529 
fxus65 kmso 091048 
afdmso 


Area forecast discussion 
National Weather Service Missoula Montana 
348 am MST Friday Jan 9 2009 


Discussion...satellite is showing decreasing clouds from 
northwest to southeast this morning as drier air moves in aloft. 
Abundant moisture from melting snow and heavy rainfall over the 
past few days will likely lead to patchy valley fog under these 
clearing skies. Cooler air has filtered into the area and will 
keep temperatures from warming up much today. 


A northwesterly flow will continue aloft through the weekend 
bringing in small disturbances. The first one will bring mainly an 
increase in clouds by this afternoon. Some showers are possible 
over the higher terrain but will have trouble moving into the 
valleys. The lower atmosphere is not quite unstable enough to 
support well formed bands of snow. A little better lift combined 
with some support from the jet stream will arrive on Saturday. 
Some showers are possible in the valleys but again the best 
potential will hold in the higher terrain of Glacier National Park 
and the Clearwater Mountains in Idaho. 


Sunday night through Friday...the models continue to advertise 
that northwesterly flow will persist over the northern rockies 
through the beginning of next week. The amount of moisture streaming 
into the region is the uncertainty at this time. On Wednesday the 
models are indicating that a strong Arctic will slide east of The 
Divide while the ridge of high pressure over the West Coast will 
amplify. The coldest air will be well east of the area...but the 
region could see the infiltration of a cooler airmass. The ridge 
of high pressure is then expected to slide over the area causing a 
drying trend. Temperatures for the long term are still expected to 
be near season normals...but the concerns is how cool will the 
airmass be on Wednesday and the strength of the inversions by the 
end of the next week. 




&& 


Aviation...some patchy valley fog will be possible this morning 
however widespread fog is not likely. Drier air moving in from the 
northwest will provide clearing skies for this morning...but a 
system arriving this afternoon will increase cloud cover once 
again. Showers may develop this afternoon over the higher terrain 
but is less likely to move into the valleys. 




&& 


Mso watches/warnings/advisories... 
Montana...none. 
Idaho...none. 
&& 


$$ 


Short term...loeffelbein 
long term....Smith 
aviation...loeffelbein