Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 2425

November 22, 200432 parishes in Louisiana; 17 counties in Mississippi; 22 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Nov 22, 2004, 6:03 PM CST for 32 parishes in Louisiana; 17 counties in Mississippi; 22 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Nov 22, 2004, 6:03 PM CST (00:03 UTC)
Expired: Nov 22, 2004, 8:30 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

All 71 counties

Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Calcasieu Parish, LA, Caldwell 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, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Tensas Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Issaquena County, MS, Jefferson County, MS, Lawrence County, MS, Lincoln County, MS, Madison County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Warren County, MS, Wilkinson County, MS, Yazoo County, MS, Austin County, TX, Brazoria County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Hardin County, TX, Harris County, TX, Jackson County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Tyler County, TX, Victoria County, TX, Waller County, TX, Wharton County, TX

The radar

The Lake Charles radar (KLCH), 70 km from the middle of the area, began a volume at 00:05 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.1 hours before the alert went out and 71 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: 2330 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 442 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

283 
ACUS11 KWNS 230004
SWOMCD
SPC MCD 230003 
MSZ000-LAZ000-ARZ000-TXZ000-230230-

MESOSCALE DISCUSSION 2425
NWS STORM PREDICTION CENTER NORMAN OK
0603 PM CST MON NOV 22 2004

AREAS AFFECTED...SE TEXAS...CNTRL/SRN LA...SW/CNTRL MS

CONCERNING...CONVECTIVE TRENDS/TORNADO WATCH 880...

VALID 230003Z - 230230Z

TRENDS WILL CONTINUE TO BE MONITORED...BUT AT THE PRESENT TIME... IT
IS ANTICIPATED THAT WW 880 WILL BE ALLOWED TO EXPIRE AT 01Z.

AS ONE HIGH LEVEL JET STREAK PROGRESSES THROUGH CREST OF LOW
AMPLITUDE SOUTHEAST STATES SUBTROPICAL RIDGE AND UPSTREAM JET STREAK
CONTINUES EASTWARD THROUGH BASE OF SOUTHWESTERN TROUGH...STRONGER
DIVERGENT UPPER FLOW FIELD WILL GRADUALLY SHIFT FROM EAST TEXAS INTO
THE LOWER MISSISSIPPI VALLEY TONIGHT.  MID-LEVEL SHORT WAVE TROUGH/
JET STREAK APPEARS TO BE PROVIDING PRIMARY SUPPORT FOR ONGOING
CONVECTIVE CLUSTER INLAND OF MID/UPPER TEXAS COASTAL AREAS AND
SOUTHWEST LOUISIANA...BUT THIS FEATURE LIKELY WILL WEAKEN THIS
EVENING AS IT LIFTS THROUGH BROADER SCALE ANTICYCLONIC FLOW REGIME.

WHILE BROAD ISENTROPIC ASCENT MAY MAINTAIN CONVECTIVE DEVELOPMENT
THROUGH THE EVENING HOURS...MUCH OF ACTIVITY APPEARS LIKELY TO
BECOME FOCUSED JUST ABOVE SHALLOW SURFACE FRONT FROM SOUTHWEST/
CENTRAL LOUISIANA INTO CENTRAL MISSISSIPPI BY LATE EVENING.  WEAK
LAPSE RATES AND WARM/MOIST PROFILES ARE EXPECTED TO MINIMIZE SEVERE
THREAT ACROSS THESE AREAS.

HOWEVER...MARGINAL SEVERE RISK MAY CONTINUE ANOTHER HOUR OR TWO WITH
ONGOING ACTIVITY WHICH REMAINS SURFACE-BASED...IN WARM SECTOR
NORTHEAST OF VICTORIA TX INTO THE LAKE CHARLES LA AREA

..KERR.. 11/23/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...JAN...LIX...LCH...SHV...HGX...CRP...EWX...

