By Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The month of April 2004 saw near normal temperatures and above normal rainfall. Compared with the same month in 2003, April 2004 was 0.2 deg. cooler, and 3.11 inches wetter. Year-to-date rainfall through April 30, 2004 was 3.76 inches greater than through the same date in 2003. The thirty-day outlook for April 2004 had called for near normal temperatures and near normal precipitation.
The week March 28-April 3 saw near normal temperatures and precipitation about one-fourth of normal. A storm system crossed on the 28th. It brought light rainfall to the central counties, but torrential rains of as much as four inches to the southeast. This was followed by a cold front, which was reinforced on the 30th. The week began and ended with above-normal temperatures, with below normal readings during the middle of the week. Humidities were quite low beginning with the 29th, and continuing through week's end. An upper air storm crossed to the south on the 3rd, which brought rain to the southern counties. The week's average temperature was 64.9 deg., and rainfall was 0.20 inch. The temperature was 0.5 deg. lower than the previous week. Compared with the same week in 2003, the week was 2.9 deg. warmer, and 0.08 inch drier.
The week April 4-10 saw near normal temperatures and near normal precipitation. A cold front on the 5th brought lower readings, and a crossing upper air storm on the 6th and 7th brought the rain. There was severe weather on the night of the 6th/7th. By late-week, Tropical Maritime air built back into the region under a weak upper air high. The week's average temperature was 64.7 deg., and precipitation was 0.92 inch. The week was 0.2 deg. cooler than the previous week. Compared with the same week in 2003, the week was 5.7 deg. warmer, and 0.32 inch drier.
The week April 11-17 saw temperatures about 7 deg. cooler than normal, and rainfall about one-half of normal. A strong cold front moved into the area early on the 11th, with a reinforcing cold surge on the 13th. This held down temperatures through the 15th. Tropical Maritime air returned on the 16th and 17th. Rain accompanied the front, with overrunning rain continuing a couple of days after frontal passage. The week's average temperature was 58.8 deg., which was 5.9 deg. cooler than the previous week. Precipitation was 0.45 inch. Compared with the same week in 2003, the week was 11.1 deg. cooler and there was no rain in 2003.
The week April 18-24 saw temperatures about 4 deg. warmer than normal, and no rainfall. Though general and heavy rain fell on the 24th, this came after the week's reporting period had ended. For the entire week, Tropical Maritime air was present at the surface. Upper atmospheric high pressure kept the region warm, and shunted disturbances to the north of the region--allowing no precipitation. The week's average temperature was 71.8 deg. This was 13.0 deg. warmer than the previous week. Compared with the same week in 2003, the week was the week was 4.5 deg. warmer, and 0.42 inch drier.
A strong upper air storm system crossed on the 24th and 25th, with a weaker one crossing on the 29th. The result was heavy rainfall on the 24th, and moderate rain on the 29th. Light rain fell with yet another weak upper air disturbance on the morning of the 30th.
The 25th-27th saw modified Polar Continental air in control, with Tropical Maritime air and warmer temperatures returning from the 28th through the 30th.
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 2004, RECORDS AND SUMMARY: