615 
fxus65 kfgz 200953 
afdfgz 


Area forecast discussion 
National Weather Service Flagstaff Arizona 
245 am MST Thursday Nov 20 2008 


Synopsis...westerly winds aloft will bring periods of high level 
clouds to northern Arizona through Monday. Daily high temperatures 
will start a slow cooling trend...but still remain above normal. 
A strong low pressure system is forecast to move towards the West 
Coast on Tuesday and Wednesday. This system should spread thickening 
clouds into Arizona and bring a chance of precipitation starting 
Tuesday night. 


&& 


Discussion... 
for today through Monday...not much to talk about for this period as 
the storm track will remain well north of our state. Light westerly 
flow aloft will bring periods of high clouds. There is a very weak 
upper level system forecast to pass overhead during the Saturday 
night...Sunday time frame. We are not expecting anything more than 
some thicker middle and high level clouds with this feature. A 
progressive ridge of high pressure is shown to move over the state 
Monday. 


Tuesday and Wednesday...the operational ec and GFS models are 
coming into agreement as they show a trough of low pressure 
approaching the West Coast during this period. This puts northern 
Arizona in a moist southwest flow aloft...and models are showing a 
cold front moving across the state Wednesday. We have kept the 
slight chance of showers Tuesday night and then increased the 
chances for more widespread precipitation on Wednesday. While this 
system is still 6 to 7 days out...it bears watching. 


Dl 


&& 


Aviation...for the 12z package...VFR conditions and light winds are 
expected for the next 24 hours...with increasing cirrus at or above 
20000 feet mean sea level moving into northern Arizona through the period. Aviation 
discussion not updated for amendments. 
&& 


Fgz watches/warnings/advisories...none. 


&& 


$$ 


Public.........41 
aviation.......kd 


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