28659736 29689664 31029478 32099356 33039195 33039076
32628979 31708960 30659164 30329204 29929306 28949575
28589669

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 23, 9:45 AM CST	Tornado Watch	SPC	Allen, Beauregard, Calcasieu, De Soto, Grant, LaSalle and 5 more	5 hr
Nov 23, 11:10 AM CST	Mesoscale Discussion	SPC	Avoyelles, Concordia, Madison, Tensas	3 hr
Nov 23, 11:38 AM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Calcasieu, Grant, LaSalle, Natchitoches and 4 more	2 hr
Nov 23, 12:48 PM CST	Mesoscale Discussion	SPC	Bossier, Caddo, De Soto, Grant, Natchitoches, Sabine and 1 more	117 min
Nov 23, 2:00 PM CST	Tornado Watch	SPC	Allen, Beauregard, Bienville, Bossier, Caddo, Calcasieu and 19 more	7 hr
Nov 23, 3:21 PM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Bienville, Bossier, Caddo, Calcasieu and 19 more	114 min
Nov 23, 5:30 PM CST	Mesoscale Discussion	SPC	Beauregard, Caldwell, Catahoula, Franklin, Grant, Jackson and 7 more	2 hr
Nov 23, 1:40 PM CST	Mesoscale Discussion	SPC	Coahoma	95 min
Nov 22, 10:30 PM CST	Mesoscale Discussion	SPC	Borden, Coke, Crockett, Dawson, Fisher, Garza and 21 more	2 hr
Nov 22, 11:00 PM CST	Tornado Watch	SPC	Andrews, Borden, Coke, Crane, Crockett, Dawson and 22 more	6 hr
Nov 23, 2:58 AM CST	Mesoscale Discussion	SPC	Borden, Coke, Crockett, Fisher, Glasscock, Howard and 11 more	92 min
Nov 23, 4:10 AM CST	Severe Thunderstorm Watch	SPC	Brown, Callahan, Coke, Coleman, Comanche, Concho and 19 more	5 hr
Nov 23, 7:06 AM CST	Mesoscale Discussion	SPC	Anderson, Angelina, Austin, Bastrop, Bell, Blanco and 46 more	84 min
Nov 23, 7:19 AM CST	Mesoscale Discussion	SPC	Brown, Callahan, Coleman, Comanche, Concho, Denton and 13 more	86 min
Nov 23, 7:40 AM CST	Mesoscale Discussion	SPC	Dallam	6 hr
Nov 23, 8:45 AM CST	Tornado Watch	SPC	Anderson, Austin, Bastrop, Bell, Blanco, Brazos and 47 more	6 hr
Nov 23, 9:15 AM CST	Mesoscale Discussion	SPC	Collin, Dallas, Delta, Denton, Fannin, Grayson and 5 more	3 hr
Nov 23, 10:37 AM CST	Mesoscale Discussion	SPC	Anderson, Austin, Bastrop, Bell, Blanco, Brazos and 47 more	113 min
Nov 23, 12:15 PM CST	Mesoscale Discussion	SPC	Carson, Dallam, Hansford, Hartley, Hutchinson, Moore and 3 more	5 hr
Nov 23, 12:16 PM CST	Mesoscale Discussion	SPC	Bosque, Brown, Coke, Coleman, Concho, Coryell and 22 more	2 hr
Nov 23, 2:14 PM CST	Mesoscale Discussion	SPC	Briscoe, Childress, Cottle, Crosby, Dickens, Fisher and 20 more	3 hr
Nov 23, 3:15 PM CST	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bexar, Blanco, Bosque, Brown and 40 more	5 hr
Nov 23, 5:30 PM CST	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 64 more	6 hr

Nearby

Mesoscale Discussions in Louisiana, 2004 Mesoscale Discussions in Texas, 2004 Mesoscale Discussions in Mississippi, 2004 Every mesoscale discussion in 2004

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; radar from the NEXRAD Level II archive.