By Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The month of April 2005 was cooler and much drier than normal. Compared with 2004, the month was 0.5 deg. cooler, and 4.05 inches drier. Year-to-date rainfall through the end of the month was 4.91 inches greater in 2004 than in 2005. The thirty-day outlook had called for near normal temperatures and near normal rainfall. The week March 27-April 2 saw temperatures about 3 deg. cooler than normal, and rainfall about 150 percent of normal. Storm systems crossed on the 27th and 31st, both of which brought widespread rain. The storm of the 31st brought severe weather. After a cool start, the week warmed rapidly ahead of the storm of the 31st, and then cooled at late-week. The week's average temperature was 60.1 deg., and precipitation was 1.21 inches. The week was 1.2 deg. cooler than the previous week. Compared with the same week in 2004, the week was 4.8 deg. cooler, and 1.01 inches wetter.
The week April 3-9 saw near normal temperatures, and rainfall about 25 percent of normal. Temperatures warmed during the first three days before a strong storm system producing widespread severe weather on the evening of the 5th. Hail of up to 2.75 inches in diameter occurred over southern Smith County. High pressure began building into the area on the 6th, keeping the region in a mild and dry air mass. This high went east of the area on the night of the 8th, preparing the way for the storm of early the following week. The week's temperatures averaged 65.0 deg., and rainfall was 0.23 inch. This was 4.9 deg. warmer than the previous week. Compared with the same week in 2004, the week was 0.3 deg. warmer, and 0.69 inch drier.
The week April 10-16 saw temperatures about 2 deg. cooler than normal, and rainfall about 5 percent of normal. Tropical Maritime air was present early in the week, replaced by modified Polar Continental air following a cold front on the evening of the 11th. A reinforcing cool surge arrived on the 14th. This resulted in cool temperatures and low relative humidities, with the air mass slowly modifying at the weekend. The week's only rain was with the front. The average temperature for the week was 64.3 deg., and precipitation was 0.05 inch. This was 0.7 deg. cooler than the previous week. Compared with the same week in 2004, the week was 5.5 deg. warmer, and 0.40 inch drier.
The week April 17-23 saw temperatures about 2 deg. warmer than normal, and no rainfall. The surface high pressure ridge, which brought the cool air of the previous week, shifted east early in the week. Tropical Maritime air moved into the area, remaining until another strong cold front crossed on the 22nd. The week's only rainfall was some isolated light showers on the morning of the 21st over the north, and more widely scattered showers with the front on the 22nd. The week's average temperature was 69.2 deg. This was 4.9 deg. warmer than the previous week. Compared with the same week in 2004, the week was 2.5 deg. cooler. No rain fell during the 2004 week, either.
The week April 24-30 saw temperatures about 3 deg. cooler than normal, and rainfall about one-fourth normal. The week began cool, with a disturbance and warm front crossing on the 25th/26th. Mid-week was warm under upper air high pressure and Tropical Maritime air. A cold front and disturbance on the 30th brought more rain, and significant cooling which continued into early-May. The week's average temperature was 66.0 deg., which was 3.2 deg. cooler than the previous week. Precipitation totaled 0.26 inch. Compared with the same week in 2004, the week was 1.2 deg. cooler, and 5.49 inches drier.
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
APRIL 2005, RECORDS AND SUMMARY: