Area Forecast Discussion
Issued by NWS Flagstaff, AZ

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FXUS65 KFGZ 211013
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
313 AM MST Thu Feb 21 2019

.SYNOPSIS...A major winter storm will bring widespread moderate to
heavy snow and dangerous travel conditions to most of northern and
central Arizona through late Friday afternoon. Quieter weather
will return for the weekend, with continued below normal
temperatures.

&&

.DISCUSSION...Well, it`s here. A major winter storm will move
across Arizona today through early Saturday. The cold low center
associated with the current system was centered over Nevada during
the morning hours, diving southward. The storm will be powered by
a 160+ mph 250 mb jet maximum that will rotate across Arizona
over the next 24 to 36 hours. During the same period, the low
center will move into southern California and pivot from moving
southward to eastward. During the pivot, a precipitation band will
remain nearly stationary across Arizona into early morning
Friday. The stationary nature of the band, along with deep
saturation, strong storm scale upward lift and strong upslope flow
is a recipe for heavy snow along and south of the Mogollon Rim.
North of the Mogollon Rim, snow will also be extensive but not
quite as heavy. Later Friday morning, the low will head eastward
as will the main band of precipitation. However, an extensive area
of wrap around snow showers will accompany the low center. The
wrap around showers will not end until early Saturday.

For today, snow levels will range from 3000 feet across northwest
Arizona to 4000 feet across far east-central Arizona. Tonight,
snow levels will range from 2000 feet across northwest Arizona to
5000 feet across far east-central Arizona (the snow levels will
rise some over the far east areas as slightly warmer air is drawn
northward by the flow around the pivoting low). Then on Friday as
the low moves eastward, snow levels will lower to around the 3000
foot level over the far east. The main message is that most
locations will see snow except for the lower deserts of central
Arizona. Snow accumulations of 1 to 2 feet are expected at many
locations along the Mogollon Rim, as well as along and south of
the White Mountains. Further north, accumulations of 6 to 12
inches will be common. Of course higher mountains peaks and passes
will see greater accumulations than the general amounts shown.

The result, a Winter Storm Warning is in effect across all of
northern Arizona. The best way to stay safe will be not to travel,
especially along the highways and interstates of northern
Arizona. If you do travel, fill that gas tank up and bring along
warm clothing, a few snacks and a fully charged cell phone. This
is a no miss system.

For Saturday into next week...Fair weather will return with slowly
moderating temperatures. Extensive snow pack will result in very
cold overnight temperatures, with single digits to below zero
readings in the mountains and teens to lower 20s elsewhere
(details on that as we draw closer). It will be Tuesday or
Wednesday before high temperatures approach average levels for
this time of year. No precipitation is expected from later
Saturday onward.

&&

.AVIATION...For the 12Z Package...Widespread snow extends along and
west of a line from Payson to the Four Corners, and will continue to
spread east through the morning hours. As it does so, expect
deteriorating conditions, with MVFR/IFR/LIFR ceilings and
visibilities spreading across all of northern Arizona by 15Z. Low
ceilings and visibilities are forecast to remain in place through at
least 12Z Friday. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...A strong winter storm system will continue to bring
widespread, heavy snow into Friday. Southwest winds will increase
from 15 to 25 mph with gusts from 35 to 45 mph Thursday afternoon.
Heavy snow will gradually taper off to showers by Friday afternoon.

Saturday through Monday...Expect dry weather. Temperatures will
remain cold, but will gradually warm into next week.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Winter Storm Warning until 5 PM
MST Friday FOR AZZ005-009>016- 018-038>040.

Winter Storm Warning until 8 PM MST Friday FOR AZZ017.

Winter Storm Warning until 11 AM MST Friday FOR AZZ004-006>008-
037.


&&

$$

PUBLIC...McCollum
AVIATION...RR


For Northern Arizona weather information visit
weather.gov/flagstaff


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