077 
fxus65 kboi 220411 
afdboi 


Area forecast discussion 
National Weather Service Boise Idaho 
911 PM MST Friday Nov 21 2008 


Discussion...minor update this evening to reduce min temperatures mainly 
in the mountains otherwise forecast is on track as upper level wave 
continues to move toward the area...spreading clouds and 
precipitation as it progresses. Latest NAM is drier than the 18z 
run...and hence more like the current forecast...which was based 
in part on the relatively dry 12z run. Updated products/grids out 
shortly. 


&& 


Aviation...VFR conditions will prevail through the remainder of 
tonight. Conditions will be mainly VFR Saturday although there will 
be local MVFR ceilings and mountain obscuration in showers in the 
kbno area...Baker County Oregon...and the west central Idaho and 
Boise Mountains. Snow level will be near 5000 feet. Surface winds 
will be light. Winds aloft will be moderate westerly. 


&& 


Previous discussion... 
short term...tonight through Sunday...GOES satellite imagery 
reveals the next Pacific storm system moving onshore along the 
Washington and Oregon coast. Clouds will increase overnight with 
scattered snow showers reaching the Oregon zones around dawn on 
Saturday morning. Rain and snow showers will spread into the Boise 
Mountains and west central mountains around noon. A weak cold 
front associated with this system will pass through the forecast 
area during the afternoon with winds shifting to west or northwest 
behind the front. The frontal passage is likely to be dry across 
the southern portion of the forecast area. Skies will clear 
Saturday night with mostly sunny skies and light winds forecast 
for Sunday as an upper level ridge begins to build over the area. 


Long term...Sunday night through Friday...progressive westerly 
flow aloft will continue to rebuild a ridge of high pressure for 
Sunday night through Tuesday with near normal temperatures...if 
not slightly above normal on Monday. Split flow will develop 
Tuesday night through the Thanksgiving Holiday weekend with a 
moist and unsettled pattern. Large scale forecast pattern is 
consistent among the models but regional details are still 
sketchy. 


&& 


Boi watches/warnings/advisories... 
Idaho...none. 
Or...none. 
&& 


$$ 


Weather.Gov/Boise 


Discussion...snow pellets 
aviation.....Jt 
previous short term...jb 
previous long term....cd/dg