956
FXUS65 KPSR 220010
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
510 PM MST Tue Oct 21 2025

.UPDATE...00Z Aviation Discussion.

&&

.KEY MESSAGES...

- Overall quiet weather conditions will continue through the rest
  of the week with temperatures within a few degrees of the
  seasonal normal.

- A weather system passing north of Arizona on Wednesday may
  bring a few light showers over the Arizona high terrain.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
Water vapor imagery continues to show upper level ridging over the
Desert SW, along with a cut-off low spinning off the coast of
Southern CA/ Northern Baja. The upper level ridging will keep the
afternoon high temperatures in the upper 80s to low 90s for today
and Wednesday. The aforementioned cut-off low will migrate
eastward, tonight into Wednesday, as cloud coverage can already be
seen to the SW of our region. These mid to high level clouds will
continue to thicken and move into our area throughout the rest of
today into Wednesday morning. Forecast soundings are showing an
almost saturated layer between 14-17 kft, which may help to drive
some very high based showers tonight and Wednesday morning, but
the boundary layer will remain very dry. This saturation is from a
slight increase in moisture introduced by the cut-off low. Although
short lived, PWATs will increase to near 0.08 in. (~160-180% of
normal) during this time, leading to some isolated sprinkles
across the south-central Arizona lower deserts. However, the
higher terrain areas could see measurable rainfall. This light
shower/virga activity looks to shift fully into far eastern
Arizona by late morning Wednesday before diminishing altogether by
late afternoon, where mostly clear skies will return.

As the cut-off low tracks into southern California on Wednesday,
portions of the region will see some increased breeziness focused
during the afternoon hours. The strongest winds are expected to
be across Imperial County, CA where some gusts of 30-40 mph will
be possible later in the afternoon through the first part of the
evening. Due to this a wind advisory has been issued for

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Late this week and through at least the weekend, we will return
to a quiet weather pattern with ridging taking over by Friday and
lasting into early Sunday. As the cut-off low exits the region on
Thursday it will help to bring a noticeable cool down with highs
in the lower 80s across the south-central Arizona lower deserts to
the mid 80s across southeast California. Once the ridging takes
over across the region starting Friday, temperatures will quickly
warm back into the mid to upper 80s. The slightly above normal
temperatures should persist through Saturday before we shift into
a zonal flow pattern starting Sunday. This zonal flow will help to
lower heights across our region and push temperatures back into
the normal range by Sunday or Monday. Other than some periods of
high clouds late in the period, we can expect a continuation of
dry conditions well into next week.

&&

.AVIATION...Updated at 0000Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation weather concerns are expected through the TAF
period. Winds will continue to exhibit normal diurnal tendencies,
with speeds remaining aob 7 kts and periods of light and vrb. Mid
and high clouds generally aoa 12 kft will increase in coverage
this evening and throught tonight, becoming SCT-BKN. Expect to see
virga showers develop overnight and through the first half of the
day tomorrow, however the chances of any measurable rainfall
remains low.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation weather concerns are anticipated through the
forecast period. Winds will remain light and vrb at both terminals
overnight before becoming established out of the WSW at KIPL and
S-SW at KBLH early tomorrow afternoon. Gusts up to 20-25 kts will
be possible at both TAF sites tomorrow afternoon through the early
evening. Mid to high lvl clouds will increase in coverage this
evening and throught tonight, becoming SCT-BKN with periods of
light virga showers possible over the region.

&&

.FIRE WEATHER...
A weather system will pass through the region tonight into
Wednesday morning. Light winds will persist throughout today,
then some afternoon and evening breeziness, particularly across
Imperial County will be common throughout Wednesday. A few
sprinkles/light showers will be possible tonight into Wednesday
morning across the eastern districts but little to no rainfall
accumulation is expected. MinRHs will mostly range between 15-20%
across the lower deserts to 20-25% for higher terrain areas east
of Phoenix. High pressure and dry conditions are then expected by
Friday, lasting well into next week.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 5 AM Wednesday to 5 AM PDT Thursday for
     CAZ562.

&&

$$

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

NWS Phoenix Office