409
FXUS65 KPSR 242356
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
456 PM MST Fri Apr 24 2026

.UPDATE...00Z Aviation Discussion.

&&

.KEY MESSAGES...

- Tranquil weather conditions and slightly above normal
  temperatures today will transition into a cool down over the
  weekend as a mostly dry weather system brings breezy to windy
  conditions to the region.

- Near normal temperatures will be common much of next week
  despite another potential weather system during the latter half
  of next week.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...
Midday synoptic analysis shows quasi-zonal flow from the Eastern
Pacific through nearly the entire southern tier of the Lower 48.
Latest water vapor imagery also shows a few low pressure features
in the Eastern Pacific including a weak shortwave moving onshore
now through middle portions of CA and a larger low another 800
miles west over the Pacific. These features will influence weather
conditions through this weekend as they progress through the West.
Ahead of these features temperatures have warmed, with lower
desert highs this afternoon forecast to top out near 90 degrees.
The first of the two mentioned lows will not do too much to the
local area besides help enhance westerly mountain top and
sundowner downslope winds this evening across Southeast CA. For
several hours this evening, beginning around 5-6 PM MST/PDT, HREF
shows high probabilities (70-90%) for wind gusts >35mph in areas
of Imperial County, including parts of the Imperial Valley. A Wind
Advisory has been issued for the far southwest corner of Imperial
County starting this evening, but held off on one for other parts
of the county.

The second low mentioned eventually will move through the region
later Saturday into Sunday and continue to drive breezy to windy
conditions, as well as cool temperatures down and bring a low-end
chance for rain. The wind and cooler temperatures will be the
primary sensible weather impact this weekend for the lower deserts
of southern AZ and southeast CA. Winds will be particularly
strong across southeast CA and portions of southwest AZ Saturday
evening through early Sunday morning, coinciding with the passing
of a very strong jet max over the area, on the southern side of
the low as it moves inland. Latest model guidance has 500mb winds
peaking around 50-60kts and 110-120kts at 200mb, which is not
completely uncommon to see this time of year, but still pushing
above the 90th percentile of climatology. The timing of the jet
moving overhead in the evening should help lead to strong
mountain wave activity and sundowner downsloping winds across
Imperial County. Latest NBM forecast has surface wind gusts
peaking around 30-35 mph across much of southeast CA, however
downsloping enhancements, mountain rotors will be capable of
pushing peak gusts locally upwards of 40-50 mph. As a result, a
Wind Advisory has been issued for most of southeast CA Saturday
evening through early Sunday morning. The Advisory for the
southwest corner of Imperial county will continue through Sunday
evening. Widespread breeziness can be expected both days this
weekend, but most areas outside of southeast CA will see peak
gusts more in the 20-30 mph range. The strong winds Saturday night
will be capable of generating localized dense blowing dust
channels in Imperial County and may lead to very hazy conditions
across even south-central AZ and the Phoenix area Sunday morning.

The main energy from the weekend disturbance is forecast to move
through southern California Saturday evening and then across the
northern half of Arizona Saturday night. This trajectory is not
ideal for rain chances across the lower deserts and the deep mid
and upper level moisture drying out, with a dry punch from the
southwest ahead of the best forcing, is not great either. There
will at least be some jet forcing, but with dry low levels (dew
points in the 30s-40s) and the mentioned drying aloft, the
prospects of rain at lower elevations is not great (10% or less).
Still, some isolated to scattered light showers across the high
terrain north of the Phoenix area with very little rainfall is
possible (10-20% chance).

Temperatures will cool off over the weekend with highs falling
back mostly into the mid 80s on Saturday with the help of the
clouds and then only in the upper 70s on Sunday behind a cold
front.

&&

.LONG TERM /MONDAY THROUGH NEXT FRIDAY/...
Model uncertainty becomes an issue for later next week as yet
another Pacific weather system begins to take shape well west of
California early in the week. For our region, the exiting of the
weekend system on Sunday will leave behind a drier air mass which
will slowly modify and warm Monday into Tuesday. Both days should
still bring nice weather and clear to mostly clear skies, but
high temperatures are forecast to warm back to near 85 degrees on
Monday and then 90 degrees Tuesday.

Over the past couple of model runs, guidance has put a little
more doubt in the timing of the Pacific system for later next
week. Models still mostly favor the system to begin approaching
the region by next Tuesday/Wednesday, but it may become more cut
off from the main flow which could delay the system to more like
Thursday or even as late as Friday. The average of the ensembles
generally indicate the system moving through our region later
Wednesday into early Thursday, but some members hold off until
late Thursday/early Friday. Early indications are for a bit better
moisture this time around which should bring at least minimal
chances for showers whenever the main shortwave moves through the
area. The latest NBM/WPC PoPs give us 15-20% chances across the
lower deserts to as high as 20-30% in the high terrain for the
latter half of Wednesday into Thursday morning. The timing
uncertainty could easily change this timeframe as well as any
significant changes in forecast moisture.

&&

.AVIATION...Updated at 2350Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Occasionally gusty SW/W winds will be main weather issue through
Saturday evening. Winds Gusts to 20-25 kts are expected to linger
for a few couple of hours, but will diminish after sunset.
Confidence remains high that the nocturnal easterly wind shift
will occur tonight, though later than usual at KPHX. After sunrise
Saturday morning, winds are expected to increase to around 7-8 kts
out of the S-SE before westerly winds become established in the
early afternoon. Westerly gusts in the 20-25 kt range will become
common again through Saturday afternoon. FEW-SCT high cirrus decks
today will be followed by increasing mid and high clouds tonight
through Saturday morning, with CIGs lowering to 15-20 kft AGL.

Southeast California/Southwest Arizona including KIPL and KBLH:
Increasingly gusty winds late this afternoon/evening will be the
main aviation weather issue. Winds will remain westerly at KIPL
and favor S-SW at KBLH. Gusts up to 20-25 kts will continue for
the next few hours at KBLH while increasing closer to 30kt for a
few hours after sunset at KIPL. Confidence is good that gusts will
subside at KBLH tonight, but wind speeds between 10-15 kts with
occasional higher gusts may be maintained overnight at KIPL. Mid
and high cloud decks will increase through Saturday morning.

&&

.FIRE WEATHER...
Dry conditions with relatively light winds are expected for much
of today before breezy conditions develop tonight and become
locally windy on Saturday. Wind gusts Saturday will commonly reach
20-30 mph in many locations to as high as 35-50 mph across
portions of southeast California, especially Saturday evening
through early Sunday morning. Expect MinRHs this afternoon
between 10-15% before increasing to 15-20% Saturday. Overnight
recoveries will improve over the next couple of nights, rising
from 25-40% tonight to 40-60% Saturday night. A mostly dry
weather system passing through the region Saturday night may bring
some high terrain showers, but CWR is less than 10%. Seasonably
breezy afternoon winds and drying conditions are forecast for
early next week, but winds should fall short of creating
widespread elevated fire weather concerns.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 5 PM Saturday to 5 AM PDT Sunday for CAZ560-
     563>568.

     Wind Advisory until 11 PM PDT Sunday for CAZ562.

&&

$$

SHORT TERM..Benedict
LONG TERM...Kuhlman
AVIATION...Salerno/Whittock
FIRE WEATHER...Kuhlman/Benedict

NWS Phoenix (PSR) Office