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fxus65 kfgz 230427 
afdfgz 


Area forecast discussion 
National Weather Service Flagstaff Arizona 
925 PM MST Sat Nov 22 2008 


Synopsis...warm and dry conditions will continue across northern 
Arizona through Monday. Then a series of Pacific storm systems will 
begin to move across the southwest Tuesday continuing into the 
Holiday weekend with much cooler temperatures and chances for snow 
in the mountains and rain in the valleys. 


&& 
Discussion...high thin clouds continue to stream over northern 
Arizona this evening and are expected to continue through the night. 
Temperatures are close to what they were last evening at this time. 
The short term forecast through Monday looks good with no updates 
needed. A major pattern change is taking shape as the first of two 
low pressure systems brings a chance of precipitation to northern 
Arizona by middle day Tuesday. This low moves northeast of Arizona by 
Thanksgiving night. By then...another low begins to move down the 
Oregon and Washington coast. Confidence is still much lower 
regarding the the track of the second low. 


&& 


Previous discussion /230 PM MST/...a high pressure ridge will remain 
over the southwest until Monday with above normal 
temperatures...light winds...and dry conditions. Beginning 
Tuesday...a somewhat complicated low pressure system from the 
northern Pacific is prognosticated to move slowly into Southern California as it 
approaches Arizona. The details of this system differ between the latest 
European model (ecmwf) and GFS models...however both depict a moderately cold system 
with a good moisture tap and multiple embedded disturbances to 
affect the southwest mainly Wednesday and Thanksgiving day. The 
effects will likely be much colder temperatures than we have been 
experiencing along with high elevation accumulating snow and valley 
rain. Snow levels appear at this time that they will fall into the 
5000 to 7000 foot range on Thursday. Models diverge widely after 
this first system...however long range model solutions indicate 
another system is likely over the following weekend. Stay tuned to 
later forecasts for greater details about these approaching weather 
systems. 


&& 


Aviation...for the 06z package...expect VFR conditions and light 
winds for the next 24 hours. Aviation discussion not updated for 
amendments. 


&& 


Fgz watches/warnings/advisories...none. 


&& 
$$ 


Public.........Mas 
aviation.......db 


Visit weather.Gov/Flagstaff for northern Arizona weather information.