Alert archive / Louisiana / Tornado Watches in 2008

Tornado Watch 30

January 31, 200828 parishes in Louisiana; 11 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jan 31, 2008, 12:35 PM CST for 28 parishes in Louisiana; 11 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jan 31, 2008, 12:35 PM CST (18:35 UTC)
Expired
Jan 31, 2008, 7:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 39 counties

Ascension Parish, LA, Assumption 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, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jan 31, 2:00 PM CSTSevere Thunderstorm WarningLIXEast Baton Rouge, East Feliciana, Livingston, Saint Helena, Tangipahoa45 min
Jan 31, 2:27 PM CSTSevere Thunderstorm WarningLIXSaint Helena, Tangipahoa, Washington33 min
Jan 31, 2:37 PM CSTSevere Thunderstorm WarningLIXLivingston, Saint Helena, Saint Tammany, Tangipahoa, Washington38 min
Jan 31, 2:49 PM CSTTornado WarningLIXTangipahoa, Washington26 min
Jan 31, 3:03 PM CSTSevere Thunderstorm WarningJANMarion42 min
Jan 31, 3:15 PM CSTSevere Thunderstorm WarningLIXSaint Tammany, Washington45 min
Jan 31, 3:37 PM CSTSevere Thunderstorm WarningJANForrest, Lamar38 min
Jan 31, 3:56 PM CSTSevere Thunderstorm WarningLIXSaint Tammany, Washington49 min
Jan 31, 3:57 PM CSTSevere Thunderstorm WarningLIXAscension, Assumption, Jefferson, Lafourche, Saint Charles, Saint James and 2 more48 min
Jan 31, 4:13 PM CSTSevere Thunderstorm WarningJANForrest33 min
Jan 31, 4:17 PM CSTSevere Thunderstorm WarningMOBPerry43 min
Jan 31, 4:20 PM CSTTornado WarningJANForrest25 min
Jan 31, 4:32 PM CSTTornado WarningMOBGreene, Perry, Wayne43 min
Jan 31, 4:42 PM CSTSevere Thunderstorm WarningLIXSaint Tammany63 min
Jan 31, 4:43 PM CSTSevere Thunderstorm WarningLIXJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more47 min
Jan 31, 4:44 PM CSTSevere Thunderstorm WarningMOBGeorge, Greene, Perry, Stone61 min
Jan 31, 4:58 PM CSTTornado WarningMOBGreene47 min
Jan 31, 5:03 PM CSTTornado WarningMOBGeorge, Greene, Perry32 min
Jan 31, 5:16 PM CSTSevere Thunderstorm WarningMOBGreene, Wayne45 min
Jan 31, 5:24 PM CSTTornado WarningMOBGeorge, Greene37 min
Jan 31, 5:29 PM CSTSevere Thunderstorm WarningLIXJefferson, Lafourche, Plaquemines, Saint Bernard46 min
Jan 31, 5:40 PM CSTSevere Thunderstorm WarningLIXHancock, Harrison, Jackson65 min
Jan 31, 6:09 PM CSTSevere Thunderstorm WarningMOBGeorge34 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 6.6 hours before the alert went out and 94 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 2008-01-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2008-01-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 296 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
794 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
296 m²/s²
0-3 km storm-relative helicity
357 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.

000
WWUS20 KWNS 311838
SEL0  
SPC WW 311838
LAZ000-MSZ000-CWZ000-010100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 30
NWS STORM PREDICTION CENTER NORMAN OK
1235 PM CST THU JAN 31 2008

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

       LARGE PART OF SOUTHERN LOUISIANA
       PARTS OF SOUTHEASTERN MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1235 PM UNTIL
700 PM 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 APPROXIMATELY ALONG AND 60 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 10 MILES NORTH NORTHWEST OF
INTRACOASTAL CITY LOUISIANA TO 40 MILES EAST OF GULFPORT
MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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 TORNADO
WATCH NUMBER 29. WATCH NUMBER 29 WILL NOT BE IN EFFECT AFTER 1235
PM CST. 

DISCUSSION...SQUALL LINE SWRN MS INTO SWRN LA CONTINUES EWD. WARM
FRONT HAS MOVED INLAND AHEAD OF THE LINE ACROSS SERN LA AND EXPECTED
TO MOVE ONSHORE SERN MS PRIOR TO THE LINE PASSAGE LATER THIS
AFTERNOON.  STRONG SHEAR PROFILES AND MLCAPES TO AROUND 1000 J/KG IN
WARM SECTOR SUPPORT DEVELOPMENT OF SUPERCELLS BOTH EMBEDDED AND JUST
AHEAD OF THE SQUALL LINE.  IN ADDITION TO WIND DAMAGE...TORNADOS
WILL BE POSSIBLE WITH ANY ROTATING UPDRAFT.

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.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 30, 11:47 PM CSTMesoscale DiscussionSPCBossier, Caddo, De Soto, Sabine2 hr
Jan 31, 5:23 AM CSTMesoscale DiscussionSPCBeauregard, Calcasieu, Cameron3 hr
Jan 31, 5:51 AM CSTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more7 hr
Jan 31, 9:57 AM CSTMesoscale DiscussionSPCCameron2 hr
Jan 31, 12:06 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Jefferson and 15 more54 min
Jan 31, 3:25 PM CSTMesoscale DiscussionSPCAscension, Assumption, Livingston, Orleans, Saint Bernard, Saint Charles and 5 more95 min

Nearby

Tornado Watches in Louisiana, 2008Tornado Watches in Mississippi, 2008Every tornado watch in 2008

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.