Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 252138
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
238 PM MST Sun Feb 25 2018

...Moderate to heavy snowfall and gusty winds to continue into
Monday morning...

.DISCUSSION...Heavy snow continues to fall this afternoon across
portions of North-central Idaho, as well as for the mountains and
valleys along the MTID border. 2 to 3 inches per hour snow rates
have been reported for a period of time today in the above
locations. Currently, Lookout Pass seems to be the hardest hit,
with severe driving conditions ongoing. If you need to travel
west along I-90 today or this evening, check the forecast at
www.weather.gov/missoula and
roadreport.mdt.mt.gov/travinfomobile/ for travel information.

Snow bands are still anticipated to develop across north-central
Idaho, and stretching east through western Montana this evening
after 5PM. The beginnings of these bands are starting to show up
in eastern Washington at this time. It`s difficult to tell where
these bands will end up. Though, we anticipate the typical
problem areas to be from Polson to Saint Ignatius, along I-90
from Lookout pass to Butte, and Missoula to Lost Trail Pass. If
caught under one of these bands, 1 to 2 inch per hour snow rates
will be possible, along with variable driving conditions from good
to hazardous in a short distance. Generally, 1 to 3 inches of
snow are expected for the valleys of western Montana and north-
central Idaho through tomorrow morning, with isolated higher
amounts under the bands. The snow bands will slowly drift south
out of the region overnight, with scattered snow showers remaining
for the morning commute, which is expected to be slow going
throughout the Northern Rockies.

Showers are forecast to linger through Monday before ending for
most by the evening. Colder temperatures return for Tuesday
morning, but cloud cover should return by the early morning hours,
thus keeping temperatures from being as exceptionally cold as last
week. Tuesday appears to be another up-slope snow day in
northwest Montana, particularly for West Glacier and vicinity.
These areas may see fairly consistent snow through much of
Wednesday.

There is high confidence that a broad low pressure system will
move into the Pacific Northwest during the second half of the
week, so below average temperatures remain. Shortwaves of energy
and increased moisture will provide high chances for snow, and one
or two of these may end up being moderate snow producers, but the
details are still a bit uncertain.

The trough is forecast to move through north-central Idaho and
western Montana during the weekend, so another round of moderate
snow is possible depending on how the low pressure features
evolve.

&&

.AVIATION...Breezy southwesterly winds will continue for all
aviation sites until around 26/0100Z, which is also the time
light to moderate snow will begin to impact KGPI and KMSO. Snow
banding still look possible later this afternoon and evening
after 26/0300Z, with periods of heavy snow and gusty westerly
winds. If an aviation site is impacted by one of these bands, 1 to
2 inch per hour snow rates with visibility as low as 1/2SM of
1/4SM will be possible. Snow bands will slowly move south out of
the KGPI and KMSO areas after 26/0800Z, though light snow showers
will continue through Monday. KBTM and KSMN, will see the snow
bands around 26/0600Z, with similar impacts noted above.


&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 8 AM MST Monday Butte/Blackfoot
     Region.

     Winter Weather Advisory until 8 AM MST Monday
     Bitterroot/Sapphire Mountains.

     Winter Weather Advisory until 8 AM MST Monday
     Missoula/Bitterroot Valleys.

     Winter Storm Warning until midnight MST tonight Lower Clark Fork
     Region.

     Winter Weather Advisory until midnight MST tonight
     Flathead/Mission Valleys...Kootenai/Cabinet Region.

     Winter Weather Advisory until midnight MST tonight West Glacier
     Region.

     Winter Weather Advisory until 8 AM MST Monday Potomac/Seeley
     Lake Region.

ID...Winter Weather Advisory from 8 PM this evening to 11 AM MST
     Monday Eastern Lemhi County...Western Lemhi County.

     Winter Weather Advisory until 11 PM PST this evening
     Orofino/Grangeville Region.

     Winter Storm Warning until 11 PM PST this evening Northern
     Clearwater Mountains...Southern Clearwater Mountains.

     Winter Weather Advisory until 11 PM PST this evening Lower Hells
     Canyon/Salmon River Region.

&&

$$



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