Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 449

April 12, 200955 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2009, 3:55 AM CDT for 55 counties in Texas. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2009, 3:55 AM CDT (08:55 UTC)
Expired
Apr 12, 2009, 5:30 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 55 counties

Atascosa County, TX, Austin County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Bosque County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Colorado County, TX, Comal County, TX, Comanche County, TX, Coryell County, TX, DeWitt County, TX, Edwards County, TX, Erath County, TX, Fayette County, TX, Fort Bend County, TX, Gillespie County, TX, Gonzales County, TX, Grimes County, TX, Guadalupe County, TX, Hamilton County, TX, Hays County, TX, Hood County, TX, Johnson County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Lampasas County, TX, Lavaca County, TX, Lee County, TX, Llano County, TX, Mason County, TX, Medina County, TX, Milam County, TX, Mills County, TX, Palo Pinto County, TX, Parker County, TX, Real County, TX, Robertson County, TX, San Saba County, TX, Somervell County, TX, Tarrant County, TX, Travis County, TX, Uvalde County, TX, Waller County, TX, Washington County, TX, Williamson County, TX, Wilson County, TX

The radar

The Ft Hood radar (KGRK), 66 km from the middle of the area, began a volume at 08:56 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, 8.9 hours before the alert went out and 192 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 2009-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2009-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 158 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1736 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
304 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 11, 7:41 PM CDTSevere Thunderstorm WatchSPCCallahan, Coke, Coleman, Concho, Crockett, Fisher and 14 more5 hr
Apr 11, 9:09 PM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Clay, Coke and 30 more96 min
Apr 11, 11:44 PM CDTMesoscale DiscussionSPCBrown, Callahan, Clay, Coleman, Comanche, Concho and 22 more91 min
Apr 12, 12:39 AM CDTSevere Thunderstorm WatchSPCBandera, Brown, Callahan, Coke, Coleman, Comanche and 38 more4 hr
Apr 12, 4:37 AM CDTMesoscale DiscussionSPCBrazoria, Chambers, Fort Bend, Hardin, Harris, Jasper and 8 more83 min
Apr 12, 7:39 AM CDTMesoscale DiscussionSPCBrazoria, Chambers, Galveston, Hardin, Harris, Jasper and 8 more66 min
Apr 12, 7:58 AM CDTTornado WatchSPCBrazoria, Chambers, Fort Bend, Galveston, Hardin, Harris and 9 more8 hr
Apr 12, 9:19 AM CDTMesoscale DiscussionSPCNacogdoches, Panola, Sabine, San Augustine, Shelby56 min
Apr 12, 9:30 AM CDTSevere Thunderstorm WatchSPCAngelina, Bowie, Cass, Gregg, Harrison, Marion and 6 more7 hr
Apr 12, 10:53 AM CDTMesoscale DiscussionSPCChambers, Galveston, Hardin, Harris, Jefferson, Liberty and 2 more2 hr
Apr 12, 12:00 PM CDTMesoscale DiscussionSPCSabine90 min
Apr 12, 2:24 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Foard, Hardeman, Jack and 7 more96 min
Apr 12, 5:20 PM CDTMesoscale DiscussionSPCClay, Collin, Cooke, Denton, Grayson, Jack and 5 more55 min

Nearby

Mesoscale Discussions in Texas, 2009Every mesoscale discussion 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.