Alert archive / Arkansas / Mesoscale Discussions in 2016

Mesoscale Discussion 618

May 12, 201623 counties in Arkansas; Dunklin County, Missouri; 4 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 12, 2016, 2:48 AM CDT for 23 counties in Arkansas; Dunklin County, Missouri; 4 counties in Oklahoma. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
May 12, 2016, 2:48 AM CDT (07:48 UTC)
Expired
May 12, 2016, 4:15 AM CDT
In force
87 min
Issued by
the Storm Prediction Center
All 28 counties

Cleburne County, AR, Conway County, AR, Craighead County, AR, Faulkner County, AR, Garland County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Montgomery County, AR, Perry County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Scott County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Yell County, AR, Dunklin County, MO, Choctaw County, OK, LeFlore County, OK, McCurtain County, OK, Pushmataha County, OK

The radar

The Western Arkansas radar (KSRX), 68 km from the middle of the area, began a volume at 07:48 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 00:00Z, 7.8 hours before the alert went out and 213 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 00:00Z on 2016-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1205 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 00:00Z on 2016-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
1205 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1636 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
149 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

As transmitted.

987 
ACUS11 KWNS 120749
SWOMCD
SPC MCD 120748 
TNZ000-MOZ000-ARZ000-OKZ000-120915-

MESOSCALE DISCUSSION 0618
NWS STORM PREDICTION CENTER NORMAN OK
0248 AM CDT THU MAY 12 2016

AREAS AFFECTED...PARTS OF SERN OK...W CNTRL THROUGH NE AR...AND
ADJACENT PORTIONS OF SE MO

CONCERNING...SEVERE THUNDERSTORM WATCH 172...

VALID 120748Z - 120915Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 172
CONTINUES.

SUMMARY...STORMS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL AND
LOCALLY STRONG WIND GUSTS MAY CONTINUE ANOTHER COUPLE OF HOURS WHILE
SPREADING EAST OF WATCH 172.  HOWEVER...WITH LITTLE POTENTIAL FOR
APPRECIABLE FURTHER INTENSIFICATION...ANOTHER WATCH IS NOT
ANTICIPATED.

DISCUSSION...FORCING FOR ASCENT ALONG A SOUTHEASTWARD ADVANCING
FRONTAL ZONE CONTINUES TO SUPPORT AN EVOLVING LINE OF STORMS ACROSS
PARTS OF SOUTHEASTERN OKLAHOMA INTO PARTS OF NORTHWESTERN ARKANSAS. 
VERTICAL SHEAR ACROSS THIS REGION IS NOT PARTICULARLY STRONG.  
HOWEVER...SOUTHEASTERLY/SOUTHERLY LOW-LEVEL SYSTEM-RELATIVE WINDS
ARE SUPPORTING INFLOW OF AIR STILL CHARACTERIZED BY MODERATELY LARGE
CAPE.  THIS MAY MAINTAIN VIGOROUS CONVECTIVE DEVELOPMENT ANOTHER FEW
HOURS...WITH 20-30 KT WESTERLY DEEP-LAYER MEAN FLOW CONTRIBUTING TO
A GRADUAL EASTWARD PROGRESSION INTO AND THROUGH PORTIONS OF THE
OZARK PLATEAU.

..KERR.. 05/12/2016

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

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

LAT...LON   34819554 34979473 35039391 35599325 35859262 36559106
            36108950 35579109 34659242 34249399 34039494 33999555
            34149571 34489593 34819554

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 8:11 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 5 more3 hr
May 11, 10:13 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more7 hr
May 11, 11:46 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Logan, Scott, Sebastian119 min
May 12, 9:10 AM CDTMesoscale DiscussionSPCCraighead, Crittenden, Cross, Greene, Mississippi, Poinsett95 min
May 12, 2:33 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Desha, Drew and 1 more87 min
May 11, 11:28 PM CDTMesoscale DiscussionSPCBollinger, Cape Girardeau, Iron, Madison, Mississippi, Perry and 2 more92 min
May 11, 10:13 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Kiowa, Tillman92 min
May 12, 2:12 AM CDTMesoscale DiscussionSPCCarter, Comanche, Cotton, Jefferson, Stephens, Tillman93 min

Nearby

Mesoscale Discussions in Arkansas, 2016Mesoscale Discussions in Oklahoma, 2016Mesoscale Discussions in Missouri, 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.