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Area forecast discussion 
National Weather Service Missoula Montana
241 PM MST Monday Mar 2 2015

Discussion...an Arctic air mass will continue to push through
the northern rockies this afternoon and evening. This Arctic will
interact with a system streaming out of British Columbia,
enhancing precipitation over the northern rockies. The models
continue to indicate that the I-90 corridor from Superior to
Garrison jct will receive the most snow and have the biggest
impact, thus a Winter Storm Warning has been issued. Not only will
the accumulating snow be an issue, but the refreezing of wet
and/or slushy roads will create hazardous driving conditions by
the Tuesday morning commute. The Arctic front will cause gusty
easterly to northeasterly winds with the strongest being at the
mouth of badrock and Hellgate canyons. These gusty winds will
cause localized blowing and drifting snow. The winds will diminish
during the over night hours, but the lingering wind combined with
the colder air mass will create significant wind chills.

Fairly dry northwesterly upper level flow will persist over the
the region Tuesday and on into Wednesday. Temperatures will be
very cold for this time of year especially during the morning
hours. The maximum temperatures will warm slightly from Tuesday to
Wednesday.

The latter half of the week is leaning toward stable and dry
conditions under a ridge, but models are not in complete
agreement on this solution. The ec keeps the ridge axis more along
the West Coast allowing a weak system to move overhead on Friday.
The drier solution has been somewhat more consistent over the past
couple days, and for now continues to be followed.

&&

Aviation...the Arctic front has passed kgpi causing gusty
northeasterly winds. Snow will be fairly minimal since the leading
edge of the front has passed. The Arctic will steadily push across
the remainder of western Montana and north central Idaho this
evening. Kmso will receive light snow around 02/22z and intensify
at 03/00z. Kbtm will be impacted by the front between 03/00z
and 03/04z. The visibility will be reduced due to the snow and
strong gusty northeast winds. The winds and snow will decrease
throughout the night into Tuesday morning.

&&

Mso watches/warnings/advisories...
Montana...Winter Storm Warning until 11 am MST Tuesday
Bitterroot/Sapphire Mountains...Butte/Blackfoot region...
Lower Clark Fork region...Missoula/Bitterroot
valleys...Potomac/Seeley Lake region.

Winter Storm Warning until 11 am MST Tuesday Flathead/mission
valleys.

Winter Weather Advisory until 8 am MST Tuesday West Glacier
region.

Winter Weather Advisory until 8 am MST Tuesday Kootenai/Cabinet
region.

Idaho...Winter Weather Advisory until 11 am MST Tuesday eastern Lemhi
County...western Lemhi County.

Winter Weather Advisory until 10 am PST Tuesday lower Hells
Canyon/Salmon river region...northern Clearwater
Mountains...Orofino/Grangeville region...southern
Clearwater Mountains.

&&

$$

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