Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 1342

June 21, 20115 parishes in Louisiana; 38 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2011, 3:43 PM CDT for 5 parishes in Louisiana; 38 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Jun 21, 2011, 3:43 PM CDT (20:43 UTC)
Expired
Jun 21, 2011, 4:45 PM CDT
In force
62 min
Issued by
the Storm Prediction Center
All 43 counties

Bossier Parish, LA, Caddo Parish, LA, De Soto Parish, LA, Red River Parish, LA, Webster Parish, LA, Anderson County, TX, Bosque County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Coryell County, TX, Dallas County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Hamilton County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Limestone County, TX, Marion County, TX, McLennan County, TX, Morris County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Rockwall County, TX, Rusk County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 156 km from the middle of the area, began a volume at 20:44 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 watches that followed

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

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 8.7 hours before the alert went out and 165 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, Shreveport, LA at 12:00Z on 2011-06-21Temperature 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, Shreveport, LA at 12:00Z on 2011-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
0 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.6

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
Jun 21, 11:58 AM CDTMesoscale DiscussionSPCAvoyelles, Catahoula, Concordia, East Carroll, Franklin, LaSalle and 3 more62 min
Jun 21, 6:59 PM CDTMesoscale DiscussionSPCBeauregard, Sabine61 min
Jun 20, 7:56 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Jack, Montague, Stephens and 3 more94 min
Jun 20, 9:46 PM CDTSevere Thunderstorm WatchSPCArcher, Bosque, Clay, Collin, Comanche, Cooke and 30 more9 hr
Jun 21, 3:15 AM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 39 more60 min
Jun 21, 4:58 PM CDTSevere Thunderstorm WatchSPCAnderson, Angelina, Bell, Bosque, Brewster, Brown and 84 more10 hr
Jun 21, 6:21 PM CDTMesoscale DiscussionSPCCollin, Dallas, Delta, Denton, Ellis, Fannin and 15 more54 min

Nearby

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Louisiana, 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.