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fxus65 kpsr 212244 
afdpsr 


Area forecast discussion 
National Weather Service Phoenix Arizona 
340 PM MST Sat Nov 21 2009 


Synopsis... 
dry weather is expected to continue at least through Thanksgiving. 
The weak southern portions of Pacific low pressure systems will bring 
temperatures down slightly with a relatively small amount of high 
clouds Sunday...but for the most part...mostly clear nights and 
sunny days are expected to continue through Thanksgiving. High 
pressure aloft between Hawaii and Baja California California is expected to 
build northeast over our area with temperatures rising to well above 
average for late November by Thanksgiving day...in the upper 70s to 
near 80 degrees in the desert areas including Phoenix...Yuma and el 
centro. 


&& 


Discussion... 
under sunny skies...temperatures were generally a degree or two 
lower early this afternoon compared with the same time yesterday. 
Wind was generally calm or light mostly from the southwest...west 
and northwest. However...there were some winds of 10 to 20 miles per hour from 
the northwest and north along portions of the lower Colorado River 
valley...eastern Riverside County...and Joshua Tree National Park. 


Dry weather is expected to continue at least through Thanksgiving. 
The flow aloft will generally be from the northwest through Tuesday. 
In this flow...the dry and weak southern portions of Pacific low 
pressure systems are expected to bring slight additional cooling 
Sunday with temperatures slightly above average for the latter part 
of November. A relatively small amount of high clouds is also 
expected tonight and Sunday...but overall mostly clear nights 
and sunny days are expected to continue through Thanksgiving. 


High pressure aloft between Hawaii and Baja California California is expected to 
build northeast over our area with temperatures rising to well above 
average for late November Wednesday and Thanksgiving day. Highs in 
the desert areas including Phoenix...Yuma and el centro are expected 
to be in the upper 70s to near 80 degrees Wednesday and 
Thanksgiving day. 


Surface high pressure is expected to build north and east of our area 
and bring some breeziness at times from the north and east by 
Wednesday and Thanksgiving. In fact...breeziness a bit of breeziness 
from the north may occur between now and Sunday in portions of 
southeast California and southwest Arizona...especially from Joshua 
Tree National Park east to the lower Colorado River valley and down 
the lower Colorado River valley...and increase somewhat Monday and 
Tuesday. 


There are still conflicting signals for the forecast after 
Thanksgiving day. Agree with previous forecast...and will go with 
scenario of only slowly weakening high pressure aloft by Saturday. 
This means similar temperatures Friday compared with Thanksgiving day 
then temperatures dropping back slightly Saturday. 


&& 


Aviation... 
southeast California...southwest and south central Arizona...including kipl... 
kblh...kphx...and kiwa. 


Some wind from the north at kblh is expected to decrease after 
0100 gmt this evening. Otherwise...light winds are expected to 
continue at all taf sites at least through Sunday evening with the 
usual diurnal directions at kphx and kiwa. Some high cirriform clouds 
at or above 20 thousand feet above sea level are expected mainly before 0200 gmt 
this evening and again between 1200 and 2000 gmt Sunday. 


Aviation discussion not updated for amended tafs. 


&& 


Fire weather... 
Monday through Friday... 
high pressure will build over the western states early next week... 
bringing warmer weather...low daytime humidity and modest overnight 
recovery through Thanksgiving day. Winds will favor north and 
northeast through Thanksgiving day...locally windy at times at the 
ridgetops. There are conflicting signals as to what the weather will 
do after Thanksgiving. The most likely scenario is for temperatures 
to drop back slightly...but check later forecasts for any possible 
changes. 




&& 


Psr watches/warnings/advisories... 


Arizona...none. 


California...none. 


&& 


$$ 


National Weather Service Phoenix is on the internet at 


Weather.Gov/Phoenix 


Discussion...Ellis 
aviation...Ellis 
fire weather...Ellis