Alert archive / Arkansas / Mesoscale Discussions in 2016

Mesoscale Discussion 710

May 24, 201637 counties in Arkansas

The Storm Prediction Center issued this mesoscale discussion at May 24, 2016, 5:05 PM CDT for 37 counties in Arkansas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 24, 2016, 5:05 PM CDT (22:05 UTC)
Expired
May 24, 2016, 7:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 37 counties

Cleburne County, AR, Conway County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Faulkner County, AR, Franklin County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Lee County, AR, Logan County, AR, Lonoke County, AR, Monroe County, AR, Montgomery County, AR, Perry County, AR, Poinsett County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sebastian 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

The radar

The Little Rock radar (KLZK), 41 km from the middle of the area, began a volume at 22:05 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 (KBYH), launched 12:00Z, 10.1 hours before the alert went out and 200 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 2016-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 319 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 12:00Z on 2016-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
319 J/kg
Mixed-layer CIN
-134 J/kg
Mixed-layer LCL
1163 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
93 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

780 
ACUS11 KWNS 242206
SWOMCD
SPC MCD 242205 
ARZ000-MOZ000-OKZ000-250030-

MESOSCALE DISCUSSION 0710
NWS STORM PREDICTION CENTER NORMAN OK
0505 PM CDT TUE MAY 24 2016

AREAS AFFECTED...NORTHERN AND CENTRAL AR/FAR WESTERN TN/EASTERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 242205Z - 250030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO CONTINUE DEVELOPING ALONG THE
EASTERN PERIPHERY /FAR SOUTHEAST MO AND NORTHEAST AR/ AND SOUTHERN
PERIPHERY /NORTHERN INTO CENTRAL AR/ OF THE ORGANIZED
EASTWARD-MOVING MCS WHICH ENCOMPASSES SOUTHEAST MO TO NORTHERN AR. 
PORTIONS OF THIS AREA FROM CENTRAL AR INTO FAR EASTERN OK MAY NEED
AN UPGRADE TO GREATER SEVERE PROBABILITIES AND A SLIGHT RISK
CATEGORY.   WW ISSUANCE IS BEING CONSIDERED.

DISCUSSION...SATELLITE IMAGERY SHOWED AN MCS WITH AN EMBEDDED MCV
TRACKING TO THE EAST ACROSS SOUTHEAST MO WITH THE SOUTHERN EXTENT OF
THIS COMPLEX...WHICH HAS REMAINED THE MOST ACTIVE WITH NEW TSTM
DEVELOPMENT...ACROSS NORTHERN AR.  DESPITE EARLIER VWP AT
SPRINGFIELD MO SHOWING A VEER-BACK-VEER WIND PROFILE WITH MODEST
DEEP-LAYER SHEAR...THE WIND FIELDS /POSSIBLY ENHANCED BY THE MCV
CIRCULATION/ APPEAR TO BE RESULTING IN STRONGER EFFECTIVE BULK SHEAR
OF 35-40 KT FROM EASTERN OK TO FAR WESTERN TN.  MEANWHILE...
S/SOUTHWESTERLY LOW-LEVEL WINDS WILL CONTINUE TO FEED THE SOUTHERN
FLANK OF THIS MCS WITH A RATHER MOIST AND MODERATELY UNSTABLE
ENVIRONMENT /GIVEN MLCAPE OF 1000-2000 J PER KG/.  

BULK SHEAR VECTORS ARE GENERALLY ORIENTED PARALLEL TO THE OUTFLOW
BOUNDARY IN NORTHERN AR...SUGGESTING EMBEDDED LINEAR STRUCTURES WILL
BE THE PRIMARY STORM MODE...THOUGH SUPERCELLS CANNOT BE RULED OUT. 
LOCALLY STRONG WIND GUSTS WILL BE THE PRIMARY THREAT...THOUGH STEEP
LAPSE RATES SHOULD SUPPORT AN ISOLATED HAIL THREAT.

ADDITIONAL CONVECTION IS DEVELOPING ALONG THE TRAILING OUTFLOW
BOUNDARY THROUGH EAST-CENTRAL OK...WITH THE EXPANDING AREA OF
COOLING CLOUD TOPS LOCATED IN NORTHWEST AR.  THIS AREA IS CLOSER TO
THE STRONGER INFLOW OF MOIST AIR AND MODERATE INSTABILITY.  STORMS
MOVING EAST FROM SOUTHEAST MO AND NORTHEAST AR SHOULD WEAKEN AS THEY
MOVE INTO A MORE STABLE ENVIRONMENT WITH EASTWARD EXTENT INTO FAR
WESTERN KY/WESTERN TN.

..PETERS/EDWARDS.. 05/24/2016

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

ATTN...WFO...MEG...LZK...TSA...

LAT...LON   34519136 34319195 34249274 34409359 34669433 34979466
            35459467 35839309 36049213 36209156 36379077 36029025
            35479018 35199026 34719079 34519136

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 10:59 AM CDTMesoscale DiscussionSPCBaxter, Boone, Fulton, Marion, Randolph2 hr
May 24, 4:43 PM CDTSevere Thunderstorm WatchSPCCrawford, Franklin, Madison, Sebastian, Washington7 hr

Nearby

Mesoscale Discussions in Arkansas, 2016Every mesoscale discussion in 2016

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.