703
FXUS65 KPSR 300535
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1035 PM MST Mon Sep 29 2025

.UPDATE...Updated 06Z Aviation Discussion.

&&

.KEY MESSAGES...

- A dry and quiet weather pattern will prevail throughout the
  week with near zero rain chances.

- Temperatures will gradually warm from near normal to slightly
  above normal by the latter half of this week as a ridge of high
  pressure builds over the region.

- A dry weather system passing north of the region will bring
  breezy conditions and slightly cooler temperatures this
  weekend.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
The latest water vapor satellite imagery as well as streamline
analysis depict a weak upper-level ridge across the region. A much
drier air mass has settled into the region with mostly clear skies
being observed. Temperatures this afternoon will continue to be
slightly below normal with highs in the lower 90s across the lower
deserts.

For Tuesday, a broad trough will be situated over the
Pacific Northwest with quasi-zonal flow in place across the Desert
Southwest. Weather conditions will continue to remain dry and
tranquil. Temperatures will continue to warm a couple of more
degrees to more seasonable levels with highs reaching the mid 90s
across the lower deserts.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
From mid to late week, ensemble and deterministic models are in
agreement that a high amplitude ridge will build over the Desert
Southwest while a cutoff low develops over California. 500 mb
hghts will gradually increase to around 588-590 dam by the end of
the week resulting in highs across the lower deserts increasing
from the mid 90s on Wednesday to the upper 90s to around 100
degrees by Thursday and Friday. Global models continue to indicate
the aforementioned shortwave trough eventually diving across the
Great Basin this weekend which will result in a slight cool down
and breezier conditions across southcentral AZ. Given the trajectory
of this system remaining north of the forecast area and the lack
of any adequate moisture return, dry conditions with near zero
precipitation chances are expected to persist.

&&

.AVIATION...Updated at 0531Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation concerns are expected through the TAF period. Winds
are expected to be light with speeds aob 10kts. Direction will
continue to follow diurnal tendencies, with periods of VRB,
similar to the past 24 hours. FEW passing high clouds will be
common, but other wise mostly clear skies.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation concerns are expected through the TAF period. Winds at
KIPL will be out of the west, and KBLH will see mostly S`rly
winds, shifting out of the SW near the end of the TAF period. Wind
speeds will be aob 10kts for the earlier portion, but look to
increase by tomorrow afternoon to above 10kts, mostly at KBLH. FEW
passing high clouds will be common, but other wise mostly clear
skies.

&&

.FIRE WEATHER...
Temperatures will gradually warm above normal through the middle of
this week as a ridge of high pressure builds over the forecast area.
Expect much drier conditions to materialize each day with MinRHs
ranging from 25-35% this afternoon and falling to around 15-25%
through the end of this week. Overnight recovery will range from
fair to good tonight and generally remain in the fair category
through this week. Winds will follow light and diurnal tendencies
for the next several days with some modest afternoon upslope gusts.

&&

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

$$

SHORT TERM...Lojero
LONG TERM...Salerno
AVIATION...Ryan
FIRE WEATHER...Salerno