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FXUS65 KFGZ 160329

Area Forecast Discussion
National Weather Service Flagstaff AZ
829 PM MST Fri Dec 15 2017

.SYNOPSIS...A weather system moving in from the north will usher 
in windy and colder weather later on Saturday through Monday. 
Chances for rain and high elevation snow will also develop, 
primarily on Sunday.


.DISCUSSION...Just a few high level clouds to grace our skies 
this evening. For the remainder of the night, high clouds will be
on the increase as the anticipated weekend system approaches. 
Otherwise, light winds and seasonable overnight low temperatures 
are in store. You know, the usual, at least for this year.

A low pressure system currently centered over Washington and
Oregon will descend southward and across Arizona on Saturday and
Sunday. Model forecasts continue to show moisture impacting the 
state late Saturday and continuing through Sunday.

There is some uncertainty as to the exact precipitation amounts 
across the area. this is due to the uncertainties associated with
a system such as the current impulse which is transitioning from 
an open trough into a closed-low.

If the system deepens and closes off sooner than projected more
moisture will impact the western areas of northern Arizona. If it
closes off later precipitation will be further restricted to the 
eastern parts the state.

Current forecasts have most of the moisture and instability
aligning with the Eastern Mogollon Rim and White Mountains.
Widespread snow is currently expected above 6000 feet with 1-2
inches across most of the Mogollon Rim. Higher elevations of the
White Mountains such as Alpine could see closer to 4-6 inches.

As the system departs initially dry and cool conditions on Monday
will slowly warm as the week progresses under the influence of 
westerly flow. An additional trough should impact northern Arizona
starting on Thursday of next week. Increasing winds will develop 
ahead of this second system late Wednesday. Confidence over timing
and impacts from this next system is low at this point due to the
systems placement at the end of the forecast window.


.AVIATION...For the 06Z package...VFR conditions expected over the 
next 24 hours. High clouds increasing overnight with the cloud deck 
slowly lowering through Saturday. Light and variable winds overnight 
becoming southwest at 5-15 kts Saturday afternoon. A slight 
chance of rain and snow showers developing Saturday evening KFLG 
north and east as a weather system approaches. Aviation discussion 
not updated for TAF amendments.


.FIRE WEATHER...Expect dry weather and above normal temperatures 
Saturday with breezy southwest winds. A cold front moving through 
from northwest to southeast early Sunday will bring light rain and 
snow showers to the area with the snow level between 5500 and 6000 
ft. Expect less than 0.25 in. precipitation mainly along and south 
of the Mogollon Rim. Temperatures will drop to 10 degrees below 

Monday through Wednesday...Temperatures will return to normal Monday 
and 5-10 degrees above normal Tuesday and Wednesday with RH values 
in the 20s. Light northerly winds will dominate the period giving 
way to south-southwest winds at 15 gusting 25 mph Wednesday 






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