It’s official: May 2015 breaks record for wettest month in Texas history

supercell thunderstorm

Image: Wikimedia Commons

May 2015 is now officially the wettest month ever in Texas history, according to figures from the Office of the State Climatologist at Texas A&M University. The state averaged 7.54 inches, beating the previous record of 6.66 inches set in June 2004.

“Many parts of the state have set records for the most rainfall ever,” said John Nielsen-Gammon, a professor of atmospheric sciences who has served as the state climatologist since 2000.

Three major factor contributed to the record rainfall, he said:

* An active El Niño in the Pacific Ocean which tends to bring the jet stream over Texas

* A steady flow of moist air from the south that becomes unstable when it undercuts the jet stream

* A stubborn weather pattern “that just won’t go away”

Nielsen-Gammon said, “It has been one continuous storm after another for the past week to 10 days in several regions of the state.  It has rained so much that the ground just can’t soak any more moisture into it, and many creeks and rivers are above flood stage.”

The state’s wettest area has been from the Dallas-Fort Worth area to the Red River, parts of which have received more than 20 inches of rain this month.

The Houston area was not hit “that hard until the past few days, but then heavy rains came in waves and areas around Sugarland have received more than 17.50 inches of rain.  The area around San Marcos has received heavy flooding, with more than 18 inches of rain this month,” Nielsen-Gammon adds.

All of that rain means many lakes and reservoirs are close to capacity.  Lakes near Wichita Falls have gone from just 20 percent capacity to 100 percent in the last month.

Still, parts of Texas remain abnormally dry, such as areas from near Abilene to San Angelo.

“About 15 percent of Texas was still in drought as of last week,” he adds, “but at this rate it won’t be long before even the driest parts of the state are drought-free.”