ZCZC SPCSWOMCD ALL
ACUS11 KWNS 182248 
SPC MCD 182248 
WIZ000-IAZ000-MNZ000-190015-

MESOSCALE DISCUSSION 1559
NWS STORM PREDICTION CENTER NORMAN OK
0548 PM CDT THU AUG 18 2016

AREAS AFFECTED...SERN MN...NERN IA...SWRN WI

CONCERNING...SEVERE THUNDERSTORM WATCH 450...

VALID 182248Z - 190015Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 450
CONTINUES.

SUMMARY...A COMPACT BOWING THUNDERSTORM CLUSTER WILL CONTINUE TO
POSE A THREAT OF DAMAGING WIND AND PERHAPS ISOLATED SEVERE HAIL FOR
THE NEXT 1-2 HOURS. A DECREASE IN INTENSITY IS EVENTUALLY EXPECTED
THIS EVENING...BUT A SMALL DOWNSTREAM WATCH MAY BE REQUIRED BEFORE
00Z.

DISCUSSION...AT 2230Z...A COMPACT AND WELL-ORGANIZED BOWING
THUNDERSTORM CLUSTER IS MOVING ACROSS SERN MN...WITH SPORADIC
REPORTS OF 40-55 KT WIND GUSTS NOTED OVER THE LAST 1-2 HOURS ALONG
THE LEADING EDGE OF THE SYSTEM. THE SYSTEM IS EXPECTED TO CONTINUE
TRACKING ESEWD ALONG A WARM FRONTAL BOUNDARY AND WILL LIKELY PERSIST
INTO PORTIONS OF NERN IA/SRN WI...GIVEN THE WELL-ORGANIZED NATURE OF
THE SYSTEM AND STRONG INSTABILITY AVAILABLE ALONG AND SOUTH OF THE
BOUNDARY. THE SEVERITY OF THE SYSTEM IS EXPECTED TO EVENTUALLY BEGIN
TO WANE...GIVEN WEAKER MIDLEVEL FLOW/DEEP-LAYER SHEAR WITH EASTWARD
EXTENT AND EVENTUAL DIURNAL COOLING/STABILIZATION. HOWEVER...SOME
SEVERE WIND THREAT WILL LIKELY EXIST DOWNSTREAM OF WW 450...AND AS A
RESULT LOCAL WATCH EXPANSIONS AND/OR NEW WATCH ISSUANCE MAY BE
REQUIRED BEFORE 00Z.

..DEAN/GRAMS.. 08/18/2016

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

ATTN...WFO...MKX...ARX...

LAT...LON   43459289 43609283 43779274 43949285 44079287 44149240
            44109137 43999062 43728991 43308980 43118995 43049019
            43189116 43259218 43349278 43459289 

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