Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 237

March 13, 200311 parishes in Louisiana; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 13, 2003, 10:53 AM CST for 11 parishes in Louisiana; 11 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 13, 2003, 10:53 AM CST (16:53 UTC)
Expired
Mar 13, 2003, 1:00 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
All 22 counties

Acadia Parish, LA, Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Chambers County, TX, Galveston County, TX, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Newton County, TX, Orange County, TX, Polk County, TX, San Jacinto County, TX, Tyler County, TX

The radar

The Lake Charles radar (KLCH), 76 km from the middle of the area, began a volume at 16:55 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 12:00Z, 4.9 hours before the alert went out and 78 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 2003-03-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2612 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 2003-03-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 square meters per square second.193958Sfc1 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
2612 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
463 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
1.1
Supercell composite
6.2

Open this sounding in Storm Lab

The text

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

568 
ACUS11 KWNS 131654
SWOMCD
SPC MCD 131653 
LAZ000-TXZ000-131900-

MESOSCALE DISCUSSION 0237
NWS STORM PREDICTION CENTER NORMAN OK
1053 AM CST THU MAR 13 2003

AREAS AFFECTED...SERN TX INTO SWRN LA

CONCERNING...SEVERE THUNDERSTORM WATCH 38...

VALID 131653Z - 131900Z

THE THREAT OF LARGE HAIL AND DAMAGING WINDS CONTINUES ACROSS SRN
HALF OF WW038.



LATEST RADAR DATA FROM LCH SHOWS TRAINING CONVECTIVE ELEMENTS
CONTINUING TO DEVELOP FROM JUST E OF LCH WWD TO E OF HOU. 
RELATIVELY STEEP MID-LEVEL LAPSE RATES AND SURFACE DEWPOINTS IN
THE UPPER 60S TO AROUND 70 HAVE CONTRIBUTED TO A MODERATELY
UNSTABLE AIRMASS WITH MLCAPES APPROACHING 1500-2000 J/KG.  LATEST
LCH VWP INDICATES A LARGELY UNIDIRECTIONAL PROFILE WITH 500 MB
WINDS INCREASING SLIGHTLY OVER THE PAST COUPLE OF HOURS.



THE THREAT OF LARGE HAIL AND DAMAGING WINDS WILL CONTINUE ACROSS
SRN PORTIONS OF WW038 IN ASSOCIATION WITH AFOREMENTIONED TRAINING
TSTMS.	THIS POTENTIAL SHOULD INCREASE AS COLD POOL ASSOCIATED
WITH CONVECTIVE LINE EXTENDING FROM EVANGELINE PARISH WWD INTO
JEFFERSON COUNTY TX ENHANCES LOW-LEVEL CONVERGENCE INVOF COASTAL
CONVECTION.    

..MEAD.. 03/13/2003

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

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

30859518 31179456 31449338 31619243 31059204 30409204
29829210 29279418 29139507 29629523 30849518

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 13, 7:52 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 8 more113 min
Mar 13, 8:30 AM CSTSevere Thunderstorm WatchSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 7 more6 hr
Mar 13, 8:50 AM CSTSevere Thunderstorm WatchSPCAvoyelles, Catahoula, Concordia, East Carroll, Franklin, Madison and 1 more5 hr
Mar 13, 10:45 AM CSTSevere Thunderstorm WatchSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Jefferson and 12 more5 hr
Mar 13, 11:29 AM CSTMesoscale DiscussionSPCCatahoula, Concordia, East Carroll, Madison, Tensas2 hr
Mar 13, 1:26 PM CSTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 5 more2 hr
Mar 13, 2:15 PM CSTMesoscale DiscussionSPCJefferson, Orleans, Plaquemines, Saint Bernard2 hr
Mar 13, 3:53 PM CSTMesoscale DiscussionSPCBeauregard, Calcasieu2 hr
Mar 13, 12:56 AM CSTMesoscale DiscussionSPCBowie, Camp, Cass, Delta, Fannin, Franklin and 6 more2 hr

Nearby

Mesoscale Discussions in Louisiana, 2003Mesoscale Discussions in Texas, 2003Every mesoscale discussion in 2003

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.