ZCZC SPCSWOMCD ALL
ACUS11 KWNS 222057 
SPC MCD 222057 
NDZ000-SDZ000-222230-

MESOSCALE DISCUSSION 0678
NWS STORM PREDICTION CENTER NORMAN OK
0357 PM CDT SUN MAY 22 2016

AREAS AFFECTED...PORTIONS OF NRN SD AND WRN/CNTRL ND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 222057Z - 222230Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THUNDERSTORM DEVELOPMENT IS POSSIBLE BY 21-22Z...WITH
INCREASING COVERAGE INTO THIS EVENING. THE STRONGEST STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. WATCH ISSUANCE
MAY BE REQUIRED.

DISCUSSION...AT 2045Z...CU WAS GRADUALLY INCREASING IN THE VICINITY
OF A WEAK COLD FRONT ACROSS WRN ND...AND ALSO FROM N-CNTRL SD W OF
ABR INTO S-CNTRL ND...WHERE SFC ANALYSIS INDICATES SOME ENHANCED
CONFLUENCE WHICH MAY BE ASSOCIATED WITH A WEAK OUTFLOW BOUNDARY
GENERATED BY OVERNIGHT CONVECTION. 

BREAKS IN THE CLOUDS HAVE ALLOWED MODEST DESTABILIZATION TO
OCCUR...WITH MLCAPE RANGING FROM AROUND 500 J/KG ACROSS WRN ND TO
THE 1000-1500 J/KG RANGE ACROSS N-CNTRL SD. STRONG SSWLY MIDLEVEL
AHEAD ON THE EAST SIDE OF AN UPPER LOW IS EXPECTED TO BEGIN
OVERSPREADING THE WARM SECTOR LATER THIS AFTERNOON...WHICH WILL
RESULT IN SUFFICIENT DEEP-LAYER SHEAR FOR ORGANIZED STORM
STRUCTURES. UNIDIRECTIONAL WIND/SHEAR PROFILES WILL SUPPORT A MIX OF
STORM MODES...WITH LARGE HAIL AND DAMAGING WINDS EXPECTED TO BE THE
PRIMARY HAZARDS. 

WHILE STORMS COULD BE RATHER ISOLATED IN THE SHORT TERM...AN
INCREASING LOW-LEVEL JET SHOULD RESULT IN AN INCREASE IN COVERAGE BY
EARLY EVENING. AS THIS OCCURS...AN INCREASINGLY LINEAR MODE IS
EXPECTED WITH PERHAPS GREATER POTENTIAL FOR SEVERE WIND. A BRIEF
TORNADO OR TWO ALSO CANNOT BE RULED OUT...ESPECIALLY AS LOW-LEVEL
SHEAR INCREASES TOWARD EVENING.

..DEAN/HART.. 05/22/2016

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

ATTN...WFO...FGF...ABR...BIS...UNR...

LAT...LON   44560205 45250253 46300266 47680224 48830175 49010155
            48990011 48209967 47229918 46439889 45099885 44560205 

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