Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 955

May 25, 20114 states

The Storm Prediction Center issued this mesoscale discussion at May 25, 2011, 11:52 AM CDT for 4 states. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
May 25, 2011, 11:52 AM CDT (16:52 UTC)
Expired
May 25, 2011, 1:15 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 75 counties

Arkansas County, AR, Clark County, AR, Clay County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Faulkner County, AR, Fulton County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Perry County, AR, Phillips County, AR, Pike County, AR, Poinsett County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Searcy County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Dunklin County, MO, Pemiscot County, MO, Alcorn County, MS, Benton County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Little Rock radar (KLZK), 88 km from the middle of the area, began a volume at 16:55 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

Little Rock, AR (KLZK), launched 12:00Z, 4.9 hours before the alert went out and 124 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, Little Rock, AR at 12:00Z on 2011-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2124 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, Little Rock, AR at 12:00Z on 2011-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 445 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
2124 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
600 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
445 m²/s²
0-3 km storm-relative helicity
413 m²/s²
Significant tornado parameter
6.0
Supercell composite
20.1

Open this sounding in Storm Lab

The text

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

798 
ACUS11 KWNS 251652
SWOMCD
SPC MCD 251652 
TNZ000-MSZ000-KYZ000-MOZ000-ARZ000-251815-

MESOSCALE DISCUSSION 0955
NWS STORM PREDICTION CENTER NORMAN OK
1152 AM CDT WED MAY 25 2011

AREAS AFFECTED...MOST OF AR...WRN TN...NRN MS

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

VALID 251652Z - 251815Z

DISCRETE SUPERCELLS SHOULD FORM BY MID-AFTERNOON WITH A POTENTIAL
THREAT OF LONG-TRACKED/STRONG TORNADOES. A PDS TORNADO WATCH WILL BE
REQUIRED...MOST LIKELY BY 18Z.

RECENT VISIBLE SATELLITE IMAGERY INDICATES A DEEPENING CU FIELD AND
CLOUD STREETS ACROSS MUCH OF AR DOWNSTREAM OF A COLD FRONT THAT
EXTENDED FROM FAR SWRN MO INTO NERN TX AS OF 16Z. 12Z WRF-NMM
DEPICTS DISCRETE CELLS EMANATING OUT OF THIS CU FIELD BY 19Z...WITH
RECENT HRRR RUNS FASTER WITH TSTM INITIATION BUT SIMILAR IN
CONVECTIVE MODE. ENVIRONMENT IS PRIMED FOR RAPID EVOLUTION TO
SUPERCELLS GIVEN VERY FAVORABLE LOW/MID-LEVEL HODOGRAPHS PER
PROFILER AND VWP DATA...AMIDST A BROAD ZONE OF STRONG INSTABILITY
WITH MLCAPE AROUND 2500 J/KG. ANY SUPERCELLS DEVELOPING WITHIN A
BROAD AXIS OF A 45-55 KT LLJ...POTENTIAL FOR LONG-LIVED/STRONG
TORNADOES WILL INCREASE GREATLY TOWARDS MID-AFTERNOON.

..GRAMS.. 05/25/2011

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

ATTN...WFO...OHX...PAH...MEG...JAN...LZK...SHV...

LAT...LON   34279379 35709309 36399217 36538867 36178817 35298827
            34278903 33749129 33649269 33759341 34279379

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 7:42 PM CDTMesoscale DiscussionSPCBenton, Crawford, Little River, Polk, Scott, Sebastian and 2 more63 min
May 24, 8:05 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Clark, Conway and 30 more7 hr
May 24, 11:24 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clark, Conway, Franklin and 21 more96 min
May 25, 12:48 AM CDTMesoscale DiscussionSPCClay, Craighead, Fulton, Greene, Independence, Jackson and 4 more57 min
May 25, 7:31 AM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Mississippi and 1 more59 min
May 25, 9:54 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clay, Cleburne, Conway and 33 more96 min
May 25, 10:18 AM CDTMesoscale DiscussionSPCFulton, Independence, Izard, Jackson, St. Francis, Sharp and 2 more57 min
May 25, 10:37 AM CDTTornado WatchSPCBaxter, Boone, Carroll, Fulton, Izard, Madison and 5 more7 hr
May 25, 11:02 AM CDTMesoscale DiscussionSPCClay28 min
May 25, 12:28 PM CDTTornado Watch PDSSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 41 more8 hr
May 25, 1:53 PM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Columbia, Dallas, Hempstead and 9 more2 hr
May 25, 2:56 PM CDTMesoscale DiscussionSPCArkansas, Calhoun, Clark, Clay, Cleburne, Cleveland and 33 more94 min
May 25, 3:10 PM CDTMesoscale DiscussionSPCClay95 min
May 25, 3:16 PM CDTTornado WatchSPCAshley, Chicot, Columbia, Lafayette, Miller, Nevada and 1 more7 hr
May 25, 5:56 PM CDTMesoscale DiscussionSPCArkansas, Craighead, Crittenden, Cross, Greene, Lee and 5 more64 min
May 24, 7:07 PM CDTMesoscale DiscussionSPCAndrew, Barton, Bates, Buchanan, Cass, Cedar and 14 more53 min
May 24, 7:26 PM CDTTornado WatchSPCAdair, Barry, Barton, Bates, Benton, Buchanan and 48 more7 hr
May 25, 1:22 AM CDTTornado WatchSPCAudrain, Boone, Callaway, Camden, Christian, Clark and 43 more7 hr
May 25, 4:58 AM CDTMesoscale DiscussionSPCCrawford, Dent, Franklin, Iron, Jefferson, Reynolds and 7 more92 min
May 25, 5:46 AM CDTTornado WatchSPCPerry7 hr
May 25, 11:09 AM CDTTornado Watch PDSSPCBollinger, Butler, Cape Girardeau, Carter, Franklin, Iron and 19 more10 hr
May 25, 1:28 PM CDTMesoscale DiscussionSPCAdair, Audrain, Boone, Caldwell, Callaway, Camden and 44 more92 min
May 25, 2:31 PM CDTTornado WatchSPCClark, Scotland7 hr
May 25, 2:32 PM CDTMesoscale DiscussionSPCAudrain, Lincoln, Marion, Monroe, Montgomery, Pike and 2 more58 min
May 25, 6:25 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Mississippi, Perry, Scott and 2 more2 hr
May 25, 3:45 PM CDTMesoscale DiscussionSPCBedford, Benton, Cannon, Cheatham, Coffee, Davidson and 24 more90 min

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Mississippi, 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.