ZCZC SPCSWOMCD ALL
ACUS11 KWNS 161910 
SPC MCD 161910 
MNZ000-IAZ000-SDZ000-NDZ000-NEZ000-162045-

MESOSCALE DISCUSSION 0662
NWS STORM PREDICTION CENTER NORMAN OK
0210 PM CDT SAT MAY 16 2015

AREAS AFFECTED...CNTRL/ERN SD...SERN ND...SWRN MN...NWRN IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 161910Z - 162045Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A FEW SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
WITH A THREAT OF LARGE HAIL...LOCALLY DAMAGING WIND...AND A COUPLE
OF TORNADOES. WW ISSUANCE IS POSSIBLE BY 19-20Z.

DISCUSSION...A COMPLEX PATTERN IS IN PLACE ACROSS THE NRN PLAINS
THIS AFTERNOON. A REMNANT MCV IS MOVING INTO SERN SD...WITH A SFC
LOW LOCATED OVER NWRN SD AND A WARM FRONT DRAPED ACROSS NRN SD INTO
CNTRL/SRN MN. BOUNDARY-LAYER DRYING HAS BEEN NOTED IN THE WAKE OF
THE MCV ACROSS FAR SRN SD INTO NEB...WITH THE BOUNDARY SEPARATING
THE DRIER AIRMASS FROM MOIST CONDITIONS TO THE NORTH RUNNING IN AN
ARC FROM S-CNTRL/SERN SD INTO NERN NEB. SOME HEATING IS OCCURRING ON
THE MOIST SIDE OF THIS BOUNDARY...WITH A RECENT ATTEMPT AT
INITIATION IN LAKE COUNTY SD. ADDITIONAL DEVELOPMENT IS POSSIBLE
ALONG BOTH OF THE BOUNDARIES DESCRIBED ABOVE /POSSIBLY AIDED BY WEAK
ASCENT ASSOCIATED WITH THE MCV/ AND ALSO NEAR THE COLD FRONT ACROSS
THE WRN PART OF THE MCD AREA. 

18Z ABR SOUNDING DEPICTS VERY WEAK BUOYANCY AT PRESENT NEAR THE WARM
FRONT...BUT CONTINUED HEATING ALONG AND SOUTH OF THE FRONT MAY
EVENTUALLY YIELD MLCAPE OF 1000-1500 J/KG. WIND PROFILES ARE LARGELY
UNIDIRECTIONAL...BUT STRONG SLY MIDLEVEL FLOW IS RESULTING IN 30-40
KTS OF EFFECTIVE SHEAR...WHICH WILL BE SUFFICIENT FOR ORGANIZED
STORM STRUCTURES WITH ANY DEEP CONVECTION THAT CAN DEVELOP. A FEW
SUPERCELLS AND/OR BOWING SEGMENTS ARE POSSIBLE...WITH A PRIMARY
THREAT OF SEVERE HAIL AND DAMAGING WIND. SOME TORNADO THREAT WILL
EXIST WITH ANY SUPERCELL THAT IS SUSTAINED...ESPECIALLY NEAR THE
WARM FRONT WHERE LOW-LEVEL SHEAR WILL BE SOMEWHAT ENHANCED. WW
ISSUANCE IS POSSIBLE IN THE NEXT 1-2 HRS IF CONVECTIVE TRENDS
CONTINUE TO INCREASE.

..DEAN/DIAL.. 05/16/2015

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

ATTN...WFO...MPX...FGF...FSD...OAX...ABR...BIS...UNR...

LAT...LON   42669692 42879747 43219836 44150099 44950134 45570160
            45840009 46299850 45979667 45519527 44509438 43899473
            43089559 42579611 42549640 42669692 

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