Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 1464

July 14, 2012Sebastian County, Arkansas; 18 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Jul 14, 2012, 2:46 PM CDT for Sebastian County, Arkansas; 18 counties in Oklahoma. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Jul 14, 2012, 2:46 PM CDT (19:46 UTC)
Expired
Jul 14, 2012, 3:45 PM CDT
In force
59 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Sebastian County, AR, Atoka County, OK, Coal County, OK, Creek County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore 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, Seminole County, OK, Sequoyah County, OK

The radar

The Tulsa radar (KINX), 129 km from the middle of the area, began a volume at 19:47 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, 7.8 hours before the alert went out and 143 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 2012-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 932 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 2012-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 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
932 J/kg
Mixed-layer CIN
-183 J/kg
Mixed-layer LCL
1416 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

171 
ACUS11 KWNS 141946
SWOMCD
SPC MCD 141946 
ARZ000-OKZ000-142045-

MESOSCALE DISCUSSION 1464
NWS STORM PREDICTION CENTER NORMAN OK
0246 PM CDT SAT JUL 14 2012

AREAS AFFECTED...W CNTRL AR...ERN OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 141946Z - 142045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLD DMGG WIND WILL BE POSSIBLE AS A LOOSELY ORGANIZED
MCS PROGRESSES SWWD. GIVEN THE MARGINAL NATURE...A WW IS NOT
EXPECTED.

DISCUSSION...A POORLY/LOOSELY ORGANIZED CLUSTER OF STORMS HAS
DEVELOPED OVER WRN AR/E CNTRL OK...LIKELY IN RESPONSE TO A REMNANT
WEAK VORT MAX AND MID/UPPER LEVEL SHEAR AXIS. SUFFICIENT DIURNAL
DESTABILIZATION HAS OCCURRED IN ADVANCE OF THE CLUSTER...WITH STEEP
LOW-LEVEL LAPSE RATES /AOB 8.5 C/KM PER MESOANALYSIS/ AND MODEST NLY
FLOW ALOFT POSSIBLY LEADING TO COLD POOL ORGANIZATION AND
CONTRIBUTING TO A FEW DMGG WIND GUSTS...SIMILAR TO WHAT OCCURRED
YESTERDAY ACROSS NERN OK/NWRN AR. A PEAK WIND AT FT SMITH AT 1848Z
RECORDED A 41 MPH WIND GUST...SUGGESTING MARGINAL TO NEAR-SEVERE
WINDS WITH THE ONGOING CLUSTER ATTM.

..HURLBUT/CARBIN.. 07/14/2012

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

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

LAT...LON   35209698 35989680 36089638 35739523 35439429 35019406
            34509442 34229515 34069616 34339680 34759693 35209698

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 14, 6:00 PM CDTMesoscale DiscussionSPCBryan, Carter, Love, Marshall60 min

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.