412
FXUS65 KPSR 222359
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
459 PM MST Thu Jan 22 2026

.UPDATE...Updated 00Z Aviation Discussion.

&&

.KEY MESSAGES...

- An unsettled weather pattern will materialize Friday and
  continue through Saturday, with temperatures cooling near to
  slightly below normal this weekend and chances for a few rounds
  of showers across South Central and Eastern Arizona.

- Dry conditions return on Sunday, with temperatures gradually
  warming during the first half of next week.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...
Current mid-level water vapor satellite imagery show the current
cut off low off the coast of Southern California. The center of
this low is expected to track south of our CWA over the next few
days, with current model runs now projecting the center of the low
progressing more south than previous runs. However, in the
meantime this system will continue to bring progressively thicker
cirrus clouds over the region today with afternoon highs in the
low to mid 70s for the lower deserts and in the mid 60s in the
higher terrain areas. Temperatures will be 2-3 degrees cooler
Friday, with a more notable drop Saturday with afternoon highs in
the low to mid 60s for Southcentral AZ, in the mid 50s in the
higher terrains, but still in the low 70s in the southwestern
portion of the CWA, in areas like Yuma and Imperial. As the low
progresses eastwards, over the Baja Peninsula, PWATs will
increase to ~150% of normal as early as Friday morning and peaking
to just over 200% of normal by Friday afternoon/evening over the
southeastern portion of AZ, lining up well with the expected areas
of highest PoPs/QPF.

The first round of activity for southeastern AZ and into the
higher terrains is expected to start Friday afternoon into the
evening mostly bringing very light showers to potentially only
virga for some localized areas, as model soundings show a very dry
atmosphere in the lower levels. A period of weak, moist
isentropic ascent ahead of this initial closed low will help force
more widespread shower activity Friday night into Saturday
morning, but again, better quality moisture and upper level
forcing (coupled with terrain influences) will focus higher
precipitation totals well to the east/southeast of the Phoenix
Metro.

By Saturday a second shortwave will dive south through the
Interior West. This will shift the flow aloft from southwest to
west northwest and providing a potential second focus for shower
development over the region. Lapse rates will not be quite as
impressive, but forecast soundings show a favorable profile for
some shallow convection (MUCAPEs peaking around 100 J/kg) Saturday
afternoon into the evening. However, showers capable of producing
lightning and small hail cannot be ruled out, but chances are
very low at this time. Over the two days the average rain totals,
for those that see showers across the lower deserts, should be
light, with totals between 0.10-0.25" for the Phoenix Metro, with
a gradient in QPF towards the east/southeast and up to 0.5-1.0"
over the higher terrain, with some localized areas potentially
seeing over 1".

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The poorly defined cold front that sweeps the area from the north
late Saturday into Sunday will usher in a cooler and much drier
air mass, ending precipitation chances by early Sunday morning.
Sunday and especially Monday are shaping up to be relatively cold
mornings with this cooler and drier air mass in place. Lows are
forecast to range from the mid 30s to mid 40s Monday morning, with
many of the typically colder rural, low-lying areas potentially
flirting with freezing temperatures (32F). Afternoon highs Sunday
will be similar to that of Saturday, though perhaps a few degrees
cooler for the western deserts.

Ensembles are in excellent agreement that ridging off the West
Coast will slide eastward and build over the Western US during the
first half of next week, promoting a gradual warming trend and
dry conditions Sunday onward. However, WPC cluster analysis
reveals discrepancies on how strong the ridge will become, and
whether any disturbances will undercut or weaken the ridge during
the latter half of next week. Regardless, after the unsettled
weather Friday- Saturday, quiet, dry weather will return Sunday
and persist through at least the middle of next week.

&&

.AVIATION...Updated at 2358Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:

A weather system will bring slight chances (20%) for -SHRA
tomorrow, but better chances for SHRA impacts will be after 06Z
Saturday so have not introduced any SHRA into the current TAFs.
However, scattered virga and sprinkles are expected throughout
the day on Friday. Despite the incoming weather system, VFR
conditions are expected to continue through the current TAF
period. CIGs will remain aoa 10 kft AGL. However, FEW-SCT clouds
around 7-8 kft will start to move in by Friday afternoon. Wind
speeds will generally be aob 5 kt through mid morning Friday. By
the late morning/early afternoon hours winds speeds will tick up
slightly, but still remain aob 10 kt.

Southeast California/Southwest Arizona including KIPL and KBLH:

No weather concerns will exist through Friday under periods of
thick mid/high level CIGs. Wind speeds under 6 kt will be common
at both terminals with extended periods of nearly calm
conditions amongst typical diurnal/nocturnal wind shifts.

&&

.FIRE WEATHER...
Dry conditions and above normal temperatures continue today until
an unsettled pattern will take hold by Friday and Saturday,
cooling temperatures near to slightly below normal for the
weekend. During this period humidities will also increase, and
will bring chances for a few rounds of showers mostly to South
Central and Eastern AZ. The best chances for wetting rains
(70-80%) will be focused east and southeast of the Phoenix area on
Saturday. MinRHs will increase from 15-25% areawide today to
30-50% Saturday, with even higher values over the higher terrain
of the eastern districts. A weak cold front will sweep the area
from the north late Saturday, increasing northerly winds
especially in the western districts along the Colorado River. As
such, anticipate mostly light winds (under 15 mph) through
Saturday morning, followed by locally breezy north winds Saturday
afternoon into the evening. Afternoon minRHs will fall back into a
15-30% range areawide Sunday onward.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

SHORT TERM...Ryan
LONG TERM...Whittock
AVIATION...Berislavich/Benedict
FIRE WEATHER...Ryan/Whittock