By the staff at WFO Corpus Christi
General Weather Summary
An extensive area of thunderstorms was located from Southeast Texas to near San Antonio Sunday morning. An outflow boundary from the complex of thunderstorms moved slowly southward into South Texas Sunday afternoon. An upper level disturbance was moving east across Northern Mexico and Southwest Texas during the same time.
Ahead of the boundary the airmass over South Texas became strongly unstable (CAPE values from 2500-3000 J/kg) during the afternoon as temperatures rose into the upper 80s over the Coastal Bend to the upper 90s near the Rio Grande. Dewpoint temperatures were also high across the area with lower 70s along the coast to the upper 60s over the eastern portions of the Rio Grande Plains. With the approach of the upper level disturbance, the shear became stronger over South Texas. The surface winds over the Coastal Bend were 25 to 30 mph from the east-southeast during the latter half of the afternoon. 0-6 km shear was 50-55 knots over the Coastal Bend and 0-1 km Storm Relative Helicity was 200-250 m2/s2. The atmospheric environment over South Texas was favorable for the development of supercells. Hailstorm Video
Severe Weather Event & Impacts
Scattered thunderstorms forming along the boundary moved into the Victoria region during the middle afternoon hours, producing hail up to quarter size in the city of Victoria. On the southwest edge of the complex an intense thunderstorm developed over northern Live Oak County around 345 PM and quickly became severe, organizing into a supercell just east of Three Rivers. Radar showed the development of a hook echo with this storm. Hail up to the size of quarters along with a funnel cloud was reported as it moved east from Three Rivers to near Ray Point. The storm weakened by 5 PM as it moved into Bee County.
Another severe thunderstorm quickly developed over southern Live Oak County, west of Lake Corpus Christi at 5 PM. The storm developed a hook echo near Lagarto and produced nickel to golf ball sized hail from Lagarto to Mathis between 530 and 600 PM. Golf ball sized hail was reported in Orange Grove at 615 pm and at San Patricio at 625 pm.
This supercell thunderstorm continued to move to the east-southeast along the Nueces River into Nueces County and eventually the western and southern portions of the Corpus Christi metropolitan area. The severe thunderstorm reached Calallen at 645 pm, with golf ball sized hail and wind gusts between 60 and 70 mph. The storm then proceeded to the Corpus Christi International Airport at 710 PM, with hail up to 1 inch in diameter and wind gusts to 60 mph. View crop damage View a photo of the Rear Flank Downdraft as the storm was impacting the Corpus Christi International Airport. The storm moved into the southern sections of the city between 725 and 740 PM, producing numerous hail reports ranging from quarter to golf ball size with the largest hail around 2 inches in diameter. The severe thunderstorm continued east-southeast into extreme Northeast Kleberg County and the coastal waters off of the Padre Island National Seashore then finally dissipating around 9 PM.
The intense supercell thunderstorm, that formed west of Lake Corpus Christi and eventually moved into Corpus Christi, had the radar appearance of a storm capable of producing a tornado several times during its life cycle. However, outflow winds from the thunderstorm appeared to stay far enough ahead of the low level circulation to prevent tornadogenesis from occurring. Also, slightly more stable near-surface conditions existed over the Coastal Bend behind the seabreeze boundary. This factor may also have precluded tornado development with this supercell.
The National Weather Service office in Corpus Christi issued 20 severe weather warnings and 6 Special Marine Warnings for this event with an average lead time of 25 minutes. Seventy-five percent of the warnings were verified by either large hail reports or strong damaging winds. There were no reports of injuries.