Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 579

April 25, 201128 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2011, 6:57 PM CDT for 28 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 25, 2011, 6:57 PM CDT (23:57 UTC)
Expired
Apr 25, 2011, 9:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 28 counties

Anderson County, TX, Angelina County, TX, Bell County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Cherokee County, TX, Falls County, TX, Freestone County, TX, Grimes County, TX, Houston County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Nacogdoches County, TX, Navarro County, TX, Polk County, TX, Robertson County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Travis County, TX, Trinity County, TX, Walker County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 121 km from the middle of the area, began a volume at 23:59 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 12.0 hours before the alert went out and 209 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 2011-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2645 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 2011-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 346 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
2645 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
564 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
346 m²/s²
0-3 km storm-relative helicity
373 m²/s²
Significant tornado parameter
6.1
Supercell composite
21.8

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 24, 7:35 PM CDTMesoscale DiscussionSPCCarson, Gray, Hansford, Hemphill, Hutchinson, Lipscomb and 5 more2 hr
Apr 24, 8:48 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 36 more117 min
Apr 24, 11:25 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Camp, Coke, Coleman and 39 more65 min
Apr 24, 11:43 PM CDTSevere Thunderstorm WatchSPCBosque, Bowie, Camp, Cass, Collin, Comanche and 40 more5 hr
Apr 24, 11:58 PM CDTMesoscale DiscussionSPCHemphill, Lipscomb, Ochiltree92 min
Apr 25, 3:29 AM CDTMesoscale DiscussionSPCBosque, Camp, Collin, Dallas, Delta, Denton and 24 more61 min
Apr 25, 4:41 AM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Collin, Dallas, Delta and 21 more7 hr
Apr 25, 7:23 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Gregg, Harrison, Marion and 3 more97 min
Apr 25, 10:46 AM CDTMesoscale DiscussionSPCAnderson, Bosque, Bowie, Brazos, Camp, Cass and 42 more59 min
Apr 25, 11:00 AM CDTTornado WatchSPCBosque, Bowie, Camp, Cass, Collin, Cooke and 34 more7 hr
Apr 25, 1:28 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Dallas and 30 more92 min
Apr 25, 2:16 PM CDTMesoscale DiscussionSPCAngelina, Bastrop, Bell, Blanco, Brazos, Burleson and 27 more59 min
Apr 25, 2:41 PM CDTTornado WatchSPCAnderson, Angelina, Bastrop, Bell, Blanco, Bosque and 49 more9 hr
Apr 25, 3:22 PM CDTTornado Watch PDSSPCBowie, Camp, Cass, Franklin, Gregg, Harrison and 7 more8 hr
Apr 25, 5:21 PM CDTMesoscale DiscussionSPCBosque, Delta, Ellis, Henderson, Hill, Hopkins and 7 more54 min
Apr 25, 5:24 PM CDTMesoscale DiscussionSPCArmstrong, Carson, Childress, Collingsworth, Donley, Gray and 3 more66 min

Nearby

Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011

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.