Alert archive / Louisiana / Tornado Watches in 1997

Tornado Watch 792

November 21, 199729 parishes in Louisiana; 18 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Nov 21, 1997, 11:15 AM CST for 29 parishes in Louisiana; 18 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Nov 21, 1997, 11:15 AM CST (17:15 UTC)
Expired
Nov 21, 1997, 5:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
All 47 counties

Ascension Parish, LA, Assumption Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Forrest County, MS, Franklin County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jefferson Davis County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wilkinson County, MS

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 21, 12:12 PM CSTSevere Thunderstorm WarningLIXWashington48 min
Nov 21, 12:24 PM CSTSevere Thunderstorm WarningJANLincoln51 min
Nov 21, 12:53 PM CSTSevere Thunderstorm WarningJANMarion37 min
Nov 21, 1:01 PM CSTSevere Thunderstorm WarningLIXLivingston, Tangipahoa44 min
Nov 21, 1:20 PM CSTSevere Thunderstorm WarningLIXSaint Tammany, Washington40 min
Nov 21, 1:22 PM CSTSevere Thunderstorm WarningJANLamar38 min
Nov 21, 1:37 PM CSTSevere Thunderstorm WarningJANForrest38 min
Nov 21, 1:41 PM CSTTornado WarningLIXSaint Tammany49 min
Nov 21, 1:41 PM CSTSevere Thunderstorm WarningMOBPerry64 min
Nov 21, 1:56 PM CSTTornado WarningLIXHancock, Pearl River49 min
Nov 21, 2:43 PM CSTTornado WarningLIXHancock, Harrison62 min
Nov 21, 3:00 PM CSTSevere Thunderstorm WarningLIXPearl River30 min
Nov 21, 3:08 PM CSTTornado WarningMOBStone37 min
Nov 21, 3:46 PM CSTTornado WarningLIXHarrison, Jackson44 min
Nov 21, 3:51 PM CSTSevere Thunderstorm WarningMOBStone69 min

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 5.3 hours before the alert went out and 133 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, Slidell Radar S, LA at 12:00Z on 1997-11-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 20 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, Slidell Radar S, LA at 12:00Z on 1997-11-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 192 square meters per square second.1939587897Sfc1 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
20 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
192 m²/s²
0-3 km storm-relative helicity
207 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.

180 
WWUS9 KMKC 211702 COR
SEL2  
MKC WW 211702 COR
LAZ000-MSZ000-212300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 792
STORM PREDICTION CENTER NORMAN OK
1102 AM CST FRI NOV 21 1997

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

SOUTH CENTRAL AND SOUTHEASTER LOUISIANA
SOUTHERN MISSISSIPPI
AND ADJACENT COASTAL WATERS

EFFECTIVE THIS FRIDAY MORNING AND AFTERNOON FROM 1115 AM UNTIL 500
PM CST.

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

THE TORNADO WATCH AREA IS ALONG AND 95 STATUTE MILES EAST AND WEST
OF A LINE FROM 50 MILES SOUTHWEST OF HOUMA LOUISIANA TO 40 MILES
NORTHEAST OF MC COMB MISSISSIPPI.

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...  

DISCUSSION...THUNDERSTORMS INCREASING ALONG SURFACE BOUNDARY AND
AHEAD OF STRONG UPPER LEVEL TROF. 70 KT FLOW AT MID LEVELS WILL
PROVIDE FAVORABLE SHEAR FOR TORNADIC SUPERCELLS AS CAPES FROM 1500
TO 2500 J/KG.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 24045.


...ROGASH

290,0925 313,0913 313,0882 290,0894

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 21, 2:30 PM CSTTornado WatchSPCGeorge, Jackson6 hr

Nearby

Tornado Watches in Louisiana, 1997Tornado Watches in Mississippi, 1997Every tornado watch in 1997

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.