ZCZC SPCSWOMCD ALL
ACUS11 KWNS 090044 
SPC MCD 090044 
SDZ000-090245-

MESOSCALE DISCUSSION 1664
NWS STORM PREDICTION CENTER NORMAN OK
0744 PM CDT THU SEP 08 2016

AREAS AFFECTED...PARTS OF S CNTRL SOUTH DAKOTA AND ADJACENT N CNTRL
NEBRASKA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 090044Z - 090245Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...FURTHER STORM INTENSIFICATION...INCLUDING AN ISOLATED
SUPERCELL OR TWO...APPEARS POSSIBLE ACROSS SOUTH CENTRAL SOUTH
DAKOTA DURING THE NEXT COUPLE OF HOURS.  HOWEVER...THIS MAY NOT
PERSIST MUCH BEYOND 03-04Z AND...GIVEN A RELATIVELY LIMITED AREAL
EXTENT...A WATCH IS NOT CURRENTLY ANTICIPATED.

DISCUSSION...SOUTHEAST OF A SURFACE LOW WITHIN LEE SURFACE TROUGHING
ACROSS THE NORTHERN HIGH PLAINS...LARGE-SCALE FORCING FOR ASCENT
APPEARS TO BE AIDING A SOMEWHAT CONFINED AREA OF INTENSIFYING
THUNDERSTORM DEVELOPMENT...WEST NORTHWEST OF WINNER SD AND VALENTINE
NEB.  THIS IS WHERE THE INTERSECTION OF AN AXIS OF STRONGER SURFACE
HEATING WITH LOW-LEVEL MOISTURE RETURN IS CONTRIBUTING TO A FAIRLY
LOCALIZED AREA OF MODERATE INSTABILITY CHARACTERIZED BY CAPE ON THE
ORDER OF 1500 J/KG.  IN THE PRESENCE OF STRONG VERTICAL SHEAR
BENEATH 50 KT WESTERLY 500 MB FLOW...AND ALONG A 30 KT SOUTHERLY 850
MB JET...THERE STILL APPEARS A WINDOW OF OPPORTUNITY FOR FURTHER
STORM INTENSIFICATION ACROSS SOUTH CENTRAL SOUTH DAKOTA THROUGH THE
01-03Z TIME FRAME.  THIS MAY INCLUDE A SUSTAINED SUPERCELL OR TWO
BEFORE BOUNDARY LAYER INSTABILITY...AND PERHAPS AN AREA OF ENHANCED
MID-LEVEL FORCING...WEAKEN.  GIVEN SIZABLE BOUNDARY LAYER
TEMPERATURE/DEW POINT SPREADS...LARGE HAIL AND LOCALLY STRONG
SURFACE GUSTS APPEAR THE PRIMARY SEVERE HAZARDS.

..KERR/GUYER.. 09/09/2016

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

ATTN...WFO...FSD...ABR...UNR...

LAT...LON   43889966 44349925 44099850 43059918 43000043 43889966 

NNNN