Alert archive / Oklahoma / Mesoscale Discussions in 2015

Mesoscale Discussion 1621

August 5, 201521 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Aug 5, 2015, 7:52 PM CDT for 21 counties in Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 5, 2015, 7:52 PM CDT (00:52 UTC)
Expired
Aug 5, 2015, 10:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 21 counties

Cleveland County, OK, Coal County, OK, Creek County, OK, Haskell County, OK, Hughes County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 113 km from the middle of the area, began a volume at 00:50 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 00:00Z, 0.9 hours before the alert went out and 123 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 00:00Z on 2015-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2563 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, Norman, OK at 00:00Z on 2015-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
2563 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1850 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.1
Supercell composite
10.6

Open this sounding in Storm Lab

The text

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

602 
ACUS11 KWNS 060052
SWOMCD
SPC MCD 060052 
ARZ000-OKZ000-060315-

MESOSCALE DISCUSSION 1621
NWS STORM PREDICTION CENTER NORMAN OK
0752 PM CDT WED AUG 05 2015

AREAS AFFECTED...CNTRL AND ERN OK INTO FAR WRN AR

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 060052Z - 060315Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED THUNDERSTORMS APPEAR LIKELY TO DEVELOP OVER THE
NEXT FEW HOURS WITH A THREAT OF MARGINALLY SEVERE HAIL AND WIND.

DISCUSSION...AN OUTFLOW BOUNDARY CONTINUES TO DRIFT SWWD ACROSS NRN
INTO CNTRL OK...AND EXTENDING EWD ACROSS CNTRL AR THIS EVENING. A
VERY WARM AND MOIST AIR MASS IS PRESENT...WITH 00Z OUN SOUNDING
DEPICTING AROUND 3000 J/KG 100 MB MLCAPE.

ALTHOUGH THE LARGE-SCALE ENVIRONMENT IS NOT PARTICULARLY SUPPORTIVE
OF ANY ORGANIZED SEVERE STORM THREAT...WEAK CONVERGENCE NEAR THE
OUTFLOW BOUNDARY AND A NEWD FLUX OF HIGHER THETA-E AIR MAY BE ENOUGH
FOR CONTINUED STORM FORMATION. AS OF 01Z...ISOLATED CELLS WERE
ALREADY DEVELOPING NEAR GUTHRIE OK. IF CAPPING DOES NOT INCREASE TOO
RAPIDLY...SOME OF THESE CELLS COULD BECOME STRONG TO SEVERE.
FURTHER...IF STORM COVERAGE INCREASES SUBSTANTIALLY...THEN A WATCH
COULD BE CONSIDERED.

..JEWELL/THOMPSON.. 08/06/2015

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

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

LAT...LON   34669659 34989748 35629803 36059781 36309697 35919578
            35409462 35139433 34619438 34349476 34309528 34669659

Nearby

Mesoscale Discussions in Oklahoma, 2015Every mesoscale discussion in 2015

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.