During the late evening of April 1st, 2012 and the early morning hours of April 2nd, a strong to severe squall line developed across Mexico and then later moved through South Texas. An area of low pressure aloft located both over the Rockies and East Texas helped set the stage for isolated severe convection embedded within the line. The upper level forcing from these two areas of low pressure along with very unstable conditions helped to maintain the squall line as it moved eastward overnight. Straight-line winds averaged between 45 and 55 mph behind the squall line with isolated gusts over 60 mph.
However, as the squall line neared the town of Port Lavaca, a downburst embedded within the squall line produced winds up to 80 mph along a narrow 1/2 mile wide path that extended for nearly 2 miles in length. Radar images indicated winds over 70 mph at an elevation of nearly 6500 feet as the squall line entered Port Lavaca. Several telephone poles were snapped along with numerous large tree limbs down and a few uprooted trees. Minor roof damage also occurred at a business in Port Lavaca.
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0220 AM TSTM WND GST 3 ESE ALICE 27.74N 98.03W 04/02/2012 M52.00 MPH JIM WELLS TX ASOS 0316 AM TSTM WND GST 1 W CORPUS CHRISTI 27.77N 97.52W 04/02/2012 M51.00 MPH NUECES TX ASOS 0324 AM MARINE TSTM WIND 15 SSW NATIONAL SEASHOR 27.29N 97.40W 04/02/2012 M48.00 MPH GMZ230 TX MESONET MESONET MEASURED 41.4 KTS. 0324 AM MARINE TSTM WIND 2 W NATIONAL SEASHORE 27.48N 97.32W 04/02/2012 M43.00 MPH GMZ230 TX MESONET MEASURED 37 KT GUSTS. 0336 AM MARINE TSTM WIND 5 SE CC NAS 27.64N 97.23W 04/02/2012 M41.00 MPH GMZ230 TX MESONET GUST TO 36 KTS. 0345 AM TSTM WND DMG 3 WSW CORPUS CHRISTI 27.69N 97.33W 04/02/2012 NUECES TX NWS EMPLOYEE POWER OUTAGES - POWER LINES DOWN NEAR OSO BAY. 0348 AM MARINE TSTM WIND 9 SSE CC NAS 27.58N 97.22W 04/02/2012 M48.00 MPH GMZ250 TX MESONET RECORDED AT BOB HALL PIER. 48 MPH /41.8 KTS/ 0355 AM TSTM WND GST 1 SW PORT ARANSAS 27.82N 97.09W 04/02/2012 M52.00 MPH NUECES TX AWOS 0405 AM TSTM WND GST 3 N ROCKPORT 28.09N 97.04W 04/02/2012 M55.00 MPH ARANSAS TX ASOS 0410 AM HAIL ROCKPORT 28.04N 97.05W 04/02/2012 M0.25 INCH ARANSAS TX TRAINED SPOTTER PEA SIZED HAIL AT INTERSECTION OF FM 3036 AND HIGHWAY 35 BYPASS. 0445 AM HAIL SEADRIFT 28.38N 96.69W 04/02/2012 E1.00 INCH CALHOUN TX PUBLIC ESTIMATED NICKEL TO QUARTER-SIZED HAIL. 0450 AM TSTM WND GST 1 WSW PORT LAVACA 28.61N 96.64W 04/02/2012 E80.00 MPH CALHOUN TX NWS STORM SURVEY A NWS STORM SURVEY TEAM CONCLUDED THAT A DOWNBURST OCCURRED IN THE CITY OF PORT LAVACA WITH WINDS ESTIMATED BETWEEN 70-80 MPH. SEVERAL HOMES IN PATH OF THE DOWNBURST SUSTAINED MINOR ROOF DAMAGE...TWO TELEPHONE POLES WERE SNAPPED AT THEIR BASES AND NUMEROUS LARGE TREE LIMBS WERE DOWN...ALONG WITH A FEW UPROOTED TREES. THE DAMAGE PATH WAS APPROXIMATELY 1/2 MILE WIDE AND 2 MILES IN LENGTH BEGINNING NEAR ALCOA DRIVE AND EXTENDING NORTHEAST TO TRAVIS STREET...GENERALLY SOUTH OF HIGHWAY 35. 0450 AM TSTM WND DMG 1 WSW PORT LAVACA 28.61N 96.64W 04/02/2012 CALHOUN TX LAW ENFORCEMENT MULTIPLE CALLS OF TREES DOWN AND WINDOWS BUSTED IN AREA. SOME TREES DOWNED POSSIBLY VERY LARGE IN HEIGHT AND DIAMTER. 0501 AM MARINE TSTM WIND 1 SSW PORT OCONNOR 28.43N 96.41W 04/02/2012 M69.00 MPH GMZ235 TX MESONET MARINE MESONET SITE MEASURED GUST TO 69 MPH /59.7 KTS/ WITH SUSTAINED WINDS OF 51 MPH /44.1 KTS/.