As a TUTT low centered itself across the Rio Grande Valley, unusually cold air well above the surface combined with low relative humidity above the clouds base, combined with the afternoon sea breeze to trigger clusters of thunderstorms. A boundary from one of these storms slid south into northern Cameron County, and helped launch an isolated storm that would ultimately cause tens of thousands…
Every event with a place to put it. Tap one for its entry below.
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.
As a TUTT low centered itself across the Rio Grande Valley, unusually cold air well above the surface combined with low relative humidity above the clouds base, combined with the afternoon sea breeze to trigger clusters of thunderstorms. A boundary from one of these storms slid south into northern Cameron County, and helped launch an isolated storm that would ultimately cause tens of thousands in property damage. The storm moved west, and then south, affecting Primera, Palm Valley, and west Harlingen, including Interstate 2. The storm, which pulsed a microburst several times and caused damage along its path.
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 Aug 17, 1:54 PM CST, 3 hours 11 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 254 PM CDT MON AUG 17 2015 .SHORT TERM.../NOW THROUGH TUESDAY NIGHT/...WATER VAPOR IMAGERY SHOWS THE MID TO UPPER LEVEL LOW/TROUGH DRIFT W-SW DEEP MOISTURE AND DEEPENING SOUTHERLY INCREASING ACROSS MUCH OF DEEP SOUTH TEXAS. THE MAJORITY OF TODAY'S CROP OF CONVECTION HAS INITIATED OVER KENEDY COUNTY DRIFTING WHERE THE BEST DIVERGENT FLOW IS OCCURRING. THE STORMS ARE DRIFTING WEST WITH ADDITIONAL CONVECTION BUILDING SOUTH ALONG THE WEAK SEA BREEZE ALONG AND EAST OF INTERSTATE 69E. ISOLATED CONVECTION IS ALSO NOTED OVER WEBB AND NORTHERN ZAPATA COUNTIES WHERE HEATING AND THE PRESENCE OF THE UPPER WEAKNESS IS SUFFICIENT TO LIFT THE LIMITED MOISTURE ACROSS THE FAR WEST. FOR TONIGHT...CONVECTION TO CONTINUE TO DEVELOP ALONG THE SEA BREEZE AND WITHIN THE AREA OF DIFFLUENCE THROUGH AT LEAST UNTIL THE DAYTIME HEATING WANES. WILL MAINTAIN THE 20-30 POPS ACROSS THE NORTH AND WEST AND MOST OF THE CWA. BRIEF DOWNPOURS AND ISOLATED GUSTY WINDS AS SOME DRIER AIR GETS ENTRAINED INTO THE CONVECTION. MODEL PROJECTIONS FOR TUESDAY HAS THE CENTER OF THE UPPER LOW DRIFTING INTO CENTRAL MEXICO BUT THE LARGE CYCLONIC FLOW ASSOCIATED WITH THE MID/UPPER TROUGH DOMINATING SOUTH TEXAS. THE POSITION OF THE LOW LOOKS FAVORABLE TO PLACE THE BEST DIFFLUENCE AREA FARTHER SOUTH POSSIBLY OVER THE LOWER AND MID VALLEY. SUFFICIENT MOISTURE, INSTABILITY AND LIFT FROM HEATING AND WEAK SEA BREEZE (SIMILAR TO DAY) SHOULD BE ENOUGH TO WARRANT LOW CHANCE POPS ACROSS THE LOWER AND MID VALLEY TUESDAY AFTERNOON. THIS IS HIGHER THEN 12Z GFS/MAV AND NAM/MET AS WELL AS THE LATEST ECMWF GUIDANCE VALUES ESPECIALLY AS YOU TRAVEL FARTHER WEST INTO HIDALGO COUNTY. NO BIG CHANGES TO THE TEMPERATURE FORECAST WITH THE UPPER TROUGH IN PLACE AND HEIGHTS AND THICKNESS REMAINING LOWER THEN LAST WEEK. WE WILL CONTINUE TO SEE TEMPERATURES NEAR SEASONAL NORMALS OR JUST A FEW DEGREES HIGHER WHERE RAIN DOES NOT FALL SINCE THE SURFACE SOILS ARE ABNORMAL DRY. OVERNIGHT