860 
fxus65 kboi 200329 
afdboi 


Area forecast discussion 
National Weather Service Boise Idaho 
929 PM MDT Friday Mar 19 2010 


Discussion...minor changes for dew points in the pfm to keep dry air 
over the area tonight. No other changes expected. Some thin high 
clouds over the area at sunset and are expected at times through 
Saturday. As ridge progresses slowly inland warming will increase. 
Very dry airmass will remain through Saturday then an increase in 
clouds in expected Sunday. Cold frontal passage Sunday night will 
be associated with light to moderate showers in the northern 
mountains. More widespread showers are expected Monday as the 
upper trough crosses the area...a very windy afternoon is likely 
from kmuo to ktwf/kjer Monday. 


&& 


Aviation...VFR conditions will continue through the weekend with 
mainly clear skies through Sunday morning. Light south-southeast 
surface winds. Winds aloft will be light to moderate from the 
northwest. 


&& 


Previous discussion... 
short term...tonight through Sunday...upper ridge off the coast 
will move into the region on Saturday then shift east and flatten on 
Sunday. Meanwhile...a Pacific trough and cold front will approach 
the area on Sunday. Mostly clear skies will continue through the 
bulk of the weekend with some increase in clouds on Sunday ahead of 
approaching Pacific system. Temperatures will be on the increase... 
warming several degrees each day. Maximum temperatures near 60f in the valleys 
Saturday and well into the 60s on Sunday. West-northwest winds this 
evening will shift to south-southeast with local gusts to 25 miles per hour 
both Saturday and Sunday afternoon. 


Long term...Sunday night through Friday...model agreement is better 
than average through Thursday. The progressive pattern persists with 
the upper level trough still scheduled to move over our area Sunday 
night and Monday...then exit on Tuesday. This will give the best 
chance of precipitation for the period...but the main impact will be 
gusty west to northwest winds Monday afternoon and evening following 
the cold front. Ridging and slight warming on Wednesday will be 
followed on Thursday by a shallow shortwave trough which damps out 
over the northern rockies...with chance showers confined to our 
northern zones. By Friday confidence lessens as the Canadian and GFS 
ensemble mean build a ridge while the GFS...ecm...and NOGAPS bring 
in another trough. So we are staying close to climatology probability of precipitation and 
temperatures. 


&& 


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


$$ 


Weather.Gov/Boise 


Discussion...vm 
aviation.....Js 
previous short term...bw 
previous long term....jt/bb