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fxus65 kfgz 080408 
afdfgz 


Area forecast discussion 
National Weather Service Flagstaff Arizona 
900 PM MST sun Sep 7 2008 


Synopsis...moisture will continue to increase across northern 
Arizona through middle week. This will bring a better chance for 
showers and thunderstorms with lower daytime temperatures and warmer 
nights over the next several days. 


&& 


Discussion...shower and thunderstorm activity has dissipated this 
evening...with clear to partly cloudy conditions across northern 
Arizona. Thunderstorm development is not anticipated overnight. Ipw 
site is indicating that both Kingman and Flagstaff precipitable 
water has increased to around 0.7 inches. Expecting around another 
0.1 inch increase in precipitable water Monday and with 500 mb temperatures between 
-9 to -10 degree c expecting more increases in shower and thunderstorm 
activity. 


No further updates are planned for the gridded and zone forecast for 
the overnight period...as current forecasts are tracking well with 
current and anticipated conditions overnight. 




&& 


Previous discussion /330 PM MST/...isolated showers and 
thunderstorms formed primarily south of Interstate 40 today...with 
just a shower or two north of this area. The activity today was due 
to an increase in midlevel moisture during the last 24 hours. 
Surface dewpoints remain on the low side across the area which is 
keeping showers and storms from producing a great deal of 
precipitation. With drier conditions in the lower levels...winds 
have been gusty in and around the stronger storms. Expect most of 
the current activity to diminish after sunset. 


For Monday through Thursday...a weak trough will drop southward 
along the California coast. Models are pretty consistent in bringing 
up additional moisture in response to a continued southerly flow 
ahead of the trough. Probability of precipitation have been raised a bit over the next 
couple days to show increased chances for showers and thunderstorms 
across northern Arizona. 


For Friday through the weekend...the models begin to diverge a bit. 
The GFS model has a broad closed low over Southern California Friday 
and moves the low over the state on Saturday with drying out on 
Sunday. The European brings a closed low down from the northwest on 
Thursday and moves it north of the state Friday...drying out the County Warning Area 
behind it about a day or two ahead of the GFS. Have kept a slight 
chance of showers and storms into next weekend with so much model 
uncertainty that far out in the forecast. 


&& 


Aviation...for the 06z package...for tonight few scattered clouds between 
120-200 knots feet will continue to diminish becoming mostly clear 
overnight. By tomorrow...expect isolated to widely scattered showers 
and thunderstorms along and north of a krqe to kflg to kprc line 
and scattered showers and thunderstorms south of that line over the higher 
terrain areas by 18z. Mostly VFR conditions will prevail with only 
isolated MVFR in the strongest storms. Aviation discussion not 
updated for amendments. 


&& 


Fire weather...see fire weather forecast (fwffgz) for discussion of 
days 1 and 2. 


Wednesday through Friday...there will be a 20 to 30 percent chance 
for showers and thunderstorms each day over the higher terrain of 
northern Arizona. Winds are expected to be breezy on Wednesday as a 
weak trough approaches Arizona from the northwest. 


&& 


Fgz watches/warnings/advisories...none. 


&& 


$$ 


Public...............tc 
aviation/fire weather.....Tc 


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