ZCZC SPCSWOMCD ALL
ACUS11 KWNS 012143 
SPC MCD 012143 
SDZ000-WYZ000-020015-

MESOSCALE DISCUSSION 1463
NWS STORM PREDICTION CENTER NORMAN OK
0443 PM CDT MON AUG 01 2016

AREAS AFFECTED...PORTIONS SWRN SD AND EXTREME ERN WY...PRIMARILY
BLACK HILLS REGION.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 012143Z - 020015Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...TSTMS OVER BLACK HILLS MAY CONTINUE TO PRODUCE OCNL SVR
HAIL...WITH ISOLATED RISK OF DAMAGING WIND...AS THEY SPREAD AWAY
FROM CENTRAL PART OF ELEVATED TERRAIN.  EXTENT OF THREAT AWAY FROM
HILLS IS UNCERTAIN...BUT SOME OF THIS ACTIVITY MAY PROPAGATE INTO
WRN BADLANDS...AREAS BETWEEN SRN HILLS AND NEB BORDER...AND/OR VERY
SLIGHTLY ONTO ADJACENT GRASSLANDS IN WY.

DISCUSSION...TSTMS HAVE DEVELOPED GRADUALLY WITHIN PAST COUPLE HOURS
OVER CORE OF BLACK HILLS...INCREASING IN INTENSITY AND COVERAGE...
WITH 2-INCH HAIL REPORTED FROM ONE CELL AT 2101Z.  PRECONVECTIVE
ENVIRONMENT WILL REMAIN CHARACTERIZED BY STEEP LOW/MIDDLE-LEVEL
LAPSE RATES AND SFC DEW POINTS MID/UPPER 60S F IN UPWIND BOUNDARY
LAYER...ALONG WITH LIGHT UPSLOPE SFC FLOW INTO ERN/NERN HILLS. 
2000-2500 J/KG MLCAPE IS APPARENT FROM MODIFIED RAOB AND MODEL
SOUNDINGS.  AMBIENT VERTICAL SHEAR IS MODEST -- ONLY 25-35 KT
EFFECTIVE-SHEAR MAGNITUDES EVIDENT IN MODIFIED FCST SOUNDINGS AND
VWP DATA...WITH DIFLUENCE ALOFT.  THIS WILL FOSTER STRONG
STORM-SCALE PROPAGATIONAL COMPONENT THAT ALREADY HAS BEEN NOTED AND
SHOULD CONTINUE.  ADDITIONAL CONVECTION INITIATION MAY BE STRONGLY
TIED TO RESIDUAL ORIGINATING PROCESSES RELATED TO HEATING OF HIGHER
TERRAIN...BUT WILL BE INCREASINGLY DRIVEN BY LOCAL-SCALE TO
MESOBETA-SCALE BOUNDARY INTERSECTIONS AND PROPAGATION.  MOTION INTO
WRN WY WILL BE LIMITED BY MUCH WEAKER MOISTURE THAN ON N AND E SIDE
OF HILLS.

DAY-1 CONVECTIVE OUTLOOK IS BEING AMENDED TO ACCOUNT FOR THIS AREA
AS WELL.

..EDWARDS/PETERS.. 08/01/2016

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

ATTN...WFO...UNR...

LAT...LON   43350395 43690407 44170415 44490381 44490305 44180220
            43700210 43150237 43050326 43180375 43350395 

NNNN