The month of March 2009 was cooler and wetter than normal. Compared with March 2008, the month was 0.7 deg. Cooler, and 1.09 inches wetter. Year-to-date rainfall through month's end was 1.68 less in 2009 than in 2008. The thirty-day outlook had called for above normal temperatures and below normal precipitation.
The week March 1-7 saw temperatures about a degree above normal, and no rainfall. A dramatic change in air masses occurred on the night of the 3rd. Polar Continental air, which had brought well-below normal temperatures early in the week, was replaced by Tropical Maritime air. A tight pressure gradient produced gusty winds between the 4th and 7th. The week's average temperature was 58.0 deg., which was 1.2 deg. Warmer than the previous week. Compared with the same week in 2008, the week was 1.0 deg. Warmer, and 0.15 inch drier.
The Tropical Maritime air persisted until just after midnight on the 11th, when it was replaced by a shallow Polar Continental air mass, which was overridden by moisture well up the vertical air column. This combined with several disturbances rotating around an upper air low over the Southwestern United States to produce cold temperatures and heavy rainfall. Amounts in the region ranged between 2.5 and 8.0 inches. Strong northeast winds on the 11th, 12th, and much of the 13th lowered the wind chill equivalent values to around 30 with air temperatures holding in the middle to high 30s. The week March 8-14 saw temperatures about 3 degrees below normal, and rainfall about 600 percent of normal. The average temperature was 55.9, 2.1 deg. Cooler than the previous week, and rainfall was 5.45 inches. Compared with the same week in 2008, the week was 4.3 deg. Cooler and 4.72 inches wetter.
The week March 15-21 saw temperatures about a degree below normal, and only 0.02 inch of rainfall. A dry and stable air mass covered the region for most of the week, resulting in mild daytime and cool nighttime temperatures. A weak cold front on the 17th reinforced this air mass. The wet soils left behind by the rains of the previous week resulted in widespread dense fog on the mornings of the 16th, 17th, and 18th. The week's average temperature was 59.7 deg., which was 3.8 deg. Warmer than the previous week. Compared with the same week in 2008, the week was 2.8 deg. Cooler, and 0.88 inch drier.
The week March 22-28 saw temperatures about 4 degrees below normal, and rainfall about 200 percent of normal. A slow-moving storm system crossed the region between the 24th and 28th, bringing rainfall daily between the 24th and 27th. Over the southern counties, these rains were heavy, and severe weather occurred on the 24th, 25th, and 26th. A weak cold front crossed on the 24th, retreated back northward on the 26th, and was succeeded by a strong Arctic front on the evening of the 27th. Strong northwest winds blew on the 28th, resulting in low wind chill values that day. The week's average temperature was 58.5 deg., and rainfall was 1.62 inches. This was 1.2 deg. Cooler than the previous week. Compared with the same week in 2008, the week was 2.0 deg. Cooler, and 1.57 inches wetter.
A storm system crossed early on the morning of the 31st, with reports of severe weather south and east of Tyler and rain and thunderstorms general over the southeastern half of the region. Otherwise, a warming trend commenced on the 29th, reversed by the cold front of the 31st. The area observed its last freeze on the morning of the 29th when the mercury briefly reached 32 deg. In Tyler.
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
March 2009, RECORDS AND SUMMARY: