwest.



Figure 2. Precipitation for the winter of 2005-2006 averaged near normal for the country, with the very dry conditions in the south-central and southwest U.S. being balanced by heavy precipitation in the northwestern U.S.

Tropical outlook for March
The oceans in the Northern Hemisphere are near their yearly minima in temperature this week. In the Atlantic, only the Caribbean is above the minimum 26 C threshold for hurricane formation. Wind shear remains high over the entire Atlantic, and is forecast to remain high for at least the next ten days. I'm not anticipating any off-season tropical development in the Atlantic this March. As the sun crosses the Equator on Spring Equinox (March 20), the oceans will slowly begin to heat up again.

Hottest temperature ever recorded
OK, so this isn't meteorology, but yesterday scientists at Sandia National Laboratories announced they had produced a superheated gas with the hottest temperature ever recorded--3.6 billion degrees Fahrenheit, or 2 billion degrees Centigrade. The Sun checks in at a mere 15 million degrees Centigrade.

Jeff Masters