Alert archive / Louisiana / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 9

January 29, 200120 parishes in Louisiana; 16 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Jan 29, 2001, 3:45 AM CST for 20 parishes in Louisiana; 16 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jan 29, 2001, 3:45 AM CST (09:45 UTC)
Expired: Jan 29, 2001, 9:00 AM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 36 counties

Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Tyler County, TX

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jan 29, 3:57 AM CST	Severe Thunderstorm Warning	HGX	Liberty, Montgomery	48 min
Jan 29, 5:01 AM CST	Severe Thunderstorm Warning	HGX	Liberty	44 min
Jan 29, 5:23 AM CST	Severe Thunderstorm Warning	HGX	Galveston	52 min
Jan 29, 5:32 AM CST	Severe Thunderstorm Warning	LCH	Jasper, Newton	58 min
Jan 29, 6:07 AM CST	Severe Thunderstorm Warning	LCH	Beauregard, Vernon	53 min
Jan 29, 7:10 AM CST	Severe Thunderstorm Warning	LCH	Beauregard, Calcasieu	50 min
Jan 29, 7:10 AM CST	Severe Thunderstorm Warning	LCH	Allen, Rapides, Vernon	50 min

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 9.8 hours before the alert went out and 116 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: 1124 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 526 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 196 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.4

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 290927
SEL9  

SEL9  
MKC WW 290920
LAZ000-TXZ000-CWZ000-291500-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 9
STORM PREDICTION CENTER NORMAN OK
320 AM CST MON JAN 29 2001

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

   NORTHERN AND SOUTHWEST LOUISIANA                          
   EAST TEXAS                              
   COASTAL WATERS                     

EFFECTIVE THIS MONDAY MORNING FROM 345 AM UNTIL 900 AM CST.

HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 65 STATUTE MILES
EAST AND WEST OF A LINE FROM 15 MILES SOUTHWEST OF GALVESTON TEXAS
TO 45 MILES NORTHWEST 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.

OTHER WATCH INFORMATION...  CONTINUE...WW 8...

DISCUSSION...LINE OF THUNDERSTORMS HAS BEEN INTENSIFYING OVER ERN
TX AS STRONG COLD FRONT MOVES EWD ACROSS THE REGION.  ALTHOUGH AIR
MASS AHEAD OF THE LINE IS ONLY MARGINALLY UNSTABLE...VAD AND
PROFILER WINDS INDICATE STRONG LOW LEVEL SHEAR AND POTENTIAL FOR
SEVERE STORMS.  STRONG DYNAMIC FORCING FOR UPWARD MOTION ASSOCIATED
WITH VIGOROUS UPPER TROUGH MOVING TOWARD CENTRAL TX WILL ENHANCE
CONVECTIVE POTENTIAL.


AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. 
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.  MEAN STORM MOTION
VECTOR 22045.


...WEISS

;291,0960 325,0934 325,0912 291,0935;

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 29, 8:00 AM CST	Severe Thunderstorm Watch	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Caldwell and 27 more	6 hr
Jan 29, 11:30 AM CST	Severe Thunderstorm Watch	SPC	Ascension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 8 more	5 hr
Jan 29, 12:00 AM CST	Severe Thunderstorm Watch	SPC	Anderson, Austin, Bastrop, Brazos, Burleson, Caldwell and 33 more	5 hr

Nearby

Severe Thunderstorm Watches in Louisiana, 2001 Severe Thunderstorm Watches in Texas, 2001 Every severe thunderstorm watch in 2001

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.