030
FXUS65 KFGZ 232306
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
406 PM MST Mon Dec 23 2024

.SYNOPSIS...Expect dry weather and above average temperatures
for today and tomorrow. A storm system then brings rain and snow
chances to northern Arizona starting very early Christmas morning
and lasting through early afternoon.

&&

.DISCUSSION...A s/wv ridge pushing onshore over SOCAL today will
move through Arizona tonight and Tuesday. Warm temperatures this
afternoon will repeat again tomorrow, as the ridge axis slides
east and mixing improves ahead of a Pacific trough.

Tonight will not feature the turbulent airmass and cloud cover that
we saw last night and we should see decent radiational cooling. The
overnight lows have been adjusted downward, especially in valleys
and sheltered locations, including the Verde Valley.

Tuesday night, the strongest winds aloft moves through as the trough
approaches. Locations west of higher terrain will see gusty SW winds
most of the night. By very early Christmas morning, rain and snow
showers should start to break out along the cold front. This is
where the forecast gets complicated.

Model dispersion has actually become worse today, with the majority
of solutions favoring a northern track, keeping Flagstaff and much
of the I-40 corridor dry. The NAM12/GFS has some solutions that
bring a strong FROPA through Flagstaff, with showers along the
Mogollon Rim and even into the White Mountains. The northern
solutions favor mainly the Kaiabab Plataea and not much else.

There lies great difficulty favoring a scenario especially when the
NAM12 does not even have the Christmas Day s/wv within its domain.
The northern solutions that are dry, well, it`s hard to imagine the
cold front will produce nothing, so they are probably too dry. We
are somewhere in between for now, slightly tilted toward NAM12/GFS.
Confidence is low.

The remainder of the forecast period features a weak trough on
Thursday that may produce a few sprinkles, otherwise, a building
ridge, dry and warmer.

&&

.AVIATION...Tuesday 24/00Z through Wednesday 25/00Z...Look for VFR
conditions with variable winds around 5 kts.

OUTLOOK...Wednesday 25/00Z through Friday 27/00Z...MVFR conditions
are expected to develop from west to east after 00Z Wednesday in
-SHRA/-SHSN. Conditions improving after 00Z Thursday. Winds south
 at 10-20 kts on Tuesday becoming west at 5-15 kts on Wednesday.

&&

.FIRE WEATHER...Tuesday and Wednesday...Warm temperatures remain on
Tuesday, then turning colder on Wednesday. Rain/snow showers develop
from west to east late Tuesday into Wednesday. South/southwest 10-20
mph on Tuesday, becoming west on Wednesday.

Thursday through Saturday...Seasonable temperatures with lingering
showers on Thursday, with drier conditions expected thereafter.
Light winds expected each day.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

PUBLIC...Peterson
AVIATION...McCollum
FIRE WEATHER...Humphreys

For Northern Arizona weather information visit
weather.gov/flagstaff