Flash Flood — Willacy, Texas

2012-03-30 · near Port Mansfield, Willacy, Texas

Event narrative

Runoff from storms in Hidalgo County was moving so swiftly that it caused the collapse of a weir in Willacy County. Estimates for repair of the structure are around $2 million.

Wider weather episode

Intense thunderstorms raked the highly populated McAllen/Edinburg/Mission area of Hidalgo County during the mid-evening of March 29th. The storms dumped hail up to the size of baseballs for more than half an hour, drove that hail with 70 to 75 mph winds, added 4 to 6 inches of torrential rains, and produced frequent cloud to ground lightning. Initial storms developed across the King Ranch during the mid afternoon of March 29th, and spread west into northern Hidalgo and Starr County by early evening. The storms, fed by warm, humid air near the surface, colder air aloft, and boundaries (providing lift) from earlier storms which moved across the Coastal Bend, appeared to have intensified further as they approached the highly populated Edinburg/McAllen/Mission area. One possibility why the storms intensified is the interaction with an upper level disturbance moving across northeast Mexico. This disturbance spawned dangerous storms in Nuevo Lon and Tamaulipas, and boundaries from these cells may have been the ultimate trigger to a night hundreds of thousands will not forget.

Damage totals have reached an estimated $200 million in property and crop damage. Updated tallies will be provided as information is received.

View location on OpenStreetMap → (26.4609, -97.4836)

Source: NOAA Storm Events Database, event_id 379522. Narrative written by the NWS forecast office that issued the report.