Alert archive / Louisiana / Mesoscale Discussions in 2008

Mesoscale Discussion 2012

August 3, 200827 parishes in Louisiana; 18 counties in Mississippi; 15 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 3, 2008, 10:50 AM CDT for 27 parishes in Louisiana; 18 counties in Mississippi; 15 counties in Texas. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Aug 3, 2008, 10:50 AM CDT (15:50 UTC)
Expired
Aug 3, 2008, 11:45 AM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 60 counties

Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Natchitoches Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Tensas Parish, LA, Vernon Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Attala County, MS, Choctaw County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Issaquena County, MS, Jefferson County, MS, Leake County, MS, Madison County, MS, Rankin County, MS, Sharkey County, MS, Warren County, MS, Webster County, MS, Wilkinson County, MS, Yazoo County, MS, Angelina County, TX, Chambers County, TX, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Trinity 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, 3.8 hours before the alert went out and 118 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 2008-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 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 2008-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -35 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
87 J/kg
Mixed-layer CIN
-387 J/kg
Mixed-layer LCL
1831 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-35 m²/s²
0-3 km storm-relative helicity
-10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 031551
SWOMCD
SPC MCD 031550 
MSZ000-LAZ000-TXZ000-031645-

MESOSCALE DISCUSSION 2012
NWS STORM PREDICTION CENTER NORMAN OK
1050 AM CDT SUN AUG 03 2008

AREAS AFFECTED...PORTIONS OF MS/LA/SERN TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 031550Z - 031645Z

CONVECTION HAS ALREADY INITIATED THIS MORNING OVER PORTIONS OF
MS/LA. EXPECTATION IS THAT STORMS WILL GRADUALLY INCREASE IN
COVERAGE AND INTENSITY OVER THE NEXT FEW HOURS AS CINH IS OVERCOME.
MAIN THREAT WITH THESE STORMS WILL BE DMGG WINDS AS THEY MOVE TO THE
WSW...ALTHOUGH LARGE HAIL MAY BE POSSIBLE AS WELL. AREA WILL BE
MONITORED FOR A POTENTIAL WW.

SHEAR AXIS REMAINS OVER PORTIONS OF MS/AL/SERN TX WITH SOMEWHAT
STRONGER FLOW AND DIVERGENCE ALOFT. RATHER COOL BOUNDARY LAYER
REMAINS FOLLOWING YESTERDAYS MCS...ALTHOUGH NLY/NELY FLOW ATOP THIS
LAYER HAS INFLUENCED THUNDERSTORM DEVELOPMENT IN SLIGHT WAA REGIME
AND A SUBTLE WSW TO ENE ORIENTED AREA OF LOW LEVEL CONVERGENCE.
TEMPERATURES ARE EXPECTED TO REACH INTO THE UPPER 90S ACROSS A
WIDESPREAD AREA TODAY...AND AS HEATING CONTINUES THE REMAINING CINH
SHOULD GRADUALLY BE OVERCOME...ALLOWING STORMS TO ROOT IN THE
BOUNDARY LAYER. VAD WIND PROFILE DATA AT LAKE CHARLES AND
SURROUNDING SITES INDICATE A MODEST NELY LOW LEVEL FLOW NEAR 30 KTS
STILL EXISTS. DMGG WINDS WILL BE LIKELY IN COLD POOLS/OUTFLOW
DOMINATED STORMS THAT WILL MOVE WSW INTO GREATER INSTABILITY AND
INITIATE NEW CONVECTION. ADDITIONAL AREA OF INTEREST LIES WITH A
SUBTLE MCV...NOTED ON SATELLITE IMAGERY JUST OFFSHORE WSW OF LCH.
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED OVER THE AREA AND A
WW WILL BE POSSIBLE OVER THE NEXT FEW HOURS.

..HURLBUT.. 08/03/2008

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

ATTN...WFO...MEG...JAN...LIX...LCH...SHV...HGX...

29099454 30079512 31409540 32559162 33778905 33178897
31029109 29249310

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 2, 7:52 PM CDTSevere Thunderstorm WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more6 hr
Aug 2, 10:57 PM CDTMesoscale DiscussionSPCEast Carroll, Madison, Tensas, West Carroll93 min
Aug 3, 1:17 AM CDTMesoscale DiscussionSPCAvoyelles, Bienville, Caldwell, Catahoula, Grant, Jackson and 6 more58 min
Aug 3, 1:07 PM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 24 more7 hr
Aug 3, 4:21 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 28 more54 min
Aug 3, 6:44 PM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 3 more3 hr
Aug 2, 7:27 PM CDTMesoscale DiscussionSPCAttala, Benton, Calhoun, Carroll, Chickasaw, Choctaw and 21 more2 hr
Aug 3, 3:09 PM CDTMesoscale DiscussionSPCBolivar, Carroll, Coahoma, Grenada, Holmes, Humphreys and 9 more66 min
Aug 3, 5:27 PM CDTMesoscale DiscussionSPCAnderson, Cherokee, Freestone, Gregg, Harrison, Henderson and 8 more63 min

Nearby

Mesoscale Discussions in Louisiana, 2008Mesoscale Discussions in Mississippi, 2008Mesoscale Discussions in Texas, 2008Every mesoscale discussion in 2008

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.