[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 211927
SWOMCD
SPC MCD 211927 
NDZ000-MTZ000-212130-

MESOSCALE DISCUSSION 1416
NWS STORM PREDICTION CENTER NORMAN OK
0227 PM CDT TUE JUN 21 2005

AREAS AFFECTED...MONTANA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 211927Z - 212130Z

WW WILL LIKELY BE ISSUED WITHIN THE HOUR. 

SELY FLOW IS SPREADING LOW LEVEL MOISTURE WWD ACROSS NRN MT WITH 60
DEWPOINTS HAVING REACHED AS FAR W AS CTB AND GTF.  WITH THE STRONG
HEATING AS RIDGE SHIFTS EWD ACROSS AREA AHEAD OF APPROACHING TROUGH
FROM PAC NW...THE AIR MASS HAS BECOME VERY UNSTABLE WITH MLCAPES TO
3000 J/KG.  WHILE THE EFFECTS OF THE UPSTREAM SYSTEM WILL NOT BE AN
INFLUENCE ON THE CONVECTIVE SCENARIO UNTIL LATER...THE SHEAR AND
INSTABILITY SUPPORT DEVELOPMENT OF SEVERE THUNDERSTORMS NEXT 1-2
HOURS. 

A SEVERE STORM HAS ALREADY FORMED JUST N OF NERN MT BORDER...LIKELY
ON NWD MOVING WARM FRONT. THE MT STORMS ARE EXPECTED TO INITIATE
OVER THE HIGHER TERRAIN CENTRAL PORTION OF THE STATE NEXT 1-2 HOURS.


WITH 40-50 KTS OF SHEAR ALONG WITH A VEERING PROFILE...SUPERCELLS
ARE LIKELY AS STORMS MOVE OFF HIGHER TERRAIN INTO THE PLAINS OF NRN
MT.  PRIMARY THREAT WILL INITIALLY BE VERY LARGE HAIL...HOWEVER THE
STRENGTH OF THERMODYNAMICS ALONG WITH THE 50KT SHEAR SUPPORT
TORNADO POTENTIAL.  DAMAGING WINDS WILL BECOME INCREASING THREAT
LATER THIS AFTERNOON AS STORMS EVOLVE INTO POSSIBLE BOW/SHORT LINES
SEGMENTS.

..HALES.. 06/21/2005

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

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

48961326 48981116 48970983 49000807 48980402 46750413
46490714 46370898 46491030 46511220 47561282 48501318 

WWWW