Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 441

April 7, 20035 states

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2003, 5:58 PM CDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 7, 2003, 5:58 PM CDT (22:58 UTC)
Expired
Apr 7, 2003, 8:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 27 counties

Baldwin County, AL, Escambia County, AL, Mobile County, AL, Escambia County, FL, Santa Rosa County, FL, Ascension Parish, LA, Assumption Parish, LA, Cameron Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Hancock County, MS, Harrison County, MS, Jackson County, MS, Chambers County, TX, Galveston County, TX, Jefferson County, TX

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.0 hours before the alert went out and 146 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, Slidell Radar S, LA at 12:00Z on 2003-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1394 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, Slidell Radar S, LA at 12:00Z on 2003-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 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
1394 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
592 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
212 m²/s²
Significant tornado parameter
1.2
Supercell composite
8.4

Open this sounding in Storm Lab

The text

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

829 
ACUS11 KWNS 072258
SWOMCD
SPC MCD 072258 
ALZ000-FLZ000-MSZ000-LAZ000-TXZ000-080100-

MESOSCALE DISCUSSION 0441
NWS STORM PREDICTION CENTER NORMAN OK
0558 PM CDT MON APR 07 2003

AREAS AFFECTED...SERN TX...SRN LA...SRN MS...SWRN AL AND THE WRN
FL PANHANDLE

CONCERNING...SEVERE THUNDERSTORM WATCH 114...

VALID 072258Z - 080100Z

THREAT FOR LARGE HAIL AND ISOLATED DAMAGING WIND GUSTS EXPECTED
TO PERSIST ANOTHER FEW HOURS ALONG MUCH OF THE GULF COASTAL AREA.


SCATTERED STORMS WILL CONTINUE DEVELOPING IN MODERATELY UNSTABLE
ENVIRONMENT ALONG AN E-W ORIENTED OUTFLOW BOUNDARY NEXT FEW
HOURS. TRENDS HAVE BEEN FOR OVERALL INTENSITIES TO DECREASE
DURING THE PAST HOUR...AND SOME OF THE STORM ARE BECOMING
SLIGHTLY ELEVATED ABOVE THE CONVECTIVE OUTFLOW. THE LOW LEVEL
FLOW IS EXPECTED TO REMAIN RELATIVELY WEAK. HOWEVER...DEEP LAYER
SHEAR WILL REMAIN SUFFICIENT FOR ORGANIZED STORMS INCLUDING
SUPERCELLS AND OCCASIONAL BOW ECHOES.

..DIAL.. 04/07/2003

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

ATTN...WFO...MOB...LIX...LCH...HGX...

29089316 28829466 28699508 29369506 29879496 30079328
30579011 30698890 31318722 31268665 30548661 30048664
29748847 29439108 29129324

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 8:13 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Dallas, Fayette, Greene and 8 more2 hr
Apr 6, 9:48 PM CDTMesoscale DiscussionSPCAutauga, Chilton, Choctaw, Clarke, Dallas, Hale and 6 more87 min
Apr 6, 10:15 PM CDTTornado WatchSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 10 more5 hr
Apr 6, 11:39 PM CDTMesoscale DiscussionSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 11 more2 hr
Apr 7, 1:51 AM CDTMesoscale DiscussionSPCBullock, Butler, Lowndes, Macon, Montgomery54 min
Apr 7, 2:55 AM CDTTornado WatchSPCAutauga, Barbour, Bullock, Chilton, Choctaw, Dallas and 13 more4 hr
Apr 7, 4:49 AM CDTMesoscale DiscussionSPCAutauga, Chambers, Chilton, Coosa, Dallas, Elmore and 11 more3 hr
Apr 7, 9:11 AM CDTMesoscale DiscussionSPCBarbour, Coffee, Conecuh, Covington, Crenshaw, Dale and 6 more3 hr
Apr 7, 9:40 AM CDTTornado WatchSPCBarbour, Bullock, Macon, Pike, Russell5 hr
Apr 7, 11:25 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more3 hr
Apr 7, 12:07 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 12:22 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 3:40 PM CDTSevere Thunderstorm WatchSPCBaldwin, Covington, Escambia, Mobile5 hr
Apr 7, 9:42 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Beauregard, Calcasieu and 16 more3 hr
Apr 7, 10:05 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 26 more6 hr
Apr 7, 11:02 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Cameron, East Baton Rouge, Iberville, Lafayette and 8 more3 hr
Apr 7, 2:13 PM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge and 20 more3 hr
Apr 7, 2:36 PM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge and 20 more114 min
Apr 7, 12:24 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bastrop, Bee, Bexar, Brazoria and 28 more66 min
Apr 7, 1:00 PM CDTSevere Thunderstorm WatchSPCAtascosa, Austin, Bee, Bexar, Brazoria, Caldwell and 23 more5 hr
Apr 7, 3:36 PM CDTMesoscale DiscussionSPCEdwards, Kinney, Maverick, Real, Uvalde, Val Verde114 min
Apr 7, 4:35 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bee, Bexar, Blanco, Caldwell and 22 more5 hr

Nearby

Mesoscale Discussions in Louisiana, 2003Mesoscale Discussions in Alabama, 2003Mesoscale Discussions in Mississippi, 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.