Alert archive / Louisiana / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 60

March 2, 20124 states

The Storm Prediction Center issued this severe thunderstorm watch at Mar 2, 2012, 1:47 PM CST for 4 states. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Mar 2, 2012, 1:47 PM CST (19:47 UTC)
Expired
Mar 2, 2012, 11:00 PM CST
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 48 counties

Ashley County, AR, Chicot County, AR, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Bolivar County, MS, Claiborne County, MS, Franklin County, MS, Issaquena County, MS, Jefferson County, MS, Leflore County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Angelina County, TX, Jasper County, TX, Nacogdoches County, TX, Newton County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Tyler County, TX

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
30%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 2, 2:03 PM CSTSevere Thunderstorm WarningSHVUnion42 min
Mar 2, 2:09 PM CSTSevere Thunderstorm WarningJANAshley, Chicot66 min
Mar 2, 2:18 PM CSTSevere Thunderstorm WarningJANAshley72 min
Mar 2, 2:18 PM CSTSevere Thunderstorm WarningSHVBienville, Claiborne, Lincoln42 min
Mar 2, 2:29 PM CSTSevere Thunderstorm WarningJANBolivar, Washington61 min
Mar 2, 2:54 PM CSTSevere Thunderstorm WarningSHVLincoln, Ouachita, Union51 min
Mar 2, 3:17 PM CSTSevere Thunderstorm WarningJANChicot43 min
Mar 2, 3:25 PM CSTSevere Thunderstorm WarningJANCarroll, Grenada, Leflore, Montgomery65 min
Mar 2, 3:30 PM CSTSevere Thunderstorm WarningSHVSabine, San Augustine, Shelby45 min
Mar 2, 3:33 PM CSTSevere Thunderstorm WarningJANMorehouse42 min
Mar 2, 3:36 PM CSTSevere Thunderstorm WarningJANLeflore, Sunflower, Washington42 min
Mar 2, 3:48 PM CSTSevere Thunderstorm WarningSHVDe Soto, Natchitoches, Red River42 min
Mar 2, 4:06 PM CSTSevere Thunderstorm WarningSHVNatchitoches, Sabine39 min
Mar 2, 4:07 PM CSTSevere Thunderstorm WarningJANChicot53 min
Mar 2, 4:22 PM CSTSevere Thunderstorm WarningSHVJackson, Natchitoches, Winn38 min
Mar 2, 4:32 PM CSTSevere Thunderstorm WarningJANCarroll, Holmes, Humphreys, Leflore, Sunflower58 min
Mar 2, 4:43 PM CSTSevere Thunderstorm WarningSHVNatchitoches, Winn62 min
Mar 2, 4:58 PM CSTSevere Thunderstorm WarningSHVCaldwell, Jackson, Ouachita, Winn47 min
Mar 2, 5:10 PM CSTSevere Thunderstorm WarningJANHumphreys, Sharkey, Washington35 min
Mar 2, 5:26 PM CSTSevere Thunderstorm WarningJANEast Carroll, Madison, Richland, West Carroll49 min
Mar 2, 5:32 PM CSTSevere Thunderstorm WarningJANFranklin, Madison, Richland43 min
Mar 2, 5:37 PM CSTSevere Thunderstorm WarningSHVCaldwell, Grant, LaSalle, Winn53 min
Mar 2, 6:03 PM CSTSevere Thunderstorm WarningJANEast Carroll57 min
Mar 2, 6:16 PM CSTSevere Thunderstorm WarningJANFranklin, Madison74 min
Mar 2, 6:24 PM CSTSevere Thunderstorm WarningJANCatahoula, Franklin66 min
Mar 2, 6:25 PM CSTSevere Thunderstorm WarningSHVCaldwell, LaSalle39 min
Mar 2, 6:28 PM CSTTornado WarningJANMadison, Tensas33 min
Mar 2, 7:18 PM CSTTornado WarningJANHinds, Madison, Warren, Yazoo22 min
Mar 2, 8:39 PM CSTSevere Thunderstorm WarningJANCatahoula, Concordia51 min
Mar 2, 9:17 PM CSTSevere Thunderstorm WarningJANClaiborne, Copiah, Hinds43 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, 7.8 hours before the alert went out and 133 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 2012-03-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1427 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 2012-03-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 347 square meters per square second.1939587897117136Sfc1 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
1427 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
626 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
347 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
2.5
Supercell composite
9.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 2, 10:28 AM CSTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Independence and 10 more62 min
Mar 2, 1:26 PM CSTMesoscale DiscussionSPCAshley, Chicot64 min
Mar 2, 3:47 PM CSTMesoscale DiscussionSPCAshley, Chicot58 min
Mar 2, 2:42 PM CSTMesoscale DiscussionSPCAscension, East Baton Rouge, East Feliciana, Livingston, Saint Helena, Saint Tammany and 2 more63 min
Mar 2, 12:57 PM CSTMesoscale DiscussionSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 32 more63 min
Mar 2, 1:20 PM CSTTornado WatchSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 24 more9 hr
Mar 2, 3:25 PM CSTMesoscale DiscussionSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 24 more65 min
Mar 2, 4:37 PM CSTTornado WatchSPCGeorge, Greene, Perry, Stone, Wayne7 hr
Mar 2, 4:47 PM CSTTornado WatchSPCAttala, Choctaw, Clarke, Clay, Copiah, Covington and 23 more6 hr

Nearby

Severe Thunderstorm Watches in Louisiana, 2012Severe Thunderstorm Watches in Mississippi, 2012Severe Thunderstorm Watches in Texas, 2012Every severe thunderstorm watch in 2012

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.