Winter Storm in Montana, February 24 to 26, 2018

Area Forecast Discussion
National Weather Service Missoula MT
358 AM MST Sat Feb 24 2018

.DISCUSSION...Precipitation will continue to increase over central
Idaho and portions of western Montana through the morning hours.
The heaviest precipitation is still expected through north central
Idaho and along the Idaho/western Montana border where an
additional 2 to 6 inches will be possible through today. Snow
levels are low enough to allow for snow even into the lowest
valley locations. Winds gusting to near 40 mph will be possible on
the Camas Prairie, and this coupled with falling snow and snow
already on the ground, will cause periods of lowered visibility,
making travel difficult at times.

The rest of western Montana will likely see an inch or two of snow
through this evening, however impacts to roadways, etc are
expected to be fairly minimal. Precipitation becomes more showery
this afternoon, which will bring variable conditions for periods
of brief moderate to heavy intensity snow.

A short decrease in snow occurs this evening before the next, more
intense weather system moves in for Sunday. The higher terrain is
expected to see periods of moderate to heavy snow all day Sunday.
Gusty west winds will create localized blowing and drifting snow
and low visibility. Valleys across central Idaho and northwest
Montana will also see periods of light to moderate snowfall, with
several new inches of snow expected. Larger valleys such as the
Missoula/Bitterroot and Mission valley, as well as southwest
Montana should initially see downsloping with this event, helping
minimize total snow accumulations. However, a period of snow
banding looks possible Sunday evening. If this were to occur, some
locations (generally from Lookout Pass and southward) could see a
period of heavy snow even down into valley locations.

For those on the Camas Prairie in central Idaho, another period of
winds gusting as high as 50 mph will be possible mid day Sunday.
This coupled with snow will likely cause another period of low
visibility, which could again make for difficult travel.

Snow showers will continue to linger on Monday as a weak cold
front pushes through the Northern Rockies. Mostly clear skies
behind the cold front on Monday night will likely lead to a cold
morning for Tuesday. The best clearing Monday night, looks to be
over southwest Montana and across central Idaho and Lemhi county
at the moment.

By the later half of next week, a deep trough is expected to
develop over the Pacific Northwest and slowly track eastward
toward the Northern Rockies. Although the details are still
uncertain, confidence is high for more unsettled weather next
week. Temperatures will likely still be on the cooler side, but
not nearly as cold as this past week.

&&

.AVIATION...Snow is expected to intensify across the Northern
Rockies this morning and continue to be present for the rest of
the next 24 hours. While widespread snow is likely, the heaviest
snow rates will be occurring through central Idaho and along the
Idaho/western Montana border. Conditions near Grangeville, ID and
vicinity are expected to deteriorate further this morning with
gusty south winds and blowing snow. Lowered ceilings and decreased
visibility will be common area wide today. Precipitation is
expected to become more showery in nature this afternoon as the
atmosphere destabilizes. An isolated lightning strike will be
possible as well, especially through central Idaho. More variable
conditions are expected with this showery precipitation, with
short bursts of more moderate to heavy snow expected at times.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...     Winter Weather Advisory until 5 PM MST this afternoon
     Kootenai/Cabinet Region.

     Winter Weather Advisory until 5 PM MST this afternoon Lower
     Clark Fork Region.

ID...Winter Weather Advisory until 4 PM PST this afternoon Northern
     Clearwater Mountains...Southern Clearwater Mountains.

     Winter Storm Warning until 4 PM PST this afternoon
     Orofino/Grangeville Region.

     Winter Weather Advisory until 4 PM PST this afternoon Lower
     Hells Canyon/Salmon River Region.

&&