804
FXUS65 KPSR 282320
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
420 PM MST Tue Apr 28 2026

.UPDATE...00Z Aviation Discussion

&&

.KEY MESSAGES...

- Near normal temperatures through mid week will turn hotter going
  into the weekend with lower desert highs into the nineties as
  early as Friday.

- A weather system for Thursday will bring an increase in rain
  chances with the best area of focus across southeast Arizona.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
Quiet weather continues today as dry quasi-zonal flow persists over
the region. Meanwhile, a weak shortwave is noted over central
California, while downstream height rises are occurring over the
Southwest. Given this, temperatures will rise through tomorrow with
daytime highs Wednesday forecast to top out in the upper 80s to
around 90 degrees across the lower deserts. In addition to the
aforementioned weak shortwave, a Pacific closed low is seen spinning
roughly 800 miles off the southern California coast. Ahead of the
low, the subtropical jet will help to advect upper level moisture
and cloud cover tonight into Wednesday. Despite the increase in
cloud cover, temperatures should still manage to warm near to
slightly above normal tomorrow.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
The uncertainty with the Pacific weather system is still an issue,
but model trends over the past 24 hours have pulled the track more
to the south across northern Mexico. If these trends hold true,
the system should bring less impacts to our area than previously
thought. The latest NBM PoPs reflect the more expected southern
track with PoPs decreasing by an average of 10-15% from the
forecast package 24 hours ago. PoPs now show 10-25% across the
south-central Arizona lower deserts to at most 30-40% over the
eastern Arizona higher terrain. The more southern track would lead
to less moisture and instability, so the chance for any isolated
thunderstorms has also gone down to more of a 5-10% chance on
Thursday. In addition to the lower rain chances, forecast
temperatures have also gone back up for Thursday with readings now
back into the upper 80s in the Phoenix area to the lower 90s
across southeast California.

Starting Friday, we may start to have some influence from a ridge
building in from the west. Temperatures may also respond to this
incoming ridge with highs rising into the mid 90s across the
western lower deserts to the lower 90s in the Phoenix area.
Another developing Pacific low off the coast of California over
the coming weekend may cause the ridge to amplify even more across
our region potentially pushing daytime highs into the upper 90s
by Sunday. Eventually, this large Pacific low is favored to inch
into our region early next week resulting in a return of breezy to
windy conditions, cooler temperatures, and possibly some higher
terrain rain chances.

&&

.AVIATION...Updated at 2320Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation concerns are expected during the TAF period.
Winds will follow light and diurnal trends with some occasional
gusts during the afternoon hours. SCT-BKN high clouds will be
common across the region through Wednesday evening.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected during the next 24 hours.
Winds will at KIPL will switch from SE to more W`rly this evening,
while KBLH sees mostly a W`rly component with windows of VRB
conditions this evening and tonight. FEW-SCT high clouds will be
present across the region through Wednesday evening.

&&

.FIRE WEATHER...
Dry conditions along with warming temperatures will be observed
through Wednesday. Winds will remain fairly light, following
diurnal trends, with a few afternoon gusts to around 20 mph
primarily across southern Gila County. A weather system will bring
increasing rain chances Thursday with the best chances remaining
south and east of Phoenix. However, chances for wetting rainfall
will be low around 10% or less. MinRH values will be around 8-15%
Wednesday before increasing to 15-20% on Thursday. Overnight MaxRH
values will generally range between 25-40% through midweek. Gusty
winds are expected to increase this weekend into early next week,
which could lead to elevated fire weather conditions in some
areas.

&&

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

$$

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