Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Great Falls Montana
249 PM MDT Wednesday may 27 2015
Tonight through Friday...upper low over north central Idaho
continues to move slowly south and east. Band of moisture rotating
into the state from this feature helping to initiate showers and
isolated thunderstorms across the area. As has been the case all
week...shear aloft is virtually nonexistent and storms remain
small but capable of producing brief heavy rains. The low opens
into a broad trough Thursday as it swings across The Divide.
Thursday will be another unsettled day with numerous showers and
thunderstorms occurring throughout the afternoon and early
evening. By Friday...the trough will have exited the area to the
east and weak upper ridging takes place. Enough energy and low
level moisture will remain across the south and southwest to
result in scattered afternoon showers and thunderstorms.
Temperatures will continue near seasonal averages.
Friday night through Wednesday...weak ridging over the region will
support drier and warmer weather through the region...with
temperatures running about 5 to 10 degrees above average. Marginal
instability will support isolated afternoon thundershowers generally
over higher terrain. A shortwave trough passing through western Canada
on Sunday will drag a weak cold front into north-central Montana on
Monday. Moisture is limited with this feature...and upper level
ridging behind the shortwave will limit probability of precipitation. The next more potent
system moves across Oregon Monday night. This will bring a return to
widespread showers and thunderstorms while dropping temperatures
back down a few degrees below normal for Tuesday and Wednesday.
Broad upper disturbance will remain over the area.
The airmass remains moist and unstable allowing numerous showers and
thunderstorms to develop and will continue to do so through 18z
Thursday. VFR conditions prevail with MVFR/IFR conditions possible
in the vicinity of precipitation. Mountains obscured.
Preliminary point temps/pops...
gtf 47 66 45 68 / 40 60 50 30
ctb 43 61 39 67 / 40 60 40 20
hln 48 66 48 74 / 40 60 60 30
bzn 43 61 44 68 / 40 60 50 30
wey 35 56 35 62 / 40 50 50 40
dln 43 63 43 70 / 50 50 50 30
hvr 47 73 38 69 / 40 60 30 10
lwt 46 66 44 64 / 40 60 60 30