| People who have lived in Texas for a long time will tell you that drought-like weather is the norm, with conditions occasionally broken by a flood or two. Droughts come in all shapes and sizes. Some droughts, like the drought of the 1950s, lasted almost 10 years, while others have lasted a year or less. Some droughts have affected the entire state, while others just a portion.
In 2003, an unusual drought developed across parts of Central Texas. It didn't cover a particularly large area of the state -- only about eight counties -- yet it was still significant. The most unusual aspect of this drought was not so much its size or severity, but how it developed and progressed.
The rainfall pattern across Central Texas last year can best be described as spotty. Although it did rain from time to time, there weren't any huge spring or fall rains, or any huge summer storms. While it didn't rain in Austin, there were generous rains in all directions of Austin.
Time after time, lines of thunderstorms moving south along cold fronts weakened and fell apart before they hit Central Texas. Areas of showers moving north from the coast also weakened and diminished before they made it into Central Texas. Rainstorms coming east out of Mexico diminished as they came through Hill Country. Despite a hurricane moving inland along the middle Texas coast in July and a hurricane moving inland along the upper Texas coast in September, most of Central Texas remained dry.
Rain deficit obvious by October
By October, the lack of rain over Central Texas was becoming apparent, with rainfall deficits approaching nine inches. By the end of the year, rainfall deficits had grown to more than 12 inches at several locations. See National Weather Service map showing precipitation patterns in 2003. When all was said and done, 2003 ended up being the 10th driest year on record at Bergstrom International Airport in Austin, and the 13th driest year on record at Austin's Camp Mabry. The ground was dry, aquifers were getting low and the fire danger was high.
National Weather Service map shows, Central Texas experienced a lack of rain, while locations just outside of Central Texas had near normal and in some cases above normal rainfall. It's interesting to note the area in drought was almost round in shape-a very unusual occurrence.
There isn't a clear explanation as to why drought developed over such a small part of the state last year while surrounding areas had near normal or even above normal rainfall. The lack of rain seemed to have much to due with chance and timing as anything else.
Weak cold fronts may have been the problem
From a scientific point of view, there weren't any strong atmospheric forces that kept the rain away from the area. This was just one of those years when most cold fronts weren't quite strong enough to make it through Central Texas, and activity coming north from the Gulf of Mexico tracked more into South or Southeast Texas rather than northwest into Central Texas. As the pattern repeated itself a number of times, the lack of rain grew worse.
Fortunately, this type of drought rarely lasts very long, as the track that storms take will usually change from one year to the next. The latest seasonal outlook from the National Weather Service suggests that rainfall will return to a more normal distribution over Texas late winter and into spring.
Bob Rose is LCRA's chief meteorologist. Write him at bob.rose@lcra.org.
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