Alert archive / Texas / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 240

May 4, 20129 counties in Oklahoma; 57 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 4, 2012, 3:49 PM CDT for 9 counties in Oklahoma; 57 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 4, 2012, 3:49 PM CDT (20:49 UTC)
Expired
May 4, 2012, 11:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 66 counties

Carter County, OK, Comanche County, OK, Cotton County, OK, Jackson County, OK, Jefferson County, OK, Love County, OK, Murray County, OK, Stephens County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coke County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Crockett County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fisher County, TX, Foard County, TX, Grayson County, TX, Hamilton County, TX, Hardeman County, TX, Haskell County, TX, Hill County, TX, Hood County, TX, Irion County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Kimble County, TX, Knox County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Rockwall County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Sterling County, TX, Sutton County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 45 km from the middle of the area, began a volume at 20:52 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

37 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 4, 4:12 PM CDTSevere Thunderstorm WarningOUNComanche, Jackson, Kiowa, Tillman63 min
May 4, 4:12 PM CDTSevere Thunderstorm WarningSJTThrockmorton18 min
May 4, 4:37 PM CDTSevere Thunderstorm WarningSJTShackelford, Throckmorton38 min
May 4, 4:45 PM CDTSevere Thunderstorm WarningOUNArcher, Clay49 min
May 4, 4:57 PM CDTSevere Thunderstorm WarningFWDYoung18 min
May 4, 5:08 PM CDTSevere Thunderstorm WarningSJTTaylor52 min
May 4, 5:12 PM CDTSevere Thunderstorm WarningSJTShackelford63 min
May 4, 5:40 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Grady, Jefferson, Stephens, Tillman65 min
May 4, 5:45 PM CDTSevere Thunderstorm WarningFWDStephens60 min
May 4, 5:57 PM CDTSevere Thunderstorm WarningSJTCallahan, Taylor63 min
May 4, 6:06 PM CDTSevere Thunderstorm WarningSJTRunnels39 min
May 4, 6:09 PM CDTSevere Thunderstorm WarningFWDJack, Palo Pinto66 min
May 4, 6:11 PM CDTSevere Thunderstorm WarningOUNCotton, Tillman64 min
May 4, 6:15 PM CDTSevere Thunderstorm WarningFWDEastland60 min
May 4, 6:15 PM CDTSevere Thunderstorm WarningSJTCallahan, Shackelford45 min
May 4, 6:33 PM CDTSevere Thunderstorm WarningFWDParker57 min
May 4, 6:49 PM CDTSevere Thunderstorm WarningSJTBrown, Callahan, Coleman41 min
May 4, 6:56 PM CDTSevere Thunderstorm WarningFWDHood64 min
May 4, 7:09 PM CDTSevere Thunderstorm WarningOUNJefferson54 min
May 4, 7:09 PM CDTTornado WarningFWDHood22 min
May 4, 7:11 PM CDTSevere Thunderstorm WarningFWDEastland38 min
May 4, 7:35 PM CDTSevere Thunderstorm WarningSJTBrown, Callahan, Coleman40 min
May 4, 7:44 PM CDTSevere Thunderstorm WarningFWDPalo Pinto, Parker19 min
May 4, 7:54 PM CDTSevere Thunderstorm WarningFWDHood, Johnson, Parker, Somervell, Tarrant66 min
May 4, 8:00 PM CDTSevere Thunderstorm WarningFWDComanche60 min
May 4, 8:02 PM CDTSevere Thunderstorm WarningFWDMontague55 min
May 4, 8:25 PM CDTSevere Thunderstorm WarningFWDErath50 min
May 4, 8:33 PM CDTSevere Thunderstorm WarningFWDBosque, Ellis, Hill, Johnson57 min
May 4, 8:38 PM CDTSevere Thunderstorm WarningFWDCooke67 min
May 4, 9:02 PM CDTSevere Thunderstorm WarningFWDComanche, Mills58 min
May 4, 9:04 PM CDTSevere Thunderstorm WarningFWDEllis26 min
May 4, 9:07 PM CDTSevere Thunderstorm WarningFWDCollin, Cooke, Denton, Grayson52 min
May 4, 9:12 PM CDTSevere Thunderstorm WarningFWDBosque, Hamilton63 min
May 4, 9:32 PM CDTSevere Thunderstorm WarningFWDEllis31 min
May 4, 9:33 PM CDTTornado WarningFWDMills27 min
May 4, 10:02 PM CDTSevere Thunderstorm WarningFWDHamilton28 min
May 4, 10:33 PM CDTSevere Thunderstorm WarningFWDCoryell, Hamilton57 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 8.8 hours before the alert went out and 187 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 12:00Z on 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2222 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 12:00Z on 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.19395878Sfc1 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
2222 J/kg
Mixed-layer CIN
-258 J/kg
Mixed-layer LCL
793 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 4, 2:50 PM CDTMesoscale DiscussionSPCComanche, Cotton, Greer, Harmon, Jackson, Tillman85 min
May 4, 5:30 PM CDTMesoscale DiscussionSPCCotton, Tillman60 min

Nearby

Severe Thunderstorm Watches in Texas, 2012Severe Thunderstorm Watches in Oklahoma, 2012Every severe thunderstorm watch in 2012

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.