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000 
FXUS65 KMSO 221040
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
340 AM MST Wed Nov 22 2017

.DISCUSSION...The next wave of moderate precipitation will 
continue to move through Idaho and western Montana this morning. 
Rain will become less common in the valleys by the afternoon, but
remain in the mountains.

Rain showers will be around for the beginning of Thanksgiving 
day, but the main story remains the damaging wind threat. The 
strong wind scenario that model guidance are depicting has been 
very consistent, so strong winds in the terrain of 50 mph and 
higher should be planned for. Areas that we are concerned with
experiencing strong winds include the Flathead Valley south to 
Missoula, through the Bitterroot Valley, and the valleys of 
southwestern Montana, so the High Wind Watch has not been 
changed. There is still a chance that a few locations in Lincoln
County may see gusts near 50 mph, but confidence is not as high. The
winds in the forecast have been increased in the latest update 
since confidence continues to increase. One aspect of this 
Thursday weather pattern that is interesting is that the upper jet
will be parallel to the cold front which is usually a good set up
for precipitation, so moderate to even heavy rain may accompany 
the strong winds. Showers may organize into a line along the 
front, and high resolution model guidance are already showing 
indications of a strong line of showers during the evening. 
Features like this are notorious strong wind producers. 

Snow levels will lower behind the cold front Thursday night so 
snow is likely to return to the high terrain and there may even be
some snow at lower elevations. 

The next impactful weather system looks to arrive to north-central
Idaho and western Montana on Sunday. Precipitation is forecast to
start as rain during Sunday and change to snow at most elevations
for Monday morning. This weather system is much colder than what
has been occurring recently, so travel impacts from snow and/or
ice are of concern. Snow chances will linger through Tuesday. 


&&

.AVIATION...Visibilities and ceilings have been quite variable at
valley locations overnight with nearly saturated surface 
conditions due to a strong plume of moisture moving through the 
region. These variable conditions will last through much of the 
morning with a mix of fog, rain, and low ceilings. Precipitation 
will taper off and mixing will increase at low elevations so 
improvements are expected by this afternoon, though a stratus deck
may remain. The higher terrain has been and will continue to be 
obscured with moisture via moist southwesterly flow today. 

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...High Wind Watch from Thursday afternoon through late Thursday 
     night Bitterroot/Sapphire Mountains...Butte/Blackfoot 
     Region...Flathead/Mission Valleys...Missoula/Bitterroot 
     Valleys...Potomac/Seeley Lake Region...West Glacier Region.

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