Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 2437

November 23, 2004Lafayette County, Miller County, Arkansas; 7 parishes in Louisiana; 64 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Nov 23, 2004, 12:48 PM CST for Lafayette County, Miller County, Arkansas; 7 parishes in Louisiana; 64 counties in Texas. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Nov 23, 2004, 12:48 PM CST (18:48 UTC)
Expired
Nov 23, 2004, 2:45 PM CST
In force
117 min
Issued by
the Storm Prediction Center
All 73 counties

Lafayette County, AR, Miller County, AR, Bossier Parish, LA, Caddo Parish, LA, De Soto Parish, LA, Grant Parish, LA, Natchitoches Parish, LA, Sabine Parish, LA, Winn Parish, LA, Anderson County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Caldwell County, TX, Calhoun County, TX, Camp County, TX, Cass County, TX, Chambers County, TX, Cherokee County, TX, Comal County, TX, Ellis County, TX, Falls County, TX, Fayette County, TX, Fort Bend County, TX, Franklin County, TX, Freestone County, TX, Galveston County, TX, Gregg County, TX, Grimes County, TX, Guadalupe County, TX, Hardin County, TX, Harris County, TX, Harrison County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Houston County, TX, Hunt County, TX, Jackson County, TX, Kaufman County, TX, Kendall County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, Marion County, TX, Matagorda County, TX, McLennan County, TX, Milam County, TX, Morris County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Refugio County, TX, Robertson County, TX, Rockwall County, TX, Rusk County, TX, Sabine County, TX, Smith County, TX, Titus County, TX, Travis County, TX, Upshur County, TX, Van Zandt County, TX, Victoria County, TX, Washington County, TX, Wharton County, TX, Williamson County, TX, Wood County, TX

The radar

The Houston radar (KHGX), 136 km from the middle of the area, began a volume at 18:52 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 6.8 hours before the alert went out and 234 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 2004-11-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 534 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 2004-11-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 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
534 J/kg
Mixed-layer CIN
-154 J/kg
Mixed-layer LCL
1172 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

701 
ACUS11 KWNS 231848
SWOMCD
SPC MCD 231848 
ARZ000-LAZ000-TXZ000-232045-

MESOSCALE DISCUSSION 2437
NWS STORM PREDICTION CENTER NORMAN OK
1248 PM CST TUE NOV 23 2004

AREAS AFFECTED...PORTIONS CENTRAL THROUGH NERN TX...NRN/WRN
LA...SERN TX

CONCERNING...TORNADO WATCH 883...884...

VALID 231848Z - 232045Z

PERSISTENT/TORNADIC TSTM WITH HYBRID OF HP SUPERCELL AND BOW
CHARACTERISTICS WILL MOVE NEWD FROM ROBERTSON COUNTY ACROSS PORTIONS
LEON/MADISON/HOUSTON COUNTIES OVER NEXT 1-2 HOURS...MAINTAINING
POTENTIAL FOR TORNADOES...LARGE HAIL AND DESTRUCTIVE WINDS AS IT
INTERACTS WITH SFC WARM FRONT. THIS STORM ALSO IS LOCATED NEAR SFC
MESOLOW...WHICH WILL MAINTAIN OPTIMALLY FAVORABLE STORM-RELATIVE
INFLOW IN BOUNDARY LAYER.

