Alert archive / Oklahoma / Mesoscale Discussions in 2016

Mesoscale Discussion 718

May 24, 201619 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 24, 2016, 9:39 PM CDT for 19 counties in Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 24, 2016, 9:39 PM CDT (02:39 UTC)
Expired: May 24, 2016, 11:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Coal County, OK, Creek County, OK, Garfield County, OK, Hughes County, OK, Kay County, OK, Lincoln County, OK, Logan County, OK, McIntosh County, OK, Noble County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Tulsa County, OK

The radar

The Norman radar (KTLX), 74 km from the middle of the area, began a volume at 02:40 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, 2.7 hours before the alert went out and 91 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1931 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 1052 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 194 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 11.9

Open this sounding in Storm Lab

The text

As transmitted.

287 
ACUS11 KWNS 250240
SWOMCD
SPC MCD 250239 
OKZ000-250445-

MESOSCALE DISCUSSION 0718
NWS STORM PREDICTION CENTER NORMAN OK
0939 PM CDT TUE MAY 24 2016

AREAS AFFECTED...CENTRAL...NORTH-CENTRAL AND NORTHEAST OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 250239Z - 250445Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED LARGE HAIL WILL BE POSSIBLE WITH THE STRONGEST
SUSTAINED STORMS ACROSS PORTIONS OF CENTRAL INTO NORTHEAST OK
THROUGH LATE EVENING AND EARLY OVERNIGHT.  CURRENT THINKING SUGGESTS
SEVERE-WEATHER COVERAGE SHOULD REMAIN TOO LIMITED TO SUPPORT WATCH
ISSUANCE.

DISCUSSION...MID-EVENING SURFACE ANALYSIS AND MOSAIC RADAR IMAGERY
SHOWED AN OUTFLOW BOUNDARY ATTENDANT TO THE NORTHEAST/EAST-CENTRAL
OK MCS EXTENDED FROM SOUTH OF FSM WESTWARD INTO NORTHEAST HUGHES
COUNTY AND THEN NORTHWESTWARD THROUGH SOUTHERN LINCOLN TO ALFALFA
COUNTIES.  GIVEN COOLING OF SURFACE TEMPERATURES ACROSS CENTRAL
OK...MODIFIED 00Z OUN SOUNDING SUGGESTS THE RECENT STORM DEVELOPMENT
ACROSS THE CENTRAL OK COUNTIES OF OKLAHOMA...CLEVELAND...AND
POTTAWATOMIE IS LIKELY ELEVATED.  THE PRESENCE OF STEEP MIDLEVEL
LAPSE RATES /9 C/KM PER THE 00Z OUN SOUNDING/ COMBINED WITH A
STRENGTHENING SOUTHERLY LLJ MAINTAINING AN INFLOW OF MODERATELY
STRONG INSTABILITY /2000-3000 J PER KG/ AND EFFECTIVE BULK SHEAR OF
40-45 KT FAVORS LARGE HAIL AS THE PRIMARY THREAT.  THIS ENVIRONMENT
IS VERY SUPPORTIVE FOR RAPID STORM INTENSIFICATION AS DEPICTED BY
THE TRENDS IN RADAR IMAGERY AND STRONG COOLING CLOUD TOPS WITH THE
INITIAL ELEVATED STORMS.  AS THE CURRENT STORMS MOVE TO THE
NORTHEAST...THEY WILL TRACK NORTH OF THE AFOREMENTIONED CONVECTIVE
OUTFLOW BOUNDARY /ABOVE A MORE STABLE BOUNDARY LAYER WITH NORTHEAST
EXTENT/.

..PETERS/EDWARDS.. 05/25/2016

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

ATTN...WFO...TSA...OUN...

LAT...LON   34549649 35549761 36099801 36559802 36749759 36939703
            36679620 36269589 35949577 35559560 35099559 34539620
            34549649

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 24, 8:26 PM CDT	Mesoscale Discussion	SPC	Beaver, Ellis, Harper	64 min
May 24, 8:39 PM CDT	Mesoscale Discussion	SPC	Adair, Cherokee, Haskell, Latimer, LeFlore, Muskogee and 2 more	96 min
May 25, 1:13 AM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Cherokee, Coal, Creek, Haskell and 14 more	3 hr
May 25, 2:47 PM CDT	Mesoscale Discussion	SPC	Kay	118 min
May 25, 3:44 PM CDT	Tornado Watch	SPC	Alfalfa, Garfield, Grant, Kay, Major, Noble and 2 more	9 hr

Nearby

Mesoscale Discussions in Oklahoma, 2016 Every 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.