Alert archive / Texas / Tornado Watches in 2001

Tornado Watch 834

November 27, 2001Calcasieu Parish, Cameron Parish, Louisiana; Chambers County, Galveston County, Jefferson County, Texas

The Storm Prediction Center issued this tornado watch at Nov 27, 2001, 8:30 PM CST for Calcasieu Parish, Cameron Parish, Louisiana; Chambers County, Galveston County, Jefferson County, Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Nov 27, 2001, 8:30 PM CST (02:30 UTC)
Expired
Nov 28, 2001, 1:00 AM CST
In force
5 hr
Issued by
the Storm Prediction Center

Counties Calcasieu Parish, LA, Cameron Parish, LA, Chambers County, TX, Galveston County, TX, Jefferson County, TX

The radar

The Houston radar (KHGX), 67 km from the middle of the area, began a volume at 02:29 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.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 2.5 hours before the alert went out and 131 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, Lake Charles Mun, LA at 00:00Z on 2001-11-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1018 joules per kilogram.LCLLFCEL10008507005003002001001 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, Lake Charles Mun, LA at 00:00Z on 2001-11-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 199 square meters per square second.193958Sfc1 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
1018 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
497 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
199 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.1

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 280208
SEL4  
SPC WW 280203
LAZ000-TXZ000-CWZ000-280700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 834
STORM PREDICTION CENTER NORMAN OK
803 PM CST TUE NOV 27 2001

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

   SOUTHWEST LOUISIANA                          
   EXTREME SOUTHEAST TEXAS                              
   AND ADJACENT COASTAL WATERS                     

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 830 PM
UNTIL 100 AM CST.

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

THE TORNADO WATCH AREA IS ALONG AND 30 STATUTE MILES EITHER SIDE OF
A LINE FROM 40 MILES WEST SOUTHWEST OF GALVESTON TEXAS TO 25 MILES
EAST SOUTHEAST OF LAKE CHARLES 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...LINE OF SUPERCELL THUNDERSTORMS JUST OFF THE TX GULF
COAST IS BEGINNING TO SHIFT SLOWLY NORTHWARD AND INLAND.  MODEL
GUIDANCE SUGGESTS THAT LOW LEVEL BOUNDARY WILL ALSO LIFT
NORTHWARD...INCREASING THE THREAT OF SURFACE-BASED CONVECTION AND
ISOLATED TORNADOES WITH STORMS.  SMALL EMBEDDED BOWS COULD ALSO
PRODUCE LOCALLY DAMAGING WINDS.

AVIATION...TORNADOES AND 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 24035.

...HART

293,0924 284,0951 293,0953 302,0930

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 28, 11:00 AM CSTTornado WatchSPCAcadia, Allen, Ascension, Avoyelles, Beauregard, Calcasieu and 24 more5 hr
Nov 28, 2:45 PM CSTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 24 more5 hr

Nearby

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