Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 107

February 3, 2012Beauregard Parish, De Soto Parish, Sabine Parish, Louisiana; 38 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 3, 2012, 7:14 PM CST for Beauregard Parish, De Soto Parish, Sabine Parish, Louisiana; 38 counties in Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Feb 3, 2012, 7:14 PM CST (01:14 UTC)
Expired
Feb 3, 2012, 8:45 PM CST
In force
91 min
Issued by
the Storm Prediction Center
All 41 counties

Beauregard Parish, LA, De Soto Parish, LA, Sabine Parish, LA, Anderson County, TX, Angelina County, TX, Austin County, TX, Bastrop County, TX, Bell County, TX, Brazos County, TX, Burleson County, TX, Cherokee County, TX, Falls County, TX, Fayette County, TX, Freestone County, TX, Grimes County, TX, Hardin County, TX, Houston County, TX, Jasper County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Montgomery County, TX, Nacogdoches County, TX, Newton County, TX, Polk County, TX, Robertson County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Williamson County, TX

The radar

The Houston radar (KHGX), 164 km from the middle of the area, began a volume at 01:16 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 00:00Z, 1.2 hours before the alert went out and 232 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 00:00Z on 2012-02-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2041 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2012-02-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
2041 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
494 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

079 
ACUS11 KWNS 040114
SWOMCD
SPC MCD 040114 
LAZ000-TXZ000-040245-

MESOSCALE DISCUSSION 0107
NWS STORM PREDICTION CENTER NORMAN OK
0714 PM CST FRI FEB 03 2012

AREAS AFFECTED...E-CNTRL TX AND W-CNTRL LA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 040114Z - 040245Z

A MARGINAL/ISOLATED SVR TSTM THREAT MAY PERSIST UNTIL 03Z ACROSS
PORTIONS OF E-CNTRL TX AND W-CNTRL LA...WITH AN OVERALL WEAKENING
TREND IN CONVECTION ANTICIPATED DURING THE EVENING HOURS.

SFC MESOANALYSIS AT 00Z REFLECTS THE LACK OF ANY SALIENT CONVERGENCE
ZONES WITHIN THE WARM SECTOR ACROSS E-CNTRL TX AND W-CNTRL LA. VERY
WEAK LOW-LEVEL WARM ADVECTION HAS RESULTED IN ISOLATED TO WIDELY
SCATTERED STRONG THUNDERSTORMS ACROSS PORTIONS OF THE AREA AMIDST A
MOSTLY UNINHIBITED WARM SECTOR /REF 00Z LAKE CHARLES RAOB/. PER AREA
RAOB DATA AND RUC SOUNDINGS...MLCAPE VALUES OF 1000-2000 J/KG ARE
BEING SUPPORTED BY SFC TEMPS IN THE LOWER 70S IN THE PRESENCE OF A
RICH AND FAIRLY DEEP MOIST LAYER...WITH SFC DEWPOINTS HOLDING IN THE
MIDDLE 60S. AS SUCH...PRIOR TO THE STRENGTHENING OF A NOCTURNAL
STABLE LAYER...A FEW STRONG STORMS WILL REMAIN POSSIBLE...WITH
OCCASIONAL UPDRAFT INTENSITY/ROTATION SUPPORTED BY A VERTICALLY
VEERING WIND PROFILE IN THE LOW LEVELS /ALBEIT WITH ONLY MODEST FLOW
MAGNITUDE/. GUSTY WINDS AND MARGINALLY SVR HAIL WILL BE THE MAIN
CONCERNS WITH THE STRONGEST STORMS. HOWEVER...WITH THIS AREA BEING
DISPLACED WELL TO THE SOUTHEAST OF THE BELT OF STRONGER MID-LEVEL
WLYS...DEEP-LAYER SHEAR WILL REMAIN RELATIVELY WEAK /0-6 KM BULK
SHEAR MAGNITUDES AOB 30 KT/. THIS NOTION...COMBINED WITH THE LACK OF
DEEP-LAYER FORCING FOR ASCENT...SHOULD GREATLY HAMPER THE THREAT FOR
MORE PERSISTENT AND/OR ORGANIZED CONVECTION...WITH A WEAKENING TREND
COMMENSURATE WITH THE GROWTH OF NOCTURNAL STABILITY.

..COHEN.. 02/04/2012

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

ATTN...WFO...LCH...SHV...HGX...FWD...EWX...

LAT...LON   30609318 29889584 29849735 30579791 31609727 32129544
            32099339 30609318

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 4, 4:46 PM CSTMesoscale DiscussionSPCPlaquemines, Saint Bernard89 min
Feb 3, 6:40 PM CSTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Dallas, Delta and 21 more95 min
Feb 3, 6:57 PM CSTSevere Thunderstorm WatchSPCCamp, Collin, Cooke, Dallas, Delta, Denton and 18 more7 hr
Feb 3, 9:04 PM CSTMesoscale DiscussionSPCCamp, Collin, Dallas, Delta, Fannin, Franklin and 9 more86 min
Feb 3, 11:38 PM CSTMesoscale DiscussionSPCBastrop, Bell, Bexar, Blanco, Brazos, Burleson and 20 more2 hr
Feb 3, 11:49 PM CSTMesoscale DiscussionSPCBowie, Camp, Cass, Franklin, Hopkins, Marion and 6 more56 min
Feb 4, 3:42 AM CSTMesoscale DiscussionSPCAngelina, Atascosa, Austin, Bexar, Caldwell, Colorado and 23 more3 hr

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Louisiana, 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; radar from the NEXRAD Level II archive.