FXUS65 KMSO 222108

Area Forecast Discussion
National Weather Service Missoula MT
308 PM MDT Sat Sep 22 2018


Winds have become breezy throughout the region and will maintain
into this evening, and rain continues to develop along and behind
a slow moving cold front. The cold font will slowly move to the
southeast tonight causing a narrow area of rain, generally
occurring south of and including Highway 12 tonight and Sunday
morning. As the main trough associated with the front continues
through central Idaho and western Montana on Sunday, cool
temperatures, rain showers, and perhaps a thunderstorm or two are

The drier northwesterly flow pattern remains on track for Monday
and Tuesday. This flow pattern is conducive for below average
temperatures and showers in northwest Montana and along the

There will continue to be a freeze threat Wednesday morning across
the lower valleys of western Montana. A weak front sliding down
the Rocky Mountain Front late Wednesday will lead to light showers
along the Divide. An easterly push of wind will likely keep
morning temperatures up on Thursday as typical valley cold pools
remain mixed.

Of considerable interest is in the Friday-upcoming weekend time
period with forecast models indicating the potential for much
colder and wetter weather with winter-type conditions possible.
Operational and ensemble forecast model runs are still struggling
between dropping the cold air from Canada into western Montana or
keeping most of it east of the Divide as well as the timing of
either occurrence. Impacts could be significant but vary
considerably depending on which solution plays out, so stay tuned!


.AVIATION...Winds are becoming gusty through much of central Idaho
and western Montana with a cold front. Gusts of 25 knots will be
common during the afternoon, but will begin to decrease this
evening. Rain is occurring along the front, that is currently
oriented southwest to northeast near Grangeville to near Seeley
Lake. Lowered ceilings will continue in vicinity of the cold
front, which will slowly pass to the southeast overnight. Obscured
terrain will be common tonight and through Sunday morning.



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