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Area forecast discussion 
National Weather Service Missoula Montana
340 am MST Monday Jan 26 2015

Discussion...high pressure remains over Idaho and western
Montana this morning and has helped to bring fog into stable
valley locations. Kalispell has been reporting dense fog
throughout the night as well as Salmon. These locations along with
many of the other cool valleys will see fog through this morning.
Missoula has seen frost develop instead of fog but patchy fog is
still possible through this morning from Stevensville through

The warm airmass aloft that has accompanied the high pressure has
left the terrain warm overnight as well as higher north-south
oriented valleys E.G., Hamilton and Deer Lodge. These locations
along with Grangeville/Camas Prairie have south winds that will
become gusty through today. Butte set a record high temperature
yesterday and is on track to break another record today.

Valleys that remain stable like Salmon will begin to see air
quality issues today and Tuesday as high pressure maintains with
fog to again be an issue for Tuesday morning.

The models are in pretty good agreement for the middle part of the
week Onward. On Wednesday, a plume of moisture originating from
the baja Mexico region will make its way up into the northern
rockies. This moisture will cause scattered showers over Lemhi
County into southwest Montana. Then towards the latter part of the
week the ridge axis retrogrades back to the west causing more of a
northwesterly flow component over the northern rockies. This
northwesterly flow will allow for some moisture to stream into the
region, but also cause a cooler airmass to settle back over the
region. Temperatures in the higher terrain will cool. At this time
the precipitation will be fairly light, so impacts to the area
will be minimal. The models are trending towards a moist
disturbance moving into the region by the first part of next week,
but the extent of the system is unknown at this time.


fog has been an issue at kgpi and ksmn overnight and will likely
remain in place through this morning. Other stable valleys of
north central Idaho and western Montana already have fog or will
see development near sunrise. Most of the fog will lift by early
afternoon. High pressure over the region has led to a mix of
cool stable conditions or warm and mixed spots. Places like
Hamilton, Grangeville, and Deer Lodge have south winds that are
also created warm temperatures. These south and southwest winds
are being observed in the high terrain with windy downslope winds
expected along the Rocky Mountain front through today. High
pressure will remain for Tuesday with a similar mix of fog or


Mso watches/warnings/advisories...


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