Alert archive / Louisiana / Tornado Watches in 2005

Tornado Watch 150

April 11, 20054 states

The Storm Prediction Center issued this tornado watch at Apr 11, 2005, 10:15 AM CDT for 4 states. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Apr 11, 2005, 10:15 AM CDT (15:15 UTC)
Expired
Apr 11, 2005, 7:00 PM CDT
In force
9 hr
Issued by
the Storm Prediction Center
All 67 counties

Ashley County, AR, Chicot County, AR, Desha County, AR, Drew County, AR, Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Claiborne County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Leflore County, MS, Montgomery County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Yazoo County, MS, Brazoria County, TX, Chambers County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Newton County, TX, Orange County, TX, Sabine County, TX, Tyler County, TX

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 11, 10:28 AM CDTSevere Thunderstorm WarningJANCarroll, Holmes, Leflore47 min
Apr 11, 10:36 AM CDTFlash Flood WarningJANCarroll3 hr
Apr 11, 11:11 AM CDTSevere Thunderstorm WarningJANCarroll, Grenada64 min
Apr 11, 11:20 AM CDTFlash Flood WarningJANHumphreys, Sunflower, Washington6 hr
Apr 11, 11:22 AM CDTSevere Thunderstorm WarningJANLeflore53 min
Apr 11, 11:25 AM CDTSevere Thunderstorm WarningLCHHardin, Jasper35 min
Apr 11, 11:28 AM CDTFlash Flood WarningJANGrenada6 hr
Apr 11, 11:37 AM CDTSevere Thunderstorm WarningSHVSabine53 min
Apr 11, 11:57 AM CDTSevere Thunderstorm WarningLCHJasper, Newton33 min
Apr 11, 12:09 PM CDTSevere Thunderstorm WarningJANCarroll, Grenada66 min
Apr 11, 12:10 PM CDTFlash Flood WarningMEGTallahatchie110 min
Apr 11, 12:24 PM CDTSevere Thunderstorm WarningLCHBeauregard36 min
Apr 11, 2:05 PM CDTFlash Flood WarningMEGPanola, Quitman, Tallahatchie, Tate115 min
Apr 11, 2:06 PM CDTSevere Thunderstorm WarningJANWashington39 min
Apr 11, 2:07 PM CDTSevere Thunderstorm WarningJANEast Carroll53 min
Apr 11, 2:20 PM CDTTornado WarningJANIssaquena, Sharkey40 min
Apr 11, 2:25 PM CDTFlash Flood WarningJANCarroll, Holmes, Leflore6 hr
Apr 11, 2:34 PM CDTSevere Thunderstorm WarningJANCatahoula, Concordia56 min
Apr 11, 2:38 PM CDTSevere Thunderstorm WarningJANHumphreys, Yazoo67 min
Apr 11, 2:52 PM CDTSevere Thunderstorm WarningJANLeflore68 min
Apr 11, 3:12 PM CDTSevere Thunderstorm WarningJANTensas48 min
Apr 11, 3:56 PM CDTFlash Flood WarningJANWarren2 hr
Apr 11, 4:03 PM CDTSevere Thunderstorm WarningJANWarren42 min
Apr 11, 4:41 PM CDTSevere Thunderstorm WarningJANClay, Webster64 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 3.3 hours before the alert went out and 89 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 12:00Z on 2005-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1084 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 12:00Z on 2005-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 285 square meters per square second.19395878Sfc1 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
1084 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
737 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
285 m²/s²
0-3 km storm-relative helicity
342 m²/s²
Significant tornado parameter
0.8
Supercell composite
12.2

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 111519
SEL0  
SPC WW 111519
ARZ000-LAZ000-MSZ000-TXZ000-CWZ000-120000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 150
NWS STORM PREDICTION CENTER NORMAN OK
1015 AM CDT MON APR 11 2005

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

       SOUTHEAST ARKANSAS
       WESTERN AND NORTHERN LOUISIANA
       WESTERN AND NORTHERN MISSISSIPPI
       EXTREME SOUTHEAST TEXAS
       COASTAL WATERS

EFFECTIVE THIS MONDAY MORNING AND EVENING FROM 1015 AM UNTIL 700
PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 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 80 STATUTE MILES
EAST AND WEST OF A LINE FROM 35 MILES NORTH NORTHWEST OF GREENWOOD
MISSISSIPPI TO 35 MILES SOUTH SOUTHWEST OF GALVESTON TEXAS.  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 SEVERE
THUNDERSTORM WATCH NUMBER 149. WATCH NUMBER 149 WILL NOT BE IN
EFFECT AFTER 1015 AM CDT. 

DISCUSSION...TORNADO THREAT EXPECTED TO INCREASE THROUGH THE
AFTERNOON OVER WW AREA AS SURFACE HEATING DESTABILIZES STRONGLY
SHEARED/INCREASINGLY MOIST ENVIRONMENT AHEAD OF EXISTING CONVECTIVE
BAND IN SE TX/WRN LA.  OTHER STORMS MAY FORM AHEAD OF CONVECTIVE
BAND...IN ZONE OF GREATER  HEATING/LOW LEVEL CONFLUENCE CLOSER TO
THE MS RIVER.  50-60 KT DEEP SSWLY SHEAR ABOVE MOIST...SELY LOW
LEVEL FLOW WILL BE SUPPORTIVE OF LOW LEVEL STORM ROTATION.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 22035.


...CORFIDI

335,0885 285,0933 285,0961 335,0914

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 8:53 PM CDTMesoscale DiscussionSPCBenton, Crawford, Sebastian, Washington2 hr
Apr 10, 9:15 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Clark, Crawford, Franklin, Howard and 10 more7 hr
Apr 11, 1:23 AM CDTMesoscale DiscussionSPCBenton, Carroll, Clark, Crawford, Franklin, Howard and 11 more67 min
Apr 11, 3:12 AM CDTMesoscale DiscussionSPCColumbia, Lafayette, Miller, Union63 min
Apr 11, 3:23 AM CDTMesoscale DiscussionSPCBenton, Carroll, Clark, Crawford, Franklin, Howard and 11 more67 min
Apr 11, 3:45 AM CDTSevere Thunderstorm WatchSPCAshley, Bradley, Columbia, Lafayette, Miller, Union7 hr
Apr 11, 6:17 AM CDTMesoscale DiscussionSPCArkansas, Clay, Cleburne, Conway, Craighead, Crittenden and 27 more118 min
Apr 11, 6:53 AM CDTMesoscale DiscussionSPCAshley, Columbia, Lafayette, Miller, Union67 min
Apr 11, 9:41 AM CDTMesoscale DiscussionSPCAshley, Bradley, Chicot, Columbia, Union2 hr
Apr 11, 12:12 PM CDTMesoscale DiscussionSPCAshley, Bradley, Chicot, Columbia, Union2 hr
Apr 11, 2:01 PM CDTMesoscale DiscussionSPCBenton, Carroll, Madison, Washington89 min
Apr 11, 3:56 AM CDTMesoscale DiscussionSPCFranklin, Madison, Tensas64 min
Apr 11, 1:41 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafourche and 14 more2 hr
Apr 11, 2:05 PM CDTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 14 more7 hr
Apr 11, 6:35 PM CDTTornado WatchSPCJefferson, Lafourche, Orleans, Saint Bernard, Saint Charles, Saint Tammany and 1 more4 hr
Apr 11, 6:52 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 9 more83 min
Apr 11, 1:17 PM CDTMesoscale DiscussionSPCAlcorn, Benton, Coahoma, Itawamba, Lafayette, Lee and 10 more58 min
Apr 11, 1:35 PM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 10 more5 hr
Apr 10, 7:39 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bell, Bexar, Blanco, Bosque and 45 more96 min
Apr 10, 10:45 PM CDTSevere Thunderstorm WatchSPCAnderson, Bastrop, Bell, Bexar, Blanco, Brazos and 39 more6 hr

Nearby

Tornado Watches in Louisiana, 2005Tornado Watches in Mississippi, 2005Tornado Watches in Texas, 2005Every tornado watch in 2005

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.