Multiple discrete supercells resulted in scattered large hail reports that spread from the Rio Grande Plains and Brush Country into the upper Valley during the late afternoon of May 13th. The individual cells merged into a mini thunderstorm complex by early evening while moving into the lower Valley, causing minor wind damage in Cameron County.
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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.
Multiple discrete supercells resulted in scattered large hail reports that spread from the Rio Grande Plains and Brush Country into the upper Valley during the late afternoon of May 13th. The individual cells merged into a mini thunderstorm complex by early evening while moving into the lower Valley, causing minor wind damage in Cameron County. The cells moved into the Laguna Madre and immediate nearshore waters east of Cameron County soon after.
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 13, 2:20 PM CST, 2 hours 30 minutes earlier.
Area Forecast Discussion National Weather Service Brownsville TX 320 PM CDT Mon May 13 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Tuesday night) Issued at 315 PM CDT Mon May 13 2024 Key Messages: -Hot temperatures today with a Heat Advisory until 7 PM. -Strong to severe storms will be possible later tonight. First up, let's talk heat. Southerly flow and 850mb temperatures of 23C-25C will allow for temperatures this afternoon to reach mid 90s. The hot temperatures combined with high humidity will make "feels like" reach the triple digits. We currently have a Heat Advisory out until 7 PM CDT for inland Kenedy, inland Willacy, inland Cameron and Hidalgo counties. Heat indices could reach 114 degrees. A weak cold front will move through Deep South Texas on Tuesday which will help keep temperatures a few degrees cooler. With that said, its still going to be hot with highs in the 90s for most of the region. Humidity levels will not be quite as high, so while heat indices are still expected to reach the triple digits (mainly along the river) we are not looking at Heat Advisory conditions for Tuesday. Now, let's talk rain and thunderstorms. We had a round of scattered rain showers and thunderstorms this morning which have all moved out of the area. As we head into later this afternoon into this evening we could get another round of thunderstorms. This activity has the potential to be more robust, thanks to building instability through this afternoon. CAMs models are beginning to come into better agreement with a line of thunderstorms over the CRP CWA and moving southeast through the afternoon and begin to push into the northern Ranchlands as early as 22z. These storms will continue to move southeast through the evening. Some of this activity may be strong to severe. Main threats will be large hail, with CAPE values across the CWA exceeding 3000 J/kg and lapse rates around 7.5C, and high wind gusts in excess of 60 mph. Brief heavy rainfall and frequent cloud to ground lighting will also be possible with this activity. The SPC has portions of Kenedy, Brooks and Jim Hogg counties in a SLIGHT risk for severe weather (2 out 5) and the remainder of the CWA in a MARGINAL risk (1 out of 5) of severe weather. This activity should move out of the region by around midnight. && .LONG TERM... (Wednesday through next Monday) Issued at 315 PM CDT Mon May 13 2024 The upper-level flow over South Texas looks to be generally south westerly for the start of the long term period. An upper level trough looks to move through the region Friday and Saturday, making way for an upper-level ridge to build into the area near the end of the period. A couple of shortwaves moving through the upper-level flow could enhance forcing over Deep South Texas Wednesday, Thursday, and Friday Afternoons. At the surface, easterly winds are expected to shift southeasterly Wednesday, transporting additional moisture and warmer air to the region. A surface low looks to develop over North Texas on Friday, with a cold front stretching southwesterly across Central Texas. This cold front is expected to drop southeast through the day Friday, possibly reaching Deep South Texas Friday afternoon. This cold front looks to be fairly weak by the time it reaches Deep South Texas, and will likely only reduce temperatures a couple of degrees. Winds look to briefly shift northeasterly behind the front Friday evening, before shifting back to the southeast by Saturday afternoon, allowing warmer air and additional moisture to mover into the area through the remainder of the period. Rain chances through the period have trended downwards with the latest guidance runs. The best chance for rain looks to be Friday, ahead of the cold front, but that is only about a 10-20% chance. The primary threat looks to be heat, with heat index values forecast to reach 111-115 Thursday and Friday afternoons for the eastern two thirds of the CWA. Heat Advisories will likely be needed both days. Additional heat advisories may be needed for the eastern counties Saturday and Sunday, though conditions look to be more borderline. && .AVIATION... (18Z TAFS) Issued at 1220 PM CDT Mon May 13 2024 VFR conditions will prevail at HRL and MFE this afternoon with MVFR at BRO. Later this evening we are expecting a line of showers and thunderstorms to move through the region. The best timing for this activity will be between 00z and 06z. At this time MVFR and potentially brief periods of IFR are possible at MFE, HRL and BRO. Along with the lowered visibilities the strongest storms will be capable of wind gusts in excess of 40kts, and 1 inch or greater hail. Activity will move out overnight with MVFR ceiling prevailing overnight. && .MARINE... Issued at 315 PM CDT Mon May 13 2024 Tonight through Tuesday night..Generally favorable conditions are expected on the waters off the lower Texas coast through much of the forecast. The caveat will be later this afternoon into tonight as a line of strong to possibly severe thunderstorms moves moves southeast. This activity could produce large hail and strong winds will lead to localized hazardous marine conditions. The best timing for the potential for severe weather will be from 22z to 00z. Showers and storms exit the region by daybreak with a cold front moving southward through the day on Tuesday. Wednesday through next Monday...High pressure across the Gulf will generally keep winds and seas light to moderate through the period. The exception looks to be Wednesday and Thursday afternoons, where an upper-level shortwave looks to enhance surface low pressure over northern Mexico, strengthening pressure gradients along the coast, and briefly increasing wind speeds. Small Craft Should Exercise Caution headlines will likely be needed both afternoons. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 78 92 76 91 / 20 10 0 10 HARLINGEN 75 92 73 93 / 20 10 0 10 MCALLEN 77 96 76 95 / 20 10 0 10 RIO GRANDE CITY 75 97 74 96 / 10 10 0 10 SOUTH PADRE ISLAND 79 84 78 84 / 20 10 0 0 BAYVIEW/PORT ISABEL 77 87 75 89 / 20 10 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory until 7 PM CDT this evening for TXZ251-253>255-353. GM...None. && SHORT TERM...68-McGinnis LONG TERM....60-BE AVIATION...68
The Corpus Christi radar (KCRP), 206 km away, was scanning. The volume nearest the first event began at 22:51 UTC.
8 hail, 2 thunderstorm wind. Local standard time, as filed.
Baseball size hail was reported in San Ygnacio, related by the Zapata County Sheriff's office.
Baseball size hail was reported between 2 and 3 miles southeast of McCook. No damage was reported at the time.
Quarter size hail was reported.
Golfball size hail was reported around 2 miles north of McCook by the public.
Half dollar size hail was reported along FM 755 north of town. Report received via the internet.
Golfball size hail was reported along FM 490 near Faysville.
Quarter size hail was reported just north of Rio Grande City, via web report.
Nickel to quarter size hail was reported. This was estimated by a resident and by video with a small cell behind earlier cells near Rio Grande City.
Bayview recorded a peak wind gust of 59 mph.
At least 3 power poles were reported down along and east of I-69E between Rancho Viejo and Olmito.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2024Every state in 2024This day in weather historyWarnings in Texas, May 2024
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: 1167175, 1167176, 1167177, 1167178, 1167179, 1167180, 1167181, 1167182, 1167174, 1167173.