726
FXUS65 KPSR 171759
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1059 AM MST Mon Nov 17 2025

.UPDATE...Updated Aviation Discussion

&&

.KEY MESSAGES...

- Another large Pacific weather disturbance will bring the next
  opportunity for rain mainly on Tuesday and Wednesday with
  additional chances likely arriving by next weekend.

- Temperatures this week will hover below the seasonal normal with
  readings around 10 degrees below normal during the middle of
  the week.

&&

.SHORT TERM /Today through Wednesday/...
The first weather system was somewhat of a miss for the region as
most of the energy ended up going through California into the
Great Basin, but it at least moistened up the atmosphere for the
next round. Current water vapor imagery shows the first system
continuing to push to the northeast through Utah and Colorado
with a second strong shortwave trough diving southward along the
northern coast of California. A much smaller vort max is also
noted just west of southern California and this feature may help
to bring some scattered shower activity later today as it quickly
swings through central Arizona.

The first part of today will remain quiet across the region with
some decent peaks of sunshine. Highs today are expected to top out
in the lower 70s, while moisture begins to increase again ahead of
the next weather system. PWATs are forecast to rise to around 1"
by later this afternoon and stay there across the Arizona lower
deserts through at least Tuesday and probably much of Wednesday.
Forecast soundings show ample moisture within a layer between
5-15K feet for later today into early Tuesday, deepening further
by Tuesday afternoon. Moisture levels of around 200% of normal are
expected to last through Wednesday providing plenty of chances
for decent rainfall on Tuesday and Wednesday as the main
shortwave trough slowly tracks across the region.

The current forecast shows the potential for mostly scattered
light showers developing as early as mid to late this afternoon
across south-central Arizona with slightly higher chances during
the evening hours. Once the low center moves closer to southern
California later tonight into early Tuesday, much of the area will
begin to see increasing forced ascent with showers and some
occasional embedded thunderstorms becoming more widespread across
southern and central Arizona. This area should continue to see
periodic showers Tuesday with southeast California likely only
seeing a brief 3-6 hour window of scattered showers. Rainfall
amounts on Tuesday are likely to exceed 0.5" in some locations
across south-central Arizona with much lower amounts across
southeast California and southwest Arizona.

Guidance then shows the low center moving across southern
California early on Wednesday before picking up speed as it
finally tracks through Arizona Wednesday night. Much of central
and eastern Arizona will continue to see occasional shower
activity Tuesday night and Wednesday with additional rainfall
amounts of 0.25-0.50" or so. Average forecast rainfall totals for
the entire event are as little as a trace across southeast
California to as high as 1-2" across the higher terrain just north
and northeast of the Phoenix area. The south-central Arizona
lower deserts are currently expected to see anywhere from 0.5-1.0"
with locally higher amounts possible. Given this expected
rainfall will fall over a 48-60 hour window, we are not
anticipating any flooding issues but area washes are likely to be
flowing at times.

Temperatures will also cool further going into the middle part of
the week with highs at or just below 70 degrees on Tuesday and
mostly in the mid 60s on Wednesday.

&&

.LONG TERM /Thursday through Sunday/...
The forecast for later this week and through the weekend is much
less certain as guidance is unsure of the track of a third weather
system. Thursday is likely to be a mostly dry day with only some
lingering light shower chances across eastern Arizona as the
second system will be exiting to the east. However, by Friday and
Saturday rain chances may again spread over the region as yet
another fairly potent Pacific trough tracks southward along the
coast of California. Over the past couple of days, guidance has
been trending toward keeping the low more to our west,
potentially far enough to the west to not bring widespread rain
chances. However, it may eventually swing through our region by
around Sunday or next Monday. Forecast PoPs and rainfall amounts
for this third event are still very uncertain and changes are
expected. If the low center does manage to stay completely to our
west and south (20-30% probability), we may not see much
additional precipitation, but it seems more likely it will at some
point swing through the Desert Southwest. We should hopefully
have a better idea what will happen during the middle part of
this week.

&&

.AVIATION...Updated at 1800Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The main aviation concerns will be the presence of VFR CIGs during
much of the period along with periods of VCSH and SHRA that could
result in reduced VIS. Multiple windows of rainfall are expected
with the first most likely occurring between 02-06Z this evening.
The next rounds look to be from 12Z onward but VCSHs through much,
if not the entire night is conceivable. In terms of sub VFR
conditions, the most likely timeframe would be with that second
round of rainfall, but confidence is still too low at this time to
include any prevailing MVFR CIGS or VIS in the TAFs. The most
likely sites to see these sub-optimal conditions would be KSDL and
KDVT where TEMPO groups have been introduced to address these
higher probabilities. Other than perhaps a brief switch to the
SSW/SW this evening associated with the first round of showers,
winds should favor and E/SE component throughout the forecast
window.


Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected during the next 24 hours.
S/SE winds at each terminal with eventually switch to the S/SW
later in the period with speeds remaining generally light (aob 10
kts). VCSH activity cannot be ruled out during the late evening
into overnight timeframe, but confidence is too low to include any
mention of rainfall impacting the terminals at this time. BKN-OVC
skies will be common through Tuesday morning with the lowest bases
around 7-8k ft.


&&

.FIRE WEATHER...
After a brief respite to the active weather pattern during the
first half of today, rain chances will increase later today with
wetting rainfall chances returning by Tuesday morning. Periods of
showers and a few isolated thunderstorms will affect much of the
eastern districts on Tuesday with much more limited activity
across the western districts. Below normal temperatures and
elevated moisture will remain in place keeping MinRHs between
40-70%, while overnight recoveries will be good to excellent at
60-100%. Locally gusty winds upwards of 20 mph will be possible at
times, though weaker wind speeds will be more common through the
period. The active weather with rain chances persisting across the
eastern districts should continue through Wednesday before a
brief break is seen on Thursday. Another weather system may
eventually affect the area by the weekend as temperatures mostly
remain below normal and humidities stay elevated.

&&

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

$$

SHORT TERM...Kuhlman
LONG TERM...Kuhlman
AVIATION...RW
FIRE WEATHER...Kuhlman