Alert archive / Louisiana / Severe Thunderstorm Watches in 2013

Severe Thunderstorm Watch 67

March 30, 201324 parishes in Louisiana; 17 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Mar 30, 2013, 2:33 PM CDT for 24 parishes in Louisiana; 17 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 30, 2013, 2:33 PM CDT (19:33 UTC)
Expired
Mar 30, 2013, 6:00 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 41 counties

Avoyelles Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Gregg County, TX, Harrison 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, Titus County, TX, Upshur County, TX

The radar

The Shreveport radar (KSHV), 12 km from the middle of the area, began a volume at 19:33 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 30, 2:46 PM CDTSevere Thunderstorm WarningSHVBowie, Cass59 min
Mar 30, 2:55 PM CDTSevere Thunderstorm WarningSHVCaddo, De Soto, Natchitoches, Red River65 min
Mar 30, 3:23 PM CDTTornado WarningSHVDe Soto, Natchitoches, Red River, Sabine37 min
Mar 30, 3:43 PM CDTSevere Thunderstorm WarningSHVCaddo62 min
Mar 30, 4:06 PM CDTSevere Thunderstorm WarningSHVDe Soto, Natchitoches, Sabine54 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 7.6 hours before the alert went out and 3 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

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 30, 2:21 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Catahoula, De Soto and 8 more84 min
Mar 30, 5:37 PM CDTMesoscale DiscussionSPCAvoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 18 more53 min
Mar 29, 7:01 PM CDTMesoscale DiscussionSPCBaylor, Borden, Briscoe, Callahan, Childress, Coke and 41 more89 min
Mar 29, 9:24 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Collin, Cooke, Delta and 16 more96 min
Mar 29, 10:30 PM CDTSevere Thunderstorm WatchSPCArcher, Clay, Collin, Cooke, Denton, Fannin and 6 more5 hr
Mar 30, 1:21 AM CDTMesoscale DiscussionSPCCollin, Dallas, Denton, Ellis, Fannin, Grayson and 8 more114 min
Mar 30, 10:24 AM CDTMesoscale DiscussionSPCBowie, Delta, Franklin, Lamar, Morris, Red River and 1 more96 min
Mar 30, 4:53 PM CDTMesoscale DiscussionSPCChildress, Collingsworth, Cottle, Foard, Hall, Hardeman97 min
Mar 30, 5:15 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Eastland and 8 more90 min
Mar 30, 6:06 PM CDTSevere Thunderstorm WatchSPCClay, Collin, Cooke, Denton, Fannin, Grayson and 5 more7 hr

Nearby

Severe Thunderstorm Watches in Louisiana, 2013Severe Thunderstorm Watches in Texas, 2013Every severe thunderstorm watch 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.