Winter Weather Advisory 46, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
406 AM MDT Mon Oct 1 2012

...Windy conditions this afternoon through Tuesday night...

...20 to 25 degrees cooler by Wednesday...

...Mountain snow in Glacier NP Tuesday night and Wednesday...

.DISCUSSION...The long advertised weather pattern change to autumn conditions
begins today. Strong westerly winds will develop in northwest Montana
this afternoon. Gusts of 40 to near 50 mph are likely. This poses some
fire weather concerns to ongoing fires along the divide.

Tuesday...Widespread strong gusty will occur as a 120 knot jet
sags into the region. This will pose several impacts:

Choppy waves on Flathead lake. A lake wind advisory is in effect
Tuesday afternoon. Strong gusty ridge winds will impact travel
over the mountain passes. They may also pose fire weather concerns
in Idaho and along the divide where ongoing fires persist.

Tuesday night and Wednesday...The main trof or low pressure system
barrels into the northern Rockies. Winds will quickly shift from
the west to the Northeast as much cooler Canadian air crosses the
divide. Strong northeast winds will impact bad rock canyon near
whitefish and hellgate canyon in Missoula. Northeast winds will
gust to near 30 mph in Kalispell and Missoula.

These strong winds may impact aviation concerns at Missoula and Kalispell

Precipitation is expected in northwest Montana and along the
continental divide. The cooler temperatures will lower snow levels
and produce some accumulating snow to impact Marias and McDonald
Passes. Stay tuned for potential highlights. Precipitation
chances decrease toward the Montana Idaho border. Precipitation is
not expected in Idaho.

Highs on Wednesday will only be in the lower to mid 50s under
windy conditions.

Thursday through Monday...A dry northwest flow will setup after
the passage of the storm system beginning Thursday keeping
temperatures cool and slightly below normal. Later into the week
and weekend temperatures should begin to rebound and warm up to
above normal into the low 70s by the end of the weekend. Another
surge of moisture looks to push south into western Montana for the
start of next week, however for now it looks to be confined to the
Continental Divide. Keep apprised to the forecast for any changes
in the near future.

&&

.AVIATION...Gusty northwest winds will increase this afternoon for
most aviation sites in western Montana and central Idaho today.
Mostly sunny skies can be expected with mid to upper level clouds
moving into northwestern Montana and KGPI this evening. Patchy
smoke can also be expected for KSMN and other valleys of Idaho,
however it isn't expected to be as thick as we have recently seen.
The strongest winds will occur on Tuesday and impact all terminals
with gusts in the 20s to possibly 30 mph range.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING from Noon today to Midnight MDT tonight
     Flathead/Mission Valleys...Kootenai/Cabinet Region...
     Potomac/SEELEY Lake Region...West Glacier Region.

     LAKE WIND ADVISORY from Noon to 9 PM MDT Tuesday
     Flathead/Mission Valleys.

ID...None.
&&