Alert archive / Texas / Mesoscale Discussions in 2013

Mesoscale Discussion 340

March 30, 201314 parishes in Louisiana; Choctaw County, Oklahoma; 23 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 30, 2013, 2:21 PM CDT for 14 parishes in Louisiana; Choctaw County, Oklahoma; 23 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Mar 30, 2013, 2:21 PM CDT (19:21 UTC)
Expired
Mar 30, 2013, 3:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 38 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Webster Parish, LA, Winn Parish, LA, Choctaw County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Hopkins County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 32 km from the middle of the area, began a volume at 19:24 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, 7.4 hours before the alert went out and 35 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 2013-03-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 137 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, Shreveport, LA at 12:00Z on 2013-03-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 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
137 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
497 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
25 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
Mar 30, 2:33 PM CDTSevere Thunderstorm WatchSPCAvoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 18 more3 hr
Mar 30, 5:37 PM CDTMesoscale DiscussionSPCAvoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 18 more53 min
Mar 29, 7:01 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Comanche, Custer and 15 more89 min
Mar 29, 9:24 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Cotton, Jefferson, Johnston and 5 more96 min
Mar 29, 10:30 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Cotton, Jefferson, Johnston and 2 more5 hr
Mar 30, 1:21 AM CDTMesoscale DiscussionSPCBryan114 min
Mar 30, 10:24 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Coal, Haskell, Hughes and 8 more96 min
Mar 30, 4:53 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Custer, Greer, Harmon, Jackson and 3 more97 min
Mar 30, 5:41 PM CDTMesoscale DiscussionSPCOttawa94 min
Mar 30, 6:06 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Caddo, Carter, Coal, Comanche and 14 more7 hr
Mar 30, 5:15 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Eastland and 8 more90 min

Nearby

Mesoscale Discussions in Texas, 2013Mesoscale Discussions in Louisiana, 2013Mesoscale Discussions in Oklahoma, 2013Every mesoscale discussion in 2013

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.