Area Forecast Discussion
Issued by NWS Missoula, MT
FXUS65 KMSO 041108
Area Forecast Discussion
National Weather Service Missoula MT
408 AM MST Wed Dec 4 2013
.DISCUSSION...Most of the precipitation has moved out of the area,
with only a few lingering light snow showers in the terrain along
the Divide remaining. Precipitation will definitely take a major
backseat for the next couple of days as the brutally cold
temperatures take precedence. Waking up this morning, temperatures
are going to feel very cold, but it`s only a prelude to what`s
expected through the week into the weekend. For today and
Thursday, highs will barely get out of the single digits across
the Northern Rockies, and will drop like a rock overnight. Ranges
for overnight lows tonight and Thursday night are going to be
anywhere from -5 to -30 (across southwest Montana, south central
Idaho, and valleys along the Continental Divide). And that isn`t
factoring in how much colder it will feel with ever just a light
breeze. If you can believe it, temperatures are only going to get
colder and more dangerous this weekend!
An even colder, polar air mass will descend from central Canada into
the Northern Rockies Friday setting up what could be one of the
more epic periods of cold weather in recent memory for this
weekend. But before things turn really cold, many areas will again
see a variety of winter weather impacts attributed to additional
snowfall, wind, and wind chill. Light to moderate snow is expected
to start overnight Thursday and fall across central Idaho,
southwest & west central Montana (including Missoula/Bitterroot
Valley, Butte and Salmon areas) through much of the day on
Friday. At the same time, a bitterly cold air mass from Canada will
descend upon the region, producing some gusty winds and bring about
wind chill and blowing snow issues across west central and
northwest Montana. However, the weather system bringing snow to the
region will be short lived, quickly moving south of the area by
Friday evening. So accumulations of powdery snowfall will likely
be light. But this also should result in fairly decent clearing
behind the system, especially over northwest Montana and lead to
temperatures plunging towards values not seen in quite some time.
And things could end up being even colder than currently forecast
for this weekend, depending upon how much wind and clouds remain
come Saturday morning.
Prolonged exposure to the cold could be quite dangerous on
Saturday morning and early afternoon across much of western
Montana with high temperature failing to climb out of the single
digits in most locations. This certainly could set the stage for
another extremely cold morning on Sunday as well.
Forecast models have backed off from their prior advertisement of
a third Arctic air mass dropping over the area, keeping it well to
our east over the central plains in the most recent model runs.
Right now, models are in decent agreement showing a gradually
moistening northwest flow aloft over the area. Temperatures will
remain very cold and well below normal with chances for
precipitation steadily increasing throughout the week.
.AVIATION...Well below normal temperatures will the main story
over the next several days as precipitation moves east of the
Northern Rockies. Skies could clear up today, and any lingering
snow showers will dissipate. Clear and cold will then persist
overnight into Thursday, with little aviation impacts in the way
MT...WIND CHILL ADVISORY until 11 AM MST this morning
Bitterroot/Sapphire Mountains...Butte/Blackfoot Region...
Flathead/Mission Valleys...Kootenai/Cabinet Region...Lower
Clark Fork Region...Missoula/Bitterroot Valleys...
Potomac/Seeley Lake Region...West Glacier Region.
ID...WIND CHILL ADVISORY until 11 AM MST this morning Eastern Lemhi
County...Western Lemhi County.
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