Alert archive / Mississippi / Tornado Watches in 2005

Tornado Watch 155

April 11, 2005Mobile County, Alabama; 7 parishes in Louisiana; 9 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Apr 11, 2005, 6:35 PM CDT for Mobile County, Alabama; 7 parishes in Louisiana; 9 counties in Mississippi. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 11, 2005, 6:35 PM CDT (23:35 UTC)
Expired
Apr 11, 2005, 11:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center

Counties Mobile County, AL, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Tammany Parish, LA, Terrebonne Parish, LA, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 11, 6:41 PM CDTSevere Thunderstorm WarningMOBPerry, Wayne49 min
Apr 11, 7:41 PM CDTSevere Thunderstorm WarningLIXSaint Bernard49 min
Apr 11, 7:44 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Tangipahoa, Washington46 min
Apr 11, 7:51 PM CDTTornado WarningLIXSaint Tammany, Washington24 min
Apr 11, 8:00 PM CDTTornado WarningLIXPearl River45 min
Apr 11, 8:17 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Washington43 min
Apr 11, 8:44 PM CDTTornado WarningLIXPearl River46 min
Apr 11, 8:59 PM CDTSevere Thunderstorm WarningLIXSaint Tammany46 min
Apr 11, 9:18 PM CDTTornado WarningJANForrest44 min
Apr 11, 10:18 PM CDTSevere Thunderstorm WarningLIXHancock, Harrison42 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, 11.6 hours before the alert went out and 25 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 2005-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 46 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 2005-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 185 square meters per square second.19395878Sfc1 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
46 J/kg
Mixed-layer CIN
-604 J/kg
Mixed-layer LCL
650 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
185 m²/s²
0-3 km storm-relative helicity
273 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.

000 
WWUS20 KWNS 112331
SEL5  
SPC WW 112331
ALZ000-LAZ000-MSZ000-CWZ000-120400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 155
NWS STORM PREDICTION CENTER NORMAN OK
635 PM CDT MON APR 11 2005

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

       SOUTHWEST ALABAMA
       SOUTHEAST LOUISIANA
       SOUTHEAST MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS MONDAY EVENING FROM 635 PM UNTIL 1100 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE MILES
EAST AND WEST OF A LINE FROM 45 MILES EAST SOUTHEAST OF HOUMA
LOUISIANA TO 45 MILES NORTH OF MOBILE ALABAMA. FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU5).

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 151...WW 152...WW 153...WW
154...

DISCUSSION...STRONG SHEAR PROFILES ACROSS WATCH AREA CONTINUE TO
FAVOR POTENTIAL FOR TORNADIC SUPERCELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 24040.


...HALES

291,0905 311,0891 311,0871 291,0885

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 11, 5:50 PM CDTMesoscale DiscussionSPCFayette, Franklin, Lamar, Marion, Pickens85 min
Apr 11, 3:12 AM CDTMesoscale DiscussionSPCBeauregard, Bienville, Bossier, Caddo, Calcasieu, Claiborne and 6 more63 min
Apr 11, 3:45 AM CDTSevere Thunderstorm WatchSPCBeauregard, Bienville, Bossier, Caddo, Calcasieu, Claiborne and 12 more7 hr
Apr 11, 3:56 AM CDTMesoscale DiscussionSPCFranklin, Madison, Tensas64 min
Apr 11, 6:53 AM CDTMesoscale DiscussionSPCBeauregard, Bienville, Bossier, Caddo, Calcasieu, Claiborne and 12 more67 min
Apr 11, 9:41 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 47 more2 hr
Apr 11, 10:15 AM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 25 more9 hr
Apr 11, 12:12 PM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 47 more2 hr
Apr 11, 1:41 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafourche and 14 more2 hr
Apr 11, 2:05 PM CDTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 14 more7 hr
Apr 11, 6:52 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 9 more83 min
Apr 11, 6:17 AM CDTMesoscale DiscussionSPCDeSoto, Tunica118 min
Apr 11, 1:17 PM CDTMesoscale DiscussionSPCAlcorn, Benton, Coahoma, Itawamba, Lafayette, Lee and 10 more58 min
Apr 11, 1:35 PM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 10 more5 hr

Nearby

Tornado Watches in Mississippi, 2005Tornado Watches in Louisiana, 2005Tornado Watches in Alabama, 2005Every tornado watch in 2005

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.