519
FXUS65 KPSR 011742
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1042 AM MST Thu Oct 1 2026

.UPDATE...18Z Aviation Discussion.

&&

.KEY MESSAGES...

- Dry conditions with zero rain chances will persist through at
  least the weekend and likely much of next week.

- As high pressure builds over the region, a gradual warming trend
  will bring temperatures at least into a normal range starting
  this weekend and eventually slightly above normal for next week.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...
A much quieter weather pattern is taking shape across much of the
Western U.S. as an unseasonably strong high pressure ridge near
the West Coast moves inland through Friday. The center of the
ridge is forecast to set up over the Desert Southwest by Saturday
and likely stay there well into next week. In the short term,
some of the `cooler` air remains over Arizona, but with abundant
sunshine and increasing heights aloft daytime highs will be back
in the lower 90s across the Phoenix area to as warm as the upper
90s across southeast California. Once the center of the ridge
moves into our region on Friday, additional warming can be
expected bringing lower desert highs up to around 95 degrees in
the Phoenix area to around 100 degrees across southeast California
and the Lower CO River Valley. Despite the drier air aloft,
surface moisture will stay a bit elevated as breezy easterly
winds are expected to set up beginning Friday morning. This
easterly fetch, with morning gusts easily reaching 20-25 mph
across southern Arizona will supply the area with some weak
moisture advection in the low levels. This moisture will not be
nearly enough to bring any rain chances, but it will keep surface
dew points in the 50s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Little will change over the weekend and likely even for the bulk
of next week. The high pressure ridge is heavily favored to remain
over or at least very close to our region well into next week
keeping us under dry air aloft but with a persistent easterly low
level semi-moist flow. Subsidence under the ridge and the dry air
should keep a lid on any potential convective chances most days.
There are some hints at maybe some convective potential early next
week over the highest peaks in eastern Arizona, but as of now the
highest PoPs barely breach 10% over the White Mountains.

Temperatures are forecast to rise a bit further during the first
half of next week with the western deserts likely reaching 100-104
degrees, while the south-central Arizona lower deserts may get
close to 100 degrees. These early October temperatures would range
from 4-8 degrees above normal. Overnight lows will also be at
least a few degrees above normal, but generally staying in the
upper 60s to lower 70s. The most interesting part of the forecast
will be the daily easterly breezy conditions due to the expected
position of the high over or just to our north and a weak trough
setting up to our south. The easterly winds should reach their
peak over the weekend and during the mid to late morning hours
with gusts in some places reaching 30-35 mph. As daytime heating
increases and the mixed layer rises, the winds will be more
dispersed and decrease during the afternoon hours. We should keep
these daily easterly mostly morning breezes through at early next
week and possibly longer.

&&

.AVIATION...Updated at 1740Z.

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

No significant aviation weather impacts expected through Friday
under mostly clear skies. Easterly winds are expected through the
TAF period, with light speeds through this evening and
strengthening to around 8-13 kts with gusts to around 20 kts
beginning around 15-16Z Friday morning. Wind directions may still
try to veer SW late this afternoon for a brief period, but
confidence of this occurring is low. There is potential for minor
LLWS impacts tonight after 07Z, but magnitudes are expected to
remain below TAF threshold (30+ kt LLWS).

Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather impacts will exist through the forecast
period under mostly clear skies. Winds will be very light and
variable through most of the TAF period at both terminals, with
speeds remaining aob 6 kts.

&&

.FIRE WEATHER...
Gradual drying as high pressure takes hold over the region will
lead to somewhat lower humidities and mostly clear skies through
the rest of the week. Near normal temperatures are expected with
the warmest temperatures consistently across the western
districts. MinRHs will mostly range from 15-25% over the western
districts to 25-35% for the eastern districts with good to
excellent overnight recoveries. After light winds today, breezy
east winds will set up tonight into Friday and persist for several
days. Morning wind gusts of 20-30 mph will be common starting
Friday.

&&

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

$$

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