Area Forecast Discussion
Issued by NWS Missoula, MT
FXUS65 KMSO 271011
Area Forecast Discussion
National Weather Service Missoula MT
411 AM MDT Thu Oct 27 2016
.DISCUSSION...Despite incoming clouds and moisture streaming
across much of the Northern Rockies early this morning, fog has
developed in valleys of northwest and west central Montana. Fog
is likely to become dense at times, particularly just after
sunrise, which will slow the morning commute through mid to late
morning. Stratus will eventually lift to reveal another cloudy,
dreary-looking day for much of the region, with showers on the
increase from the west throughout the day.
With a strong jet poised across west central Montana, showers may
have a difficult time making their way down to valley floors for
much of the day, however later this afternoon into this evening,
rain should make an appearance to most locations of north central
Idaho and western Montana, lasting through the night into Friday
morning. Unfortunately, the overall cloudy/moist weather will
persist through Friday and Friday night as well.
A brief break in the overcast and rain may develop Saturday
morning for western Montana, but likely not for north central
Idaho. The flipside of a break in rain for western Montana is more
patchy valley fog present through midday Saturday. Travelers may
be delayed by sudden low visibility. By early evening Saturday,
the next burst of moisture will envelope the entire Northern
Rockies. Rainfall amounts appear most impressive for the northern
Clearwater Range of Idaho.
Models suggest that the barrage of light rain and overcast skies
will continue for the Northern Rockies Sunday through at least next
Thursday. Snow levels are expected to drop below 5000 feet on
Monday night through Tuesday morning, with possible brief impact
to travel from snowfall on area mountain passes.
There are signs of relatively dry conditions across the region by
next weekend, however no large scale pattern change is evident.
Based on the recent poor performance of model precipitation in the
extended range, there is little confidence in a truly dry
scenario in the next week plus.
.AVIATION...Fog and low stratus will impact KGPI and KMSO through
roughly 27/1600Z before conditions begin to improve. For KMSO,
fog may slosh temporarily in the morning as it tries to clear, but
should dissipate by 27/1800Z at the very latest. Thereafter, all
terminals should expect mountain obscurations from incoming
precipitation, and eventually precip reaching down to valley
floors by 28/0000Z. Fog will once again be possible through
28/1500Z, though not as thick as what is occurring this morning.