Convergence ahead of an approaching front combined with ample Gulf moisture led to the development of thunderstorms early on the morning of September 30th. Gusty winds accompanied some of these storms, a few of which became severe.
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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.
Convergence ahead of an approaching front combined with ample Gulf moisture led to the development of thunderstorms early on the morning of September 30th. Gusty winds accompanied some of these storms, a few of which became severe. During this event, a severe storm impacted the Brownsville airport, which reported a wind gust to 52 knots/60 mph.
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 Sep 30, 3:18 AM CST, 1 hour 19 minutes earlier.
Area Forecast Discussion National Weather Service Brownsville TX 418 AM CDT Thu Sep 30 2021 .SHORT TERM (Now through Friday): Unsettled weather will prevail through the short term as a shortwave ejects from the 500mb low over the Four Corners region. This feature in combination with an upper level jet over northern Mexico into central Texas, deep tropical moisture (PWATS between 1.8 to 2.2 inches), and daytime heating, will support scattered convection today. Brownsville radar currently indicate isolated to scattered activity across the lower Texas coastal waters. The latest HRRR model suggests that most of the convection today should remain near the coast. Therefore, the best rain chances are expected across the eastern portions of the CWA and over the Gulf waters. Better rain chances are expected on Friday as the 500mb low moves farther eastward. Will continue to lean towards an NBM/CONSALL blend as the NBM pops appear a little over done. Temperatures will remain slightly above normal through the period, with heat indices near 105 to 110 degrees this afternoon. .LONG TERM (Friday Night through Wednesday): Mid-level low pressure migrating east from the Four Corners area to the Upper Mississippi Valley will be the driving force for scattered to numerous showers and thunderstorms through a majority of the period. Drier conditions, featuring little to no chance of rain, will occur for Tuesday and Wednesday as the 500 mb flow shifts from out of the northwest to north in the wake of the low. Near to slightly above normal temperatures will also occur due to the sustained chance of rain and the rapid shortening of days as the march into Autumn continues. && .MARINE (Now through Friday): Buoy 42020 reported south winds around 16 knots gusting to around 19 knots with seas slightly over 4.6 feet with a period of 7 seconds at 300 CDT/800 UTC. A slightly enhanced pressure gradient will support moderate southeast winds and moderate seas along the lower Texas coast through the period. Winds and seas will likely be higher due to showers and thunderstorms across the coastal waters today through Friday. Friday Night through Wednesday: Favorable marine conditions are expected during the period with light to moderate winds and low to moderate seas. Small Craft Exercise Caution and Small Craft Advisory are not likely to be needed. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 90 76 88 76 / 50 40 50 20 BROWNSVILLE 93 77 91 77 / 50 30 60 30 HARLINGEN 92 75 90 75 / 50 30 60 30 MCALLEN 94 76 90 75 / 40 30 60 30 RIO GRANDE CITY 99 75 93 74 / 30 30 60 40 SOUTH PADRE ISLAND 86 80 86 81 / 50 50 50 30 && .BRO WATCHES/WARNINGS/ADVISORIES...None. && This product is also available on the web at: https://weather.gov/rgv Short Term...Caceres-63 Long Term/Upper Air...Tomaselli-66
Hazardous Weather Outlook National Weather Service Brownsville TX 449 AM CDT Thu Sep 30 2021 TXZ248>257-351-353-011000- Zapata-Jim Hogg-Brooks-Inland Kenedy-Starr-Southern Hidalgo- Inland Willacy-Inland Cameron-Coastal Willacy-Coastal Cameron- Coastal Kenedy-Northern Hidalgo- 449 AM CDT Thu Sep 30 2021 This Hazardous Weather Outlook is for portions of Deep South Texas. .DAY ONE...Today and Tonight There is a Moderate Risk of rip currents at the beaches of South Padre Island and at Boca Chica Beach. Scattered showers and thunderstorms are expected today. Locally heavy rainfall, producing nuisance flooding in low-lying and poorly-draining areas, is possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday An elevated risk of rip currents is possible at the beaches of South Padre Island and at Boca Chica Beach Friday through Monday. Scattered to numerous showers and thunderstorms are forecast through the period. Locally heavy rainfall, producing nuisance flooding in low-lying and poorly-draining areas, is possible. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. GMZ130-132-135-150-155-170-175-011000- 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- 449 AM CDT Thu Sep 30 2021 This Hazardous Weather Outlook is for portions of 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...Friday through Wednesday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The Brownsville radar (KBRO), 1 km away, was scanning. The volume nearest the first event began at 10:37 UTC.
1 thunderstorm wind. Local standard time, as filed.
The Brownsville/South Padre Island International Airport recorded a wind gust to 52 knots/60 mph as severe thunderstorms moved through the area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2021Every state in 2021This day in weather historyWarnings in Texas, September 2021
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: 978556.