429
FXUS65 KFGZ 240515
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1015 PM MST Tue Dec 23 2025

.SYNOPSIS...Cooler temperatures and periods of precipitation
look to return tonight and continue at times through Friday. Most
of the precipitation is expected to be rain except the highest
mountain peaks. Additional showers will be possible Friday night
into Saturday, with lowering snow levels.

&&

.DISCUSSION...Our lengthy period of dry weather and near-record
warmth will end later this evening as the first in a series of
disturbances brings widespread rain to much of the area. The main
low is off the west coast, pulling a mild and moisture-laden air
mass northward that is forecast to arrive in Yavapai and western
Coconino counties early this evening, then spread eastward along
the Mogollon Rim and Gila County after midnight through Wednesday
morning. The air mass arriving tonight is notable as the
precipitable water (a measure of moisture through the entire depth
of the atmosphere) is forecast to be above the 99th percentile
for this time of year. In addition, south-southwesterly winds of
35-45 kts at 700 mb should bring a significant upslope
precipitation enhancement to southwest facing slopes from Yavapai
County to the Mogollon Rim. Forecast rainfall amounts have
increased tonight into Wednesday, with a general 0.50"-1.00" from
the Mogollon Rim into NW Gila/Yavapai counties. In the favored
upslope zones, upwards of 1.50" is possible and this could lead to
some rises on streams/rivers in this area including Oak Creek,
Wet/Dry Beaver Creeks, and eventually the Verde River. Low water
crossings will be at risk of becoming impassable. As this is a
very mild air mass for this time of year, snow levels will start
above 8000 feet and quickly rise to 10000 feet or even higher
overnight. There is a low chance of a rain/snow mix as low as
7000-7500 feet for a brief time at the start of the precipitation,
but impacts are not anticipated at that elevation. By Wednesday
afternoon, this initial surge of moisture slides east and there
should be somewhat of a lull in the activity for most areas.

Wednesday night into Thursday morning - the next disturbance and
deep moisture plume is forecast to affect the region, with much of
the precipitation again favoring areas west of a Page to Payson
line. Overall precipitation amounts for this period have decreased a
bit with the latest model cycle, with an additional 0.30"-0.60"
in general and closer to 1.00" in those favored upslope zones.
Snow levels should remain very high for this time of year, mostly
around the 10000 ft level.

Friday and Saturday - models are in a bit better agreement today
that the next disturbance will move across the area from the
northwest from Friday night into Saturday. This one looks colder,
with snow levels falling closer to 6000-7000 feet. Amounts don`t
look heavy at this time, with the NBM chance of 1" or greater
snowfall around 25-40% above about 6500 feet. There is still
uncertainty in the forecast, so it would be best to keep checking
the latest updates if you have travel plans.

Sunday and Monday - most of the guidance now shows part of the west
coast trough cutting off into a closed low well offshore. Some of
the solutions wrap some moisture back northward into our region, but
most show a drier scenario. We currently have cool conditions with
about a 10-20% chance of precipitation at this time.

&&

.AVIATION...Wednesday 24/06Z through Thursday 25/06Z...VFR conditions
becoming MVFR or lower in increasing SHRA from west to east, mainly
along and west/south of KPGA-KPAN-KSOW line. S-SW winds 5-15 kts
with gusts 20-30 kts continuing through the night.

OUTLOOK...Thursday 25/06Z through Saturday 27/06Z...SCT/NMRS SHRA
with areas of MVFR/IFR or lower, mainly along and west of KGCN-
KFLG-KPAN line. S-SW winds 10-20 kts with gusts 25-35 kts each
day, remaining elevated at night.

&&

.FIRE WEATHER...Tonight through Thursday...Multiple periods of rain
showers starting tonight and continuing through Thursday. Rainfall
chances will be highest along and west of the Mogollon Rim and
Kaibab Plateau, with forecasted accumulations 0.5-1.5`` (locally
2+`` in upslope areas). Accumulating snow only along the highest
elevation features above 9,000-10,000`. Winds are south through
southwest 10-20 mph with gusts 30-35 mph each day.

Friday through Sunday...Chances for showers will continue, declining
on Sunday. Wetting rains will remain primarily along and west of
the Mogollon Rim and Kaibab Plateau, with lighter accumulations
expected through this period. Snow levels may lower down to 6,000-
7,000 feet on Saturday. Winds south to southwest 10-20 mph
gusting 30-35 mph on Friday, becoming west 5-15 mph on Saturday,
then turning northeast through east on Sunday.

&&

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

&&

$$

PUBLIC...JJ
AVIATION...Meola
FIRE WEATHER...Lewandowski

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