929
FXUS65 KPSR 200621
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1121 PM MST Wed Nov 19 2025

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- A slow moving weather disturbance will continue to bring
  periodic rain showers with a few isolated thunderstorms mainly
  across southern and central Arizona through tonight.

- A Flood Watch has been issued for northern Maricopa County and
  is in effect through much of today.

- Another weather system will then bring very good chances for
  moderate rainfall Thursday night and Friday across southeast
  California and southwest Arizona with light rain chances
  extending through the rest of southern Arizona on Saturday.

- Temperatures through the rest of the workweek will be around 10
  degrees below normal before getting closer to normal over the
  weekend.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
Another round of shower activity across central Arizona is
expected to continue today into tonight as the upper level low
continues its slow journey eastwards across the region. Currently
the center of this low pressure system is positioned over Southern
California, projected to be over the Lower Colorado River by tonight
and to the east of our region by Thursday night. However, another
troughing feature, originating from the Gulf of Alaska, is
forecasted to dig down the NW coastline and conjoin with the
current trough as early as tomorrow afternoon, sustaining low
pressure over the region, with 500 MB heights dropping as low as
558-561dam tomorrow. This will keep afternoon highs in the desert
SW in the low to mid 60s, which is about 10 degrees below normal
for this time of year.

Water vapor imagery shows abundant low and mid level moisture
continuing to stream northward, centered across central Arizona,
just ahead of the low. This will produced scattered showers with
some isolated thunderstorms through most of tonight. PWAT values
remain quite elevated at ~200% of normal, along with MU CAPE
between 100-300 J/kg through the remainder of today. With an
additional 0.5-1.5" of rainfall expected today a Flood Watch has
been issued for northern and much of western Maricopa County. By
tomorrow instability will struggle to reach 100 J/kg across most
of the region, and PWATS will decrease slightly to ~125-150% of
normal, which can still be enough for Maricopa County to see more
rainfall Thursday morning before shifting to the east into the
higher terrain areas and Gila County.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
The last of the Pacific weather systems will quickly take shape
across northern and central California early on Thursday with the
low really wrapping up Thursday evening and Thursday night across
southern California. Guidance shows additional moisture advection
just ahead of the system reaching southeast California with PWATs
near 200% of normal by Thursday evening. Upper level jet forcing
will also be ramping up quickly during the latter half of Thursday
with the strongest forcing likely focused across southeast
California Thursday night into Friday. The combination of the jet
forced ascent, multiple vort lobes rotating through the area
around the low center, and the abundant moisture should give rise
to a large area of rain developing across southeast California by
Thursday night before expanding through southwest Arizona on
Friday.

The latest guidance shows average rainfall amounts of 0.5-1.0"
across southeast California and far southwest Arizona Thursday
night and Friday. Locally higher amounts of more than an inch are
likely to occur, especially over higher elevation areas of
southeast California and where any banding of heavier showers
occurs. It seems fairly likely this will cause some flooding
issues on Friday for the typical flood prone areas. A Flood Watch
may end up being needed.

The track of the Friday and Saturday system is still shown to
move south southeastward to over northern Baja Friday night into
Saturday before shifting to the east later Saturday into Sunday.
Guidance is still a bit uncertain with the latter half of the
track and how close the low center will be to the Arizona/Mexico
border. Rain chances should extend through the rest of southern
and to a lesser degree across central Arizona later Friday into
Saturday, but the potential rainfall amounts are much less
certain. The current forecast for south-central and eastern
Arizona mainly keeps rainfall amounts less than 0.25", but any
track farther to the north would likely bump up those amounts.

Models then favor the weather system exiting to the east on Sunday
with ridging gradually spreading in from the west on Monday. This
should allow for drier and much quieter weather to settle in
across the region by next Monday, likely lasting for most if not
all of next week. NBM forecast highs are also shown to rise back
into the normal range by early next week with readings around or
just over 70 degrees and lows in the 40s to low 50s.

&&

.AVIATION...Updated at 0621Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Areas of SHRA are expected to focus primarily just east and
southeast of all terminals through tonight, but still with a
chance for redevelopment of activity across the Phoenix area with
best chances for SHRA at KIWA. SHRA should clear up by 12-16Z. The
focused area of SHRA will likely lead to a persistent E`rly wind
during the night, but it is uncertain how long it will persist and
how far west the E`rlies will reach. Models indicate a tendency to
want to shift W`rly at at least KPHX and KDVT by 8-10Z tonight,
but E`rly winds may hold through sunrise and then shift W`rly
closer to midday Thursday. Wind speeds will remain light. A
filling in of CIGs around 4-6K ft AGL is anticipated tonight, with
low odds (30%) for MVFR CIGs. Lower CIGs will scatter out by
16-18Z Thursday, with plenty of sun in the afternoon.

Another weather system will reach the Phoenix area Friday, with
increasing clouds Thursday night - Friday morning and likely virga
initially pushing in followed by better rain chances not until
later Friday afternoon/night.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns expected through Thursday afternoon
with westerly winds prevailing at KIPL and light variable winds at
KBLH becoming S heading into the afternoon. A weather system will
then bring a band of showers to the terminals heading into
Thursday night and Friday morning, beginning initially as virga.
CIGs and Vis will lower in any showers, with slight chances (30%)
for MVFR conditions. Once the rain starts to fall, winds are
expected to shift N`rly at both terminals and may initially
increase up to around 10 kts.

&&

.FIRE WEATHER...
Periodic showers along with a few isolated thunderstorms will
affect much of Arizona through tonight providing very good
chances for wetting rains. Thursday morning will have lingering
chances for wetting rains over Central AZ before chances increase
in the afternoon in the eastern AZ higher terrains. Below normal
temperatures and elevated moisture will remain in place keeping
MinRHs in a 40-70% range following excellent overnight recovery
greater than 80%. Locally gusty winds upwards of 20 mph will be
possible at times, though weaker wind speeds will be more common
through the period. Another weather system is expected to move
mainly across the western districts on Friday leading to very good
chances for wetting rains with more scattered shower activity
across the eastern districts lasting through Saturday.
Temperatures will mostly remain below normal through the weekend
with humidities staying elevated.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Flood Watch until 6 AM MST Thursday for AZZ541-542-545-547-557.

CA...None.
&&

$$

SHORT TERM...Ryan
LONG TERM...Kuhlman
AVIATION...Benedict
FIRE WEATHER...Ryan/Kuhlman