Alert archive / Mississippi / Tornado Watches in 2011

Tornado Watch 96

April 4, 20114 states

The Storm Prediction Center issued this tornado watch at Apr 4, 2011, 5:28 PM CDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 4, 2011, 5:28 PM CDT (22:28 UTC)
Expired
Apr 4, 2011, 11:59 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 68 counties

Baldwin County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Amite County, MS, Clarke County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 106 km from the middle of the area, began a volume at 22:29 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 4, 5:34 PM CDTSevere Thunderstorm WarningJANNeshoba, Winston31 min
Apr 4, 5:36 PM CDTSevere Thunderstorm WarningLIXAscension, East Baton Rouge, Iberville, Livingston, West Baton Rouge54 min
Apr 4, 5:39 PM CDTTornado WarningJANRankin, Simpson, Smith51 min
Apr 4, 5:45 PM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, East Feliciana, Saint Helena, West Baton Rouge60 min
Apr 4, 5:47 PM CDTSevere Thunderstorm WarningLIXPike, Walthall58 min
Apr 4, 5:48 PM CDTSevere Thunderstorm WarningJANJefferson Davis, Lawrence, Lincoln42 min
Apr 4, 5:50 PM CDTSevere Thunderstorm WarningJANKemper, Neshoba, Noxubee, Winston55 min
Apr 4, 5:56 PM CDTTornado WarningJANJefferson Davis, Lawrence64 min
Apr 4, 6:03 PM CDTSevere Thunderstorm WarningLIXEast Feliciana, Saint Helena, Tangipahoa, Washington42 min
Apr 4, 6:07 PM CDTSevere Thunderstorm WarningJANJasper, Simpson, Smith38 min
Apr 4, 6:08 PM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, Livingston, Saint Helena, Saint Tammany, Tangipahoa, Washington67 min
Apr 4, 6:19 PM CDTSevere Thunderstorm WarningJANJasper, Newton, Scott, Smith41 min
Apr 4, 6:23 PM CDTTornado WarningJANCovington, Forrest, Lamar, Marion27 min
Apr 4, 6:24 PM CDTTornado WarningLIXLivingston, Tangipahoa36 min
Apr 4, 6:28 PM CDTSevere Thunderstorm WarningJANCovington, Jones62 min
Apr 4, 6:34 PM CDTSevere Thunderstorm WarningLIXAscension, Assumption, Livingston, Saint Charles, Saint James, Saint John the Baptist and 1 more41 min
Apr 4, 6:39 PM CDTSevere Thunderstorm WarningJANLauderdale51 min
Apr 4, 6:43 PM CDTSevere Thunderstorm WarningMOBChoctaw, Washington47 min
Apr 4, 6:47 PM CDTTornado WarningLIXAssumption, Lafourche, Saint Charles, Saint James, Saint John the Baptist28 min
Apr 4, 6:51 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Tangipahoa, Washington54 min
Apr 4, 6:51 PM CDTSevere Thunderstorm WarningJANClarke39 min
Apr 4, 6:51 PM CDTSevere Thunderstorm WarningJANMarion39 min
Apr 4, 6:52 PM CDTSevere Thunderstorm WarningJANCovington, Forrest, Jones, Lamar68 min
Apr 4, 7:00 PM CDTTornado WarningLIXSaint Tammany45 min
Apr 4, 7:05 PM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke, Washington55 min
Apr 4, 7:08 PM CDTTornado WarningMOBChoctaw, Clarke, Washington67 min
Apr 4, 7:09 PM CDTTornado WarningJANForrest, Jones, Lamar27 min
Apr 4, 7:17 PM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Saint Charles, Saint James, Saint John the Baptist43 min
Apr 4, 7:30 PM CDTSevere Thunderstorm WarningMOBChoctaw, Clarke, Mobile, Washington, Wilcox60 min
Apr 4, 7:32 PM CDTSevere Thunderstorm WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard43 min
Apr 4, 7:37 PM CDTTornado WarningLIXJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles23 min
Apr 4, 7:38 PM CDTTornado WarningMOBWashington56 min
Apr 4, 7:42 PM CDTTornado WarningLIXSaint Tammany48 min
Apr 4, 7:47 PM CDTSevere Thunderstorm WarningLIXSaint Tammany73 min
Apr 4, 7:54 PM CDTTornado WarningMOBChoctaw, Clarke, Washington53 min
Apr 4, 7:55 PM CDTTornado WarningLIXPlaquemines, Saint Bernard35 min
Apr 4, 8:04 PM CDTTornado WarningLIXHarrison41 min
Apr 4, 8:16 PM CDTSevere Thunderstorm WarningLIXJefferson, Plaquemines, Saint Bernard44 min
Apr 4, 8:21 PM CDTTornado WarningMOBClarke, Monroe, Washington39 min
Apr 4, 8:30 PM CDTSevere Thunderstorm WarningMOBBaldwin, Butler, Clarke, Conecuh, Escambia, Mobile and 3 more60 min
Apr 4, 8:31 PM CDTTornado WarningLIXJackson44 min
Apr 4, 8:49 PM CDTSevere Thunderstorm WarningLIXPlaquemines71 min
Apr 4, 9:41 PM CDTSevere Thunderstorm WarningMOBButler, Conecuh, Covington, Crenshaw, Escambia64 min
Apr 4, 9:44 PM CDTSevere Thunderstorm WarningMOBBaldwin, Covington, Escambia61 min
Apr 4, 10:46 PM CDTSevere Thunderstorm WarningMOBCovington44 min
Apr 4, 11:01 PM CDTTornado WarningMOBOkaloosa14 min
Apr 4, 11:30 PM CDTSevere Thunderstorm WarningMOBOkaloosa15 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 10.5 hours before the alert went out and 72 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, Slidell Radar S, LA at 12:00Z on 2011-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1669 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, Slidell Radar S, LA at 12:00Z on 2011-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 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
1669 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
624 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
245 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.

