Heavy rain and flash flooding possible along Texas coast
Flash flooding threat: Heavy rain capable of producing flash flooding is possible across the middle to lower Texas coast through 6:45 a.m. CDT. Rainfall rates over 2 inches per hour are likely, with isolated totals of 3 to 5 inches or more.
Context
Heavy rainfall from showers and thunderstorms will be the primary concern from tonight through Tuesday, mainly across the mid to lower Rio Grande Valley and lower Texas coast, with PWATs around 2.5 inches supporting very heavy rainfall at times.
What’s Driving It
A mesoscale circulation is moving toward the lower Texas coast within a highly anomalously moist airmass with precipitable water near 2.8 inches. Hourly rainfall rates of 2 to 3 inches or more are possible, and occasional training of heavy rain cores along the immediate coast will maintain a threat for continued heavy precipitation. Areas receiving multiple rounds of heavy rain face a higher risk for localized flooding.
What To Look For
The mesoscale circulation should reach the lower Texas coast within the next few hours, bringing a locally higher threat for high rain rates pushing roughly 50 miles inland. Onshore flow from the Gulf may continue to train heavy rain along the immediate coast. Flash flooding will be possible, particularly where higher rainfall rates and totals overlap with urban areas.