A little more than a day after a thunderstorm system brought more severe weather to the Rio Grande Valley, the last vestige of very unstable air held forth mainly along and east of Highway 77. Despite unfavorable upper level conditions, the combination of the unstable air with a trigger in the form of a wind shift/dry line which moved within striking distance of Highway 77 allowed a small but…
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BRO wrote it up.
A little more than a day after a thunderstorm system brought more severe weather to the Rio Grande Valley, the last vestige of very unstable air held forth mainly along and east of Highway 77. Despite unfavorable upper level conditions, the combination of the unstable air with a trigger in the form of a wind shift/dry line which moved within striking distance of Highway 77 allowed a small but potent cluster of thunderstorms to explosively grow initially in northern Willacy County just before 4 PM CDT. These storms would produce south moving outflows, which added to the dryline trigger. Additional storms would fire in only a half hour, working on the very unstable atmosphere (above right) to increase updraft speed and develop quarter to half dollar sized hail at least between west Harlingen and La Feria and points south between 515 and 545 PM. Once again, there was some damage to vehicles caught in the hail, much containing jagged edges. Many residents caught by surprise by the rapid development moved their vehicles under gas station canopies, car washes, and highway underpasses.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Brownsville, TX wrote its last area forecast discussion before the first event at May 12, 12:56 PM CST, 2 hours 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 156 PM CDT SAT MAY 12 2012 .SHORT TERM /TONIGHT TROUGH SATURDAY NIGHT/...SATELLITE IMAGERY SHOWS SOUTHEAST WINDS BETWEEN 20 TO 25 MPH SUSTAINED ACROSS THE VALLEY WITH OCCASIONAL GUSTS UP TO 30 MPH. WINDS WILL GRADUALLY DIMINISH AFTER SUNSET AS SURFACE GRADIENT WEAKENS A LITTLE BIT. SOUTHWEST FLOW ALOFT WILL PREVAIL THROUGH THE SHORT PERIOD AS AN AMPLIFIED TROUGH MOVES SLOWLY ACROSS THE DESSERT SOUTHWEST. HIGH CLOUDS WILL CONTINUE TO STREAM ACROSS THE RIO GRANDE VALLEY AS SOUTHWEST FLOW ALOFT ADVECTS MID LEVEL MOISTURE INTO THE AREA. LOW CLOUDS WILL RETURN AFTER MIDNIGHT BUT NOT EXPECTING FOG TO DEVELOP AT THIS TIME. LOW TEMPERATURES WILL REMAIN IN THE 70S ACROSS THE VALLEY WITH NO CHANCE OF PRECIPITATION EXPECTED. SURFACE GRADIENT BEGINS TO TIGHTEN ONCE AGAIN SATURDAY INCREASING SOUTHEAST WINDS ACROSS THE RGV. CONDITIONS SHOULD BE SIMILAR TO TODAY. HIGHS WILL REMAIN IN THE MID 80S FOR SATURDAY. .LONG TERM /MONDAY THROUGH FRIDAY NIGHT/...BENIGN CONDITIONS ON MONDAY WILL GIVE WAY TO UNSETTLED WEATHER HEADING INTO TUESDAY AND EARLY WEDNESDAY AS A SHORT WAVE TROUGH DIGS SOUTHEAST ACROSS SOUTH TEXAS. A MODERATE ONSHORE FLOW WILL PREVAIL MONDAY AS A FRONT MOVES INTO NORTH TEXAS AND AS AN ACCOMPANYING SHORT WAVE TROUGH MOVES SOUTH ALONG THE SPINE OF THE ROCKIES INTO NORTH AND WEST TEXAS. SHOULD SEE CONVECTION GET GOING IN THE BIG BEND AREA MONDAY NIGHT WITH THE REMNANTS MOVING INTO DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY ON TUESDAY. AS THE SHORT WAVE TROUGH ALOFT APPROACHES...THUNDERSTORMS WILL CONTINUE TUESDAY AND TUESDAY NIGHT AREA WIDE BEFORE CLEARING ON WEDNESDAY. BUMPED UP POPS DURING THIS PERIOD OF UNSETTLED WEATHER BUT THAT WAS THE MAIN CHANGE MADE TO THE INHERITED FORECAST. AFTER WEDNESDAY CONDITIONS WILL IMPROVE FOR THE REST OF THE WEEK AS MID LEVEL RIDGING AND HIGH PRESSURE SET UP SHOP OVER THE AREA. && .MARINE... TONIGHT THROUGH SATURDAY NIGHT...SOUTHEAST WINDS AT AROUND 20 KTS WILL PREVAIL THROUGH THE DAY AND INTO SATURDAY KEEPING CHOPPY CONDITIONS ON THE BAY. SCA CONDITIONS CONTINUES THROUGH THIS EVENING AT THE LAGUNA MADRE. SE WINDS WILL BEGIN TO DECOUPLE LATER THIS EVENING. EXPECT SEAS UP TO 5 FEET TO RETURN SATURDAY AS SURFACE GRADIENT OVER THE AREA STRENGTHENS. NO PRECIPITATION EXPECT THROUGH THE SHORT TERM PERIOD. MONDAY THROUGH WEDNESDAY NIGHT...A SHORT WAVE TROUGH WILL DIG SOUTHEAST INTO SOUTH TEXAS EARLY IN THE WEEK...SENDING A PULSE OF MID LEVEL ENERGY ACROSS THE AREA AND PRODUCING UNSETTLED MARINE CONDITIONS. A SURFACE COLD FRONT WILL MOVE INTO THE COASTAL WATERS ON TUESDAY. THE BEST SHOT AND SHOWER AND THUNDERSTORM ACTIVITY WILL BE TUESDAY AND TUESDAY NIGHT...WITH POTENTIALLY STRONG STORMS FOR THE MARINE ZONES...SOME POSSIBLY SEVERE WITH THE 34 KT WIND CRITERIA. LIGHTNING...RAIN...AND STRONG WINDS WILL PERSIST INTO WEDNESDAY AS THE UPPER TROUGH SWINGS OVERHEAD. CONDITIONS WILL IMPROVE LATE WEDNESDAY. THE MODELS ARE NOT BUILDING WAVE HEIGHTS SIGNIFICANTLY OR SHOWING STRONG WINDS AT THIS POINT SINCE THE FRONT IS NOT OVERPOWERING. THE MAIN THEME IN THIS SCENARIO WILL BE THE UPPER FORCING AND THE LOCALIZED EFFECTS ON THE MARINE WATERS. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 51/67/MARTINEZ
