Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 894

May 23, 201111 counties in Arkansas; 5 counties in Missouri; Lake County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 23, 2011, 1:16 PM CDT for 11 counties in Arkansas; 5 counties in Missouri; Lake County, Tennessee. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
May 23, 2011, 1:16 PM CDT (18:16 UTC)
Expired
May 23, 2011, 2:45 PM CDT
In force
89 min
Issued by
the Storm Prediction Center

Counties Baxter County, AR, Clay County, AR, Craighead County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Lawrence County, AR, Randolph County, AR, Sharp County, AR, Stone County, AR, Butler County, MO, Dunklin County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Lake County, TN

The radar

The Memphis radar (KNQA), 138 km from the middle of the area, began a volume at 18:16 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 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, 6.3 hours before the alert went out and 181 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 2011-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2279 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 2011-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 184 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
2279 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
553 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
184 m²/s²
0-3 km storm-relative helicity
229 m²/s²
Significant tornado parameter
2.1
Supercell composite
10.2

Open this sounding in Storm Lab

The text

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

440 
ACUS11 KWNS 231817
SWOMCD
SPC MCD 231816
TNZ000-MOZ000-ARZ000-231945-

MESOSCALE DISCUSSION 0894
NWS STORM PREDICTION CENTER NORMAN OK
0116 PM CDT MON MAY 23 2011

AREAS AFFECTED...NRN-NE AR...SE MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 231816Z - 231945Z

AN ISOLATED THREAT FOR WIND DAMAGE AND A BRIEF TORNADOES SHOULD
EXIST ACROSS NE AR AND SE MO OVER THE NEXT FEW HOURS. A WW MAY
BECOME NECESSARY ACROSS THE REGION.

AN LINE OF STRONG TO SEVERE THUNDERSTORMS IS ONGOING FROM NEAR ST
LOUIS SWWD ACROSS SRN MO INTO NRN AR. THESE STORMS ARE BEING
SUPPORTED BY LIFT ASSOCIATED WITH THE NOSE OF A 35 TO 45 KT
LOW-LEVEL JET. MESOANALYSIS SUGGESTS THAT MODERATE TO STRONG
DESTABILIZATION HAS TAKEN PLACE ACROSS SE MO AND NE AR WHERE SBCAPE
VALUES ARE IN THE 2500 TO 3500 J/KG RANGE. THIS COMBINED WITH 40 KT
OF DEEP LAYER SHEAR EVIDENT ON THE LITTLE ROCK WSR-88D VWP SHOULD
SUPPORT A WIND DAMAGE THREAT WITH THE STRONGER CELL ELEMENTS IN THE
LINE. SUPERCELL DEVELOPMENT WILL BE POSSIBLE AND AN ISOLATED THREAT
FOR BRIEF TORNADOES MAY ALSO PERSIST. THE GREATEST POTENTIAL FOR
SEVERE WILL LIKELY EXIST WITH THE ERN MOST CELLS WITHIN THE MCS
WHERE LIFT IS MAXIMIZED BY AN UPSTREAM SHORTWAVE TROUGH EVIDENT ON
WATER VAPOR IMAGERY. THE SEVERE THREAT SHOULD CONTINUE INTO THE LATE
AFTERNOON AS THE CELLS APPROACH THE MS RIVER WHERE INSTABILITY IS
STRONGEST.

..BROYLES.. 05/23/2011

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

ATTN...WFO...PAH...MEG...LZK...SGF...

LAT...LON   35838970 35699123 35689222 36139264 36549250 36649179
            36719098 36729021 36678971 36358946 35838970

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 7:52 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Conway, Crawford and 13 more53 min
May 22, 8:47 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 34 more7 hr
May 22, 11:46 PM CDTMesoscale DiscussionSPCClay, Cleburne, Conway, Craighead, Crawford, Cross and 23 more89 min
May 23, 5:07 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Fulton and 10 more113 min
May 23, 7:38 AM CDTMesoscale DiscussionSPCBenton, Carroll97 min
May 23, 9:14 AM CDTMesoscale DiscussionSPCClark, Cleburne, Conway, Crawford, Dallas, Faulkner and 26 more91 min
May 23, 9:57 AM CDTMesoscale DiscussionSPCLafayette, Little River, Miller33 min
May 23, 10:34 AM CDTMesoscale DiscussionSPCBenton, Carroll, Fulton86 min
May 23, 12:10 PM CDTMesoscale DiscussionSPCLafayette, Miller65 min
May 23, 12:12 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clay, Craighead and 13 more93 min
May 23, 1:34 PM CDTSevere Thunderstorm WatchSPCClay, Cleburne, Conway, Craighead, Crittenden, Cross and 20 more6 hr
May 23, 3:58 PM CDTMesoscale DiscussionSPCClay, Cleburne, Conway, Craighead, Crittenden, Cross and 20 more92 min
May 23, 5:07 PM CDTMesoscale DiscussionSPCBenton, Crawford, Washington23 min
May 23, 5:24 PM CDTTornado WatchSPCCrawford, Franklin, Sebastian, Washington4 hr
May 23, 6:18 PM CDTMesoscale DiscussionSPCCleburne, Craighead, Crittenden, Cross, Faulkner, Independence and 11 more87 min
May 22, 8:26 PM CDTTornado WatchSPCBarry, Bollinger, Butler, Cape Girardeau, Carter, Crawford and 33 more8 hr
May 22, 10:24 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Madison, Perry, Sainte Genevieve and 2 more66 min
May 23, 5:41 AM CDTMesoscale DiscussionSPCBarton, Bates, Cedar, Dade, Hickory, Jasper and 5 more94 min
May 23, 6:08 AM CDTSevere Thunderstorm WatchSPCBarry, Barton, Bates, Benton, Camden, Cass and 34 more7 hr
May 23, 10:55 AM CDTSevere Thunderstorm WatchSPCAudrain, Bollinger, Boone, Butler, Callaway, Cape Girardeau and 28 more7 hr
May 23, 12:37 PM CDTMesoscale DiscussionSPCCity of Saint Louis83 min
May 23, 3:20 AM CDTMesoscale DiscussionSPCClay, Davidson, Fentress, Jackson, Macon, Overton and 9 more85 min
May 23, 4:24 PM CDTMesoscale DiscussionSPCBedford, Benton, Carroll, Cheatham, Chester, Davidson and 29 more96 min
May 23, 4:57 PM CDTSevere Thunderstorm WatchSPCBedford, Benton, Carroll, Cheatham, Chester, Davidson and 29 more4 hr

Nearby

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