Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 406

April 11, 201142 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2011, 1:27 AM CDT for 42 counties in Texas. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Apr 11, 2011, 1:27 AM CDT (06:27 UTC)
Expired
Apr 11, 2011, 3:00 AM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 42 counties

Anderson County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Brown County, TX, Burnet County, TX, Collin County, TX, Comanche County, TX, Coryell County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lampasas County, TX, Limestone County, TX, Llano County, TX, Mason County, TX, McLennan County, TX, Mills County, TX, Navarro County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, San Saba County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Van Zandt County, TX, Williamson County, TX, Wood County, TX

The radar

The Ft Hood radar (KGRK), 95 km from the middle of the area, began a volume at 06:31 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 00:00Z, 6.5 hours before the alert went out and 151 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 2011-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 637 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 2011-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
637 J/kg
Mixed-layer CIN
-268 J/kg
Mixed-layer LCL
1994 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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 10, 7:02 PM CDTSevere Thunderstorm WatchSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 41 more8 hr
Apr 10, 9:09 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Cooke and 21 more66 min
Apr 10, 11:39 PM CDTTornado WatchSPCAnderson, Bandera, Bell, Blanco, Bosque, Burnet and 28 more7 hr
Apr 11, 1:49 AM CDTTornado WatchSPCBowie, Camp, Cass, Delta, Franklin, Gregg and 14 more4 hr
Apr 11, 4:19 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Gregg, Harrison, Marion and 7 more56 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.