Alert archive / Louisiana / Mesoscale Discussions in 2012

Mesoscale Discussion 86

February 1, 201218 parishes in Louisiana; 17 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 1, 2012, 1:36 PM CST for 18 parishes in Louisiana; 17 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Feb 1, 2012, 1:36 PM CST (19:36 UTC)
Expired
Feb 1, 2012, 3:00 PM CST
In force
84 min
Issued by
the Storm Prediction Center
All 35 counties

Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Chambers County, TX, Galveston 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, Shelby County, TX, Trinity County, TX, Tyler County, TX

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.6 hours before the alert went out and 83 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 2012-02-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 717 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 2012-02-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 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
717 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
525 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.5

Open this sounding in Storm Lab

The text

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

508 
ACUS11 KWNS 011937
SWOMCD
SPC MCD 011936
LAZ000-TXZ000-012100-

MESOSCALE DISCUSSION 0086
NWS STORM PREDICTION CENTER NORMAN OK
0136 PM CST WED FEB 01 2012

AREAS AFFECTED...PORTIONS OF SERN TX AND SWRN LA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 011936Z - 012100Z

THUNDERSTORMS WILL INCREASE IN COVERAGE ACROSS SERN TX INTO SWRN LA
THIS AFTERNOON. WHILE THESE STORMS MAY PRODUCE SMALL HAIL AND GUSTY
WINDS...WIDESPREAD SEVERE WEATHER IS NOT EXPECTED AT THIS TIME.

TEMPERATURES HAVE WARMED INTO THE UPPER 60S TO MID 70S EARLY THIS
AFTERNOON AS BREAKS IN CLOUDS HAVE ALLOWED SURFACE
HEATING/DESTABILIZATION. WITH DEWPOINTS IN THE MID 60S TO NEAR
70...SBCAPE VALUES RANGE FROM 1500-2000 J/KG. LATEST VISIBLE
SATELLITE INDICATED A LARGE...AGITATED CU FIELD ACROSS SERN TX INTO
SWRN LA WITH A LINE OF THUNDERSTORMS FROM NEAR GLS TO ACP. NORTH OF
THIS LINE OF STORMS...SATELLITE AND RADAR INDICATED OTHER ACTIVITY
TRYING TO DEVELOP IN THE UNSTABLE AIR MASS. GIVEN LACKLUSTER MID
LEVEL LAPSE RATES /NEAR 6 C/KM PER LATEST MESOANALYSIS/ AND THAT THE
STRONGEST FORCING FOR ASCENT WILL REMAIN NORTH OF THE AREA...UPDRAFT
STRENGTH IS NOT EXPECTED TO BE STRONG ENOUGH TO SUPPORT LARGE HAIL
GROWTH AND/OR STRONG WINDS. THEREFORE...A WATCH IS NOT CURRENTLY
EXPECTED AT THIS TIME.

..LEITMAN.. 02/01/2012

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

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

LAT...LON   32009353 31869488 30949532 29669523 29189486 29589299
            29719236 30369179 31619198 32029244 32009353

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 1, 1:06 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Calcasieu, Cameron, East Feliciana and 5 more114 min
Feb 1, 10:18 AM CSTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 6 more117 min
Feb 1, 12:37 PM CSTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Claiborne, Lincoln, Union and 1 more5 hr
Feb 1, 1:22 PM CSTMesoscale DiscussionSPCBossier, Caddo, Claiborne, Union, Webster113 min
Feb 1, 2:58 PM CSTMesoscale DiscussionSPCBienville, Bossier, Claiborne, Lincoln, Morehouse, Union and 2 more2 hr
Feb 1, 3:45 PM CSTSevere Thunderstorm WatchSPCEast Carroll, Morehouse, West Carroll3 hr
Feb 1, 5:18 PM CSTMesoscale DiscussionSPCAscension, Livingston, Orleans, Saint Charles, Saint James, Saint John the Baptist and 2 more87 min

Nearby

Mesoscale Discussions in Louisiana, 2012Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012

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.