🌊 Flash Flood Alerts & Heavy Rain Radar

How Radar Reveals Flash Flood Danger

Flash floods are hard to see coming from the ground, but radar tells the story early. Watch for two patterns: very bright reflectivity that stays parked over the same area, and storms that keep forming and moving over the same place, a pattern forecasters call training. When heavy rain falls faster than the ground and drains can carry it away, water rises quickly, especially in cities, low-lying roads, and normally dry creeks.

Radar rain-rate and rainfall-total products estimate how much water has already fallen. Deep colors that persist for an hour or more over one area are a warning sign even before any official alert appears. If you see that pattern near you, check the live flood warnings above and avoid low-water crossings and underpasses.

Why Central Texas Is Called Flash Flood Alley

The corridor of central Texas between the Hill Country and the coastal plain is known as Flash Flood Alley because steep terrain, thin soils, and intense Gulf moisture combine to produce some of the fastest-rising floods in the country. Cities like Austin and San Antonio sit right in this corridor, which is why their radar pages are worth bookmarking during storm season. Flash flooding can also strike far from any river: urban streets, parking lots, and small creeks can flood within minutes of a heavy downpour.

Flood Safety Rules

• Never drive through flooded roads. Turn around, do not drown: even shallow, fast-moving water can sweep a vehicle away, and the road beneath may be washed out.
• Move to higher ground immediately if a flash flood warning covers your area, and avoid basements and underpasses.
• Do not walk through floodwater. It can hide open drains, debris, and downed power lines, and just a few inches of moving water can knock a person down.
• Keep children and pets away from creeks, culverts, and drainage channels during and after heavy rain.
• Wait for official word that it is safe before returning to a flooded area, and never drive around barricades.

Flash Flood Watch vs Warning vs Emergency

A Flood Watch means flooding is possible in the watch area and you should be prepared. A Flash Flood Warning means flash flooding is occurring or imminent and you should move to higher ground right away. A Flash Flood Emergency is the most urgent level, issued when flash flooding poses a severe threat to human life and catastrophic damage is occurring or expected. Treat every level seriously, and act fastest when a warning or emergency names your location.