Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 455, NWS Fort Worth, TX

September 21, 20094 counties in Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at Sep 21, 2009, 7:18 PM CDT for 4 counties in Texas. It was in force for 57 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
Sep 21, 2009, 7:18 PM CDT (00:18 UTC)
Expired
Sep 21, 2009, 8:15 PM CDT
In force
57 min
Issued by
NWS Fort Worth, TX
Area
Storm-based polygon

Counties Hood County, TX, Johnson County, TX, Parker County, TX, Tarrant County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 25 km from the middle of the area, began a volume at 00:21 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 21, 4:29 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 0.3 hours before the alert went out and 38 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-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2009-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2664 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2009-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
2664 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1499 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
190 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 Sep 21, 5:33 PM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Sep 21, 5:33 PM CDT, 1 hour 45 minutes before
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Hazardous weather outlook, Sep 21, 3:18 PM CDT, 4 hours before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FORT WORTH TX
318 PM CDT MON SEP 21 2009

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-221145-
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-
318 PM CDT MON SEP 21 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR A BOWIE TO BRECKENRIDGE
LINE LATE THIS AFTERNOON...AND THEN BECOME MORE NUMEROUS WHILE
MOVING SOUTHEAST DURING THE EVENING AND OVERNIGHT HOURS AS A COLD
FRONT MOVES THROUGH THE OUTLOOK AREA. ANY STORMS THAT DEVELOP THIS
AFTERNOON THROUGH THE OVERNIGHT HOURS WILL BE CAPABLE OF PRODUCING
DAMAGING WINDS IN EXCESS OF 60 MPH AND LARGE HAIL.

IN ADDITION TO ANY SEVERE WEATHER...HEAVY RAINFALL WILL BE
POSSIBLE AS THE FRONT MOVES THROUGH LEADING TO FLASH FLOODING. A
FLASH FLOOD WATCH IS IN EFFECT FOR AREAS NORTH AND EAST OF A
GAINESVILLE TO MERIDIAN TO ATHENS LINE THROUGH TONIGHT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

SHOWERS AND THUNDERSTORMS WILL CONTINUE MAINLY ACROSS THE
SOUTHEAST HALF OF NORTH TEXAS INTO TUESDAY. HEAVY RAINFALL WILL BE
THE MAIN THREAT DURING THIS TIME.

THE CHANCE FOR THUNDERSTORMS WILL CONTINUE FOR ALL OF NORTH TEXAS
THURSDAY AND FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY LATE THIS AFTERNOON AND INTO THE
EVENING HOURS FOR AREAS GENERALLY ALONG AND NORTH OF INTERSTATE
20. SPOTTER ACTIVATION MAY BE NEEDED ACROSS ALL OF NORTH TEXAS
DURING THE OVERNIGHT HOURS.

CAVANAUGH

In the hours before

Special weather statement, Sep 21, 6:49 PM CDT, 29 minutes before
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Special weather statement, Sep 21, 6:53 PM CDT, 25 minutes before
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Local storm report, Sep 21, 6:59 PM CDT, 19 minutes before
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Special weather statement, Sep 21, 7:03 PM CDT, 15 minutes before
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Local storm report, Sep 21, 7:05 PM CDT, 13 minutes before
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Special weather statement, Sep 21, 7:15 PM CDT, 3 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Sep 21, 7:03 PM CDTSpecial Weather StatementFWDErath27 min
Sep 21, 7:15 PM CDTSpecial Weather StatementFWDHood30 min
Sep 21, 7:20 PM CDTSevere Thunderstorm WarningFWDComanche, Erath70 min
Sep 21, 7:38 PM CDTSpecial Weather StatementFWDPalo Pinto37 min
Sep 21, 8:05 PM CDTAreal Flood AdvisoryFWDJohnson, Tarrant3 hr
Sep 21, 8:09 PM CDTSpecial Weather StatementFWDHill36 min
Sep 21, 8:12 PM CDTSpecial Weather StatementFWDDallas33 min
Sep 21, 8:16 PM CDTSevere Thunderstorm WarningFWDDallas, Ellis, Johnson, Tarrant59 min
Sep 21, 8:23 PM CDTAreal Flood AdvisoryFWDErath3 hr
Sep 21, 8:24 PM CDTSpecial Weather StatementFWDCollin36 min
Sep 21, 8:28 PM CDTSevere Thunderstorm WarningFWDErath62 min
Sep 21, 8:29 PM CDTSpecial Weather StatementFWDMills31 min
Sep 21, 8:33 PM CDTAreal Flood AdvisoryFWDHood, Somervell2 hr
Sep 21, 8:54 PM CDTSevere Thunderstorm WarningFWDHamilton, Mills66 min
Sep 21, 8:55 PM CDTFlash Flood WarningFWDJohnson3 hr
Sep 21, 8:56 PM CDTSpecial Weather StatementFWDDallas, Rockwall34 min
Sep 21, 8:59 PM CDTAreal Flood AdvisoryFWDDallas, Ellis2 hr
Sep 21, 8:59 PM CDTFlash Flood WarningFWDErath3 hr
Sep 21, 9:03 PM CDTSpecial Weather StatementFWDHill27 min
Sep 21, 9:13 PM CDTSevere Thunderstorm WarningFWDBosque, Hamilton62 min
Sep 21, 9:15 PM CDTSpecial Weather StatementFWDEllis, Hill, Kaufman, Rockwall30 min
Sep 21, 9:21 PM CDTSevere Thunderstorm WarningFWDEllis, Hill, Johnson, Navarro54 min
Sep 21, 9:34 PM CDTAreal Flood AdvisoryFWDBosque, Hill3 hr
Sep 21, 9:53 PM CDTSevere Thunderstorm WarningFWDBosque, Coryell, Hamilton, McLennan67 min
Sep 21, 9:59 PM CDTSpecial Weather StatementFWDHenderson, Kaufman, Rains, Van Zandt31 min
Sep 21, 10:02 PM CDTSpecial Weather StatementFWDLampasas28 min
Sep 21, 10:20 PM CDTSpecial Weather StatementFWDHill, McLennan25 min
Sep 21, 10:27 PM CDTSpecial Weather StatementFWDFannin, Lamar33 min
Sep 21, 10:32 PM CDTAreal Flood AdvisoryFWDMills3 hr
Sep 21, 11:12 PM CDTSpecial Weather StatementFWDLamar33 min
Sep 22, 12:10 AM CDTAreal Flood AdvisoryFWDCoryell, Lampasas2 hr
Sep 22, 1:08 AM CDTSpecial Weather StatementFWDBell37 min

Nearby

Severe Thunderstorm Warnings in Texas, 2009Every severe thunderstorm warning in 2009

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.