by Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The month of February 2003 was colder and wetter than normal. The southern branch of the jet stream became active early in the month, after having been dormant for much of January. This allowed frequent storms to cross, which produced rainfall. Arctic air was able to come southward during the month because of the positioning of upper air high pressure off the United States Pacific Coast. Last month was 0.9 deg. colder than February 2002, and 3.66 inches wetter. Year-to-date precipitation through the end of the month was 2.70 inches greater this year than last. The Winter of 2002-2003 was colder than normal, with below normal temperatures in January and February, and near normal temperatures in December. February 2003 average temperatures and total precipitation are not records. February 2003 was, however, the coldest February since 1989, when the average that month was 2.0 deg. colder than last month. The 30-day outlook for February 2003 had called for below normal temperatures and above normal precipitation.
The week January 26-February 1 saw near normal temperatures and precipitation about one-half of normal. Cold fronts crossed on the 26th, 29th, and 31st. Significant warm-ups occurred between these. Strong warming occurred on the 1st as southwesterly winds blew as high pressure shifted eastward through the Gulf of Mexico, and the region experienced nearly full sun. The week's average temperature was 49.9 deg., which was 6.0 deg. warmer than the previous week. Precipitation totalled 0.38 in. Compared with the same week in 2002, the week was 6.6 deg. cooler, and 0.17 in. drier.
The week February 2-8 was four degrees colder than normal, and rainfall was near normal. Tropical Maritime air was over the region early in the week, but was replaced by Polar Continental air on the 4th, and Arctic air on the 6th. The result was a steady downward trend in temperatures. The cold front of the 3rd/4th brought light showers to parts of the region. A crossing upper air storm brought widespread rain on the 5th and 6th, with conditions remaining overcast on the 7th and 8th. The week's average temperature was 46.0 deg., which was 3.9 deg. colder than the previous week. Precipitation totaled 1.02 inches. Compared with the same week in 2002, the week was 0.3 deg. warmer, and 0.57 in. drier.
The week February 9-15 saw temperatures one degree warmer than normal, and precipitation about 150 percent of normal. The week began and ended wet. A crossing storm on the 9th brought rainfall early in the week. Another storm brought rain on the 13th, 14th, and 15th. A Polar Continental air mass chilled temperatures early in the week. Tropical Maritime air returned at mid-week, ahead of the powerful storm which crossed at late-week. Modified Arctic air built into the area on the 15th. The week's average temperature was 53.4 deg., which was 7.4 deg. warmer than the previous week. Precipitation totaled 1.28 inches. Compared with the same week in 2002, the week was 6.5 deg. warmer; there was no rainfall during the 2002 week.
The week February 16-22 saw temperatures five degrees colder than normal, and rainfall about 325 percent of normal. Two cold fronts crossed during the week: on the night of the 18th, and the morning of the 22nd. Temperatures warmed from the afternoon of the 17th until the arrival of the first cold front. An upper air storm crossed between the 19th and 22nd, causing rains of between one and seven inches in East Texas. Rains were heavier over the southern counties, with amounts in the Tyler/Longview area averaging between three and four inches. Skies were overcast from the night of the 18th through the morning of the 22nd, when the second front finally brought clearing. The week's average temperature was 48.4 deg., which was 5.0 deg. cooler than the previous week. Precipitation totalled 3.28 inches. Compared with the same week in 2002, the week was 7.3 deg. cooler, and 2.49 inches wetter.
The final six days of the month started warm and windy, with the 24th-28th cold and icy. Sleet and freezing rain occurred over the northwestern one-half of the area on the 25th and 26th. In Tyler, there was some light freezing rain which accumulated on vegetation on the morning of the 26th. Major highways and many school systems were closed to the north and west of Tyler from the night of the 24th/25th through the afternoon of the 26th. A shallow layer of Arctic air was trapped beneath a warmer air layer after the evening of the 23rd. This kept an overcast, and temperatures well below normal through the 28th. Beginning on the 27th, the Arctic layer eroded slowly, and temperatures warmed a few degrees.
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 2003, RECORDS AND SUMMARY: