Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 84, NWS Fort Worth, TX

April 12, 2009Collin County, Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at Apr 12, 2009, 11:43 PM CDT for Collin County, Texas. It was in force for 17 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: Apr 12, 2009, 11:43 PM CDT (04:43 UTC)
Expired: Apr 13, 2009, 12:00 AM CDT
In force: 17 min
Issued by: NWS Fort Worth, TX
Area: Storm-based polygon

County Collin County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 97 km from the middle of the area, began a volume at 04:43 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

Fort Worth, TX (KFWD), launched 00:00Z, 4.7 hours before the alert went out and 78 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: 784 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 947 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 161 m²/s²
0-3 km storm-relative helicity: 201 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 3.7

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 Apr 12, 7:48 PM CDT, 3 hours 55 minutes earlier.

Area forecast discussion, Apr 12, 7:48 PM CDT, 3 hours 55 minutes before

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Hazardous weather outlook, Apr 12, 9:09 PM CDT, 2 hours 34 minutes before

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In the hours before

Special weather statement, Apr 12, 9:19 PM CDT, 2 hours 24 minutes before

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Local storm report, Apr 12, 9:39 PM CDT, 2 hours 4 minutes before

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Special weather statement, Apr 12, 10:38 PM CDT, 1 hour 5 minutes before

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Local storm report, Apr 12, 10:52 PM CDT, 51 minutes before

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Local storm report, Apr 12, 11:14 PM CDT, 29 minutes before

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Local storm report, Apr 12, 11:39 PM CDT, 4 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
Apr 12, 7:15 PM CDT	Tornado Warning	FWD	Montague	30 min
Apr 12, 7:28 PM CDT	Severe Thunderstorm Warning	FWD	Cooke, Montague	62 min
Apr 12, 8:21 PM CDT	Severe Thunderstorm Warning	FWD	Montague	54 min
Apr 12, 8:26 PM CDT	Severe Thunderstorm Warning	FWD	Cooke, Grayson	64 min
Apr 12, 9:14 PM CDT	Severe Thunderstorm Warning	FWD	Cooke, Montague	61 min
Apr 12, 9:19 PM CDT	Special Weather Statement	FWD	Fannin	26 min
Apr 12, 10:13 PM CDT	Severe Thunderstorm Warning	FWD	Cooke, Grayson	62 min
Apr 12, 10:38 PM CDT	Special Weather Statement	FWD	Denton	37 min
Apr 12, 10:44 PM CDT	Severe Thunderstorm Warning	FWD	Collin, Denton, Grayson	61 min
Apr 12, 11:56 PM CDT	Special Weather Statement	FWD	Fannin	34 min
Apr 13, 12:16 AM CDT	Special Weather Statement	FWD	Lamar	29 min
Apr 13, 12:29 AM CDT	Special Weather Statement	FWD	Delta	31 min
Apr 13, 12:58 AM CDT	Special Weather Statement	FWD	Delta	32 min
Apr 13, 1:34 AM CDT	Special Weather Statement	FWD	Hopkins	26 min
Apr 13, 2:01 AM CDT	Special Weather Statement	FWD	Delta	29 min

Nearby

Severe Thunderstorm Warnings in Texas, 2009 Every 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.