477
FXUS65 KPSR 022352
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
452 PM MST Mon Mar 2 2026

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- Near record warmth expected once again today as high
  temperatures top out at or just above 90 degrees.

- A series of dry weather systems will influence the region during
  the remainder of the week leading to periods of breezy
  conditions and cooler but still above normal temperatures.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
A transition in the overall weather pattern is beginning to take
shape across the Desert Southwest as the ridge of high pressure,
responsible for bringing the record warmth the last couple of days,
is shifting eastward as a compact upper-level shortwave trough is
traversing the Great Basin. Even though upper-level heights are
lowering across the region, low-level thermal profiles continue to
remain quite warm with 850 mb temperatures ranging between
17-20C. Therefore, another day of near record warmth is expected
as afternoon high temperatures across most of the lower desert
communities top out around to just above 90 degrees. With the
upper-level shortwave trough traversing the Great Basin, the
regional pressure gradient will tighten somewhat leading to
widespread breezy conditions this afternoon/early this evening
with peak gusts upwards of 20-30 mph, strongest across the western
deserts and the AZ higher terrain.

The upper-level trough will move into the central Rockies on Tuesday
with the overall trough axis hanging back across the region. A
cooler air mass in the wake of the trough will lead to a 4-5 degree
drop in 850 mb temperatures and thus cause afternoon high
temperatures to retreat into the mid 80s across the lower deserts.
Heading into Wednesday, weak ridging will move in out ahead of
the next troughing feature moving into the Pacific Northwest and
will influence the weather pattern heading towards the latter half
of the week. Afternoon high temperatures on Wednesday will remain
nearly similar to Tuesday with readings in the mid 80s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The main forecast concern late week into early next week is the
uncertainty with a potential cut-off low that could develop near
our region and linger for several days. The initial development of
the system begins on Wednesday across Oregon and California before
likely moving through Nevada into our region by Thursday. Models
have been in good agreement with the initial development of the
system, but high uncertainty remains with the eventual track and
how long it may impact our region. Increase winds will be the
first aspect that will affect our region with breezy to locally
windy conditions over much of the area starting Thursday. A cooler
air mass should also move in for Thursday, lowering daytime highs
down to around 80 degrees for the lower deserts.

By Friday into Saturday, guidance indicates the low may become
cut off from the main flow. If this occurs, it would likely
retrograde to the southwest, possibly stalling out somewhere to
our southwest for a day or more into early next week. Given the
system is expected to contain very little moisture as it
initially moves through our region late this week, no realistic
precipitation chances are forecast. For our region to receive any
chances for precipitation, the low would have to become cut-off
and stall out to our southwest for at least a day or two allowing
moisture to get entrained into the system and eventually making
its way northward. The EPS is more bullish on this potential
solution as its ensemble mean QPF shows an average of 0.10-0.20"
across southern and central Arizona later Sunday into next Monday.
The GEFS also attempts to show some precipitation chances around
the same time, but to a much lesser degree. Forecast temperatures
for next weekend into early next week are also quite uncertain as
they will depend on the evolution of the low, but we are still
expected to keep above normal temperatures in place.

&&

.AVIATION...Updated at 2352Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:

Winds will continue to follow typical diurnal directions through
Tuesday, with westerly breezes to around 20 kts expected to
subside this evening. Winds will be lighter Tuesday, with speeds
mostly staying below 10 kts. There will likely be a period of
light variability late Tuesday morning through noon, during the
diurnal westerly wind shift. High cirrus will continue to pass
over the area through tonight and clear by sunrise Tuesday.

Southeast California/Southwest Arizona including KIPL and KBLH:

Westerly winds will prevail at both terminals through Tuesday
morning. Wind gusts to around 20-25 kts will continue through
sunset before subsiding tonight. Winds will shift northerly at
both terminals during the late-morning hours Tuesday, with lighter
speeds, mostly aob 10 kts, at KIPL, while KBLH sees speeds up to
10-15 kts with gusts to around 20 kts. The high cirrus over the
area will clear tonight.

&&

.FIRE WEATHER...
Above normal temperatures and dry conditions will persist this
week, however the overall weather pattern become more active with
a few dry systems influencing the region. Afternoon minRHs each
day will range between 10-15% areawide, followed by fair
overnight recoveries commonly between 30-50%. A passing dry
system today will act to increase afternoon and evening
breeziness, with widespread gusts 15-25 mph and locally higher
over the AZ high terrain and portions of Southeast CA. Expect
lingering breeziness Tuesday for the typical wind prone areas of
the western districts. Another dry weather system later this week
should again bring widespread breezy conditions by Thursday.

&&

.CLIMATE...

Daily High Temperature Records:

       Phoenix      Yuma      El Centro
      ---------   ---------   ---------
3/2   90 (2016)   94 (1910)   92 (2016)

&&

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

$$

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

NWS Phoenix (PSR) Office