A Level 4 of 4 High Risk for flooding continues overnight and Wednesday across portions of the Edwards Plateau, western Hill Country, and areas west of San Antonio.
Heavy thunderstorms are already redeveloping across Uvalde, Medina, Bandera, and Bexar counties—some of the same areas that received 5–20 inches of rain Tuesday morning.
Another concentrated round of very heavy rain may develop overnight into Wednesday morning. Where storms repeatedly affect the same areas, an additional 5–15 inches of rain may fall by Wednesday morning.
That could push combined two-day rainfall totals above 20–25 inches in isolated locations.
The highest-concern corridor includes:
• Uvalde and Hondo
• Bandera and Medina counties
• Del Rio and Eagle Pass
• Edwards Plateau
• Western Hill Country
• Kerr, Gillespie, Kendall, Real, and Kimble counties
• Interstate 10 from Fort Stockton toward San Antonio
• Areas immediately west of San Antonio
Heavy rain could also develop farther east toward Highway 281 and the Interstate 35 corridor, but the precise overnight storm placement remains uncertain.
Small-scale circulations known as mesoscale convective vortices may determine where storms organize and remain nearly stationary. Short-term models often struggle to place these features accurately, making this more of a nowcast situation than a precise hourly forecast.
Potential impacts include:
• Additional rainfall of 5–15 inches in localized areas
• Combined storm totals above 20 inches in isolated locations
• Rapid-onset flash flooding
• Roads becoming submerged or completely washed out
• Major rises on creeks, streams, and rivers
• Dangerous overnight travel
• Flooding continuing beyond sunrise Wednesday
Not everyone inside the Level 3 or Level 4 risk area will receive extreme rain. The worst flooding may affect only a few counties. However, wherever the overnight rain band develops, saturated ground will make flooding begin much faster than it did Tuesday morning.
Have Wireless Emergency Alerts enabled and keep your phone charged overnight. Avoid driving after dark in areas receiving heavy rain, especially west of San Antonio and across the Edwards Plateau and Hill Country.
Never drive through water covering a road. Floodwater may conceal a washed-out roadway beneath it.
Interactive radar:
https://texasstormchasers.com/radar
Local forecasts, alerts, interactive radar, and frequent updates are available through the free Texas Storm Chasers mobile app.
Texas Storm Chasers will continue providing overnight updates through social media, video, the website, app, and 24/7 YouTube radar stream.
Chapters:
0:00 High flooding risk overnight and Wednesday
0:23 HTeaO sponsor and Tuesday evening update
0:54 Heavy rain redeveloping west of San Antonio
1:19 Small-scale circulations controlling tonight’s storms
2:15 Level 4 High Risk along Highway 90
2:49 Wednesday flooding risk remains extreme
3:34 Overnight rainfall timeline and uncertainty
4:11 Another 5–15 inches possible in localized areas
4:34 Potential for catastrophic compounded flooding
4:52 Hill Country areas farther north must remain alert
5:13 Wednesday storm development across more of Texas
5:31 Overnight warnings and travel safety
6:18 Why this is primarily a nowcast situation
6:57 Radar, app, and overnight update plans