Area Forecast Discussion
Issued by NWS Flagstaff, AZ

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000
FXUS65 KFGZ 190429
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
908 PM MST Wed Jan 18 2017

.SYNOPSIS...A series of winter storms will affect the region from
Thursday through Saturday. Additional storms are anticipated early
next week. These will be cold systems, with significant
accumulations of snow across the high country. Hazardous driving
conditions should be anticipated for several days, beginning
Thursday.

&&

.DISCUSSION...The new model forecasts are rolling in and nothing
has really changed. Winter weather ahead. Starting Thursday
afternoon and lasting into Saturday avoiding travel on the
highways/interstates in the high country of northern Arizona is
the safest bet. If you decide to travel, make sure and fill up
that tank and bring along some drinks and snacks. For the rest of
you, this looks like the best storm so far this winter with plenty
of snow to go around.

&&

.PREV DISCUSSION /333 PM MST/...

SHORT TERM...Hazardous winter weather will arrive across the high
country Thursday and continue at times through Saturday...and a
Winter Storm Warning has been issued for areas above 5500 feet
elevation from the Kaibab Plateau along the Mogollon Rim to the
White Mtns...southward into Yavapai and northern Gila Counties.
Here are the latest details and forecast challenges. Wave #1 of
precipitation is expected to begin early Thursday morning across
Yavapai and Coconino counties with snow levels around 5500 ft.
Precip will spread east through the day...producing several inches
of snow above 5500 feet by Friday morning. The first wave exits
the region Friday morning, with precipitation intensity likely
decreasing. However, there is still a moist and cold westerly flow
during the day Friday, and periods of snow are likely to persist
especially over the higher elevations. The next even colder wave
arrives late Friday afternoon and moves slowly eastward across
northern Arizona through Saturday morning. This is when the
heaviest precipitation is expected, with snow levels 5000-5500 ft
Friday afternoon falling to 4000-4500 ft by Saturday morning.
Travel conditions are likely to become hazardous, please plan
accordingly. Precip intensity will decrease Saturday afternoon,
though a cold northwest flow will allow for snow showers to
persist along the higher terrain. Total snowfall accumulations for
the 3-day event will be heavy, in general 1-2 feet above 6500 feet
elevation, 8-16 inches 5500-6500, lesser amounts down to around
5000 feet. Please check your point specific forecast at
weather.gov/Flagstaff.

LONG TERM...From Saturday night through Tuesday - Models are in
good agreement showing clearing weather from west to east Saturday
night. From Sunday onward, timing issues and the number of
additional shortwaves bringing bouts of winter weather bring
decreasing confidence. The GFS has strong warm air advection
Sunday with rising snow levels and precip redeveloping across
Coconino county. This followed by a another strong cold front
passage Monday then a broad trough generating instability showers
through Tuesday. The ECMWF and to a lesser extend the Canadian
have two waves crossing our area. The first Sunday night and the
second Monday night. All 3 models have 500 mb temps near -30c
over the area on Tuesday. So we have kept scattered to numerous
showers going Sunday across Coconino county Sunday and expended
them across the area Monday. Tuesday should see decreasing shower
coverage. High and low temps to be well below normal.

&&

.AVIATION...For the 06Z package...A storm system will move across
northern Arizona over the next 24 hours. Through 09z...look for
general VFR conditions. The exception, local MVFR conditions in the
area of KFLG. After 09z...Widespread MVFR conditions in rain and
snow showers will spread from west to east across the area reaching
the New Mexico border by 16z. Local IFR/LIFR conditions will be
possible over the higher terrain. Aviation discussion not updated
for TAF amendments.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

1) Winter Storm Warning from 6 AM Thursday to noon MST Saturday
FOR AZZ004-006>008-015-038.

2) Winter Storm Warning from noon Thursday to noon MST Saturday
FOR AZZ016>018.


&&

$$

PUBLIC...McCollum/JJ
AVIATION...McCollum/DL


For Northern Arizona weather information visit
weather.gov/flagstaff


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