852
FXUS65 KPSR 270003
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
503 PM MST Tue May 26 2026

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- A large low pressure system will meander across California
  through the latter half of the week leading to breezy to locally
  windy conditions and elevated fire weather conditions across
  the region.

- Temperatures will cool to below normal levels starting Wednesday
  with afternoon highs in the mid to upper eighties across the
  western deserts to the low nineties across the south-central
  Arizona lower deserts.

- Above normal temperatures are forecast to return by early next
  week with highs topping 100 degrees as early as Sunday.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
The latest water vapor satellite imagery as well as streamline
analysis show a large, potent upper-level low centered near northern
CA. Modest height falls and an increasing pressure gradient will
lead to increasing winds this afternoon through this evening,
particularly across southeast CA through the western third of
Arizona, where gusts between 25-35 mph can be expected. Across the
western half of Imperial County, mountain rotors will lead to
even higher wind gusts in excess of 40 mph where wind advisories
are in effect. With the strong winds will also come the potential
for blowing dust, resulting in temporarily reductions in
visibilities. Afternoon high temperatures today will top out in
the mid 90s across most of the lower desert locations.

The aforementioned upper-level low will slightly migrate into
central CA on Wednesday. As it does so, 500 mb height fields will
decrease into the 568-576dm range and thus cooler surface
temperatures into a below normal category can be expected. Afternoon
highs across the western deserts are only expected to top out into
the mid to upper 80s, which will be a solid 10 degrees below normal
for late May. Across the south-central AZ lower deserts,
afternoon highs will be warmer, with readings topping out in the
low 90s. Breezy to locally windy will extend areawide as the
upper-level jet on the southeast periphery of the trough extends
into AZ. Widespread afternoon/evening peak gusts are expected to
range between 25-35 mph, with locally higher gusts across the
western half of Imperial County once again.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Model guidance heavily favors the Pacific low staying in place
across California into Nevada through Thursday, but it expected to
begin filling and lessening the threat for windy conditions.
Thursday should be another breezy day, but more muted compared to
today and Wednesday. The low is forecast to finally begin shifting
more into the Great Basin while continuing to weaken on Friday.
NBM forecast temperatures will stay below normal Thursday and
Friday with highs anywhere from the mid to upper 80s across the
western deserts to around the lower 90s across the south-central
Arizona lower deserts.

The upper level weather pattern should weaken across much of the
Western U.S. over the weekend with weak ridging to zonal westerly
flow taking over across the Desert Southwest. Height rises and
warming conditions are expected beginning this weekend, likely
persisting through early next week. The latest NBM/WPC forecast
temperatures shows highs around 100 degrees by Sunday and as high
as 104-108 degrees by next Tuesday.

&&

.AVIATION...Updated at 0003Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Breezy afternoon and evening winds will be the main aviation
weather impact through Wednesday. W-SW winds gusting as high as
20-25 kts will continue through 04-05Z this evening before
subsiding and diurnal E winds will develop by 07-09Z. Gusty S
winds will develop by 15-17Z Wednesday and persist through 00-01Z
before shifting more W-SW. Wind gusts Wednesday will be around
20-25 kts again. Gusty southerly crosswinds will be an impact for
PHX and DVT for much of the day. FEW to SCT high clouds will clear
out tonight.

Southeast California/Southwest Arizona including KIPL and KBLH:
Strong wind gusts will be the primary aviation weather impact
through Wednesday, with westerly wind gusts exceeding 30 kts at
KIPL and SW-S gusts up to 25-30 kts at KBLH. The gusty winds will
subside overnight, but pick up again by late morning Wednesday and
peak in the evening. The winds will generate blowing dust
regionally, which may reduce slantwise visibility, but the wind
orientation is not ideal for significant surface visibility
reductions at the terminals. High clouds now will clear out later
tonight.

&&

.FIRE WEATHER...
A much larger weather system will dive southward into the
Southwestern U.S. over the next couple of days creating breezy to
locally windy conditions. Elevated fire weather conditions will
become a concern starting this afternoon as winds pick up and
MinRHs stay between 10-20%. The gusty winds will continue through
at least Wednesday with the strongest gusts of over 30 mph
affecting portions of the western districts, while temperatures
dip and MinRHs improve slightly (15-25%). Breezy conditions may
persist into Thursday before dying down into Friday as the weather
system weakens and moves away from the region. High pressure is
then expected to build across the region over the weekend into
early next week leading to an increase in temperatures and falling
RHs, but winds are forecast to be fairly light.

&&

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

     Wind Advisory until 3 AM PDT Wednesday for CAZ566-567.

&&

$$

SHORT TERM...Lojero
LONG TERM...Kuhlman
AVIATION...Benedict
FIRE WEATHER...Kuhlman