FXUS65 KPSR 151110
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
410 AM MST Wed Apr 15 2026

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- Breezy to locally windy conditions will return for the back half
  of the work week with elevated Fire Weather conditions focused
  around the Lower Colorado River Valley on Friday.

- After near normal temperatures through Saturday, daytime highs
  will warm back into the low to mid 90s for at least Sunday and
  Monday.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
Weak upper level ridging is currently moving into the region from
the west, but a large Pacific trough moving into the Pacific
Northwest is already beginning to disrupt and flatten the ridge.
However, height rises today will be enough to raise daytime highs
back into the mid 80s in Phoenix to as warm as the upper 80s
across southeast California under sunny skies.

The Pacific trough is then forecast to track southeastward into
the Great Basin later on Thursday, but any height falls over the
Desert Southwest will be late Thursday allowing highs to warm
further into the upper 80s to maybe a few spots reaching 90
degrees. The pressure gradient will also begin to tighten Thursday
leading to a return of breezy conditions during the afternoon and
early evening hours.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Model guidance over the past couple of runs has shifted the track
of the Pacific trough a bit farther to the north with the track of
the main shortwave across Utah into Colorado. However, it should
still be close enough to our area to bring a period of northerly
windy conditions down the Lower CO River Valley during the first
half of Friday while also resulting in a noticeable cooldown. Wind
gusts Friday morning across southeast California and the Lower CO
River Valley are likely to reach Advisory level in some spots
before gradually weakening during the afternoon hours. Elsewhere
Friday, afternoon wind gusts should be similar to Thursday with
gusts mostly under 25 mph. The latest NBM forecast highs Friday
have actually dropped a degree or two from previous runs with
readings in the upper 70s to lower 80s across the western deserts
to the lower 80s across south-central Arizona.

The weather pattern into the weekend and early next week supports
another passing ridge with the expectation this ridge will last
a bit longer and have more influence on temperatures. The weekend
shows very low RHs with readings dipping into the single digits
during the afternoon across the lower deserts, while temperatures
warm back to near 90 degrees Saturday before topping out in the
low to mid 90s on Sunday. Ensembles then favor a deep Pacific low
dropping southward off of Oregon and northern California late
Sunday and Monday before eventually moving inland somewhere across
the Great Basin or even the Desert Southwest by next Tuesday
and/or Wednesday. Assuming this occurs, the system would lower
temperatures again going into the middle of next week, but it is
unlikely to result in any meaningful precipitation chances.

&&

.AVIATION...Updated at 1110Z.

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

No major weather concerns will exist through Thursday morning.
Expect winds to follow familiar diurnal patterns across the
Phoenix airspace with speeds generally AOB 8 kts. Winds for the
Southeast CA terminals will favor S/SE during the afternoon and
then veer out of a more westerly direction this evening into the
overnight hours, with sustained speeds AOB 10 kts and extended
periods of variability likely. Clear skies today will be followed
by increasing high clouds tonight into Thursday.

&&

.FIRE WEATHER...
Gradual drying conditions will prevail over the next couple of
days as temperatures return into a normal range. Winds today will
again be light while MinRHs fall to 10-15%. Thursday will bring
an increase in winds by the afternoon with occasional gusts
between 20-25 mph for much of the area. MinRHs Thursday will also
fall into the upper single digits across the lower deserts.
Locally windy conditions across the western districts on Friday
are likely to bring elevated to possibly critical fire weather
conditions late morning into the afternoon. Warmer temperatures,
even drier conditions, but lighter winds are then expected for the
coming weekend.

&&

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

$$

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