ZCZC SPCSWOMCD ALL
ACUS11 KWNS 211946 
SPC MCD 211946 
NDZ000-MTZ000-212145-

MESOSCALE DISCUSSION 1005
NWS STORM PREDICTION CENTER NORMAN OK
0246 PM CDT TUE JUN 21 2016

AREAS AFFECTED...N-CNTRL AND NE MT INTO WRN ND

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 211946Z - 212145Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SEVERE THUNDERSTORM THREAT WILL INCREASE ACROSS PARTS OF
NORTHEAST MT INTO WESTERN ND THIS AFTERNOON AND EVENING. VERY LARGE
HAIL AND DAMAGING WIND GUSTS WILL BE POSSIBLE AND A WATCH WILL
LIKELY BE NEEDED BY 22Z. FURTHER WEST...A FEW MARGINALLY SEVERE
STORMS ALSO WILL BE POSSIBLE THIS AFTERNOON ACROSS NORTH-CENTRAL MT.
SMALL HAIL AND GUSTY WINDS ARE POSSIBLE WITH THESE STORMS...BUT A
WATCH IS NOT EXPECTED FURTHER WEST.

DISCUSSION...THUNDERSTORMS WERE ONGOING TO THE WEST OF HVR EARLY
THIS AFTERNOON IN LOW LEVEL UPSLOPE FLOW REGIME. SOME SMALL HAIL AND
STRONG WINDS HAVE BEEN NOTED WITH THIS CONVECTION...BUT ACTIVITY
APPEARS TO BE SUB-SEVERE. THESE STORMS WILL CONTINUE TO TRACK
EASTWARD INTO BETTER LOW-LEVEL MOISTURE WHERE DEWPOINTS WERE IN THE
MID TO UPPER 50S ACROSS NE MT. WHILE CAPPING STILL EXISTS DOWNSTREAM
OF CURRENT STORMS...CONTINUED HEATING/MODEST INCREASES IN MOISTURE
COUPLED WITH INCREASED FORCING FOR ASCENT AS THE UPPER SHORTWAVE
TRACKS EASTWARD...SHOULD RESULT IN EROSION OF THE CAP AND AN
INCREASE IN STORM INTENSITY ACROSS NE MT AND EVENTUALLY NW ND LATER
THIS EVENING. 

STEEP MIDLEVEL LAPSE RATES AND FAVORABLE VERTICAL SHEER PROFILES
WILL SUPPORT ROTATING UPDRAFTS CAPABLE OF VERY LARGE HAIL. 50+ KT
0-6 KM SHEAR ALSO WILL SUPPORT SUPERCELLS AND BOWING SEGMENTS WITH
STRONG DOWNBURST WINDS. UPSCALE GROWTH INTO AN EAST/SOUTHEASTWARD
PROPAGATING MCS WILL BE POSSIBLE DURING THE EVENING INTO THE
OVERNIGHT HOURS ACROSS PARTS OF WESTERN ND. GIVEN CURRENT TRENDS IN
HI-RES DATA...AN UPGRADE TO AN ENHANCED RISK APPEARS PRUDENT IN THE
FORTHCOMING 20Z DAY 1 CONVECTIVE OUTLOOK. ADDITIONALLY...A WATCH
WILL LIKELY BE NEEDED ACROSS PARTS OF NE MT INTO WRN ND BY 22Z.

..LEITMAN/GUYER.. 06/21/2016

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

ATTN...WFO...BIS...BYZ...GGW...TFX...

LAT...LON   47221103 47841160 48411184 48741139 49051051 49200923
            49090496 49120389 49000179 48590125 47920099 47440112
            47100130 46880170 46810283 46800449 46810517 46760933
            46961068 47061088 47221103 

NNNN