Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 1126

June 11, 20125 counties in Arkansas; 28 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2012, 3:59 PM CDT for 5 counties in Arkansas; 28 counties in Oklahoma. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2012, 3:59 PM CDT (20:59 UTC)
Expired
Jun 11, 2012, 5:30 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 33 counties

Crawford County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Atoka County, OK, Cherokee County, OK, Cleveland County, OK, Coal County, OK, Creek County, OK, Delaware County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Mayes County, OK, McCurtain County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Okmulgee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK

The radar

The Tulsa radar (KINX), 116 km from the middle of the area, began a volume at 20:56 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

Norman, OK (KOUN), launched 12:00Z, 9.0 hours before the alert went out and 144 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, Norman, OK at 12:00Z on 2012-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3329 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, Norman, OK at 12:00Z on 2012-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 392 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
3329 J/kg
Mixed-layer CIN
-435 J/kg
Mixed-layer LCL
1295 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
392 m²/s²
0-3 km storm-relative helicity
404 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

940 
ACUS11 KWNS 112059
SWOMCD
SPC MCD 112059 
ARZ000-OKZ000-112230-

MESOSCALE DISCUSSION 1126
NWS STORM PREDICTION CENTER NORMAN OK
0359 PM CDT MON JUN 11 2012

AREAS AFFECTED...OK...AR

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 112059Z - 112230Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THERE IS SOME POTENTIAL FOR EVENING TSTM DEVELOPMENT
ACROSS PARTS OF ERN OK AND WRN AR. VERY UNSTABLE CONDITIONS ACROSS
THESE AREAS WOULD SUPPORT SEVERE STORMS WITH LARGE HAIL AND HIGH
WINDS IF CONVECTION CAN OVERCOME CONSIDERABLE CAPPING CURRENTLY IN
PLACE.

DISCUSSION...PERSISTENT CONVERGENCE NEAR FRONT/OUTFLOW BOUNDARY
INTERSECTION ACROSS NERN OK...IN CONCERT WITH VERY HOT AND LOCALLY
EXTREME INSTABILITY /MLCAPE TO AT LEAST 3000 J PER KG/...MAY
CONTRIBUTE TO STORM DEVELOPMENT IN THE AREA OVER THE NEXT 1-3 HOURS.
LATEST INDICATIONS SUGGEST THAT STORM INITIATION IS BEING INHIBITED
BY 1) VERY WARM AIR ALOFT ACTING TO KEEP AIR MASS CAPPED...AND 2)
LACK OF GREATER LARGE SCALE FORCING FOR ASCENT ACROSS THE REGION.

LATEST GUIDANCE PROVIDES MIXED SIGNALS ON WIDESPREAD TSTM
DEVELOPMENT POTENTIAL WITH RAPID REFRESH INDICATING STORM INITIATION
BY 00Z...NAM SHOWING LITTLE IN THE WAY OF DEVELOPMENT...AND 18Z HRRR
SHOWING ONLY ISOLATED STORMS ACROSS NWRN AR AND ERN OK IN THE NEXT
1-2 HOURS. IF STORMS CAN DEVELOP...MAGNITUDE OF INSTABILITY AND
MODEST WLY FLOW AROUND 30KT WILL CONTRIBUTE TO SEVERE POTENTIAL WITH
LARGE HAIL AND HIGH WINDS POSSIBLE. AREA WILL CONTINUE TO BE
MONITORED AND A WATCH IS POSSIBLE IF STORM DEVELOPMENT BEGINS TO
OCCUR.

..CARBIN/MEAD.. 06/11/2012

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

ATTN...WFO...LZK...SHV...TSA...OUN...

LAT...LON   35199734 34569715 34279680 34049584 34069460 34349388
            35169382 36189406 36629533 36449644 35779727 35199734

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 9:31 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 16 more59 min
Jun 11, 9:45 AM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 23 more6 hr
Jun 11, 1:12 PM CDTMesoscale DiscussionSPCArkansas, Craighead, Crittenden, Cross, Faulkner, Garland and 17 more93 min
Jun 11, 1:28 PM CDTSevere Thunderstorm WatchSPCArkansas, Cleveland, Crittenden, Cross, Dallas, Faulkner and 19 more7 hr
Jun 11, 3:29 PM CDTMesoscale DiscussionSPCArkansas, Cleveland, Crittenden, Cross, Dallas, Garland and 14 more2 hr
Jun 11, 5:05 PM CDTMesoscale DiscussionSPCArkansas, Calhoun, Cleburne, Cleveland, Conway, Craighead and 27 more55 min
Jun 11, 5:17 PM CDTSevere Thunderstorm WatchSPCAshley, Chicot6 hr

Nearby

Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Arkansas, 2012Every mesoscale discussion in 2012

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.