BROWNSVILLE, TEXAS — A severe flash flood threat is targeting the Lower Texas Coast on Sunday, October 4, as relentless rounds of tropical downpours push in from the Gulf. A Moderate Risk (level 3 of 4) for excessive rainfall is in effect between Brownsville and Corpus Christi, where explosive thunderstorms could produce 2 to 3 inches of rain per hour. With soils already waterlogged from up to 8 inches of rain over the past three days, forecasters say there is a high probability of localized totals topping 8 to 10 inches. Farther east, a separate barrage of heavy rain threatens the central Gulf Coast from Mobile Bay to the Florida Panhandle, while a localized flood threat targets Savannah, Georgia.
Storms Keep Rolling In From the Gulf
Between Brownsville and Corpus Christi, thunderstorms developing over the Gulf are expected to repeatedly push onshore throughout the day. Fueled by intense atmospheric moisture, these storms can dump rain at extreme rates in a very short time.
Communities such as Harlingen, San Benito, Port Isabel, South Padre Island, Raymondville and Kingsville sit inside or near the Moderate Risk zone.
Waterlogged Ground Can’t Take More
Parts of the Rio Grande Valley and Coastal Bend have already picked up as much as 8 inches of rain over the past three days. The region’s soil is naturally sandy, which normally helps absorb rain, but forecasters warn that the sheer volume of water will quickly overwhelm both urban corridors and sensitive soils.
Streets, drainage ditches, resacas and low-lying neighborhoods could flood rapidly as each new round of storms arrives.
8 to 10 Inches Possible in Spots
With renewed downpours falling on saturated ground, localized totals could top 8 to 10 inches. Flooding could affect highways such as U.S. 77, U.S. 281 and Interstate 69E, along with city streets in Brownsville and Harlingen.
Central Gulf Coast: Stalled Storms and Training Rain
Farther east, a stalled front and near-record atmospheric moisture, running above the 99th percentile, are setting the stage for another round of heavy rain across the central Gulf Coast…