LOWS TO SEE A SLIGHT INCREASE AS SURFACE WINDS AND ADDED MOISTURE TO LIMIT HEAT ESCAPE. SURFACE WINDS TO BE BUMPED UP A NOTCH WITH THE AFTERNOON HOURS SEEING BREEZY CONDITIONS AS THE GRADIENT TIGHTENS AS A STRONG MID LEVEL TROUGH MOVES INTO THE CENTRAL PLAINS INDUCING PRESSURE FALLS OVER THE CENTRAL AND SOUTHERN PLAINS. && LONG TERM /WEDNESDAY THROUGH SUNDAY/...THE MAIN SYNOPTIC DETAILS WILL CONSIST OF AN H5 WEAKENESS OVERHEAD AND BROAD HIGH PRESSURE OVER THE NORTH AND WEST GULF. THE WEAKNESS WILL REMAIN ALOFT OVERTHE AREA AT LEAST UNTIL A DEEP MID LEVEL TROUGH AND CLOSED UPPER LOW MOVING ACROSS THE NORTHERN PLAINS EXITS EAST... WHEN SOME H5 FILLING ACROSS THE LOWER LATITUDES WILL OCCUR TOWARD THE END OF THE WEEK. THUS...THE THEME OF UNSETTLED WEATHER OVER THE MARINE AREAS...AND DAILY SEA BREEZES...SHOULD CONTINUE TO HOLD MERIT. THAT THOUGHT ISSUPPORTED BY FORECAST AFTERNOON SOUNDING PWATS OF AROUND TWO INCHES OF MAINLY LOWER LEVEL MOISTURE. MAY SEE SOME LOCAL ENHANCEMENT THU AND FRIDAY AS THE WEAKNESS ALOFT OVER THE WESTERN SECTIONS AND NORTHEAST MEXICO REMAINS IN PLAY. INHERITED FORECAST SEEMED TO BE TRACKING AND REALLY ONLY CHANGE MADE WAS TO SLIGHTLY INCREASE POPS THU NIGHT INTO FRIDAY. && .MARINE... NOW THROUGH TUESDAY...SOUTHERLY FLOW HAS RETURNED TO THE WESTERN GULF OF MEXICO AND THE LOWER TEXAS COASTAL WATERS. THIS SOUTHERLY GRADIENT IS EXPECTED TO STRENGTHEN STEADILY BEGINNING TO TONIGHT AND CONTINUING INTO THE LONG TERM. A STRONG LOW PRESSURE MID LEVEL TROUGH TO MOVE INTO THE CENTRAL PLAINS ALLOW FOR PRESSURE TO FALL ACROSS THE SOUTHERN PLAINS AND THE LEE SIDE OF THE SIERRA MADRE. THE LOWER PRESSURE TO COMBINE WITH BROAD SURFACE HIGH PRESSURE OVER THE GULF INCREASING THE SOUTH TO SOUTHEAST WINDS. SEAS TO RESPOND BY TUESDAY AND CONTINUE TO BUILD THROUGH THE END OF THE SHORT TERM. EXERCISE CAUTION OR EVEN SMALL CRAFT ADVISORY CONDITIONS MAY BE INITIATED BY THE OVERNIGHT SHIFT FOR THE LAGUNA MADRE TUESDAY AFTERNOON AND POSSIBLY ACROSS THE GULF WATERS TUESDAY NIGHT MAINLY FOR WINDS IF THE GRADIENT CONTINUES TO STRENGTHEN. WEDNESDAY THROUGH FRIDAY...BROAD HIGH PRESSURE WILL CONTINUE ACROSSTHE NORTH AND NORTHWEST GULF OF MEXICO WEDNESDAY THROUGH FRIDAY...MAINTAINING LIGHT TO MODERATE SOUTHEAST WINDS AND LOW TO MODERATE SEAS. A COMPLICATING FACTOR WILL BE A MID LEVEL STORM SYSTEM AND SHORT WAVE TROUGH SWINGING ACROSS THE NORTHERN PLAINS BY WEDNESDAY. THE SYSTEM WILL RESULT IN PRESSURE FALLS OVER THE SOUTHERN HIGH PLAINS WEDNESDAY...EXTENDING SOUTH INTO WEST TEXAS AND NORTH CENTRAL MEXICO. THE LWR PRESSURE INLAND...WORKING WITH GULF HIGH PRESSURE...WILL TIGHTEN THE PRESSURE GRADIENT OVER THE COAST...RESULTING IN STRONGER WINDS WEDNESDAY INTO THURSDAY... BEFORE HIGH PRESSURE FILLS IN AFTERWARD. GULF WINDS WILL INCREASE INTO THE MID AND UPPER TEENS IN KNOTS...WITH SEAS AT 4 TO 6 FEET OFFSHORE. THUS...SMALL CRAFT EXERCISE CAUTION CONDITIONS WILL BE POSSIBLE. OTHERWISE...MID LEVEL TROUGHING OVER THE WEST GULF AND LOWER TEXAS COAST WILL MAINTAIN INSTABILITY AND KEEP THE POSSIBILITY OF MARINE SHOWERS AND TSTMS GOING THROUGH THE LONG TERM FORECAST. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 79 93 81 93 / 20 30 20 20 BROWNSVILLE 78 93 80 94 / 20 30 20 20 HARLINGEN 77 97 79 97 / 20 30 0 20 MCALLEN 79 100 81 99 / 30 30 0 20 RIO GRANDE CITY 77 101 79 101 / 20 20 0 20 SOUTH PADRE ISLAND 81 87 82 87 / 20 30 20 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 59/54
