by Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The month of February 2001 was warmer and much wetter than normal. For much of the month, the southern branch of the jet stream was the pathway for storms which slowly crossed the continent. These would form off the Pacific Coast, linger there a while, and then creep eastward. As a consequence, there were few significant cold air outbreaks, since Arctic air was bottled up in Canada for most of the month. Nonetheless, February 2001 was 5.9 degrees cooler than February 2000. February 2001 was 4.40 inches wetter than February 2000. Year-to-date rainfall through February 28, 2001 was 13.73 inches. This compares with 5.69 inches for the same date in 2000.
Precipitation over the past twelve months is 143.8 percent of normal. This reflects a wet Spring of 2000 and a very wet Autumn 2000 and Winter 2000-2001. This total takes into account the dry mid-Summer 2000 through early-Autumn 2000. The thirty-day outlook for February 2001 had called for above normal temperatures and below normal precipitation.
Temperatures during the week January 28-February 3 were near normal, and rainfall was about 125 percent of normal. A vigorous storm system crossed on the morning of the 29th bringing thunderstorms. Otherwise, the week saw a procession of swiftly-moving cold fronts, which brought weak cold air flows. A southwesterly surface flow on the 29th and 2nd sent temperatures up into the 60s on those afternoons. A warm front moved through on the morning of the 28th, which brought fog ahead of it.
The week February 4-10 saw temperatures five degrees warmer than normal and rainfall about one-third normal. Tropical Maritime air was resident over the area much of the week. A storm, pulling a cold front in its wake, crossed late in the week. This brought the week's only rain. Conditions on the afternoon of the 9th were quite windy, as high pressure built into the region.
Temperatures during the week February 11-17 were three degrees warmer than normal, and rainfall was 500 percent of normal. The week was one of contrasts. It started cool and damp, with overrunning rainfall. A warm front moved slowly northward on the 12th-13th, causing dense fog which virtually shut down commercial aviation over Northeast Texas on those days. A strong cold front and its accompanying upper air storm crossed on the 15th-16th. The upper air storm combined with favorable moisture flow brought torrential rains on the morning of the 16th, which caused considerable flooding of secondary roads and of some urban intersections.
The week February 18-24 saw temperatures six degrees above normal, and rainfall near normal. Polar Maritime air masses changed places with Tropical Maritime air masses during the week as a procession of storms in the southern branch of the jet stream crossed. A storm on the 21st brought light rainfall, while one on the 23rd-24th brought more substantial rains. There were reports of severe weather over the northern counties on the 24th. It was windy on the 24th as a deep surface low, in association with the upper air storm, approached and crossed.
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 2001, RECORDS AND SUMMARY: