Alert archive / Louisiana / Tornado Watches in 2006

Tornado Watch 101

March 20, 20067 parishes in Louisiana; 4 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 20, 2006, 4:44 AM CST for 7 parishes in Louisiana; 4 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Mar 20, 2006, 4:44 AM CST (10:44 UTC)
Expired: Mar 20, 2006, 10:00 AM CST
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Evangeline Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Vernon Parish, LA, Hardin County, TX, Jasper County, TX, Newton County, TX, Tyler County, TX

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Mar 20, 8:40 AM CST	Severe Thunderstorm Warning	LCH	Jasper	65 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 00:00Z, 10.7 hours before the alert went out and 123 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 875 J/kg
Mixed-layer CIN: -54 J/kg
Mixed-layer LCL: 696 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 201043
SEL1  
SPC WW 201043
LAZ000-TXZ000-201600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 101
NWS STORM PREDICTION CENTER NORMAN OK
440 AM CST MON MAR 20 2006

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

       SOUTHWEST AND CENTRAL LOUISIANA
       EXTREME SOUTHEAST TEXAS

EFFECTIVE THIS MONDAY MORNING FROM 440 AM UNTIL 1000 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 APPROXIMATELY ALONG AND 40 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 50 MILES SOUTHWEST OF LUFKIN TEXAS
TO 30 MILES SOUTH SOUTHEAST OF ALEXANDRIA LOUISIANA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU1).

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...CONVECTIVELY INDUCED VORT MAX OVER SE TX WILL MOVE
EWD/ENEWD INTO LA THROUGH THE MORNING. EXPECT STORMS TO CONTINUE
DEVELOPING IN ADVANCE OF THIS SYSTEM AND ALONG A SURFACE WARM FRONT
TO THE N OF I-10...WHERE THE ENVIRONMENT IS SUPPORTIVE OF
SUPERCELLS.  RICH LOW-LEVEL MOISTURE AND STRONG LOW-LEVEL SHEAR ARE
PRESENT ALONG THE WARM FRONT...AND THIS BOUNDARY WILL HELP FOCUS A
NARROW CORRIDOR WHERE A TORNADO OR TWO WILL BE POSSIBLE THIS
MORNING.

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 500.
MEAN STORM MOTION VECTOR 26030.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 20, 3:36 AM CST	Mesoscale Discussion	SPC	Beauregard, Calcasieu	24 min
Mar 20, 4:21 AM CST	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Calcasieu, Evangeline, Grant and 6 more	24 min
Mar 20, 6:36 AM CST	Mesoscale Discussion	SPC	Acadia, Allen, Beauregard, Evangeline, Rapides, Vernon	54 min
Mar 20, 9:20 AM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Concordia and 12 more	85 min
Mar 20, 9:53 AM CST	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 19 more	7 hr
Mar 20, 2:12 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 19 more	93 min
Mar 20, 3:09 PM CST	Tornado Watch	SPC	Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Pointe Coupee and 6 more	7 hr
Mar 19, 6:09 PM CST	Severe Thunderstorm Watch	SPC	Andrews, Bailey, Castro, Cochran, Crane, Deaf Smith and 12 more	7 hr
Mar 19, 8:34 PM CST	Tornado Watch	SPC	Atascosa, Austin, Bandera, Bastrop, Bell, Bexar and 39 more	7 hr
Mar 19, 8:54 PM CST	Mesoscale Discussion	SPC	Andrews, Bailey, Castro, Cochran, Crosby, Dawson and 17 more	2 hr
Mar 19, 9:48 PM CST	Severe Thunderstorm Watch	SPC	Baylor, Borden, Briscoe, Callahan, Childress, Coke and 33 more	5 hr
Mar 19, 10:32 PM CST	Mesoscale Discussion	SPC	Atascosa, Austin, Bandera, Bastrop, Bexar, Brazos and 28 more	118 min
Mar 19, 11:37 PM CST	Mesoscale Discussion	SPC	Atascosa, Austin, Bandera, Bastrop, Bexar, Brazos and 28 more	83 min
Mar 20, 1:26 AM CST	Mesoscale Discussion	SPC	Angelina, Aransas, Atascosa, Austin, Bastrop, Bee and 59 more	64 min
Mar 20, 2:08 AM CST	Mesoscale Discussion	SPC	Baylor, Callahan, Childress, Coke, Coleman, Cottle and 17 more	67 min
Mar 20, 12:47 PM CST	Mesoscale Discussion	SPC	Clay, Hardeman, Montague, Wichita, Wilbarger	88 min

Nearby

Tornado Watches in Louisiana, 2006 Tornado Watches in Texas, 2006 Every 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.