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BROWNSVILLE TX 425 PM CDT MON AUG 17 2015 TXZ248>257-182130- ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY- INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON- 425 PM CDT MON AUG 17 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF DEEP SOUTH TEXAS. .DAY ONE...TONIGHT ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP AND MOVE ACROSS PORTIONS OF DEEP SOUTH TEXAS TONIGHT...WITH ANY OF THE HEAVIER OR SLOWER-MOVING THUNDERSTORMS PRODUCING PONDING OF WATER ON ROADS AND HIGHWAYS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN ELEVATED RISK OF RIP CURRENTS IS POSSIBLE AT THE BEACHES OF SOUTH PADRE ISLAND AND AT BOCA CHICA BEACH THURSDAY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST TUESDAY THROUGH FRIDAY...WITH ANY OF THE HEAVIER OR SLOWER- MOVING THUNDERSTORMS PRODUCING PONDING OF WATER ON ROAD AND HIGHWAYS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. GMZ130-132-135-150-155-170-175-182130- 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- 425 PM CDT MON AUG 17 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE GULF OF MEXICO AND THE LAGUNA MADRE. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. CASTILLO
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
356 PM CDT MON AUG 17 2015
TXZ254-172115-
INLAND WILLACY TX-
356 PM CDT MON AUG 17 2015
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL WILLACY COUNTY UNTIL 415
PM CDT...
AT 355 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
WILLAMAR...OR 10 MILES SOUTHWEST OF PORT MANSFIELD...MOVING NORTH AT
5 MPH.
DIME SIZE HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.
LOCATIONS IMPACTED INCLUDE...
SAN PERLITA...WILLAMAR...PORFIRIO AND SAN PERLITA HIGH SCHOOL.
LAT...LON 2639 9765 2658 9768 2657 9762 2658 9753
2649 9752 2642 9749
TIME...MOT...LOC 2055Z 164DEG 5KT 2647 9757
BSSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
413 PM CDT MON AUG 17 2015
TXZ254-256-172145-
INLAND WILLACY TX-COASTAL WILLACY TX-
413 PM CDT MON AUG 17 2015
...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL WILLACY COUNTY
UNTIL 445 PM CDT...
AT 411 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
SAN PERLITA...OR 8 MILES SOUTHWEST OF PORT MANSFIELD...MOVING NORTH
AT 5 MPH.
NICKEL SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM. RAINFALL AMOUNTS OF 1 TO 2 INCHES CAN BE EXPECTED WITHIN
A VERY SHORT PERIOD OF TIME WITH THIS STORM.
LOCATIONS IMPACTED INCLUDE...
SAN PERLITA AND SAN PERLITA HIGH SCHOOL.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.
&&
LAT...LON 2649 9746 2649 9747 2646 9747 2646 9748
2645 9747 2638 9749 2645 9766 2659 9762
2659 9744
TIME...MOT...LOC 2111Z 200DEG 6KT 2650 9755
BSSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
446 PM CDT MON AUG 17 2015
TXZ254-256-172215-
INLAND WILLACY TX-COASTAL WILLACY TX-
446 PM CDT MON AUG 17 2015
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL WILLACY COUNTY UNTIL 515
PM CDT...
