by Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
February 2010 was the fifth coldest and second snowiest on record. It was also the coldest February since 1978, and replaces February 1900 as fifth coldest. Snowfall was 7.7 inches, behind the 7.8 inches which fell in February 1985. Total precipitation was near normal. In fact, February 2010 was 1.3 deg. Colder than January.
An El Nino event in the East Central Equatorial Pacific Ocean combined with a negative Arctic Oscillation and positive Pacific-North America Tele-connection explains the cold and snow. Compared with February 2009, the month was 13.2 deg. Colder, and 1.93 inches wetter. Year-to-date precipitation was 3.39 inches greater in 2010 than in 2009. The thirty-day outlook had called for below normal temperatures and above normal precipitation.
The week January 31-February 6 saw temperatures about 7 degrees below normal, and rainfall about 150 percent of normal. For most of the week, the area remained under a weak Arctic air mass. An upper air low, crossing on the 3rd and 4th, brought the week's rainfall. The week's average temperature was 43.1 deg., 1.5 deg. Cooler than the previous week. Rainfall was 1.30 inches. Compared with the same week in 2009, the week was 9.6 deg. Cooler, and 0.98 inch wetter.
The week February 7-13 saw temperatures about 15 degrees below normal, and precipitation nearly 200 percent of normal. Widespread and heavy snow fell in the area on the night of the 11th/12th, with Tyler measuring 6.0 inches. It was the heaviest snow in Tyler since January 13, 1982. There were power failures, with electric service not completely restored until the afternoon of the 14th. The snow did not melt entirely until that day. The snow was the result of an Arctic air mass, a continuous supply of Gulf moisture, and a strong upper air trough. Otherwise, low temperatures were below freezing on six of the week's seven days. A storm system crossing earlier in the week brought general rains of between one-half and one inch. The week's average temperature was 36.4 deg., which was 6.7 deg. Cooler than the previous week. Precipitation was 1.60 inches. The contrast with the same week in 2009 is dramatic: the week was 22.5 deg. Colder, and 0.77 inch wetter. The average minimum during the week in 2009 was 6 degrees higher than the average maximum in 2010.
Cold weather continued until the end of the week February 14-20. On the 20th, the daily temperature was above normal for the first time since January 28. The week was about 9 deg. Colder than normal overall, and there was no precipitation. Polar Continental air dominated the region until the end of the week, when Tropical Maritime air made a two-day appearance on the 20th and 21st. The dry air mass meant sunny skies for most of the week. Under upper atmospheric high pressure, there were no mechanisms to generate any precipitation. The week's average temperature was 43.6 deg., which was 7.2 deg. Warmer than the previous week. Compared with the same week in 2009, the week was 8.6 deg. Colder, and 0.46 inch drier.
The week February 21-27 saw temperatures about 11 degrees below normal, and precipitation about two-thirds normal. Two storm systems crossed during the week: the one on the 23rd brought snow accumulations of three to six inches from Jacksonville and Palestine southward about 75 miles; the second on the 26th brought widespread rainfall. Only a trace of snow accumulated in Tyler, though 1.7 inches fell. The week's average temperature was 43.5 deg. 0.1 deg. Cooler than the previous week; precipitation was 0.67 inch. "Compared with the same week in 2009, the week was 13.3 deg. Cooler, and there was no rain in 2009.
The last day of the month saw clouds and moisture increase ahead of yet another progressive storm system.
The reporting period for temperatures and phenomenon on each day is for the twenty-four hours ending at midnight hours GMT--6 p.m. CST and 7 p.m. CDT. The reporting period for precipitation is for the twenty-four hours ending at noon GMT--6 a.m. CST and 7 a.m. CDT. All times are given using the twenty-four hour clock, and are expressed in Greenwich Mean Time.
Observations are from NWS Station 41/9207/4 in Tyler, Texas. The term "normal" refers to averages from the standard climatic period 1971-2000.
MX MN OBS PCPN REMARKS
February 2010, RECORDS AND SUMMARY: