SPC MESOSCALE DISCUSSION 1641 FOR ERN MT...SRN ND...NRN SD
CONCERNING...SEVERE THUNDERSTORM WATCH 616...

VALID 240221Z - 240430Z

WILL MONITOR PORTIONS OF SWRN ND AND NWRN SD FOR POSSIBLE WW AS
EXISTING SEVERE THUNDERSTORMS SHIFT EWD AWAY FROM WW 616.

SURFACE RIDGE IS BUILDING SEWD ACROSS ERN DAKOTAS INTO MN THIS
EVENING WITH GRADUAL VEERING IN LOW LEVEL FLOW AHEAD OF SHORTWAVE
TROUGH OVER THE NRN HIGH PLAINS.  LARGE SCALE PATTERN SUPPORTS EWD
MOVEMENT OF SHORTWAVE TROUGH OVER CENTRAL MT THIS EVENING.  AS
LARGE SCALE ASCENT SPREADS EWD CONVECTION OVER ERN MT SHOULD SHIFT
EWD INTO SWRN ND AND PORTIONS OF WRN SD.  THERE IS SOME CONCERN
THIS ACTIVITY MAY NOT WEAKEN SIGNIFICANTLY BEFORE EXITING ERN
PORTIONS OF WW.  WILL CONTINUE TO MONITOR THIS AREA FOR POSSIBLE
WW.

..DARROW.. 07/24/01