Alert archive / Louisiana / Tornado Watches in 2005

Tornado Watch 810

September 23, 20054 counties in Alabama; 36 parishes in Louisiana; 15 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Sep 23, 2005, 5:10 PM CDT for 4 counties in Alabama; 36 parishes in Louisiana; 15 counties in Mississippi. It was in force for 13 hr.

The area

The outline as issued.

The facts

Issued
Sep 23, 2005, 5:10 PM CDT (22:10 UTC)
Expired
Sep 24, 2005, 5:43 AM CDT
In force
13 hr
Issued by
the Storm Prediction Center
All 55 counties

Baldwin County, AL, Clarke County, AL, Mobile County, AL, Washington County, AL, Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Rapides 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 Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wilkinson County, MS

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 23, 5:14 PM CDTTornado WarningLIXLivingston, Tangipahoa31 min
Sep 23, 5:20 PM CDTTornado WarningJANMarion14 min
Sep 23, 7:02 PM CDTTornado WarningLIXEast Baton Rouge, Livingston28 min
Sep 23, 8:06 PM CDTTornado WarningLIXLivingston24 min
Sep 23, 9:59 PM CDTTornado WarningLCHLafayette31 min
Sep 23, 9:59 PM CDTTornado WarningLCHLafayette31 min
Sep 23, 9:59 PM CDTTornado WarningLCHCameron2 hr
Sep 23, 10:18 PM CDTTornado WarningLCHAllen27 min
Sep 23, 10:28 PM CDTTornado WarningLCHAcadia, Vermilion32 min
Sep 23, 10:37 PM CDTTornado WarningLCHJefferson Davis23 min
Sep 23, 11:53 PM CDTTornado WarningLCHCalcasieu, Cameron2 hr
Sep 23, 11:55 PM CDTFlash Flood WarningLIXAscension, Assumption, Iberville, Lafourche, Pointe Coupee, Saint James and 2 more4 hr
Sep 24, 12:53 AM CDTTornado WarningLCHAvoyelles, Rapides37 min
Sep 24, 12:55 AM CDTTornado WarningLIXEast Baton Rouge, West Baton Rouge20 min
Sep 24, 1:34 AM CDTFlash Flood WarningLIXEast Baton Rouge3 hr
Sep 24, 1:52 AM CDTTornado WarningLCHCalcasieu, Cameron, Jefferson Davis2 hr
Sep 24, 1:52 AM CDTTornado WarningLCHCalcasieu, Cameron, Jefferson Davis2 hr
Sep 24, 2:29 AM CDTFlash Flood WarningLIXLivingston, Saint Charles, Saint John the Baptist3 hr
Sep 24, 3:32 AM CDTTornado WarningLIXLivingston, Saint Helena13 min
Sep 24, 4:13 AM CDTTornado WarningLCHBeauregard, Calcasieu, Cameron, Vernon62 min
Sep 24, 4:43 AM CDTTornado WarningLIXSaint Helena, Tangipahoa17 min
Sep 24, 5:10 AM CDTTornado WarningLCHAllen, Beauregard, Vernon65 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, 10.2 hours before the alert went out and 155 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 2005-09-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 377 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 2005-09-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 268 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
377 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
686 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
268 m²/s²
0-3 km storm-relative helicity
298 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 232209
SEL0  
SPC WW 232209
ALZ000-LAZ000-MSZ000-CWZ000-241100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 810
NWS STORM PREDICTION CENTER NORMAN OK
510 PM CDT FRI SEP 23 2005

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

       EXTREME SOUTHWESTERN ALABAMA
       SOUTHERN AND PARTS OF CENTRAL LOUISIANA
       SOUTHERN MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS FRIDAY AFTERNOON AND SATURDAY MORNING FROM 510 PM
UNTIL 600 AM CDT.

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

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 25 MILES WEST OF LAKE CHARLES
LOUISIANA TO 30 MILES EAST OF MOBILE ALABAMA.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU0).

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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 809. WATCH NUMBER 809 WILL NOT BE IN EFFECT AFTER 510
PM CDT. 

DISCUSSION...HRCN RITA CONTINUES TO MOVE WNWWD TOWARD THE LA/TX
COAST AND WILL BE LOCATED VERY NEAR SHORE LATE TONIGHT.  LOW-LEVEL
SHEAR PROFILES CONTINUE TO STRENGTHEN ACROSS SRN LA EWD TO SWRN AL. 
SPIRAL RAINBANDS WILL CONTINUE TO ROTATE ONSHORE THROUGH THE
NIGHT...PARTICULARLY ACROSS SRN AND PARTS OF CNTRL LA WITH EMBEDDED
SUPERCELLS AND POSSIBLE TORNADOES.

THE FORECAST MAXIMUM WIND GUSTS AND MEAN CELL MOTION APPLY TO SEVERE
THUNDERSTORMS OUTSIDE THE HURRICANE EYEWALL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 13035.


...RACY/EVANS

310,0933 314,0874 293,0874 290,0933

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 23, 9:55 AM CDTTornado WatchSPCBaldwin, Mobile7 hr
Sep 23, 2:12 PM CDTMesoscale DiscussionSPCBaldwin, Mobile93 min
Sep 23, 4:33 PM CDTMesoscale DiscussionSPCBaldwin, Mobile87 min
Sep 23, 7:44 AM CDTMesoscale DiscussionSPCAscension, Assumption, Cameron, Iberville, Lafayette, Orleans and 5 more91 min

Nearby

Tornado Watches in Louisiana, 2005Tornado Watches in Mississippi, 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.