Tropical air mass will bring threat of heavy rainfall and isolated flooding/flash flooding threat through Friday
According to the National Weather Service, the Hill Country area could be seeing a lot of rain Wednesday afternoon.
The forecast calls for locally heavy rainfall with rain rates that may exceed 2-3 inches per hour. Minor flooding and isolated flash flooding is possible with rain totals potentially reaching up to 5 inches.
The areas of concern are listed as the Hill Country, the Interstate 35 corridor from Austin to San Antonio and the coastal plains east of I-35.
The peak hours of thunderstorm activity are expected to be Wednesday afternoon and evening with the possibility of rains occurring overnight. This could also happen Thursday afternoon and evening with a smaller change on Friday.
From the National Weather Service:
“The atmosphere over South Central Texas is primed for locally heavy rainfall as moisture from what was once Hurricane Odile in the Pacific is spilling into the desert Southwest and portions of West Texas. This mid and high level tropical moisture is combining with rich Gulf of Mexico moisture, setting the stage for shower and thunderstorm development later today...and again on Thursday and maybe even Friday. While we are lacking a good trigger for storm development, daytime heating will be just enough of a trigger to develop scattered to numerous showers and thunderstorms late this morning into this afternoon and evening. Like we saw on Tuesday, the storms will be slow moving, while bringing rain rates of 2-3 inches per hour. This will lead to urban type flooding of streets and drainages as well as small stream flooding. We could easily see isolated rain totals of 3-5 inches today somewhere in South Central Texas. Because there is no real good focus for storm development, we do not see any favored locations of where the heaviest rain might set up.
We will continue to watch the weather models and radar trends carefully the next 12-24 hours. If trends become apparent, a Flash Flood Watch may be issued.
The storms are expected to be most numerous across the eastern 2/3rds of South Central Texas...mainly east of a Rocksprings to Pleasanton line. Look for the activity to peak during the late afternoon/early evening hours and then linger through the first part of the night, maybe even past midnight. So isolated flash flooding may be occurring later tonight. Remember that most of our Flash Flood Fatalities are related to driving at night. Thursday will see a repeat of the storm activity, mainly firing with daytime heating. Again we will carry the threat of isolated flooding/flash flooding with isolated totals of 3-5 inches possible.
Rain chances will finally decrease by Friday into Saturday although isolated to scattered storms are still possible.
We will need to watch this scenario closely. Everybody associated with emergency management/road conditions/ etc...need to monitor the weather over the next 48 hours. Whenever you are dealing with tropical moisture from left over tropical storms/hurricanes...it bears watching over South Central Texas.
You can see the latest forecasts and watches/warnings/advisories by going to the Austin-San Antonio National Weather Service website at www.weather.gov/austin.”
