Alert archive / Texas / Tornado Watches in 2001

Tornado Watch 849

December 16, 20019 parishes in Louisiana; 22 counties in Texas

The Storm Prediction Center issued this tornado watch at Dec 16, 2001, 1:45 PM CST for 9 parishes in Louisiana; 22 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Dec 16, 2001, 1:45 PM CST (19:45 UTC)
Expired: Dec 16, 2001, 7:00 PM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 31 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Webster Parish, LA, Anderson County, TX, Angelina County, TX, Brazos County, TX, Cherokee County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Houston County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Robertson County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Trinity County, TX

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Dec 16, 3:50 PM CST	Flash Flood Warning	FWD	Henderson	4 hr
Dec 16, 5:21 PM CST	Tornado Warning	SHV	Gregg	39 min
Dec 16, 5:26 PM CST	Tornado Warning	HGX	Polk, Trinity	49 min
Dec 16, 6:01 PM CST	Flash Flood Warning	SHV	Gregg	4 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 7.8 hours before the alert went out and 137 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 425 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 140 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 161922
SEL9  
SPC WW 161914
LAZ000-TXZ000-170100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 849
STORM PREDICTION CENTER NORMAN OK
114 PM CST SUN DEC 16 2001

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

   NORTHWEST LOUISIANA                          
   NORTHEAST TEXAS                              

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 145 PM UNTIL 700
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 55 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 100 MILES SOUTHWEST OF TYLER TEXAS TO 65 MILES
EAST OF SHREVEPORT 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.


DISCUSSION...SURFACE LOW VICINITY ACT AT 19Z  WITH WARM FRONT
EXTENDING ENEWD INTO NRN LA.  WITH APPROACH OF STRONG S/WV TROUGH
NOW ENTERING WRN TX A VERY FAVORABLE KINEMATIC ENVIRONMENT HAS
DEVELOPED FOR FORMATION OF SUPERCELLS  VICINITY WARM FRONT.  AIR
MASS IN WARM SECTOR HAS DESTABILIZED WITH VIRTUALLY NO CAP
REMAINING. SBCAPE HAS RISEN TO 1500 J/KG WHICH IS SUFFICIENT TO
SUPPORT DEEP CONVECTION.  SEVERE THUNDERSTORMS WILL DEVELOP AHEAD
OF SURFACE LOW NERN TX AND THEN ENEWD INTO NWRN LA.  IN ADDITION TO
POTENTIAL FOR WIND DAMAGE WITH BOWING SEGMENTS IN STRONG
FLOW...ISOLATED TORNADOES ARE ALSO LIKELY WITH
SUPERCELLS...PARTICULARLY VICINITY WARM FRONT.


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 24035.


...HALES

313,0924 303,0963 320,0963 331,0924

Nearby

Tornado Watches in Texas, 2001 Tornado Watches in Louisiana, 2001 Every tornado 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.