Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 747

May 11, 201118 counties in Arkansas; 26 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 7:43 PM CDT for 18 counties in Arkansas; 26 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
May 11, 2011, 7:43 PM CDT (00:43 UTC)
Expired
May 11, 2011, 8:45 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 44 counties

Clark County, AR, Conway County, AR, Faulkner County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Johnson County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Perry County, AR, Pike County, AR, Pope County, AR, Saline County, AR, Yell County, AR, Anderson County, TX, Bell County, TX, Blanco County, TX, Bowie County, TX, Burnet County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Marion County, TX, Milam County, TX, Morris County, TX, Robertson County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Williamson County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 161 km from the middle of the area, began a volume at 00:44 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, 0.7 hours before the alert went out and 164 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 2011-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 26 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 00:00Z on 2011-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 270 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
26 J/kg
Mixed-layer CIN
-441 J/kg
Mixed-layer LCL
1482 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
270 m²/s²
0-3 km storm-relative helicity
219 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
May 12, 1:46 PM CDTMesoscale DiscussionSPCBenton, Crawford, Franklin, Madison, Sebastian, Washington119 min
May 12, 3:17 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Conway, Crawford and 20 more7 hr
May 12, 6:30 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Johnson and 8 more90 min
May 11, 11:25 PM CDTMesoscale DiscussionSPCAustin, Bandera, Bastrop, Bexar, Brazos, Burleson and 27 more65 min
May 12, 2:57 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell and 25 more33 min
May 12, 3:18 AM CDTSevere Thunderstorm WatchSPCBandera, Dimmit, Edwards, Frio, Kerr, Kinney and 7 more5 hr
May 12, 7:27 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bee, Bexar, Brooks, Dimmit and 26 more33 min
May 12, 7:52 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Bandera, Bee, Bexar, Brooks and 33 more9 hr
May 12, 8:46 AM CDTMesoscale DiscussionSPCBastrop, Bell, Bosque, Brazos, Burleson, Caldwell and 22 more59 min
May 12, 9:02 AM CDTSevere Thunderstorm WatchSPCAnderson, Austin, Bastrop, Bell, Blanco, Bosque and 53 more6 hr
May 12, 11:43 AM CDTMesoscale DiscussionSPCAnderson, Aransas, Austin, Bee, Brazos, Burleson and 33 more92 min

Nearby

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Arkansas, 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.