Unusual and Destructive Spring Hailstorms in McAllen, Texas

Several severe thunderstorms impacted McAllen, Texas during spring 2012. A slow-moving supercell thunderstorm affected the city between 830 and 930 PM CDT (0130 and 0230 UTC) on 29 March. Hailstones between golf ball and baseball size (45 and 70 mm in diameter) accumulated with this storm, resulting in hail drifts up to 1.22 m. The hail was driven by occasional wind gusts up to hurricane force (33 m s-1). Rainfall amounts between 102 and 152 mm flooded numerous streets around the city. The combination of hail, wind, and flooding resulted in more than 200 rescues by emergency personnel, and between $200 million and $500 million of insured property damage. Additional damage occurred on 20 April in McAllen, as severe thunderstorms dropped hailstones between golf ball and softball size (45 and 114 mm in diameter) during the evening rush hour.

Despite the unusual nature of these storms, there were no critical injuries or fatalities from either event. An e-mail message alerted emergency management and media partners to the potential for damaging hail and destructive winds more than four hours prior to the event, and severe weather warnings were issued with more than 20 minutes of lead time.

Impacts from the spring hailstorms extended beyond physical damage. Interviews with residents affected by the core of the 29 March event indicated a “fear of the unknown,” as the event continued beyond the typical time frame expected with severe thunderstorms. As windows shattered, roofs leaked, and wind battered homes, fear turned to concern for personal and family members' lives. For the remainder of spring, the mere threat of hail was met with trepidation by residents shocked by the events of 29 March. The 20 April event only added to these concerns. Because of the rarity of events such as these across the region, the National Weather Service in Brownsville will continue working with our partners across the Rio Grande Valley to provide additional education on societal impacts.