Alert archive / Texas / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 240, NWS Fort Worth, TX

May 21, 2017McLennan County, Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at May 21, 2017, 7:32 AM CDT for McLennan County, Texas. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 21, 2017, 7:32 AM CDT (12:32 UTC)
Expired: May 21, 2017, 8:15 AM CDT
In force: 43 min
Issued by: NWS Fort Worth, TX
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County McLennan County, TX

The radar

The Ft Hood radar (KGRK), 94 km from the middle of the area, began a volume at 12:34 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Shreveport, LA (KBAD), launched 12:00Z, 0.5 hours before the alert went out and 341 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 237 J/kg
Mixed-layer CIN: -297 J/kg
Mixed-layer LCL: 779 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 212 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.6

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Fort Worth, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at May 21, 7:08 AM CDT, 24 minutes earlier.

Area forecast discussion, May 21, 7:08 AM CDT, 24 minutes before

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Hazardous weather outlook, May 21, 3:53 AM CDT, 3 hours 39 minutes before

Hazardous Weather Outlook
National Weather Service Fort Worth TX
353 AM CDT Sun May 21 2017

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-220900-
Montague-Cooke-Grayson-Fannin-Lamar-Young-Jack-Wise-Denton-Collin-
Hunt-Delta-Hopkins-Stephens-Palo Pinto-Parker-Tarrant-Dallas-
Rockwall-Kaufman-Van Zandt-Rains-Eastland-Erath-Hood-Somervell-
Johnson-Ellis-Henderson-Comanche-Mills-Hamilton-Bosque-Hill-Navarro-
Freestone-Anderson-Lampasas-Coryell-Bell-McLennan-Falls-Limestone-
Leon-Milam-Robertson-
353 AM CDT Sun May 21 2017

This Hazardous Weather Outlook is for North and Central Texas.

.DAY ONE...Today and Tonight.
Scattered thunderstorms are possible today and tonight with the best
chances south of Interstate 20. A few storms may become strong to
marginally severe with hail and gusty winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.
Thunderstorm chances will continue Monday through Tuesday with the
best storm chances Monday and Monday night. Some strong to
marginally severe storms will be possible with hail and gusty winds.

.SPOTTER INFORMATION STATEMENT...
Widespread spotter activation is not anticipated due to short
duration and marginal strength of the expected storms.

In the hours before

Special weather statement, May 21, 5:40 AM CDT, 1 hour 52 minutes before

Special Weather Statement
National Weather Service Fort Worth TX
540 AM CDT SUN MAY 21 2017

TXZ148-211130-
Anderson TX-
540 AM CDT SUN MAY 21 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN ANDERSON COUNTY
UNTIL 630 AM CDT...

At 539 AM CDT, Doppler radar was tracking a strong thunderstorm near
Grapeland, or 16 miles northwest of Crockett, and another strong
thunderstorm 5 miles east of Elkhart, both moving northeast at 25
mph.

Nickel size hail will be possible with these storms.

Locations impacted include...
Elkhart.

LAT...LON 3159 9528 3154 9565 3153 9566 3194 9544
      3193 9542 3185 9545 3182 9540 3176 9540
      3175 9536 3173 9537 3173 9533 3172 9534
      3171 9531 3167 9528 3163 9529 3162 9526
      3161 9526
TIME...MOT...LOC 1039Z 228DEG 23KT 3153 9556

Carlaw

Special weather statement, May 21, 5:51 AM CDT, 1 hour 41 minutes before

Special Weather Statement
National Weather Service Fort Worth TX
551 AM CDT SUN MAY 21 2017

TXZ148-211130-
Anderson TX-
551 AM CDT SUN MAY 21 2017

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL ANDERSON COUNTY UNTIL 630
AM CDT...

At 551 AM CDT, Doppler radar was tracking a strong thunderstorm 10
miles southwest of Palestine, moving northeast at 25 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Palestine.

LAT...LON 3153 9565 3158 9573 3160 9571 3162 9571
      3165 9574 3164 9576 3161 9575 3160 9576
      3163 9580 3169 9578 3167 9581 3170 9583
      3169 9586 3204 9578 3188 9546
TIME...MOT...LOC 1051Z 224DEG 22KT 3168 9580

Carlaw

Special weather statement, May 21, 5:55 AM CDT, 1 hour 37 minutes before

Special Weather Statement
National Weather Service Fort Worth TX
555 AM CDT SUN MAY 21 2017

TXZ157-211145-
Coryell TX-
555 AM CDT SUN MAY 21 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CORYELL COUNTY UNTIL
645 AM CDT...

At 555 AM CDT, Doppler radar was tracking a strong thunderstorm 11
miles east of Evant, or 13 miles west of Gatesville, moving east at
30 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Gatesville, Fort Gates and South Mountain.

LAT...LON 3143 9804 3153 9804 3168 9767 3158 9760
      3135 9760
TIME...MOT...LOC 1055Z 261DEG 26KT 3148 9795

Carlaw

Local storm report, May 21, 6:38 AM CDT, 54 minutes before

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Special weather statement, May 21, 6:46 AM CDT, 46 minutes before

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Special weather statement, May 21, 7:15 AM CDT, 17 minutes before

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The office that day

Everything else NWS Fort Worth, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 21, 12:11 AM CDT	Special Weather Statement	FWD	Leon	34 min
May 21, 3:38 AM CDT	Special Weather Statement	FWD	Leon	37 min
May 21, 4:25 AM CDT	Special Weather Statement	FWD	Leon	35 min
May 21, 5:03 AM CDT	Special Weather Statement	FWD	Anderson	42 min
May 21, 5:40 AM CDT	Special Weather Statement	FWD	Anderson	50 min
May 21, 5:51 AM CDT	Special Weather Statement	FWD	Anderson	39 min
May 21, 5:55 AM CDT	Special Weather Statement	FWD	Coryell	50 min
May 21, 6:46 AM CDT	Special Weather Statement	FWD	Coryell	29 min
May 21, 7:15 AM CDT	Special Weather Statement	FWD	McLennan	45 min
May 21, 8:11 AM CDT	Severe Thunderstorm Warning	FWD	McLennan	47 min
May 21, 8:15 AM CDT	Special Weather Statement	FWD	Ellis, Johnson	45 min
May 21, 8:50 AM CDT	Special Weather Statement	FWD	Navarro	55 min
May 21, 8:56 AM CDT	Special Weather Statement	FWD	Ellis	34 min
May 21, 9:03 AM CDT	Special Weather Statement	FWD	Henderson	42 min
May 21, 9:16 AM CDT	Special Weather Statement	FWD	Johnson	29 min
May 21, 9:24 AM CDT	Special Weather Statement	FWD	Somervell	66 min
May 21, 9:29 AM CDT	Special Weather Statement	FWD	Henderson	46 min
May 21, 9:36 AM CDT	Special Weather Statement	FWD	Kaufman	39 min
May 21, 9:45 AM CDT	Special Weather Statement	FWD	Van Zandt	30 min
May 21, 9:50 AM CDT	Special Weather Statement	FWD	Navarro	40 min
May 21, 10:40 AM CDT	Special Weather Statement	FWD	Henderson	65 min

Nearby

Severe Thunderstorm Warnings in Texas, 2017 Every severe thunderstorm warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.