Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 2302

November 8, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Nov 8, 2011, 1:03 PM CST for 4 states. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Nov 8, 2011, 1:03 PM CST (19:03 UTC)
Expired
Nov 8, 2011, 2:00 PM CST
In force
57 min
Issued by
the Storm Prediction Center
All 67 counties

Calhoun County, AR, Clark County, AR, Columbia County, AR, Conway County, AR, Dallas County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Logan County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sevier County, AR, Van Buren County, AR, Yell County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Red River Parish, LA, Sabine Parish, LA, Webster Parish, LA, Choctaw County, OK, McCurtain County, OK, Anderson County, TX, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Delta County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Houston County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 88 km from the middle of the area, began a volume at 19:07 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 7.1 hours before the alert went out and 88 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, Shreveport, LA at 12:00Z on 2011-11-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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, Shreveport, LA at 12:00Z on 2011-11-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 296 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
12 J/kg
Mixed-layer CIN
-185 J/kg
Mixed-layer LCL
496 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
296 m²/s²
0-3 km storm-relative helicity
361 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

385 
ACUS11 KWNS 081904
SWOMCD
SPC MCD 081903
ARZ000-LAZ000-TXZ000-OKZ000-082000-

MESOSCALE DISCUSSION 2302
NWS STORM PREDICTION CENTER NORMAN OK
0103 PM CST TUE NOV 08 2011

AREAS AFFECTED...SERN OK...WRN/CENTRAL AR...NERN TX AND NWRN LA

CONCERNING...TORNADO WATCH 875...

VALID 081903Z - 082000Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 875 CONTINUES.

STRONGEST FORCING ASSOCIATED WITH UPPER WAVE IN THE TX PANHANDLE WAS
MOVING EWD THROUGH CENTRAL/NRN AR. DESPITE WEAK INSTABILITY
...MUCAPES FROM 250-500 J/KG...DEEP/LOW LEVEL SHEAR AT 50KT/40 KT
RESPECTIVELY ARE SUPPORTIVE OF ROTATING STORMS/BOWS...WITH WIND
DAMAGE AND EVEN A TORNADO OR TWO EXPECTED AS THE STORMS SHIFT EWD
THROUGH THE AFTERNOON.

FURTHER SWWD...A COLD FRONT WAS NEAR A DUA-AUS LINE...WITH A
A WEAK E-W ORIENTED FRONT LOCATED IN CENTRAL AR. EAST AND SOUTH OF
THESE FRONTS...TEMPERATURES HAD WARMED INTO THE LOWER/MID
70S...RESULTING IN STRONGER INSTABILITY...MUCAPES AROUND 1500 J/KG.
CONVECTION HAS INCREASED IN COVERAGE AND INTENSITY DURING THE PAST
HOUR AS THE AIR MASS HAS DESTABILIZED. WITH ADDITIONAL HEATING AND
DEEP LAYER SHEAR AT 40-50 KT...A FEW SUPERCELLS ARE LIKELY TO EVOLVE
THROUGH THE AFTERNOON. THE STRONG WIND FIELDS SUGGEST WIND DAMAGE
SHOULD BE THE PRIMARY THREAT...THOUGH 20-30 KT LOW LEVEL SHEAR AND A
MOIST ENVIRONMENT WILL ALSO SUPPORT TORNADOES.

..IMY.. 11/08/2011

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

ATTN...WFO...LZK...SHV...TSA...HGX...FWD...OUN...

LAT...LON   31169527 31399643 34109584 34519487 35469373 35649218
            35169192 34069223 31419351 31189429 31169527

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 8, 1:17 AM CSTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 16 more118 min
Nov 8, 9:38 AM CSTMesoscale DiscussionSPCCrawford, Franklin, Sebastian67 min
Nov 8, 10:31 AM CSTMesoscale DiscussionSPCBaxter, Clark, Cleburne, Columbia, Conway, Dallas and 31 more29 min
Nov 8, 10:49 AM CSTTornado WatchSPCClark, Cleburne, Columbia, Conway, Dallas, Faulkner and 25 more7 hr
Nov 8, 3:48 PM CSTMesoscale DiscussionSPCClark, Cleburne, Columbia, Conway, Faulkner, Garland and 18 more87 min
Nov 8, 5:09 PM CSTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 7 more66 min
Nov 8, 5:30 PM CSTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 17 more7 hr
Nov 7, 7:43 PM CSTMesoscale DiscussionSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Creek and 22 more62 min
Nov 7, 8:28 PM CSTTornado WatchSPCAdair, Caddo, Canadian, Carter, Cherokee, Cleveland and 36 more8 hr
Nov 7, 11:20 PM CSTMesoscale DiscussionSPCCarter, Cherokee, Cleveland, Cotton, Craig, Creek and 22 more85 min
Nov 8, 2:12 AM CSTMesoscale DiscussionSPCAtoka, Bryan, Carter, Coal, Jefferson, Johnston and 4 more93 min
Nov 7, 6:44 PM CSTTornado WatchSPCBosque, Camp, Collin, Cooke, Coryell, Dallas and 24 more2 hr
Nov 7, 8:53 PM CSTMesoscale DiscussionSPCBorden, Coke, Fisher, Glasscock, Haskell, Howard and 9 more2 hr
Nov 7, 9:16 PM CSTTornado WatchSPCBorden, Callahan, Coke, Coleman, Concho, Crane and 31 more8 hr
Nov 8, 1:44 PM CSTMesoscale DiscussionSPCAustin, Chambers, Grimes, Hardin, Harris, Jasper and 10 more61 min
Nov 8, 1:59 PM CSTTornado WatchSPCChambers, Grimes, Hardin, Harris, Houston, Jasper and 12 more6 hr
Nov 8, 3:53 PM CSTMesoscale DiscussionSPCAngelina, Grimes, Hardin, Harris, Jasper, Liberty and 7 more2 hr

Nearby

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Louisiana, 2011Every mesoscale discussion in 2011

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.