Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 321

April 10, 20045 parishes in Louisiana; 6 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2004, 5:38 PM CDT for 5 parishes in Louisiana; 6 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 10, 2004, 5:38 PM CDT (22:38 UTC)
Expired
Apr 10, 2004, 7:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Vernon Parish, LA, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Newton County, TX, Orange County, TX, Tyler County, TX

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, 10.6 hours before the alert went out and 42 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 2004-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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 2004-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
4 J/kg
Mixed-layer CIN
-485 J/kg
Mixed-layer LCL
1232 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

248 
ACUS11 KWNS 102238
SWOMCD
SPC MCD 102238 
LAZ000-TXZ000-110045-

MESOSCALE DISCUSSION 0321
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT SAT APR 10 2004

AREAS AFFECTED...EXTREME SE TX AND SW

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 102238Z - 110045Z

STORMS MAY BEGIN SPREADING INTO EXTREME SERN TX AND SWRN LA WITHIN
THE NEXT 2-3 HOURS ACCOMPANIED BY THREAT FOR ISOLATED DAMAGING WIND
AND HAIL. AREA WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

THIS EVENING A CONVECTIVELY ENHANCED COLD FRONT EXTENDS FROM SE TX
JUST N OF JASPER SWWD TO NEAR KATY TO NW OF COTULLA. THE ATMOSPHERE
AHEAD OF THIS BOUNDARY IS MODERATELY UNSTABLE OVER SE TX AND SW LA
WITH MLCAPE AROUND 1500 J/KG. THOUGH THE LOW LEVEL FLOW IS WEAK...
SHEAR THROUGH A DEEP LAYER IS SUFFICIENT FOR ORGANIZED STORMS
INCLUDING SUPERCELLS. HOWEVER...STRONGEST SURGE AND LARGEST PRESSURE
RISES APPEAR TO BE ALONG THE CNTRL PORTIONS OF THIS BOUNDARY OVER S
CNTRL TX. THUS SERN PORTIONS OF THE BOUNDARY WILL BE SLOWER TO MAKE
SWD PROGRESS...AND THIS SUGGESTS STORMS MAY TAKE LONGER TO DEVELOP
IN MUCH OF THIS AREA. THE PROGRESS OF THIS BOUNDARY WILL CONTINUE TO
BE MONITORED.

..DIAL.. 04/10/2004

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

ATTN...WFO...LCH...HGX...

29799299 29899350 29829422 30739464 31109405 31119257

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 2:50 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, Jackson, Lincoln and 7 more115 min
Apr 10, 3:25 PM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more6 hr
Apr 10, 6:30 PM CDTSevere Thunderstorm WatchSPCBeauregard, Calcasieu, Cameron, Vernon5 hr
Apr 9, 7:02 PM CDTMesoscale DiscussionSPCDelta, Fannin, Grayson, Lamar, Red River58 min
Apr 9, 7:40 PM CDTSevere Thunderstorm WatchSPCDelta, Fannin, Lamar, Red River5 hr
Apr 9, 9:25 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Castro, Childress, Collingsworth and 16 more95 min
Apr 9, 10:06 PM CDTMesoscale DiscussionSPCDelta, Fannin, Lamar, Red River54 min
Apr 9, 11:57 PM CDTMesoscale DiscussionSPCBowie, Delta, Fannin, Lamar, Red River63 min
Apr 10, 5:57 AM CDTMesoscale DiscussionSPCLamar, Red River93 min
Apr 10, 9:08 AM CDTMesoscale DiscussionSPCBandera, Bell, Blanco, Bosque, Brown, Burnet and 21 more2 hr
Apr 10, 10:20 AM CDTSevere Thunderstorm WatchSPCBandera, Bastrop, Bell, Bexar, Blanco, Bosque and 33 more6 hr
Apr 10, 12:43 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bell, Bexar, Blanco, Burleson and 26 more2 hr
Apr 10, 2:50 PM CDTSevere Thunderstorm WatchSPCAtascosa, Austin, Bandera, Bastrop, Bee, Bexar and 52 more5 hr
Apr 10, 6:09 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bee, Brazoria, Colorado, DeWitt and 17 more96 min

Nearby

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