Alert archive / Texas / Tornado Watches in 2001

Tornado Watch 833

November 27, 20015 parishes in Louisiana; 15 counties in Texas

The Storm Prediction Center issued this tornado watch at Nov 27, 2001, 12:00 AM CST for 5 parishes in Louisiana; 15 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Nov 27, 2001, 12:00 AM CST (06:00 UTC)
Expired: Nov 27, 2001, 5:00 AM CST
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Rapides Parish, LA, Vernon Parish, LA, Angelina County, TX, Chambers County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Tyler County, TX

The radar

The Houston radar (KHGX), 103 km from the middle of the area, began a volume at 06:02 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

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

Issued	Product	Office	Counties	Lasted
Nov 27, 1:10 AM CST	Flash Flood Warning	HGX	Montgomery, Polk, San Jacinto	3 hr
Nov 27, 4:13 AM CST	Flash Flood Warning	HGX	Montgomery, San Jacinto	2 hr

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 6.0 hours before the alert went out and 132 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: 2361 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 572 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 146 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 8.5

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 270544
SEL3  
SPC WW 270541
LAZ000-TXZ000-CWZ000-271100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 833
STORM PREDICTION CENTER NORMAN OK
1141 PM CST MON NOV 26 2001

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

   SOUTHWEST LOUISIANA                          
   SOUTHEAST TEXAS                              
   AND ADJACENT COASTAL WATERS                     

EFFECTIVE THIS TUESDAY MORNING FROM MIDNIGHT CST UNTIL 500 AM 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 75 STATUTE MILES EAST AND WEST
OF A LINE FROM 20 MILES EAST SOUTHEAST OF HOUSTON TEXAS TO 25 MILES
NORTH NORTHWEST OF FORT POLK 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 SEVERE
THUNDERSTORM WATCH NUMBER 829.  WATCH NUMBER 829 WILL NOT BE IN
EFFECT AFTER MIDNIGHT CST.  CONTINUE...WW 830...WW 831...WW 832...

DISCUSSION...LINE OF STRONG/SEVERE THUNDERSTORMS EXTENDS ACROSS
SOUTHEAST TX...WHILE OTHER ISOLATED CELLS CONTINUE TO DEVELOP AHEAD
OF LINE OVER SOUTHEAST TX/SOUTHWEST LA.  SUFFICIENT LOW LEVEL
SHEAR...AMPLE LOW LEVEL MOISTURE...AND APPROACHING UPPER TROUGH
WILL MAINTAIN A RISK OF DAMAGING WINDS...LARGE HAIL...AND ISOLATED
TORNADOES THROUGH MUCH OF THE NIGHT.

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.

...HART

312,0920 293,0934 293,0961 312,0943

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 26, 6:00 PM CST	Tornado Watch	SPC	Bienville, Caldwell, Catahoula, Claiborne, Concordia, De Soto and 18 more	5 hr
Nov 26, 8:00 PM CST	Severe Thunderstorm Watch	SPC	Beauregard, Vernon	5 hr
Nov 26, 11:00 PM CST	Tornado Watch	SPC	Bienville, Caldwell, Catahoula, East Carroll, Franklin, Grant and 14 more	5 hr

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; radar from the NEXRAD Level II archive.