ZCZC SPCSWOMCD ALL
ACUS11 KWNS 311927 
SPC MCD 311927 
NDZ000-SDZ000-MTZ000-312130-

MESOSCALE DISCUSSION 1456
NWS STORM PREDICTION CENTER NORMAN OK
0227 PM CDT SUN JUL 31 2016

AREAS AFFECTED...FAR ERN MT...WRN ND...NWRN SD

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 311927Z - 312130Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO DEVELOP NEAR THE MT/ND BORDER THIS
AFTERNOON AND SPREAD EWD ACROSS WRN/CNTRL PORTIONS OF THE DAKOTAS.
POTENTIAL HAZARDS INCLUDE LARGE HAIL AND DMGG WIND GUSTS...AND A
WATCH WILL LIKELY BE ISSUED WITHIN THE NEXT 1-2 HRS.

DISCUSSION...VISIBLE SATELLITE TRENDS SHOW A PERSISTENT MID-LEVEL CU
FIELD LIKELY AIDED BY WEAK WAA ACROSS WRN ND...WITH OCCASIONAL
LIGHTNING STRIKES NOTED. A SFC TROUGH WAS ANALYZED AT 19Z JUST W OF
THE MT/ND BORDER...EXTENDING NEARLY DUE SWD INTO FAR ERN WY...AND
THIS FEATURE IS EXPECTED TO PROVIDE THE FOCUS FOR SFC-BASED TSTM
DEVELOPMENT THIS AFTERNOON. RAP-BASED MESOANALYSIS DATA SUGGEST WEAK
CAPPING IS STILL PRESENT ACROSS THE REGION...BUT SHOULD ERODE AS
TEMPERATURES HEAT INTO THE LOW-MID 90S F. MIDLEVEL HEIGHT RISES HAVE
ALSO BEEN OCCURRING ACROSS THE NRN PLAINS AHEAD OF A SHORTWAVE
TROUGH MOVING THROUGH THE NRN ROCKIES...BUT SHOULD BECOME MORE
FOCUSED INTO ERN PORTIONS OF THE DAKOTAS BY THIS EVENING. VARIOUS
VERSIONS OF HRRR GUIDANCE SUGGEST CONVECTIVE INITIATION WILL OCCUR
BY 21Z ALONG THE SFC TROUGH. SFC DEWPOINTS IN THE 60S F AMIDST
STRONG HEATING AND STEEP MIDLEVEL LAPSE RATES ARE YIELDING MLCAPE
VALUES OF 2000-3000 J/KG. EFFECTIVE-LAYER SHEAR MAGNITUDES OF 30-40
KT WILL BE SUFFICIENT FOR A FEW SUPERCELLS WITH PRIMARY THREATS OF
LARGE HAIL AND DMGG WIND GUSTS AND PERHAPS A TORNADO...POTENTIALLY
EVOLVING INTO A COUPLE ORGANIZED CLUSTERS OR LINES LATER THIS
EVENING. TRENDS CONTINUE TO BE MONITORED FOR A WATCH...WHICH MAY BE
ISSUED WITHIN THE NEXT 1-2 HRS.

..ROGERS/KERR.. 07/31/2016

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

ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...

LAT...LON   48969987 46809989 45600018 44740215 45040435 47370471
            48380485 48970437 48969987 

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