Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 746

May 11, 20115 states

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 6:35 PM CDT for 5 states. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 11, 2011, 6:35 PM CDT (23:35 UTC)
Expired
May 11, 2011, 7:30 PM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 55 counties

Benton County, AR, Boone County, AR, Carroll County, AR, Clark County, AR, Conway County, AR, Crawford County, AR, Franklin County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Johnson County, AR, Little River County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Cherokee County, KS, Labette County, KS, Barry County, MO, Christian County, MO, Dade County, MO, Greene County, MO, Jasper County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Stone County, MO, Taney County, MO, Adair County, OK, Cherokee County, OK, Craig County, OK, Delaware County, OK, LeFlore County, OK, Mayes County, OK, Nowata County, OK, Ottawa County, OK, Sequoyah County, OK, Bowie County, TX, Camp County, TX, Morris County, TX, Titus County, TX

The radar

The Western Arkansas radar (KSRX), 57 km from the middle of the area, began a volume at 23:35 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

Springfield, MO (KSGF), launched 12:00Z, 11.6 hours before the alert went out and 135 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, Springfield, MO at 12:00Z on 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2359 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, Springfield, MO at 12:00Z on 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 203 square meters per square second.19395878Sfc1 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
2359 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
1112 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
203 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
1.1
Supercell composite
5.4

Open this sounding in Storm Lab

The text

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

822 
ACUS11 KWNS 112335
SWOMCD
SPC MCD 112335 
ARZ000-MOZ000-TXZ000-OKZ000-KSZ000-120030-

MESOSCALE DISCUSSION 0746
NWS STORM PREDICTION CENTER NORMAN OK
0635 PM CDT WED MAY 11 2011

AREAS AFFECTED...EASTERN OK/WESTERN AR/SOUTHEAST KS/SOUTHWEST MO

CONCERNING...SEVERE THUNDERSTORM WATCH 280...284...

VALID 112335Z - 120030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
280...284...CONTINUES.

AN EXTENSIVE SQUALL LINE WILL CONTINUE TO POSE A RISK FOR DAMAGING
WINDS OVER THE NEXT FEW HOURS ACROSS FAR EASTERN OK INTO WESTERN
AR/SOUTHWEST MO...BUT A GRADUAL WEAKENING TREND IS ANTICIPATED
THROUGH EARLY/MID EVENING. AN ADDITIONAL WATCH IS NOT ANTICIPATED TO
THE EAST OF WW 280...ALTHOUGH PORTIONS OF WW 280 WILL BE
TEMPORALLY/SPATIALLY EXTENDED PRIOR TO 00Z SCHEDULED EXPIRATION.

EXTENSIVE SQUALL LINE CONTINUES TO PROGRESS EAST-NORTHEASTWARD AT
AROUND 35-40 KT INTO WESTERN AR/ACROSS FAR NORTHEAST OK AND FAR
SOUTHEAST KS AS OF 2330Z. CLAREMORE OK RECENTLY REPORTED A MEASURED
52 KT WIND GUST. WITH TIME...IN SPITE OF COLD POOL DRIVEN
MOMENTUM...A GRADUAL DECOUPLING OF THE BOUNDARY LAYER AND
INCREASINGLY MORE STABLE INFLOW SHOULD LEAD TO WEAKENING TREND OVER
THE NEXT FEW HOURS.

..GUYER.. 05/11/2011

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

ATTN...WFO...LZK...SGF...SHV...TSA...ICT...

LAT...LON   37029576 37449495 37559352 35829223 34309260 32799512
            34379457 35909537 37029576

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 1:16 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more8 hr
May 11, 2:51 PM CDTMesoscale DiscussionSPCLafayette, Little River, Miller, Sevier84 min
May 11, 3:46 PM CDTSevere Thunderstorm WatchSPCClark, Conway, Garland, Hempstead, Hot Spring, Howard and 15 more8 hr
May 11, 7:30 AM CDTMesoscale DiscussionSPCMeade, Seward, Stevens60 min
May 11, 11:21 AM CDTMesoscale DiscussionSPCButler, Chase, Clay, Cloud, Coffey, Dickinson and 22 more84 min
May 11, 12:16 PM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Brown, Butler, Chase, Chautauqua and 48 more5 hr
May 11, 1:51 PM CDTMesoscale DiscussionSPCClark, Comanche, Edwards, Finney, Ford, Gove and 25 more84 min
May 11, 3:57 PM CDTMesoscale DiscussionSPCAllen, Anderson, Atchison, Bourbon, Brown, Cherokee and 25 more48 min
May 11, 4:00 PM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Atchison, Bourbon, Brown, Chautauqua and 24 more8 hr
May 11, 4:52 PM CDTTornado WatchSPCCheyenne, Decatur, Gove, Graham, Logan, Norton and 7 more6 hr
May 11, 6:02 PM CDTMesoscale DiscussionSPCBarber, Barton, Clark, Comanche, Edwards, Ellis and 9 more88 min
May 11, 8:09 AM CDTMesoscale DiscussionSPCAdair, Grundy, Knox, Linn, Macon, Mercer and 4 more66 min
May 11, 2:18 PM CDTMesoscale DiscussionSPCLincoln, Pike, Saint Charles, Saint Louis, City of Saint Louis57 min
May 11, 3:38 PM CDTMesoscale DiscussionSPCClark, Schuyler, Scotland2 hr
May 11, 6:17 PM CDTMesoscale DiscussionSPCAdair, Grundy, Knox, Macon, Mercer, Putnam and 3 more28 min
May 11, 2:28 AM CDTMesoscale DiscussionSPCTexas92 min
May 11, 12:33 PM CDTMesoscale DiscussionSPCAtoka, Coal, Creek, Haskell, Hughes, Johnston and 19 more87 min
May 11, 3:29 AM CDTSevere Thunderstorm WatchSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Carson and 46 more8 hr
May 11, 9:56 AM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Comanche, Concho and 20 more94 min
May 11, 10:21 AM CDTSevere Thunderstorm WatchSPCBell, Bosque, Brown, Burnet, Callahan, Coleman and 52 more5 hr

Nearby

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