By Robert K. Peters, Ph.D. - National Weather Service Cooperating Observer
The month of April 2010 saw near normal temperatures and well-below normal rainfall.
In fact, April 2010 becomes the fourth driest April since weather records began in Tyler in 1896. The 0.85 inch accumulation nosed April 1898 with 0.87 inch into fifth place. April 1983 was the driest on record with 0.38 inch.
Year-to-date rainfall was about 25 percent below normal, and was 3.15 inches less in 2010 than in 2009. April 2010 was 3.1 deg. Warmer, and 3.15 inches drier than April 2009.
The thirty-day outlook had called for below normal temperatures and above normal precipitation.
The week March 28-April 3 saw near normal temperatures and no precipitation. The week began cool, but warmed beginning the 29th and saw near to above normal temperatures through the remainder of the week. This was the result of upper air high pressure. A cold front crossed on the 2nd, lowering readings slightly. Rain did not accompany the front because of a warm air layer at about 5,000 feet. The week's average temperature was 63.1 deg., which was 9.8 deg. Warmer than the previous week. Compared with the same week in 2009, the week was 6.3 deg. Warmer, and 1.08 inches drier.
The week April 4-10 saw near normal temperatures and negligible precipitation. The week began warm under surface and upper air high pressure. The storm system, which crossed on the 7th, again failed to erode a low-level warm air layer, and only isolated showers fell. The exception was along the Louisiana border, where a couple of severe thunderstorms formed, and rains of an inch or greater were common. The second half of the week cooled, with windy conditions on the 8th. The week's average temperature was 64.6 deg., and rainfall was 0.01 inch. This was 1.5 deg. Warmer than the previous week. Compared with the same week in 2009, the week was 7.0 deg. Warmer, and 0.04 inch drier.
The week April 11-17 saw temperatures about 2 degrees above normal, and only a trace of rainfall. Surface and upper air high pressure controlled the weather until late on the 17th when a cold front and its accompanying upper air storm system approached. That brought the trace of rainfall, and lowered temperatures for the first half of the following week. The week's average temperature was 67.9 deg., which was 3.3 deg. Warmer than the previous week. Compared with the same week in 2009, the week was 7.8 deg. Warmer, and 2.79 inches drier.
The week April 18-24 saw temperatures about 2 degrees below normal, and rainfall about 40 percent of normal. The week began cool, with warming at mid-week ahead of a storm system which crossed on the 23rd and 24th. This brought the week's rain, and considerable severe weather during the evening of the 23rd and early-morning of the 24th including two tornadoes. Neither of these affected Smith County.
The week's average temperature was 65.5., which was 2.4 deg. Cooler than the previous week. Rainfall was 0.46 inch. Compared with the same week in 2009, the week was 4.1 deg. Cooler, and 0.16 inch wetter. After a cool start, the final six days of the month were warm. A weak storm system, which crossed on the 30th, brought the week's only rainfall.
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 2010, RECORDS AND SUMMARY: