Area Forecast Discussion
Issued by NWS Missoula, MT

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FXUS65 KMSO 240951

Area Forecast Discussion
National Weather Service Missoula MT
351 AM MDT Mon Oct 24 2016

.DISCUSSION...With an upper level trough situated just offshore of
the west coast, the Northern Rockies will continue to be under
southwest flow with middle to upper clouds streaming northward.
Despite these clouds, a few locations will see patchy fog or low
clouds this morning. Low clouds were observed via a Polson web cam
while fog was seen in Elk City, Idaho already this morning. A weak
disturbance will move across the Northern Rockies today and will
bring a few showers mainly to the higher terrain, especially
across the Clearwater Mountains and portions of southern Lemhi
County Idaho.

A more organized weather disturbance and front will move through
on Tuesday bringing with it showers for both mountain and valley
locations. Confidence is a little higher that locations will see
morning showers, but then it will become more convective and
sporadic in nature by the afternoon. Snow is not anticipated to
be an impact for most people, except for a few backcountry
hunters, as snow levels will gradually lower to around 7000 feet
across northwest Montana and around 8000 feet across southwest

A warm frontal feature will sweep through the Northern Rockies
Wednesday, spreading precipitation from south to north through the
day. The main focus of moisture is expected across central Idaho
into far northwest Montana, while southwest Montana will see the
least precipitation. Due to warm southwesterly flow, snow levels
with this system are expected to increase as high as 8000-9000
feet, thus most locations will experience rain. A cold front will
pass through the region during the day Thursday, lowering snow
levels slightly and bringing a period of showers to the entire

Forecast models maintain warm southwesterly flow for Friday and
into the weekend, with weather disturbances periodically moving
through the flow. The timing of these features varies from model
to model, but the main result will be periods of showers with
temperatures running slightly above seasonal normals. The current
forecast shows climatological chances for precipitation until
better agreement in timing becomes evident.


.AVIATION...Mid to high level clouds will continue to increase
over the region this morning. The combination of cloud cover and a
northeasterly pressure gradient will largely keep fog at bay this
morning. However, patchy valley fog will be possible, especially
across northwest Montana and central Idaho. KMSO and KGPI may
briefly flirt with some shallow fog towards sunrise, however
impacts due to low visibility/ceiling should be short lived. A few
showers will be possible by mid day today, particularly across
Lemhi County in Idaho and southwest Montana. In addition, breezy
southerly winds up to 25 kts are expected to develop over the
Camas Prairie in Idaho and across Lemhi County, including at airfield



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