Alert archive / Louisiana / Tornado Watches in 2003

Tornado Watch 12

February 21, 200338 parishes in Louisiana; 9 counties in Mississippi; 11 counties in Texas

The Storm Prediction Center issued this tornado watch at Feb 21, 2003, 3:40 PM CST for 38 parishes in Louisiana; 9 counties in Mississippi; 11 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 21, 2003, 3:40 PM CST (21:40 UTC)
Expired
Feb 21, 2003, 10:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
All 58 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Grant 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, Sabine 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, Adams County, MS, Amite County, MS, Franklin County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS, Angelina County, TX, Chambers County, TX, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Sabine County, TX, San Augustine County, TX, Tyler County, TX

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Feb 21, 3:46 PM CSTFlash Flood WarningSHVGrant, Jackson, Natchitoches, Winn4 hr
Feb 21, 5:01 PM CSTFlash Flood WarningJANLamar, Marion6 hr
Feb 21, 5:48 PM CSTFlash Flood WarningJANFranklin, Jefferson Davis, Lawrence, Lincoln6 hr
Feb 21, 6:05 PM CSTSevere Thunderstorm WarningLIXPointe Coupee, West Feliciana25 min
Feb 21, 6:35 PM CSTFlash Flood WarningLIXEast Feliciana, Pointe Coupee, West Feliciana4 hr
Feb 21, 7:11 PM CSTSevere Thunderstorm WarningJANFranklin, Lincoln59 min
Feb 21, 8:05 PM CSTTornado WarningJANLincoln30 min
Feb 21, 8:27 PM CSTTornado WarningJANLawrence43 min
Feb 21, 9:03 PM CSTSevere Thunderstorm WarningJANLincoln32 min
Feb 21, 9:38 PM CSTTornado WarningJANLawrence32 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 9.7 hours before the alert went out and 84 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, Lake Charles Mun, LA at 12:00Z on 2003-02-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 543 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, Lake Charles Mun, LA at 12:00Z on 2003-02-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 253 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
543 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
433 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
253 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 212141
SEL2
SPC WW 212140
LAZ000-MSZ000-TXZ000-CWZ000-220400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 12
STORM PREDICTION CENTER NORMAN OK
340 PM CST FRI FEB 21 2003

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

   SOUTHERN AND CENTRAL LOUISIANA                          
   SOUTHWEST MISSISSIPPI                        
   SOUTHEAST TEXAS                              
   COASTAL WATERS                     

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 340 PM UNTIL 1000
PM CST.

 ...THIS IS A PARTICULARLY DANGEROUS SITUATION...
 
DAMAGING TORNADOES...LARGE 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 ALONG AND 75 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 65 MILES NORTHWEST OF PORT ARTHUR TEXAS TO 45
MILES NORTHEAST OF NEW ORLEANS LOUISIANA.

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 11.  WATCH NUMBER 11 WILL NOT BE IN EFFECT AFTER 340 PM CST.

DISCUSSION...STRONG TROUGH AND JET MAX ROTATING EWD ACROSS S TX
WILL BECOME NEGATIVELY TILTED AS IT APPROACHES SERN TX/LA LATER
THIS EVENING. RAPIDLY DEEPENING SURFACE LOW SERN TX WITH PRONOUNCED
BOUNDARY EXTENDING EWD ACROSS SRN LA.  LOW WILL CONTINUE TO DEEPEN
NEWD WITH BOUNDARY SHIFTING NWD THIS EVENING.  SEVERE THUNDERSTORMS
SERN TX WILL CONTINUE AND WITH STRONG UPPER SUPPORT AN INCREASING
THREAT OF TORNADIC SUPERCELLS IS EXPECTED AS SYSTEM MOVES EWD. 
PARAMETERS SUPPORT POTENTIAL FOR STRONG  TORNADOES THIS EVENING AS
VIGOROUS UPPER TROUGH APPROACHES.


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 550. 
MEAN STORM MOTION VECTOR 23040.


...HALES

314,0944 313,0894 292,0894 293,0944

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 21, 1:43 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 6 more2 hr
Feb 21, 4:35 AM CSTMesoscale DiscussionSPCAscension, Assumption, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 16 more115 min
Feb 21, 9:02 AM CSTMesoscale DiscussionSPCBeauregard, Calcasieu, Cameron, Sabine, Vernon58 min
Feb 21, 9:40 AM CSTTornado WatchSPCAcadia, Allen, Beauregard, Calcasieu, Caldwell, Cameron and 11 more6 hr
Feb 21, 11:47 AM CSTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 4 more118 min
Feb 21, 3:32 PM CSTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Vernon118 min
Feb 21, 5:20 PM CSTMesoscale DiscussionSPCClaiborne, East Carroll, Franklin, Jackson, Lincoln, Madison and 5 more4 hr
Feb 21, 5:50 PM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more115 min
Feb 21, 2:43 AM CSTMesoscale DiscussionSPCDimmit, Edwards, Frio, Kinney, La Salle, Maverick and 5 more3 hr
Feb 21, 3:53 AM CSTMesoscale DiscussionSPCAransas, Austin, Brazoria, Calhoun, Colorado, Fort Bend and 13 more3 hr
Feb 21, 4:10 AM CSTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more6 hr
Feb 21, 4:25 AM CSTTornado WatchSPCAustin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 15 more6 hr
Feb 21, 5:58 AM CSTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more2 hr
Feb 21, 6:16 AM CSTMesoscale DiscussionSPCAustin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 17 more119 min
Feb 21, 1:30 PM CSTMesoscale DiscussionSPCHardin, Harris, Jasper, Liberty, Montgomery, Newton and 3 more2 hr

Nearby

Tornado Watches in Louisiana, 2003Tornado Watches in Texas, 2003Tornado Watches in Mississippi, 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.