Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 960

May 25, 201139 counties in Arkansas; Dunklin County, Pemiscot County, Missouri

The Storm Prediction Center issued this mesoscale discussion at May 25, 2011, 2:56 PM CDT for 39 counties in Arkansas; Dunklin County, Pemiscot County, Missouri. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 25, 2011, 2:56 PM CDT (19:56 UTC)
Expired
May 25, 2011, 4:30 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 41 counties

Arkansas County, AR, Calhoun County, AR, Clark County, AR, Clay County, AR, Cleburne County, AR, Cleveland County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Fulton 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, Ouachita County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, White County, AR, Woodruff County, AR, Dunklin County, MO, Pemiscot County, MO

The radar

The Little Rock radar (KLZK), 51 km from the middle of the area, began a volume at 19:56 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, 7.9 hours before the alert went out and 163 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.

379 
ACUS11 KWNS 251956
SWOMCD
SPC MCD 251956 
TNZ000-MOZ000-ARZ000-MSZ000-252130-

MESOSCALE DISCUSSION 0960
NWS STORM PREDICTION CENTER NORMAN OK
0256 PM CDT WED MAY 25 2011

AREAS AFFECTED...CNTRL/ERN AR...MO BOOTHEEL

CONCERNING...TORNADO WATCH 371...

VALID 251956Z - 252130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 371 CONTINUES.

...THREAT INCREASING FOR DISCRETE SUPERCELLS CAPABLE OF PRODUCING
LONG-TRACK/STRONG TORNADOES ACROSS WW 371...

INITIAL DISCRETE SUPERCELL THAT PROGRESSED ACROSS SHARP COUNTY AR
HAS RECENTLY SHIFTED INTO SERN MO. ADDITIONAL DISCRETE CELLS ARE
FORMING SW OF THIS TSTM WITHIN A CONFLUENCE AXIS THAT STRETCHED
TOWARDS TXK. ENVIRONMENT ACROSS CNTRL/ERN AR IS EXTREMELY CONDUCIVE
TO RAPID SUPERCELL EVOLUTION. MODIFIED 18Z LZK RAOB SUGGESTS MLCAPE
HAS NOW REACHED 3500 TO 4000 J/KG WITH 0-1 KM SHEAR AROUND 30 KT.
LARGE HODOGRAPHS...STRONG INSTABILITY AND A DISCRETE CONVECTIVE MODE
WILL ALL REMAIN HIGHLY FAVORABLE FOR LONG-TRACKED SUPERCELLS
PRODUCING STRONG TORNADOES AND VERY LARGE HAIL.

..GRAMS.. 05/25/2011

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

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

LAT...LON   33839355 35199245 35859225 36349204 36559172 36569061
            36328976 36058976 34699058 33899113 33579155 33519220
            33549302 33839355

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, 11:52 AM CDTMesoscale DiscussionSPCArkansas, Clark, Clay, Cleburne, Cleveland, Conway and 38 more83 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, 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

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Missouri, 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.