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FXUS65 KFGZ 171647

Area Forecast Discussion
National Weather Service Flagstaff AZ
945 AM MST Tue Jan 17 2017

.SYNOPSIS...Scattered light shower activity will persist
today across eastern Arizona. Otherwise look for mostly cloudy skies
and some patchy fog. Warmer weather is forecast for Wednesday. A
period of cold and wet weather will arrive starting Thursday, with
several disturbances delivering winter weather through next Tuesday.
Stay tuned to the forecast as there is potential for heavy snow
accumulation in the high country.


Made a few changes the forecast for today, expand area of light rain
and snow showers into the Holbrook area, add patchy fog to the
Prescott area through this morning. 

.PREV DISCUSSION 411 AM...A broad trough remains over the region this
morning with a couple of embedded circulations. One of these
circulations across northeast Arizona and northwest New Mexico is
keeping clouds and perhaps a few light showers across the east. The
trough hangs over eastern Arizona today keeping a chance for showers
across areas from Heber to Window Rock eastward.
Elsewhere, relatively cool northeast flow will continue.

Very brief high pressure ridging will slide over the state
Wednesday resulting in a nice warm up in daytime temperatures.
Enjoy the warmth as it won't last long.

We continue to have high confidence in the wet and colder pattern
developing from Thursday into the coming weekend. The first in a
series of weather systems is still forecast to move into the area
Thursday through Thursday night bringing rain and mountain snow as
a cold front pushes eastward through the state. There are slight
differences on timing of how early the precipitation will begin
and we have trended toward the earlier consensus of the
NAM/European model solutions. This has also bumped up rain/snow
amounts slightly. Expect accumulating snow above 6000 feet where 2
to 6 inches is forecast. Lighter amounts are possible down to
around 5000 feet on the tail end of system late Thursday
night/Friday morning.

Mountainous terrain will not see much of a break between systems
as light snow may very well continue right on through Friday
morning, but the bulk of the heaviest precipitation will arrive
late Friday afternoon or early evening and last through Saturday
morning. This is in response to a strong Pacific jet nosing into
the southwest with rapidly falling heights as much colder air
pushes into the state. This second system will likely bring snow
accumulations to the high country above 5000 feet. The potential
for the heaviest precipitation looks to be from the Grand Canyon,
across the Rim and White Mountains, south into Yavapai and Gila
Counties. Expect winter driving in the high country with heavy
snow possible from Friday evening through at least Saturday

A transitory ridge passes overhead Sunday/Monday with another
brief break of drier weather. A third, potent system is likely
early next week which could bring additional rain and mountain

This is a very active winter weather pattern developing - stay
tuned to the forecast for the latest.


.AVIATION...For the 18Z package...Areas west of a KPGA-KFLG-KPRC line
with VFR for the next 24 hours. East of this line, areas of mvfr
cigs and scattered -shra/ -shsn through 06z then VFR.  Aviation
discussion not updated for TAF amendments.





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