ZCZC SPCSWOMCD ALL
ACUS11 KWNS 181931 
SPC MCD 181931 
MNZ000-WIZ000-IAZ000-182100-

MESOSCALE DISCUSSION 1557
NWS STORM PREDICTION CENTER NORMAN OK
0231 PM CDT THU AUG 18 2016

AREAS AFFECTED...SOUTHERN MN...EXTREME NORTHEAST IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 181931Z - 182100Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...SEVERE THREAT IS INCREASING ACROSS SOUTHERN MN INTO
EXTREME NORTHEASTERN IA.  LARGE HAIL IS THE PRIMARY SEVERE
THREAT...ALONG WITH DAMAGING WINDS.  WW MAY BE ISSUED.

DISCUSSION...EARLY-DAY MCS HAS PROGRESSED SEWD ACROSS THE NRN PLAINS
INTO THE UPPER MS VALLEY WHERE THE LEADING REMNANTS ARE NOW CROSSING
THE MN/WI BORDER.  LOW-LEVEL FLOW ATOP THE SWRN FLANK OF THIS
COMPLEX APPEARS TO BE PARTLY RESPONSIBLE FOR RENEWED UPDRAFTS OVER
SWRN MN.  THIS ACTIVITY IS LIKELY ELEVATED IN NATURE...BUT IS
INGESTING STEEPER LAPSE RATES/BUOYANCY ATOP RAIN-COOLED BOUNDARY
LAYER.  LATEST MRMS DATA SUGGESTS LARGE HAIL IS NOTED WITH UPDRAFTS
MOVING ACROSS REDWOOD INTO BROWN COUNTY.  AS TEMPERATURES WARM
ACROSS SRN MN CONVECTION MAY ROOT INTO THE BOUNDARY LAYER WHERE
LOW-LEVEL SHEAR MAY ENHANCE ROTATIONAL POTENTIAL.  SEVERE
THUNDERSTORM WATCH MAY BE REQUIRED ACROSS THIS REGION SOON.

..DARROW/THOMPSON.. 08/18/2016

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

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   44739489 44409195 43479178 43299301 44029539 44739489 

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