Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 545

April 23, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Apr 23, 2011, 10:40 PM CDT for 5 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 23, 2011, 10:40 PM CDT (03:40 UTC)
Expired
Apr 24, 2011, 12:15 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 27 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Clay County, AR, Fulton County, AR, Izard County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Washington County, AR, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, McCracken County, KY, Butler County, MO, Mississippi County, MO, New Madrid County, MO, Ripley County, MO, Stoddard County, MO, Adair County, OK, Lake County, TN

The radar

The Memphis radar (KNQA), 174 km from the middle of the area, began a volume at 03:40 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 nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 3.7 hours before the alert went out and 214 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 00:00Z on 2011-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 781 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 00:00Z on 2011-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 166 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
781 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
1432 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
166 m²/s²
0-3 km storm-relative helicity
226 m²/s²
Significant tornado parameter
0.3
Supercell composite
5.7

Open this sounding in Storm Lab

The text

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

836 
ACUS11 KWNS 240341
SWOMCD
SPC MCD 240340
KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-OKZ000-240515-

MESOSCALE DISCUSSION 0545
NWS STORM PREDICTION CENTER NORMAN OK
1040 PM CDT SAT APR 23 2011

AREAS AFFECTED...SEVERE AND TORNADO WATCHES OVER NRN AR...SRN
MO...SRN IL/WRN KY

CONCERNING...TORNADO WATCH 189...190...

VALID 240340Z - 240515Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 189...190...CONTINUES.

THE SEVERE THREAT APPEARS TO BE DIMINISHING ACROSS THE SEVERE
THUNDERSTORM AND TORNADO WATCHES. THE WATCHES REMAIN IN EFFECT UNTIL
05Z...BUT PORTIONS OF THE WATCHES MAY BE ABLE TO BE CLEARED BEFORE
THAT TIME.

TORNADIC SUPERCELL OVER NRN AR HAS DIMINISHED AS IT CROSSED THE
SURFACE BOUNDARY...AND THE AIR MASS IN GENERAL IS STABILIZING WITH
INCREASING CIN. THE MAIN THREAT ACROSS THE AREA WILL BE SPORADIC
MARGINAL HAIL CORES...AND ADDITIONAL WATCHES ARE NOT ANTICIPATED.

..JEWELL.. 04/24/2011

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

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

LAT...LON   36268940 36109121 35749369 35869469 36169487 36449398
            36609180 36869000 37248884 37118855 36628865 36268940

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 23, 8:09 PM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Cleburne, Conway, Craighead and 25 more2 hr
Apr 23, 8:19 PM CDTTornado WatchSPCBaxter, Clay, Craighead, Fulton, Greene, Independence and 9 more4 hr
Apr 24, 11:58 AM CDTMesoscale DiscussionSPCBaxter, Clay, Cleburne, Conway, Craighead, Faulkner and 19 more62 min
Apr 24, 12:27 PM CDTTornado WatchSPCBaxter, Clay, Cleburne, Conway, Craighead, Fulton and 16 more7 hr
Apr 24, 3:31 PM CDTMesoscale DiscussionSPCCleburne, Craighead, Greene, Independence, Izard, Jackson and 9 more59 min
Apr 24, 5:34 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Madison, Polk, Scott, Sebastian and 1 more26 min
Apr 24, 5:36 PM CDTTornado WatchSPCConway, Crawford, Franklin, Garland, Johnson, Logan and 8 more7 hr
Apr 24, 6:23 PM CDTMesoscale DiscussionSPCBaxter, Clay, Cleburne, Conway, Craighead, Faulkner and 32 more2 hr
Apr 24, 3:01 PM CDTMesoscale DiscussionSPCAdair, Allen, Ballard, Barren, Bell, Boyle and 51 more89 min
Apr 23, 7:04 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Jefferson and 9 more86 min
Apr 23, 9:08 PM CDTMesoscale DiscussionSPCAdair, Canadian, Cherokee, Cleveland, Craig, Creek and 26 more97 min
Apr 23, 9:53 PM CDTSevere Thunderstorm WatchSPCAdair, Atoka, Bryan, Caddo, Canadian, Carter and 47 more7 hr
Apr 24, 2:02 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Caddo, Canadian, Carter, Cherokee and 42 more88 min
Apr 24, 4:17 AM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Cherokee, Cleveland, Coal and 29 more28 min
Apr 24, 1:13 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Cotton and 13 more92 min
Apr 24, 2:28 PM CDTSevere Thunderstorm WatchSPCAdair, Atoka, Bryan, Carter, Cherokee, Choctaw and 31 more7 hr

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Kentucky, 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.