A strong unstable air mass developed south of a slow moving frontal boundary near the southern portion of the Texas Hill Country. Scattered severe thunderstorms formed over the northern Brush Country during the afternoon.
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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 CRP wrote it up.
A strong unstable air mass developed south of a slow moving frontal boundary near the southern portion of the Texas Hill Country. Scattered severe thunderstorms formed over the northern Brush Country during the afternoon. The storms moved southeast through the Brush Country into the early evening hours. Wind gusts to 60 mph along with quarter to half dollar sized hail occurred with these storms across the Brush Country.
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 Corpus Christi, TX wrote its last area forecast discussion before the first event at May 20, 12:05 PM CST, 2 hours 39 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Corpus Christi TX 105 PM CDT Sat May 20 2017 .DISCUSSION... Updated for the 18Z Aviation Discussion. && .AVIATION... Seeing a bit more shower activity this afternoon farther inland generally west of ALI toward LRD and COT. But with any additional heating, possibility of thunder exists through the evening hours. There is a weak frontal boundary sagging slowly to the south where additional showers and thunderstorms are expected to develop, leading to extending mention of SHRAs/TSRAs toward VCT this AFTN/EVNG. Some waning in activity will be possible late this evening, but instability and weakening of the cap as the front sags farther may lead to redevelopment of thunder activity late tonight through early Sunday. So have reintroduced VCTS late in the TAF period. VFR CIGs (should reach VFR soon at CRP) are expected to lower overnight to MVFR. Maintained MVFR CIGs through the end of the TAF period mainly as the weak boundary should remain while keeping rain chances in the forecast. Winds through the period are expected to become more E-ly today backing more out of the NE overnight through Sunday. && .PREVIOUS DISCUSSION... /Issued 1111 AM CDT Sat May 20 2017/ DISCUSSION... Severe Thunderstorm Watch 253 now in effect for Bee, Goliad, La Salle, Live Oak, McMullen and Victoria Counties. We're monitoring a storm to the northwest across Uvalde county that has maintained itself through the morning hours and slowly progresses farther south-southeast. As daytime heating continues, CIN values decrease allowing for instability aloft to come into play to further feed into developing showers/storms, especially as the surface boundary across S Central Texas continues to drift farther south. Expecting to see more development heading into the afternoon focusing across the northern Brush Country and spreading farther south and east as the hours go by. Some of these storms may strengthen into strong or even severe thunderstorms, with large hail and damaging winds. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 90 76 89 76 84 / 20 20 50 50 70 Victoria 89 72 87 72 81 / 50 30 50 60 70 Laredo 95 76 92 73 88 / 30 40 50 60 60 Alice 94 75 90 73 86 / 20 30 50 60 70 Rockport 86 77 87 76 85 / 20 20 50 50 70 Cotulla 90 73 88 71 87 / 50 50 40 60 60 Kingsville 92 76 90 74 88 / 20 20 50 60 70 Navy Corpus 84 78 87 76 84 / 10 20 40 50 70 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && CB/85...AVIATION
Hazardous Weather Outlook National Weather Service Corpus Christi TX 1041 AM CDT Sat May 20 2017 GMZ230-235-250-255-270-275-TXZ229>234-239>247-211545- Bays and Waterways from Baffin Bay to Port Aransas- Bays and Waterways from Port Aransas to Port O'Connor- Coastal waters from Baffin Bay to Port Aransas out 20 NM- Coastal waters from Port Aransas to Matagorda Ship Channel out 20 NM-Waters from Baffin Bay to Port Aransas from 20 to 60 NM- Waters from Port Aransas to Matagorda Ship Channel from 20 to 60 NM-La Salle-McMullen-Live Oak-Bee-Goliad-Victoria-Webb-Duval- Jim Wells-Kleberg-Nueces-San Patricio-Aransas-Refugio-Calhoun- 1041 AM CDT Sat May 20 2017 This hazardous weather outlook is for South Texas and the Middle Texas Coastal Waters. .DAY ONE...Today and Tonight Severe Thunderstorm Watch 253 is in effect for the following counties Bee, Goliad, La Salle, Live Oak, McMullen, and Victoria Counties Isolated to scattered thunderstorms expected today from the Brush Country east to the Victoria Crossroads. A few storms may be strong to severe with damaging wind in excess of 60 mph and large hail greater than 1 inch as the primary threat. .DAYS TWO THROUGH SEVEN...Sunday through Friday Scattered thunderstorms are expected Sunday through Tuesday night. There is a slight risk for severe thunderstorms Sunday afternoon and evening, mainly near and north of a Laredo to George West to Yorktown line. Additionally, locally heavy rainfall will be possible Sunday night and Monday. Non-severe thunderstorms are expected Monday through Tuesday night. Brief Small Craft Advisory conditions are possible behind a cold front late Tuesday night and Wednesday over portions of the gulf waters. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed later today or tonight and possibly again Sunday.
Special Weather Statement National Weather Service Corpus Christi TX 248 PM CDT SAT MAY 20 2017 TXZ229-202030- La Salle- 248 PM CDT SAT MAY 20 2017 ...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN LA SALLE COUNTY... At 246 PM CDT, a strong thunderstorm was located near Las Vegas, or 9 miles east of Big Wells, slowly moving to the northeast. Additional strong thunderstorms may also develop to the south of this storm. Winds in excess of 40 mph and half inch hail are possible with these storms. Locations impacted include... Millett and Woodward. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. A severe thunderstorm watch remains in effect until 500 PM CDT for South Texas. LAT...LON 2864 9911 2833 9939 2864 9940 TIME...MOT...LOC 1946Z 235DEG 16KT 2853 9942 Hart
The Laughlin AFB radar (KDFX), 137 km away, was scanning. The volume nearest the first event began at 20:41 UTC.
3 hail, 1 thunderstorm wind. Local standard time, as filed.
Cotulla-La Salle County Airport ASOS measured a gust to 59 MPH.
Storm chaser reported half dollar sized hail on Highway 44 northwest of Freer.
Storm chaser reported quarter sized hail near Freer.
Public reported quarter sized hail in Freer through social media.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Texas in 2017Every state in 2017This day in weather historyWarnings in Texas, May 2017
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: 698160, 698165, 698174, 698176.