Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 124

February 24, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Feb 24, 2011, 10:34 AM CST for 4 states. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Feb 24, 2011, 10:34 AM CST (16:34 UTC)
Expired
Feb 24, 2011, 11:30 AM CST
In force
56 min
Issued by
the Storm Prediction Center
All 44 counties

Garland County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Montgomery County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Yell County, AR, Bossier Parish, LA, Caddo Parish, LA, Choctaw County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McCurtain County, OK, Pushmataha County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rusk 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), 143 km from the middle of the area, began a volume at 16:37 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, 4.6 hours before the alert went out and 148 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 2011-02-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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 2011-02-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 243 square meters per square second.1939587897Sfc1 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
36 J/kg
Mixed-layer CIN
-228 J/kg
Mixed-layer LCL
741 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
243 m²/s²
0-3 km storm-relative helicity
282 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.

943 
ACUS11 KWNS 241634
SWOMCD
SPC MCD 241634 
ARZ000-LAZ000-TXZ000-OKZ000-241730-

MESOSCALE DISCUSSION 0124
NWS STORM PREDICTION CENTER NORMAN OK
1034 AM CST THU FEB 24 2011

AREAS AFFECTED...PARTS OF ERN OK/TX...WRN AR AND NWRN LA

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 241634Z - 241730Z

THUNDERSTORMS ARE GRADUALLY INCREASING IN BOTH AREAL COVERAGE AND
INTENSITY WITHIN BROADER WARM CONVEYOR FROM THE I-35 CORRIDOR SOUTH
OF THE DFW METROPLEX...NWD INTO OK.  THIS ACTIVITY IS EVOLVING
WITHIN A VERY STRONGLY SHEARED ENVIRONMENT THAT IS EXPECTED TO ONLY
STRENGTHEN INTO THE AFTERNOON HOURS AS LLJ INCREASES IN RESPONSE TO
DEEPENING CYCLONE.  ALTHOUGH CONSIDERABLE CLOUDINESS IS OBSERVED
ACROSS THE WARM SECTOR IT APPEARS LARGE SCALE ASCENT/COOLING WILL
GRADUALLY STEEPEN LAPSE RATE ENVIRONMENT ENABLING NEAR-SFC BASED
CONVECTION TO ROOT INTO MORE BUOYANT BOUNDARY LAYER PARCELS. 
SUPERCELLS AND POSSIBLE TORNADOES CAN BE EXPECTED...ESPECIALLY LATER
THIS AFTERNOON AS CONVECTION SPREADS INTO THE LOWER MS VALLEY.

..DARROW.. 02/24/2011

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

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

LAT...LON   32029634 35599561 35039295 31689387 32029634

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 24, 11:25 AM CSTTornado WatchSPCBradley, Calhoun, Clark, Cleburne, Cleveland, Columbia and 38 more9 hr
Feb 24, 2:12 PM CSTMesoscale DiscussionSPCCrittenden, Cross, Lee, Mississippi, Phillips, Poinsett and 1 more93 min
Feb 24, 2:34 PM CSTTornado WatchSPCArkansas, Ashley, Chicot, Clay, Craighead, Crittenden and 14 more7 hr
Feb 24, 2:39 PM CSTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleburne, Cleveland, Columbia and 31 more66 min
Feb 24, 5:26 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 39 more94 min
Feb 23, 8:43 PM CSTMesoscale DiscussionSPCCraig, Nowata, Osage, Ottawa, Pawnee, Rogers and 1 more62 min
Feb 24, 3:07 AM CSTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Custer and 17 more113 min
Feb 24, 4:10 AM CSTSevere Thunderstorm WatchSPCBeckham, Caddo, Canadian, Carter, Cleveland, Comanche and 17 more7 hr
Feb 24, 7:47 AM CSTMesoscale DiscussionSPCCleveland, Cotton, Garvin, Grady, Jefferson, McClain and 3 more118 min

Nearby

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Oklahoma, 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.