TORNADO THREAT IS INCREASING OVER CENTRAL/NRN PORTIONS OF WWS AS
WELL.  WARM FRONT -- NOW ANALYZED FROM FREESTONE COUNTY GENERALLY
EWD ACROSS NACOGDOCHES AREA INTO CENTRAL LA -- SHOULD CONTINUE TO
LIFT NWD ACROSS NE TX AND ALLOW SFC-BASED BUOYANCY TO SPREAD INTO
ARKLATEX REGION.  AS A RESULT...WWS MAY NEED REPLACEMENT WITHIN NEXT
COUPLE HOURS TO INCLUDE MORE OF NRN LA AND PERHAPS SRN AR.  LARGE
MASS OF CONVECTION NOW DEVELOPING OVER SE TX MAY RESTRICT FURTHER
SFC DESTABILIZATION...HOWEVER MLCAPES 2000-2500 J/KG ARE COMMON
ALREADY ACROSS THIS REGION BASED ON 18Z SHV/LCH/CRP RAOBS AND
RUC/ETA-KF MODEL SOUNDINGS.  EXPECT KINEMATIC WEAKNESSES IN 2-6 KM
AGL PORTION OF HODOGRAPH TO GO AWAY AS LOW-MIDLEVEL FLOW STRENGTHENS
IN RESPONSE TO APCHG UPPER TROUGH...AND ASSOCIATED SFC CYCLOGENESIS
OVER CENTRAL/NERN TX.

..EDWARDS.. 11/23/2004

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

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

29519646 29529912 33349610 33309335 

28109478 28159766 32049458 32079161

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 23, 8:45 AM CSTTornado WatchSPCLafayette, Miller6 hr
Nov 23, 10:37 AM CSTMesoscale DiscussionSPCLafayette, Miller113 min
Nov 23, 1:40 PM CSTMesoscale DiscussionSPCArkansas, Conway, Cross, Faulkner, Garland, Grant and 14 more95 min
Nov 23, 2:00 PM CSTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 25 more7 hr
Nov 23, 3:21 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 25 more114 min
Nov 22, 6:03 PM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 26 more2 hr
Nov 23, 9:45 AM CSTTornado WatchSPCAllen, Beauregard, Calcasieu, De Soto, Grant, LaSalle and 5 more5 hr
Nov 23, 11:10 AM CSTMesoscale DiscussionSPCAvoyelles, Concordia, Madison, Tensas3 hr
Nov 23, 11:38 AM CSTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Grant, LaSalle, Natchitoches and 4 more2 hr
Nov 23, 5:30 PM CSTMesoscale DiscussionSPCBeauregard, Caldwell, Catahoula, Franklin, Grant, Jackson and 7 more2 hr
Nov 22, 10:30 PM CSTMesoscale DiscussionSPCBorden, Coke, Crockett, Dawson, Fisher, Garza and 21 more2 hr
Nov 22, 11:00 PM CSTTornado WatchSPCAndrews, Borden, Coke, Crane, Crockett, Dawson and 22 more6 hr
Nov 23, 2:58 AM CSTMesoscale DiscussionSPCBorden, Coke, Crockett, Fisher, Glasscock, Howard and 11 more92 min
Nov 23, 4:10 AM CSTSevere Thunderstorm WatchSPCBrown, Callahan, Coke, Coleman, Comanche, Concho and 19 more5 hr
Nov 23, 7:06 AM CSTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Blanco and 46 more84 min
Nov 23, 7:19 AM CSTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Denton and 13 more86 min
Nov 23, 7:40 AM CSTMesoscale DiscussionSPCDallam6 hr
Nov 23, 9:15 AM CSTMesoscale DiscussionSPCCollin, Dallas, Delta, Denton, Fannin, Grayson and 5 more3 hr
Nov 23, 12:15 PM CSTMesoscale DiscussionSPCCarson, Dallam, Hansford, Hartley, Hutchinson, Moore and 3 more5 hr
Nov 23, 12:16 PM CSTMesoscale DiscussionSPCBosque, Brown, Coke, Coleman, Concho, Coryell and 22 more2 hr
Nov 23, 2:14 PM CSTMesoscale DiscussionSPCBriscoe, Childress, Cottle, Crosby, Dickens, Fisher and 20 more3 hr
Nov 23, 3:15 PM CSTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bexar, Blanco, Bosque, Brown and 40 more5 hr
Nov 23, 5:30 PM CSTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 64 more6 hr

Nearby

Mesoscale Discussions in Texas, 2004Mesoscale Discussions in Louisiana, 2004Mesoscale Discussions in Arkansas, 2004Every 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.