147
FXUS65 KPSR 191942
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1242 PM MST Sun Oct 19 2025

.KEY MESSAGES...

- Tranquil weather conditions will persist through the entirety of
  the coming week with temperatures within a few degrees of the
  seasonal normal.

- A weather system passing north of Arizona during the middle of
  the week may bring a few light showers over the Arizona high
  terrain.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
Dry, sunny conditions continue this weekend as the Desert
Southwest remains under an upper level ridge, while a cutoff low
remains well removed from our area west of the northern Baja
Peninsula. RAP analysis shows 500 mb heights today around 588 dm,
which is around the 90th climatological percentile. Temperatures
in response will warm near to slightly above normal through the
first part of the upcoming workweek. Lower desert highs during
this time will top out in the upper 80s to around 90 degrees,
while morning lows range in the upper 50s to low 60s. Dry
conditions will persist through the start of the workweek with
mostly clear skies outside of occasional passing high clouds.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Guidance eventually shows the cut-off low tracking toward southern
California on Tuesday before likely moving onshore Tuesday
night/Wednesday morning. There is quite good model agreement
showing the track of the low moving across far northwest Arizona
later on Wednesday before exiting northeast of the region on
Thursday. We are still expecting a modest moisture increase into
Arizona from the south as the system passes by to the northwest,
but nearly all of the moisture will be above 10-12kft. The best
system forcing will also be focused well to the northwest of the
better moisture, but due to some upslope forcing some light shower
activity is likely to occur over the higher terrain north and
northeast of the Phoenix area on Wednesday. NBM PoPs have come
down even further since last night with only 10-15% chances
largely just outside of our CWA. The passing low will also bring
an increase in westerly winds on Wednesday, some of which may
result some gusts upwards of 30 mph across Imperial County
Wednesday afternoon/evening. Winds elsewhere may become breezy at
times, but gusts are likely to stay closer to 20 mph.

Temperatures will cool slightly on Wednesday across the western
deserts before spreading throughout Arizona for Thursday. The
coolest day of this coming week should occur on Thursday with
lower desert highs anywhere from 80-85 degrees. Shortwave ridging
is then expected to briefly pass through our region on Friday
before more zonal flow is likely to take over through next weekend
as a large Pacific trough affects the Northwestern U.S. The ridge
should help to bring temperatures back up into the upper 80s for a
good portion of the lower deserts starting Friday with stable
temperatures likely persisting through next weekend. The Pacific
trough may end up bringing periods of higher clouds to our
region, but any precipitation is expected to miss our region to
the north.

&&

.AVIATION...Updated at 1731Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation concerns throughout the TAF period. Winds will
continue typical diurnal trends with wind speeds aob 5kts, with
periods of variability. Skies will remain mostly clear with some
FEW high clouds passing.

&&

.FIRE WEATHER...
High pressure will take a stronger hold across the region through
the early part of this week as temperatures gradually rise to a
few degrees above normal by Monday. Humidities will remain fairly
stable with MinRHs mostly between 15-20% across the lower deserts
to 20-25% for higher terrain areas. Light winds are also
anticipated through at least Monday with directions mostly
following common diurnal patterns. A mostly dry weather system is
then expected to pass through the region during the middle of the
week bringing slightly chances for mostly higher terrain light
showers. The system should also boost humidities slightly while
also leading to a period of occasional breezy westerly conditions
focused on Wednesday.

&&

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

$$

SHORT TERM...Smith
LONG TERM...Kuhlman
AVIATION...Ryan
FIRE WEATHER...Kuhlman

NWS Phoenix Office