Alert archive / Mississippi / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 134

April 3, 20125 counties in Arkansas; 22 parishes in Louisiana; 23 counties in Mississippi

The Storm Prediction Center issued this severe thunderstorm watch at Apr 3, 2012, 2:22 PM CDT for 5 counties in Arkansas; 22 parishes in Louisiana; 23 counties in Mississippi. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Apr 3, 2012, 2:22 PM CDT (19:22 UTC)
Expired
Apr 3, 2012, 10:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 50 counties

Columbia County, AR, Hempstead County, AR, Lafayette County, AR, Nevada County, AR, Union County, AR, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, East Carroll 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, Red River Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Attala County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Warren County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 114 km from the middle of the area, began a volume at 19:23 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
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 3, 3:08 PM CDTSevere Thunderstorm WarningJANEast Carroll, West Carroll15 min
Apr 3, 3:12 PM CDTSevere Thunderstorm WarningSHVUnion63 min
Apr 3, 3:25 PM CDTFlash Flood WarningSHVUnion3 hr
Apr 3, 3:50 PM CDTSevere Thunderstorm WarningJANEast Carroll40 min
Apr 3, 4:59 PM CDTSevere Thunderstorm WarningSHVOuachita, Union41 min
Apr 3, 6:17 PM CDTSevere Thunderstorm WarningSHVColumbia, Lafayette, Miller58 min
Apr 3, 6:35 PM CDTSevere Thunderstorm WarningJANClaiborne, Copiah18 min
Apr 3, 6:46 PM CDTSevere Thunderstorm WarningJANCopiah, Jefferson, Lincoln34 min
Apr 3, 6:53 PM CDTTornado WarningSHVLafayette, Miller67 min
Apr 3, 6:56 PM CDTSevere Thunderstorm WarningSHVColumbia, Union52 min
Apr 3, 7:12 PM CDTSevere Thunderstorm WarningSHVColumbia, Lafayette, Nevada63 min
Apr 3, 7:25 PM CDTSevere Thunderstorm WarningSHVColumbia65 min
Apr 3, 7:33 PM CDTSevere Thunderstorm WarningSHVColumbia, Hempstead, Lafayette, Miller, Nevada57 min
Apr 3, 7:37 PM CDTSevere Thunderstorm WarningSHVClaiborne38 min
Apr 3, 8:12 PM CDTSevere Thunderstorm WarningSHVBienville, Bossier, Caddo, Claiborne, De Soto, Webster63 min
Apr 3, 8:16 PM CDTSevere Thunderstorm WarningJANFranklin, Lincoln44 min
Apr 3, 8:22 PM CDTSevere Thunderstorm WarningJANJefferson Davis, Lawrence, Lincoln, Simpson53 min
Apr 3, 8:33 PM CDTSevere Thunderstorm WarningSHVColumbia, Union57 min
Apr 3, 9:12 PM CDTSevere Thunderstorm WarningSHVBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more63 min
Apr 3, 9:28 PM CDTSevere Thunderstorm WarningSHVUnion62 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

Jackson, MS (KJAN), launched 12:00Z, 7.4 hours before the alert went out and 104 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, Jackson, MS at 12:00Z on 2012-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 159 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, Jackson, MS at 12:00Z on 2012-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939Sfc1 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
159 J/kg
Mixed-layer CIN
-252 J/kg
Mixed-layer LCL
1092 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
-33 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
Apr 3, 1:42 PM CDTMesoscale DiscussionSPCChicot93 min
Apr 3, 2:36 PM CDTTornado WatchSPCHoward, Little River, Miller, Sevier7 hr
Apr 3, 3:05 PM CDTMesoscale DiscussionSPCHempstead, Howard, Little River, Montgomery, Nevada, Pike and 2 more85 min
Apr 3, 3:43 PM CDTSevere Thunderstorm WatchSPCBoone, Bradley, Calhoun, Clark, Crawford, Dallas and 16 more6 hr
Apr 3, 5:00 PM CDTMesoscale DiscussionSPCLittle River, Miller60 min
Apr 3, 5:24 PM CDTMesoscale DiscussionSPCAshley, Chicot, Union66 min
Apr 3, 6:53 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more67 min
Apr 2, 10:10 PM CDTMesoscale DiscussionSPCIberia, St. Mary3 hr
Apr 3, 1:46 PM CDTMesoscale DiscussionSPCCaddo, De Soto89 min

Nearby

Severe Thunderstorm Watches in Mississippi, 2012Severe Thunderstorm Watches in Louisiana, 2012Severe Thunderstorm Watches in Arkansas, 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; radar from the NEXRAD Level II archive.