AT 445 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7
MILES SOUTHWEST OF PORT MANSFIELD CHAMBER OF COMMERCE...OR 7 MILES
SOUTHWEST OF PORT MANSFIELD...MOVING EAST AT 10 MPH.
WINDS IN EXCESS OF 40 MPH AND RAINFALL RATES OF 1 TO 2 INCHES PER
HOUR WILL BE POSSIBLE WITH THIS STORM. RADAR ESTIMATES OF 2 TO 3
INCHES OF RAINFALL HAVE FALLEN WITH THIS STORM.
THIS STORM WILL REMAIN OVER MAINLY RURAL AREAS OF CENTRAL WILLACY
COUNTY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.
&&
LAT...LON 2644 9744 2644 9743 2642 9742 2640 9745
2641 9743 2641 9742 2636 9748 2639 9759
2656 9751 2651 9742 2648 9745 2649 9741
2647 9742 2645 9746 2644 9745 2646 9742
2647 9740
TIME...MOT...LOC 2145Z 290DEG 7KT 2645 9748
BSSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BROWNSVILLE TX 515 PM CDT MON AUG 17 2015 TXZ254-255-172300- INLAND WILLACY TX-INLAND CAMERON TX- 515 PM CDT MON AUG 17 2015 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CAMERON AND SOUTHWESTERN WILLACY COUNTIES UNTIL 600 PM CDT... AT 515 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR VALLEY INTERNATIONAL AIRPORT...OR NEAR RIO HONDO...MOVING SOUTHWEST AT 10 MPH. NICKEL SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... HARLINGEN...RIO HONDO...PALM VALLEY...SEBASTIAN...PRIMERA...COMBES... HARLIGEN MUNICIPAL GOLF COURSE...VALLEY INTERNATIONAL AIRPORT...TEXAS STATE TECHNICAL COLLEGE HARLINGEN AND HARLINGEN SOCCER COMPLEX. PRECAUTIONARY/PREPAREDNESS ACTIONS... TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD TO MINOR RURAL FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS. FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE SHELTER INSIDE A BUILDING OR VEHICLE. THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. && LAT...LON 2613 9777 2639 9785 2641 9757 2624 9751 TIME...MOT...LOC 2215Z 074DEG 7KT 2629 9765 CASTILLO
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
555 PM CDT MON AUG 17 2015
TXZ255-172345-
INLAND CAMERON TX-
555 PM CDT MON AUG 17 2015
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CAMERON COUNTY UNTIL
645 PM CDT...
AT 555 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
PRIMERA...OR OVER PALM VALLEY...MOVING SOUTHWEST AT 15 MPH.
NICKEL SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.
LOCATIONS IMPACTED INCLUDE...
HARLINGEN...LA FERIA...SANTA ROSA...RIO HONDO...PALM VALLEY...LOS
INDIOS...RANGERVILLE...SANTA MARIA...PRIMERA AND COMBES.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO MINOR RURAL FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.
THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.
&&
LAT...LON 2603 9779 2605 9779 2606 9780 2606 9781
2605 9781 2606 9782 2605 9784 2607 9786
2628 9786 2633 9777 2630 9754 2627 9751
2603 9776 2605 9777 2604 9778 2604 9777
2603 9778
TIME...MOT...LOC 2255Z 049DEG 16KT 2622 9775
CASTILLOThe Brownsville radar (KBRO), 47 km away, was scanning. The volume nearest the first event began at 23:03 UTC.
2 thunderstorm wind. Local standard time, as filed.
Microburst produced 60 mph winds that removed the roof from an old outbuilding roof, removed a new tin roof from an outdoor shed, as well as broken numerous tree limbs from mesquite, cottonwood, sycamore, and poplar trees.
Microburst produced 60 to 65 mph winds that flipped an unanchored Gulfstream trailer, partialy removed the roof at an auto dealershpi on Altas Palmas Road, knocked down telephone poles, as well as broken hundred of tree limbs from mesquite, cottonwood, sycamore, and poplar trees, two of which fell onto a residence and damaged the roof.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2015Every state in 2015This day in weather historyWarnings in Texas, August 2015
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: 600732, 600733.