Alert archive / Texas / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 548

July 4, 200925 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Jul 4, 2009, 3:07 PM CDT for 25 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 2009, 3:07 PM CDT (20:07 UTC)
Expired
Jul 4, 2009, 8:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
70 kt
All 25 counties

Borden County, TX, Briscoe County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Foard County, TX, Gaines County, TX, Garza County, TX, Hall County, TX, Hardeman County, TX, Kent County, TX, King County, TX, Knox County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Scurry County, TX, Stonewall County, TX, Terry County, TX, Wheeler County, TX

The radar

The Lubbock radar (KLBB), 86 km from the middle of the area, began a volume at 20:07 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 4, 6:23 PM CDTSevere Thunderstorm WarningLUBCottle, King24 min
Jul 4, 6:32 PM CDTSevere Thunderstorm WarningOUNFoard, Knox58 min
Jul 4, 7:19 PM CDTSevere Thunderstorm WarningAMAArmstrong, Donley56 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

Midland Regional, TX (KMAF), launched 12:00Z, 8.1 hours before the alert went out and 265 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, Midland Regional, TX at 12:00Z on 2009-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 598 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, Midland Regional, TX at 12:00Z on 2009-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 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
598 J/kg
Mixed-layer CIN
-195 J/kg
Mixed-layer LCL
1507 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
202 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
Jul 4, 11:52 AM CDTMesoscale DiscussionSPCLeFlore, Sequoyah53 min
Jul 4, 12:25 PM CDTSevere Thunderstorm WatchSPCHaskell, Latimer, LeFlore, McIntosh, Pittsburg, Pushmataha and 1 more8 hr
Jul 4, 12:45 PM CDTSevere Thunderstorm WatchSPCAtoka, Beckham, Bryan, Caddo, Canadian, Carter and 25 more7 hr
Jul 4, 2:46 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Kiowa59 min
Jul 4, 3:36 PM CDTMesoscale DiscussionSPCAtoka, Beckham, Caddo, Carter, Coal, Comanche and 16 more54 min
Jul 4, 6:20 PM CDTMesoscale DiscussionSPCHaskell, Latimer, LeFlore, Pittsburg, Pushmataha, Sequoyah55 min
Jul 4, 6:29 PM CDTMesoscale DiscussionSPCGreer, Harmon, Jackson, Tillman61 min
Jul 4, 6:57 PM CDTMesoscale DiscussionSPCAtoka, Beckham, Bryan, Caddo, Canadian, Carter and 26 more63 min

Nearby

Severe Thunderstorm Watches in Texas, 2009Every severe thunderstorm watch 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.