HEB, San Antonio, TX
On April 25, 2015 at 3:59AM local time, the tornadoAlert alarm indicated a “Tornado Risk” within the San Antonio area for the possibility of imminent formation of a tornado associated with a severe thunderstorm approaching from the southwest. Multiple reports of 1″ to 2″ hail, 2-3 inches of heavy rain, and a “healthy 3 foot diameter mesquite tree snapped off 3 feet above ground level” accompanied the passage of this storm. At 3:54AM the NWS issued a severe thunderstorm warning located 7 miles southeast of Sabinal or 16 miles southwest of Hondo moving east at 25 mph. At 4:06AM the NWS issued a second warning for a severe thunderstorm located over Leon Valley or 8 miles northwest of San Antonio moving northeast at 45 mph, advising residents of hail damage to vehicles and wind damage to roofs. Subsequent evaluation of doppler radar imagery revealed mesocyclone rotation associated with the damage reports produced by this very dangerous severe thunderstorm around 4AM, justifying the “Tornado Risk” alarm provided by the tornadoAlert product.