397 
WWUS20 KWNS 042228
SEL6
SPC WW 042228
ALZ000-FLZ000-LAZ000-MSZ000-CWZ000-050600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 96
NWS STORM PREDICTION CENTER NORMAN OK
530 PM CDT MON APR 4 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       SOUTHERN ALABAMA
       WESTERN FLORIDA PANHANDLE
       EASTERN LOUISIANA
       CENTRAL AND SOUTHERN MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 530 PM
UNTIL 100 AM CDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 120 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTHWEST OF
EVERGREEN ALABAMA TO 40 MILES SOUTH OF HOUMA LOUISIANA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 91...WW 93...WW 94...WW
95...

DISCUSSION...SRN FRINGES OF QLCS IS EXPECTED TO INTENSIFY ACROSS THE
REGION AS UPPER LEVEL TROUGH CONTINUES EWD THIS EVENING.  STRONG
PRESSURE FALLS DOWNSTREAM WILL RESULT IN ENHANCED LOW-LEVEL RESPONSE
WITH THREAT FOR TORNADOES WITH ANY EMBEDDED ROTATING STRUCTURES
EMBEDDED WITHIN THE LINE.  OTHERWISE...BOWS/LEWPS WILL BE CAPABLE OF
DAMAGING WIND GUSTS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 26040.


...RACY

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 10:25 AM CDTMesoscale DiscussionSPCColbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 9 more2 hr
Apr 4, 1:03 PM CDTTornado WatchSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 16 more7 hr
Apr 4, 2:52 PM CDTMesoscale DiscussionSPCChoctaw, Fayette, Greene, Pickens, Sumter, Tuscaloosa113 min
Apr 4, 4:28 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bullock, Butler, Calhoun, Chambers and 29 more62 min
Apr 4, 4:55 PM CDTTornado WatchSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 28 more6 hr
Apr 4, 6:50 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Blount, Butler, Calhoun and 36 more85 min
Apr 4, 7:44 AM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more8 hr
Apr 4, 10:53 AM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more7 hr
Apr 4, 11:20 AM CDTMesoscale DiscussionSPCBeauregard, Bienville, Caldwell, Claiborne, De Soto, Grant and 12 more115 min
Apr 4, 7:22 AM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Coahoma, DeSoto and 16 more7 hr

Nearby

Tornado Watches in Mississippi, 2011Tornado Watches in Louisiana, 2011Tornado Watches in Alabama, 2011Every tornado watch 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.