Flash flood risk in West and Central Texas as heavy rain moves in through Friday

Parts of West and Central Texas face a risk of flash flooding from Thursday afternoon, October 29, into Friday morning as heavy rain spreads across the state. The National Weather Service's Weather Prediction Center placed portions of West and Central Texas and southeastern New Mexico under a Slight Risk of excessive rainfall, a category it defines as a chance of at least 15%, in its outlook issued at 4:08 a.m. EDT on Thursday. On Wednesday, Gov. Greg Abbott directed the Texas Division of Emergency Management to activate state emergency response resources.

The Weather Prediction Center ties the rain to a disturbance associated with the remnants of Tropical Cyclone Vance, and the governor's office, citing the National Weather Service, also points to moisture from the Gulf. Vance itself was still a weakening tropical storm off western Mexico on Thursday morning, and the National Hurricane Center said moisture carried northeast from it will bring heavy rain to parts of the Southern Plains and New Mexico into Friday. Weather Prediction Center forecasters wrote that confidence "remains high in a heavy rainfall event" from Thursday afternoon through the night. Models show a corridor of 2 to 5 inches from the Stockton and western Edwards Plateaus to southeastern New Mexico, with a 70% to 90% chance of more than 3 inches in 24 hours in the wettest part and isolated totals of 5 to 7 inches possible.

Widespread cloud cover should limit instability, so the chance of rain falling fast enough within an hour to exceed local flash flood thresholds is low, the forecasters said. The wider flood risk comes from how long the rain lasts: moderate to locally heavy rain is expected across much of West and Central Texas through Thursday night and into Friday morning. In southern New Mexico, they warned, downpours on sensitive terrain and wildfire burn scars could trigger flash flooding, because soils there are already soaked from recent heavy rain.

Where and when

The governor's office, citing the National Weather Service, said the greatest concern for excessive rain on Thursday is in parts of the Permian Basin, Big Bend, South Plains, Big Country, Hill Country and Texas Border regions. About 1.5 million people live inside Thursday's Slight Risk area, by the center's count. On Friday the heaviest rain should shift northeast, and the center expects only isolated flash flooding, most likely where Thursday's and Friday's rain overlap.

What the state has ready

The resources on call include swiftwater rescue boat squads from Texas A&M Task Force 1, game wardens, rescue boat teams and helicopters with hoists from Texas Parks and Wildlife, Highway Patrol troopers and helicopters from the Department of Public Safety, and medics and ambulances from the Texas Emergency Medical Task Force, the governor's office said. The Public Utility Commission is monitoring power outages with utilities.

Texans should monitor local forecasts, heed guidance from state and local officials, and avoid flooded roadways.

How to stay safe

Driving into floodwater is the biggest danger. Citing the Centers for Disease Control and Prevention, the National Weather Service says more than half of flood-related drownings happen when a vehicle is driven into hazardous floodwater. Six inches of fast-moving water can knock over an adult, 12 inches of rushing water can carry away most cars, and 2 feet can carry away SUVs and trucks. Never drive around barriers on a flooded road, the agency adds, because the road beneath the water may have collapsed.

State officials want residents to keep an eye on the weather, do what local officials tell them, go over their family's emergency plan and put together a supply kit. Road conditions are posted at DriveTexas.org, and safety tips are at TexasReady.gov.