Area Forecast Discussion
Issued by NWS Flagstaff, AZ
FXUS65 KFGZ 151058
Area Forecast Discussion
National Weather Service Flagstaff AZ
358 AM MST Sun Jan 15 2017
.SYNOPSIS...A Pacific storm system will bring another round of
rain and high elevation snow to northern Arizona today, with
decreasing chances for showers on Monday. Fair weather and warming
daytime temperatures are forecast for Tuesday and Wednesday.
Then, an active weather pattern will likely set up across
northern Arizona leading to increasing chances for showers late
next work week and into next weekend.
.DISCUSSION...Satellite imagery reveals a closed low currently
centered over northern Mexico near Hermosillo. This low is
forecast to track east-northeast today, passing through New Mexico
on its way to the southern Plains by Monday morning. At the same
time, a shortwave trough over the Pacific Northwest is expected to
drop southward, reinforcing the existing longwave trough over the
southwest United States.
For today, expect another round of rain and high elevation snow
showers - albeit with less intensity and coverage than yesterday.
Snow levels are once again forecast to vary within the 6500 to
7500 foot range across the majority of northern Arizona, making
any meaningful snow accumulations difficult below about 7500 feet
or so. The greatest snowfall looks to be within the White
Mountains region, where a Winter Weather Advisory above 7500 feet
remains in effect.
Chances for showers will begin to decrease from west to east this
evening as the low in northern Mexico continues its eastward
track. However, model forecasts are consistent in forming a
secondary low over northern Arizona, extending the chances for
showers over higher terrain along the Mogollon Rim, White
Mountains and mountainous terrain of northeast Arizona through
On Tuesday, the longwave trough over the southwest United States
moves southward, as a shortwave ridge approaches from the north.
Skies are expected to clear, allowing temperatures on Tuesday
morning to drop into the 20`s across much of the high country. By
Wednesday, the fast moving ridge spreads across all of northern
Arizona leading to a day of quiet weather and likely the warmest
daytime temperatures of the week. Daytime high temperatures are
expected to be a few degrees above average at most places. Enjoy
it, as a shift to a cooler and active weather pattern is expected
as early as Thursday.
From Thursday onward, model forecasts have been consistent in
developing a longwave trough across the western United States.
Although there are some noticeable differences in timing,
confidence is growing that northern Arizona will experience the
passage of a shortwave trough/surface cold front late next work
week, with a second front possible over the weekend. At any rate,
while many of the details have yet to be worked out, a period of
wet and cold weather is probable.
.AVIATION...For the 12Z package...Areas of low clouds and fog
will be common through about 15Z producing local LIFR/IFR
conditions. Otherwise, expect scattered to numerous rain and
mountain snow showers across northern AZ over the next 24 hrs
producing MVFR to IFR conditions. Coverage of showers will begin to
decrease aft 06Z Monday. Aviation discussion not updated for TAF
.FGZ WATCHES/WARNINGS/ADVISORIES...Winter Weather Advisory until 5
AM MST Monday FOR AZZ017.
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