Weather

491 
fxus65 kboi 112021 
afdboi 


Area forecast discussion 
National Weather Service Boise Idaho 
221 PM MDT Sat Oct 11 2008 


Short term...tonight through Monday...strong winter system 
continues to impact the area. Snowfall has been occurring most of 
the day in the western Magic Valley and in southeast Owyhee and 
southern Twin Falls counties. Snow showers were also noted over 
the Boise Mountains. Winds have been above advisory criteria in southeast 
Oregon. Therefore...we will let the advisory continue until its 
scheduled termination at 8 PM PDT. For tonight...the upper low 
will move slowly NE from east central Nevada to SW Wyoming. This 
motion will keep our winter weather warning area...the western 
Magic Valley and southern Twin Falls County...in a favorable 
position for continued snowfall. This snow is expected to be heavy 
at times. Therefore...the winter weather warning will be allowed 
to continue through the night until its scheduled termination at 6 
am MDT. Winds will remain up tonight in southeast Oregon...much like last 
night...and so we have kept min temperatures up above what they would 
normally have been. Elsewhere...highs Sunday through Monday and 
lows Monday in the winter weather warning area will be 
significantly below MOS forecasts because of the snow on the 
ground. Have made adjustments accordingly. As the upper system 
pulls further away Sunday...the chance for snow will diminish and 
by Sunday evening...the snow will have ended in almost all of our 
area. Monday will be cool...but warmer than the past few days. We 
will see ridging begin to build into the area. 


Long term...Monday night through Saturday...upper level ridge will 
break down on Tuesday as a series of shortwaves move into the 
region. Timing of individual shortwaves remains uncertain...so have 
continued the trend of the previous forecast of probability of precipitation towards 
climatology. By Thursday...a dirty upper level ridge will begin to 
build into the region for warmer temperatures across the forecast 
area...with temperatures Thursday and Friday a few degrees above 
normal. Unsettled and cooler weather returns to the region by 
Saturday as a Pacific trough moves into the region. 


&& 


Aviation...widespread MVFR with areas of IFR conditions and 
mountain obscuration will continue in the western Magic Valley and 
the Boise Mountains and east for the remainder of the afternoon and 
evening. VFR elsewhere with isolated MVFR conditions in widely 
scattered snow showers...mainly in SW Idaho. Strong northwest surface winds 
of 25 to 35 kts with gusts to 45 knots over eastern Oregon...with 
surface winds of 15 to 25 kts with gusts to 35 kts over SW Idaho 
through at least 03z. Moderate to strong NE winds aloft. 
Precipitation will gradually decrease in coverage and intensity 
after 12z Sunday. 


&& 


Boi watches/warnings/advisories... 
Idaho...Winter Storm Warning until 6 am MDT Sunday for idz016-idz030. 
Or...Wind Advisory until 9 PM MDT /8 PM PDT/ this evening for orz061- 
orz062-orz063-orz064. 
&& 


$$ 


Weather.Gov/Boise 


Short term...snow pellets 
long term....sl/LH 
aviation.....Sl