Area Forecast Discussion
Issued by NWS Flagstaff, AZ

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FXUS65 KFGZ 290543
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1043 PM MST Thu Mar 28 2024

.SYNOPSIS...A potent Pacific storm is still on track to deliver
widespread rain and snow to northern Arizona late Saturday through
Monday. But first...wind.

&&

.UPDATE...Much of northern Arizona remains in a fairly dry slot of
air, with mid-to-high levels clouds north and south of our CWA.
Cloud cover will gradually increase overnight, but another mostly
sunny day is in store for tomorrow. Outside of sky conditions,
winds are still on track to ramp up quickly over the next couple
of days. As a result, there is a wind advisory valid from 11 AM
MST through 7 PM MST Friday. Winds will remain elevated overnight
on Friday into Saturday, but should drop below the criteria
threshold.

Be thinking about your Easter Weekend plans, as winter weather
conditions will likely impact travel/outdoor festivities.

The previous discussion and forecast package remain largely on
track. No edits were needed at this time.

&&

.PREV DISCUSSION /443 PM MST/...Confidence is increasing in the wintry impacts from
the incoming low pressure system. But before the precipitation
arrives, southwest winds will become quite strong. The pressure
gradient is already tightening as the trough digs into the West
Coast. A Wind Advisory remains in effect for locations along and
north of the Mogollon Rim tomorrow due to gusts in excess of 40
mph. On Saturday, winds will strengthen yet again and gusts
stronger than 40 mph will become widespread across the whole CWA.
Look for the issuance of a larger Wind Advisory sometime in the
next 24 hours. Crosswinds will create difficult travel for high
profile vehicles, especially on I-40 between Winslow and
Flagstaff. Blowing dust over the desert areas of the Colorado
Plateau could also reduce visibility at times.

The incoming system is projected to move down the coast of
California in the coming days. It will tap into a strong stream of
oceanic moisture, of which Arizona will get a healthy helping. By
Saturday night, the 500 mb low will sit near the Channel Islands.
Its associated surface cold front will begin to march eastward
through Arizona at that time. A robust frontal band of
precipitation will affect northern Arizona late Saturday night
through Sunday. This band will produce heavy precipitation,
dropping the bulk of rain and snow that we anticipate from the
incoming system. Snow levels will quickly fall to around 6000 feet
with the passage of the front. Snowfall amounts of more than 4
inches will likely be confined to elevations above 6500 feet. More
than 8 inches of snow is possible above 7000 feet.

In the wake of the front Sunday into Monday, atmospheric
conditions will become ripe for convective rain and snow showers.
This is due to the instability created by the plentiful cold air
aloft. Expect off and on snow showers in the high country (as low
as 5000 feet) and rain showers in the valleys. Some storm cells
will become strong and produce heavy rain, snow, or graupel.
Thunder and lightning is also a threat. The upper low should hang
around long enough to sustain these conditions through at least
Monday. Difficult travel in the high country can be anticipated
during this time, but it will be very difficult to predict when
and where the heaviest snow showers will occur.

It looks like the low pressure system will slide far enough south
or east to allow Arizona to dry out after Monday. However,
conditions will probably remain favorable for isolated showers in
the high country on Tuesday. As a result, mentionable
precipitation chances were included in Tuesday`s forecast. There`s
a good chance that mild, seasonable temperatures and fair skies
will return for the subsequent days. Given the nature of the
upcoming week`s setup, and the potential for the formation of a
stubborn cutoff low, the forecast remains fluid. Stay tuned for
updates as we continue to track this dynamic situation.

&&

.AVIATION...Friday 29/06Z through Saturday 30/06Z...VFR conditions
will continue. South to southwest winds at 5-15 kts are forecast
for much of northern Arizona overnight. However, just downwind of
terrain features gusts of 25-35 kts are likely. After 15Z
southwest winds at 15-25 kts gusting to 35 kts will become
widespread.

OUTLOOK...Saturday 30/06Z through Monday 01/06Z...Look for VFR
conditions through 18Z Saturday, gradually giving way to areas of
MVFR/IFR and local LIFR conditions in rain/snow, first west of a
KPGA-KPRC line but then spreading across all of northern Arizona
by 18Z Sunday. Friday night, strong southwest winds at 15 to 25
knots gusting to 45 kts over and downwind of higher terrain
will spread area-wide on Saturday. Expect lighter but still very
gusty southwest winds on Sunday.

&&

.FIRE WEATHER...Friday and Saturday...Cooler and windier each
day. On Friday, southwest winds 20 to 30 mph, gusting 35 to 45 mph.
On Saturday, southwest winds 25 to 35 mph, gusting 40 to 50 mph. Dry
until a winter storm arrives Saturday night.

Sunday through Tuesday...Widespread precipitation Sunday through
Monday and isolated showers on Tuesday with a few embedded
thunderstorms. Accumulating snowfall is expected above 6000 feet. On
Sunday, southwest winds 10 to 20 mph gusting to 30 mph, except for
far eastern Arizona where gusts to 40 mph are likely. Winds weaken
and turn west on Monday, then north on Tuesday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 11 AM MST /noon MDT/ to 7 PM MST /8 PM MDT/
Friday for AZZ004-006-007-009-011>017-039-040.

&&

$$

PUBLIC...Konieczny/Benji
AVIATION...McCollum
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff


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