Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 121123

Area Forecast Discussion
National Weather Service Missoula MT
423 AM MST FRI FEB 12 2016

.DISCUSSION...A warm front continues to cross north central Idaho
and much of western Montana this morning, bringing light rain
showers to valleys and areas of fog. Rain will become more
focused across northwest Montana through the day, relieving
locations along I-90 and south from further precipitation. Later
tonight, a cold front will approach from the northwest and lower
snow levels area-wide to below 4000 feet by Saturday morning.
This will bring about accumulating snowfall to area mountain
passes and high terrain, resulting in changing travel conditions.
In addition, winds will increase and become gusty throughout the
afternoon and evening on Saturday. For valleys, expect rain to
linger into Saturday morning before becoming a messy rain/snow
mixture. This could result in fluctuating conditions as the
transition occurs, so take heed of this if you`re venturing out
Saturday afternoon.

The next surge of rain/snow will be present over the Northern
Rockies early Sunday through Monday afternoon. The Clearwater
Mountains of north central Idaho continue to be the most favored
area of significant rainfall (1 to 2 inches), while snow levels
will vary from 5000 to 7500 feet. Travel through north central
Idaho will be impacted during this time by standing water on
roadways and some possible rockfall along highway embankments.
Some of the broader valleys of western Montana will be deprived of
significant rainfall due to breezy downslope winds. Temperatures
will generally be warm for this time of year, particularly over
the high terrain.

The moisture surge will relent for Tuesday and Wednesday across
the Northern Rockies, with relatively warm high pressure in-place.
Considering the strength of the high pressure currently depicted
by the European Model, some low elevation locations in Idaho could
reach 60 degrees on Wednesday afternoon.

Unlike the previous expectation of a colder pattern across the
Northern Rockies after the middle of next week, the pattern
through next weekend appears to be a combination of a slight
cool-down followed by a strong Pacific jet stream. Due to very
limited confidence (and consistency) in the currently depicted
pattern change, climatology has been leaned upon heavily for the
forecast after Thursday next week. Nevertheless, the odds of more
active weather (rain/snow) arriving over the weekend appear fairly
good at this time. Will this be a brief return to wintry
conditions? Not sure at this time.


.AVIATION...Rain showers have been prevalent this morning due to a
warm front crossing the region. Most terminals have seen periodic
reductions in both ceiling and visibility from a combination of
rainfall and fog, and should continue to be a threat for the
duration of this morning. A cold front will then cross overnight
and bring about a change from rain to snow throughout the morning
for all terminals. Expect steadily degrading aviation conditions
after 13/0600Z.



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