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BROWNSVILLE TX 435 AM CDT SAT MAY 12 2012 TXZ248>257-131100- ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY- INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON- 435 AM CDT SAT MAY 12 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS. .DAY ONE...TODAY AND TONIGHT. ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY. SOME THUNDERSTORMS MAY BE STRONG PRODUCING SMALL HAIL AND GUSTY WINDS. THERE IS A HIGH RISK OF RIP CURRENTS AT THE BEACHES OF SOUTH PADRE ISLAND AND AT BOCA CHICA BEACH. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED. GMZ130-132-135-150-155-170-175-131100- LAGUNA MADRE FROM THE PORT OF BROWNSVILLE TO THE ARROYO COLORADO- LAGUNA MADRE FROM THE ARROYO COLORADO TO 5 NM NORTH OF PORT MANSFIELD TX- LAGUNA MADRE FROM 5 NM NORTH OF PORT MANSFIELD TO BAFFIN BAY TX- COASTAL WATERS FROM PORT MANSFIELD TO THE RIO GRANDE OUT 20 NM- COASTAL WATERS FROM BAFFIN BAY TO PORT MANSFIELD OUT 20 NM- WATERS FROM PORT MANSFIELD TO THE RIO GRANDE EXTENDING FROM 20 TO 60 NM- WATERS FROM BAFFIN BAY TO PORT MANSFIELD EXTENDING FROM 20 TO 60 NM- 435 AM CDT SAT MAY 12 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE GULF OF MEXICO AND THE LAGUNA MADRE. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BROWNSVILLE TX 358 PM CDT SAT MAY 12 2012 TXZ254-122145- INLAND WILLACY- 358 PM CDT SAT MAY 12 2012 ...A STRONG THUNDERSTORM WILL AFFECT RAYMONDVILLE... A THUNDERSTORM...MOVING SOUTHWEST AT 5 MPH...WILL AFFECT YTURRIA... WILLAMAR...RAYMONDVILLE AND LYFORD...UNTIL 445 PM CDT. GUSTY WINDS UP TO 40 MPH WILL OCCUR. FREQUENT CLOUD TO GROUND LIGHTNING IS EXPECTED. IF CAUGHT OUTSIDE...CROUCH DOWN IN A LOW SPOT...AWAY FROM TALL OBJECTS. DIME SIZE HAIL IS EXPECTED. RAINFALL RATES OF 1 INCH PER HOUR ARE EXPECTED. 61
The Brownsville radar (KBRO), 71 km away, was scanning. The volume nearest the first event began at 21:04 UTC.
7 hail, 1 lightning. Local standard time, as filed.
Public reported nickel size hail near Raymondville, about 2 miles east of Highway 77.
Palm Valley resident reported 5 palm trees set on fire by a lightning strike.
The Willacy County Emergency Manager reported quarter size hail near Yturria. The public reported quarter size hail on the north side of Raymondville. Each report was from the same hail core, which moved quickly northeast of town and may have dropped larger hail over rural locations north of the City.
Nickel sized hail was reported at the intersection of 1st St. and Tampico Ave., also on the north side of town, at 434 PM CDT, by the public. Report was relayed to the NWS by a local weather broadcaster.
Public reported quarter size hail near La Feria.
Nickel sized hail was reported by the public on the west side of Harlingen along the Highway 77 and 83 interchange at 515 PM; penny sized hail was reported at the intersection of Harrison and U.S. Highway 77 at 520 PM, with another report of penny sized hail at the same time relayed by amateur radio from the general public in the same area. Continuation of the hail for another five minutes was estimated by radar.
Nickel to quarter size hail reported at Altas Palmas and Highway 83 and quarter size hail along Highway 83 on the west side of Harlingen. Report from spouse of NWS employee that car windshield was broken from the hail.
Cameron County Emergency Manager reported quarter size hail at the intersection of County Road 800 and Rangerville Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2012Every state in 2012This day in weather historyWarnings in Texas, May 2012
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 384557, 384596, 384558, 384560, 384572, 384571, 384574, 384575.