Alert archive / Louisiana / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 913

December 6, 200415 counties in Arkansas; 19 parishes in Louisiana

The Storm Prediction Center issued this severe thunderstorm watch at Dec 6, 2004, 8:50 PM CST for 15 counties in Arkansas; 19 parishes in Louisiana. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Dec 6, 2004, 8:50 PM CST (02:50 UTC)
Expired
Dec 7, 2004, 2:00 AM CST
In force
5 hr
Issued by
the Storm Prediction Center
All 34 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Lincoln County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Union Parish, LA, West Carroll Parish, LA, Winn Parish, LA

The radar

The Shreveport radar (KSHV), 126 km from the middle of the area, began a volume at 02:53 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Dec 6, 10:39 PM CSTSevere Thunderstorm WarningSHVBienville36 min
Dec 6, 10:57 PM CSTSevere Thunderstorm WarningJANAshley48 min
Dec 6, 11:01 PM CSTSevere Thunderstorm WarningSHVJackson, Winn59 min
Dec 6, 11:11 PM CSTSevere Thunderstorm WarningSHVLincoln, Union64 min
Dec 6, 11:12 PM CSTSevere Thunderstorm WarningSHVOuachita63 min
Dec 6, 11:38 PM CSTSevere Thunderstorm WarningLZKArkansas22 min
Dec 6, 11:49 PM CSTSevere Thunderstorm WarningSHVCaldwell56 min
Dec 6, 11:50 PM CSTTornado WarningJANChicot25 min
Dec 6, 11:51 PM CSTSevere Thunderstorm WarningJANMorehouse, Richland39 min
Dec 7, 12:01 AM CSTSevere Thunderstorm WarningJANCatahoula44 min
Dec 7, 12:08 AM CSTSevere Thunderstorm WarningJANFranklin52 min
Dec 7, 12:11 AM CSTSevere Thunderstorm WarningJANEast Carroll, West Carroll49 min
Dec 7, 12:36 AM CSTTornado WarningJANCatahoula, Concordia39 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

Shreveport, LA (KSHV), launched 00:00Z, 2.8 hours before the alert went out and 117 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, Shreveport, LA at 00:00Z on 2004-12-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Shreveport, LA at 00:00Z on 2004-12-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 349 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1991 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
349 m²/s²
0-3 km storm-relative helicity
401 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 070250
SEL3  
SPC WW 070250
ARZ000-LAZ000-070800-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 913
NWS STORM PREDICTION CENTER NORMAN OK
850 PM CST MON DEC 6 2004

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

       SOUTHEASTERN ARKANSAS
       NORTHERN LOUISIANA

EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 850 PM UNTIL
200 AM CST.

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

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 60 STATUTE MILES
EAST AND WEST OF A LINE FROM 20 MILES NORTH OF PINE BLUFF ARKANSAS
TO 80 MILES SOUTH SOUTHWEST OF MONROE LOUISIANA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 912...

DISCUSSION...STRONGLY FORCED SQUALL LINE SWRN AR SSWWD INTO NERN TX
WILL CONTINUE RAPIDLY E/NEWD AHEAD OF STRONG UPPER TROUGH.  WHILE
INSTABILITY IS MARGINAL...VERY STRONG DEEP LAYER SHEAR WILL SUPPORT
CONTINUED THREAT OF DAMAGING WINDS WITH THE SQUALL
LINE...PARTICULARLY ASSOCIATED WITH SHORT LINE SEGMENTS/BOWS.

AVIATION...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 24045.


...HALES

342,0905 312,0913 312,0933 342,0925

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 6, 8:36 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 36 more84 min
Dec 6, 9:51 PM CSTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Independence and 13 more114 min
Dec 6, 11:00 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 10 more90 min
Dec 6, 11:20 PM CSTTornado WatchSPCAshley, Chicot, Desha, Drew6 hr
Dec 7, 1:25 AM CSTMesoscale DiscussionSPCConcordia, Tensas95 min

Nearby

Severe Thunderstorm Watches in Louisiana, 2004Severe Thunderstorm Watches in Arkansas, 2004Every severe thunderstorm 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; radar from the NEXRAD Level II archive.