Alert archive / Louisiana / Tornado Watches in 2003

Tornado Watch 977

November 27, 200312 counties in Alabama; 17 parishes in Louisiana; 15 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Nov 27, 2003, 5:25 AM CST for 12 counties in Alabama; 17 parishes in Louisiana; 15 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Nov 27, 2003, 5:25 AM CST (11:25 UTC)
Expired
Nov 27, 2003, 11:00 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
All 44 counties

Bibb County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Dallas County, AL, Hale County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Perry County, AL, Washington County, AL, Wilcox County, AL, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans 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 Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Clarke County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jones County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 27, 5:43 AM CSTTornado WarningJANJones47 min
Nov 27, 6:08 AM CSTSevere Thunderstorm WarningLIXJefferson, Orleans, Saint Charles, Saint John the Baptist52 min
Nov 27, 6:52 AM CSTSevere Thunderstorm WarningLIXSaint Tammany38 min
Nov 27, 7:25 AM CSTFlash Flood WarningJANJones95 min
Nov 27, 7:27 AM CSTSevere Thunderstorm WarningLIXSaint Tammany63 min
Nov 27, 9:42 AM CSTTornado WarningBMXDallas, Marengo, Perry48 min
Nov 27, 10:22 AM CSTSevere Thunderstorm WarningLIXJefferson, Orleans, Plaquemines38 min
Nov 27, 10:26 AM CSTTornado WarningBMXDallas34 min
Nov 27, 10:47 AM CSTSevere Thunderstorm WarningMOBWashington43 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 00:00Z, 11.4 hours before the alert went out and 69 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 00:00Z on 2003-11-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2003-11-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 278 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
1 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
602 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
278 m²/s²
0-3 km storm-relative helicity
334 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 271126
SEL7  
SPC WW 271125
ALZ000-LAZ000-MSZ000-CWZ000-271700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 977 
NWS STORM PREDICTION CENTER NORMAN OK 
525 AM CST THU NOV 27 2003

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

       SOUTH-CENTRAL AND SOUTHWESTERN ALABAMA
       SOUTHEASTERN LOUISIANA
       SOUTHEASTERN MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS THURSDAY MORNING FROM 525 AM UNTIL 1100 AM CST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 65 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 40 MILES WEST OF HOUMA LOUISIANA TO 5 MILES
EAST SOUTHEAST OF SELMA ALABAMA.

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 976. WATCH NUMBER 976 WILL NOT BE IN EFFECT AFTER 525
AM CST. 


DISCUSSION...BANDS OF SEVERE TSTMS SHOULD MOVE EWD ACROSS REGION
BETWEEN GULF COAST AND WARM FRONT...IN ENVIRONMENT OF FAVORABLE
SHEAR AND NEAR SFC-BASED INSTABILITY TO SUPPORT TORNADO AND DAMAGING
WIND POTENTIAL.  WARM FRONT SHOULD LIFT NEWD INTO SWRN
AL...INCREASING THREAT OVER THAT AREA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 24035.


...EDWARDS/EVANS

303,0912 331,0865 312,0865 283,0912

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 27, 7:48 AM CSTMesoscale DiscussionSPCBibb, Choctaw, Clarke, Conecuh, Dallas, Hale and 6 more117 min
Nov 27, 9:53 AM CSTMesoscale DiscussionSPCBibb, Choctaw, Clarke, Conecuh, Dallas, Hale and 6 more2 hr
Nov 26, 6:55 PM CSTSevere Thunderstorm WatchSPCBeauregard, Bossier, Caddo, Calcasieu, Cameron, De Soto and 4 more6 hr
Nov 26, 9:18 PM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 48 more87 min
Nov 26, 9:55 PM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 19 more5 hr
Nov 26, 11:41 PM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Cameron and 18 more94 min
Nov 27, 1:36 AM CSTMesoscale DiscussionSPCBienville, Caldwell, Catahoula, Claiborne, Concordia, East Carroll and 13 more2 hr
Nov 27, 2:31 AM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 19 more59 min
Nov 27, 3:00 AM CSTTornado WatchSPCAcadia, Ascension, Assumption, Cameron, East Baton Rouge, East Feliciana and 16 more5 hr
Nov 27, 5:03 AM CSTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Cameron, East Baton Rouge, East Feliciana and 16 more117 min
Nov 27, 7:49 AM CSTMesoscale DiscussionSPCAcadia, Calcasieu, Cameron, Iberia, Jefferson Davis, Lafayette and 2 more2 hr

Nearby

Tornado Watches in Louisiana, 2003Tornado Watches in Mississippi, 2003Tornado Watches in Alabama, 2003Every tornado watch in 2003

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.