Austin Faces Continued Rain and Flood Risk Amid Gulf Moisture Surge

Austin can’t shake off its rain chances just yet. Although we’ve been able to enjoy at least a couple of rain-free days this week, the National Weather Service forecast calls for a 40% chance of afternoon rain on both Saturday and Sunday, thanks to surge in atmospheric moisture from the Gulf of Mexico.

Daytime temperatures in Austin will steadily increase over the coming days, including afternoon highs of 93 on Saturday and 95 on Sunday. Southerly winds of 5 to 10 mph that have been delivering moisture-rich air from the Gulf means humidity will make those 90-degree temps feel closer to 100. Recent rains, though, have helped keep daily maximum temps to near or below normal levels for mid-July, but that will change soon.

Central Texas on Saturday will find itself dealing with an upper-atmosphere wave of low pressure that could trigger storms and an increasingly deep flow of Gulf moisture.

This has led the weather service’s Weather Prediction Center, which specializes in flood forecasts, to place the northern half of Texas under a level 2 of 4 risk, or at least a 15% chance, of excessive rainfall. A portion of Texas that includes flood-ravaged Kerr County and Interstate 35 corridor counties like Travis, Williamson and Hays, faces a level 1 of 4 risk, or at least a 5% chance of excessive rainfall.

Precipitable water values, or the amounts of liquid that could be condensed from water vapor in a given column of air, also are rising along and east of the I-35 corridor, the weather service said.

“This will promote the return for isolated to scattered rain/storm activity, with the greatest coverage likely in the Coastal Plains,” the weather service said in a forecast bulletin Friday.

Saturday night into Sunday, forecasters said, a shortwave trough of low atmospheric pressure out of Colorado will help drive a cold front southward into the Texas Panhandle.

“This boundary… results in increased rain and thunderstorm chances from West Texas to the Red River and northeastward through Oklahoma,” the weather service said. “Our local region looks to be more on the southern end of this weather system with primarily isolated to scattered rain/storm activity across our region through Sunday afternoon.”

Forecast modeling “continues to show the greatest footprint for rainfall and potential for any flooding instances centering from the Midland/San Angelo area northeastward to the Red River and into Oklahoma,” the weather service said, adding that “details, however, will continue to be fine-tuned.”

Rain chances diminish quickly as we enter the work week. Sunshine takes over the weather starting on Monday, as high temperatures in the mid-90s through midweek increase to 97 degrees Wednesday and Thursday.