Annual weather capsule for 2009 in Deep South Texas

Calendar year 2009 was relatively quiet compared with the extremes of 2008. Still, after a rather benign start, things began to heat up – literally – as spring arrived and an oppressively hot summer followed. Winds, heat, and a few rounds of severe weather led May into June; wind and heat took the headlines in July and August, as nary a tropical cyclone was to be found in the western Gulf of Mexico. After the heat and drought wiped out much of the dryland crop, September arrived with thirst–quenching rainfall. October began with more unusual heat, which gave way to transitional cooling in November. The year ended with El Niño’s anticipated gray chill, which finished the drought across all of Deep South Texas. For the time being.

Winter: Wildfire and Warmth

January began with springlike warmth, followed by a minor freeze across rural locations of Deep South Texas and the Rio Grande Valley, sparing the more populous Rio Grande Valley and most crop areas from Hidalgo through Willacy and Cameron Counties with nothing more than some light frost. Dry, mild to warm, and occasionally windy weather set the stage for a small outbreak of wildfires on the 19th and 20th across the middle Rio Grande Valley. One fire destroyed four buildings at the Moore Air Force Base west of Edinburg, scorching more than 2500 acres and leaving an estimated $10 million in damage. Temperatures were a balmy 4 to 5 degrees above average, setting a tone for the first half of 2009 as La Niña slowly faded away.

The Spring in Winter theme would continue into February, as average high temperatures rose past 80 for the month for all but the immediate coast, and departures would be more than 6 degrees for most, placing the month in the top 15 warmest February’s at most locations. The paltry rainfall – less than an inch for most – combined with the warm, dry conditions led to a few more wildfires; fortunately, the sole fire that threatened homes near La Joya was brought under control.

Spring: Drought, Wildfire, Heat, and Storms (Again?)

Continuing the theme common through the end of winter, March began warm, dry, and breezy, with temperatures some 5 to 10°F above average combining with dry ground and no rainfall to kick off spotty wildfires during the first week. A rare cold front for the Winter/Spring of 2009 brought cloudy, chilly conditions by mid month, putting a damper on the 2009 CAF Air Fiesta. The chill was short lived; less than 10 days later, afternoon temperatures would soar into the upper 80s and 90s away from the coast, culminating in near–record temperatures above the century mark while the Texas Panhandle saw nearly 2 feet of snow! April brought continued warmth, as average afternoon temperatures reached the upper 80s to lower 90s for most, with the mean overall temperature more than 3° above the long term averages. The month also saw the return of severe drought conditions, which quickly became extreme to exceptional across the Lower RGV through the King Ranch under the increasing sun angle. The arrival of increasingly unstable air by mid month set off localized hailstorms across the mid and upper Valley, starting in Zapata County the evening of April 17th and affecting Starr and Hidalgo County on the 18th. The month would conclude with summer like heat, as daytime temperatures in the upper 80s and lower 90s only dropped into the 70s at night.

The first half of May would begin where April left off: Hot, breezy, and rain free, with daytime temperatures in the 90s throughout the region, nearing or exceeding 100°F in the Mid and Upper Valley to the Rio Grande Plains. The early may heat wave had temperatures between 6 and 9°F above average. Drought intensified through mid month, reaching Extreme to Exceptional levels before some rain relief arrived during the second half of the month. In that second half, several upper level disturbances helped kick off scattered to locally numerous thunderstorms, some which produced strong winds and hail. The first of these, on May 16th and 17th.

Recently, Deep South Texas has experienced a one to two week period of severe weather in Spring. In 2009, this period began around Memorial Day and would continue into the first week of June. Between May 24th and May 28th, more than a dozen reports of wind gusts and hail were received, as well as two reports of destructive lightning, one which burned a large home in McAllen early on the 28th, with a replacement cost estimated to be around $1 million.