Alert archive / Louisiana / Tornado Watches in 2006

Tornado Watch 856

November 15, 2006Ashley County, Chicot County, Arkansas; 25 parishes in Louisiana

The Storm Prediction Center issued this tornado watch at Nov 15, 2006, 5:31 AM CST for Ashley County, Chicot County, Arkansas; 25 parishes in Louisiana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Nov 15, 2006, 5:31 AM CST (11:31 UTC)
Expired
Nov 15, 2006, 9:44 AM CST
In force
4 hr
Issued by
the Storm Prediction Center
All 27 counties

Ashley County, AR, Chicot County, AR, Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Rapides Parish, LA, Richland Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Tensas Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, West Carroll Parish, LA

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 15, 5:41 AM CSTSevere Thunderstorm WarningJANChicot49 min
Nov 15, 5:46 AM CSTSevere Thunderstorm WarningJANEast Carroll44 min
Nov 15, 5:50 AM CSTSevere Thunderstorm WarningJANFranklin, Richland40 min
Nov 15, 6:01 AM CSTTornado WarningJANChicot44 min
Nov 15, 6:04 AM CSTSevere Thunderstorm WarningJANCatahoula41 min
Nov 15, 6:21 AM CSTSevere Thunderstorm WarningJANMadison54 min
Nov 15, 6:34 AM CSTSevere Thunderstorm WarningJANEast Carroll41 min
Nov 15, 6:40 AM CSTTornado WarningJANMadison50 min
Nov 15, 6:47 AM CSTSevere Thunderstorm WarningJANTensas43 min
Nov 15, 6:56 AM CSTSevere Thunderstorm WarningJANConcordia49 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

Shreveport, LA (KSHV), launched 00:00Z, 11.5 hours before the alert went out and 166 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, Shreveport, LA at 00:00Z on 2006-11-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1091 joules per kilogram.LCLEL10008507005003002001001 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, Shreveport, LA at 00:00Z on 2006-11-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 161 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
1091 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
942 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
161 m²/s²
0-3 km storm-relative helicity
270 m²/s²
Significant tornado parameter
1.5
Supercell composite
6.8

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 151135
SEL6  
SPC WW 151135
ARZ000-LAZ000-CWZ000-151900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 856
NWS STORM PREDICTION CENTER NORMAN OK
530 AM CST WED NOV 15 2006

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

       SOUTHEAST ARKANSAS
       CENTRAL AND SOUTHERN LOUISIANA
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 530 AM UNTIL
100 PM CST.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES EAST AND WEST OF A LINE FROM MONTICELLO ARKANSAS TO 15
MILES SOUTH OF INTRACOASTAL CITY LOUISIANA.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU6).

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 850...TORNADO WATCH NUMBER 852. WATCH NUMBER 850 852
WILL NOT BE IN EFFECT AFTER 530 AM CST. CONTINUE...WW 851...WW
853...WW 854...WW 855...

DISCUSSION...TSTMS EXPECTED TO CONTINUE INCREASING IN COVERAGE AND
INTENSITY ALONG PREFRONTAL CONVERGENCE BAND AS COLD FRONT OVERTAKES
STORMS.  STRONG DEEP SHEAR AND MOIST LOW LEVEL ENVIRONMENT WILL
FAVORABLE FOR ADDITIONAL SUPERCELLS AND POSSIBLE TORNADOES.

SPECIAL NOTE: WW 850 WILL BE EXTENDED LOCALLY ANOTHER HOUR OR SO IN
SMALL PORTIONS OF CNTRL LA AND SE AR WITHIN THE SHREVEPORT AND
LITTLE ROCK NWS COUNTY WARNING AREAS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24040.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 14, 6:46 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 39 more119 min
Nov 14, 9:15 PM CSTMesoscale DiscussionSPCArkansas, Cleburne, Craighead, Crittenden, Cross, Faulkner and 13 more2 hr
Nov 14, 9:20 PM CSTTornado Watch PDSSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more9 hr
Nov 14, 11:01 PM CSTSevere Thunderstorm WatchSPCCleburne, Conway, Faulkner, Independence, Jackson, Johnson and 16 more7 hr
Nov 14, 11:32 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 47 more58 min
Nov 15, 2:16 AM CSTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Clark, Cleveland and 15 more119 min
Nov 15, 2:29 AM CSTMesoscale DiscussionSPCCleburne, Conway, Crawford, Crittenden, Cross, Faulkner and 25 more2 hr
Nov 15, 4:30 AM CSTTornado WatchSPCCrittenden, Cross, Lee, Phillips, St. Francis5 hr
Nov 14, 10:07 PM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Evangeline and 7 more83 min
Nov 14, 11:25 PM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 22 more6 hr
Nov 15, 1:30 AM CSTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 2 more2 hr
Nov 15, 1:59 AM CSTTornado Watch PDSSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more8 hr
Nov 15, 3:25 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 14 more2 hr
Nov 15, 5:55 AM CSTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 10 more95 min
Nov 15, 7:14 AM CSTMesoscale DiscussionSPCAcadia, Ascension, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 14 more2 hr
Nov 15, 9:30 AM CSTMesoscale DiscussionSPCOrleans, Saint Bernard, Saint Tammany, Tangipahoa, Washington60 min
Nov 15, 9:54 AM CSTTornado WatchSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more11 hr
Nov 15, 12:46 PM CSTMesoscale DiscussionSPCAlcorn, Benton, Lafayette, Marshall, Prentiss, Tippah and 2 more119 min

Nearby

Tornado Watches in Louisiana, 2006Tornado Watches in Arkansas, 2006Every tornado watch in 2006

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.