National Weather Service United States Department of Commerce

Double Severe Squall Line Merger - June 2nd, 2010

During the late afternoon on June 2, 2010, thunderstorms developed over central Texas and the Sierra Madre of Mexico. A very unstable air mass was present over South Texas (CAPE values from 4500 to 5500 J/kg). At 7 pm CDT, the first line of severe thunderstorms entered the Rio Grande Valley and produced hail up to the size of nickels, localized flooding and strong winds. The second line of thunderstorms extended across much of Central Texas and began accelerating and tracking southward from Tilden to Goliad by late in the evening. The two lines of thunderstorms merged around Tilden and Choke Canyon Reservoir near 1000 pm CDT causing intensification to the convective complex of storms. This was evident by severe storms over Live Oak and Bee counties with increased reflectivity and cloud to ground lightning between 1030 and 1100 pm CDT. At the same time, the northern line of thunderstorms continued through the Victoria Crossroads area and slowly weakened.

The strongest portion of the solid line of thunderstorms continued southeastward into the central Coastal Bend. Reports of trees down and power outages increased from along I-37 to Corpus Christi from the most intense portion of the line of thunderstorms.  WSR-88D detected small areas of rotation over Aransas, San Patricio and Nueces Counties between 1100 and midnight CDT when tornado warnings were issued. Wind gusts of 60 mph were common from automated weather stations as the storms slammed the lower Coastal Bend. Power outages from the wind were significant by midnight and there were many reports of trees and power lines down, and rescue operations for recreational trailers that were tipped over on the base of Navy Corpus Christi and a flipped 18-wheeler. In this area, automated sensors measured wind as high as 80 mph. The lightning was intense and continuous at times, which caused additional damage to a few structures. The line of thunderstorms produced widespread 1 to 2 inches of rain across South Texas with locally higher amounts. Total cloud to ground lightning strikes observed by the National Lightning Detection Network were near 38,000 from 800 pm to 200 am CDT. In Nueces County up to 31,000 residence had interruption to their power according to AEP.

Information from the NWS survey team that visited Navy Corpus Christi estimated wind speeds up to 90 mph had occurred at the peak of the storms. Wind damage was consistent with straight-line wind damage. Four recreational trailers were flipped and a couple were moved a few feet. There were 6 injuries reported and 1 was critical. In addition, debris from a boat barn was blown into the Laguna Madre and a boat was thrown into a nearby parking lot. The survey team also observed over 40 trees that were damaged, uprooted or snapped across the Naval base. Further east on Mustang Island, winds were also estimated to have reached up to 90 mph and numerous power poles were snapped, a billboard knocked down, shingles torn off a couple businesses, and several story sections of brick ripped off from 2 resort buildings. Further north, damage was also found in Rockport and Aransas Pass, consistent with straight-line winds. An 18-wheeler was tipped over at Highway 35 and 16th street and Cove Harbor Marina signs were snapped with roofs partially damaged. At the intersection of FM 2801 and 1069 several cars were moved and a barn roof was peeled off. Oak lane and county road 188 had residents trapped due to down powerlines and a church in Aransas Pass had a portion of the roof peeled away with at least one trailer found flipped over. Additional damage was scattered across Flour Bluff, and in Corpus Christi on Alameda and Everhart streets. Finally, small damage paths from a tornado were observed by the public and verified by the NWS survey team near Chapman Ranch. Finally, the survey team visited an area west of Rockport and determined that an EF2 (wind estimated 115 to 120 mph) tornado produced a path of 4 miles and was up to 1/3 of mile wide crossing FM 1069. The tornado originated in Copano Bay and tracked southeast producing damage west of Rockport and Highway 35.

Radar Loop

Composite Radar 7pm through 2am

Satellite Loop

Lightning Strikes

Total Precipitation Analysis June 2-3

COOP and CoCoRaHS analysis June 2-3

Mesoanalysis Loop

KCRP Sounding

CAPS ARW Model Loop of Reflectivity