Alert archive / Louisiana / Tornado Watches in 2004

Tornado Watch 11

February 23, 200412 parishes in Louisiana; Hancock County, Harrison County, Jackson County, Mississippi

The Storm Prediction Center issued this tornado watch at Feb 23, 2004, 10:00 AM CST for 12 parishes in Louisiana; Hancock County, Harrison County, Jackson County, Mississippi. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Feb 23, 2004, 10:00 AM CST (16:00 UTC)
Expired: Feb 23, 2004, 3:00 PM CST
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Assumption Parish, LA, Iberia Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, St. Mary Parish, LA, Terrebonne Parish, LA, Hancock County, MS, Harrison County, MS, Jackson County, MS

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Feb 23, 10:09 AM CST	Tornado Warning	LIX	Saint Charles	36 min
Feb 23, 10:44 AM CST	Tornado Warning	LIX	Plaquemines	31 min
Feb 23, 1:43 PM CST	Severe Thunderstorm Warning	LIX	Plaquemines	62 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, 4.0 hours before the alert went out and 109 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 618 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: 476 m²/s²
0-3 km storm-relative helicity: 736 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 231558
SEL1  
SPC WW 231600
LAZ000-MSZ000-CWZ000-232100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 11
NWS STORM PREDICTION CENTER NORMAN OK
1000 AM CST MON FEB 23 2004

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

       SOUTHEAST LOUISIANA
       EXTREME SOUTHERN MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 1000 AM UNTIL 300
PM CST.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 45 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 90 MILES WEST SOUTHWEST OF HOUMA LOUISIANA TO
45 MILES EAST SOUTHEAST OF GULFPORT MISSISSIPPI.

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.




DISCUSSION...CLUSTER OF STRONG/SEVERE STORMS HAS DEVELOPED ALONG
SURFACE BOUNDARY OVER SOUTHERN LA.  THESE STORMS WILL LIKELY TRACK
EASTWARD THROUGH THE DAY...IN AN INCREASINGLY MOIST/UNSTABLE
AIRMASS.  CURRENT VAD/MODEL DATA SUGGEST VERY FAVORABLE LOW LEVEL
AND DEEP LAYER VERTICAL SHEAR PROFILES FOR SUPERCELLS AND POSSIBLE
TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 25035.


...HART

294,0920 304,0882 292,0882 282,0920

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 23, 9:36 AM CST	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, East Baton Rouge, Iberia, Iberville and 18 more	114 min
Feb 23, 11:55 AM CST	Mesoscale Discussion	SPC	Assumption, Iberia, Jefferson, Lafourche, Orleans, Plaquemines and 7 more	2 hr

Nearby

Tornado Watches in Louisiana, 2004 Tornado Watches in Mississippi, 2004 Every tornado watch in 2004

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.