181
FXUS65 KPSR 261742
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1042 AM MST Sat Apr 26 2025

.UPDATE...Updated Aviation Discussion.

&&

.SYNOPSIS...
Cooler temperatures, with continued breezy to locally windy
conditions, will be the main weather highlights today. Dry
conditions with below normal temperatures continue into next
week, with steady warming extending into the latter portions of
the work week.

&&

.DISCUSSION...
While clear skies encompass the Desert Southwest early this
morning, a deep low circulation continues to deepen along the
central to southern California coastline. This disturbance is
ushering in much cooler temperatures into the region over the next
several days as negative mid-level height anomalies linger into
early next week. The coolest day is set for tomorrow, where highs
could be around 10 degrees below normal as the core of this trough
brushes across northern Arizona.

The main weather impacts for today include breezy to locally windy
conditions, which are anticipated to match or exceed winds
observed yesterday, especially across south-central Arizona. A
Wind Advisory remains in effect for the southwest corner of
Imperial County, where stronger gusts up to 55 mph are anticipated
in the higher terrain. Elected to not expand wind advisories into
the lower deserts of Imperial County due to marginal chances
(20-40%) of extended periods of advisory-level winds, but don`t be
surprised if there are periodic wind gusts in excess of 40 mph
with some lofted dust late this afternoon and into the evening
hours. In addition to the elevated winds across the region,
elevated fire weather conditions are a concern for the southern
portions of Gila County due to the combination of strong winds
(gusts to 35 mph), low RH`s (8-10%), and burnable fuels exceeding
the 70th percentile in spots.

As the core of the upper level trough migrates eastward across
Arizona tomorrow, the pressure gradient will begin to relax,
resulting in winds weakening going into next week. Ensembles
remain in excellent agreement of the main longwave energy lifting
northeastward into the northern Plains by Tuesday, but residual
troughing locally across southwest CONUS keeping temperatures from
rebounding by no more than a couple of degrees each day through
the middle of next week. At that point, flat or weak ridging will
build across western CONUS, enhancing the warming trend through
the end of next week. Thus, temperatures will remain below or near
normal through at least Wednesday, with above normal temperatures
returning through the end of the week.

Larger ensemble spread becomes more noticeable late next week and
into next weekend, as attention turns towards the next troughing
feature that will reach the West Coast. Clustering analysis shows
a variety of scenarios ranging from a weak trough that may only
cool temperatures slightly, with much deeper solutions resulting
much cooler temperatures by next weekend. Thus, low confidence at
this point of the pattern evolution beyond next Friday, as
temperatures spreads continue to be large (10-15 degrees between
the NBM interquartile ranges).

&&

.AVIATION...Updated at 1740Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
No significant aviation weather concerns are anticipated through
the TAF period. Winds will continue to veer toward the WSW heading
into this afternoon as winds increase. Breezy afternoon conditions
are expected today with gusts climbing upwards of 20-25 kts at the
terminals. Breezy conditions decrease this evening but expect a
westerly component to persist well into the overnight hours.
Confidence in a diurnal switch to the east overnight is low with
perhaps more light and variable conditions favored early Sunday
morning. Otherwise, mostly clear skies will continue with a few
passing high clouds Sunday.

Southeast California/Southwest Arizona including KIPL and KBLH:
The primary aviation weather concern through the next 24 hours
will be strong, gusty winds at the TAF sites, particularly at
KIPL. Westerly gusts generally around 25-30 kts can be expected at
KIPL through the afternoon with an uptick to around 35 kts at
times this evening. With these strong winds, blowing dust may
result in some surface/slantwise visibility restrictions. Strong
gusts look to subside around midnight but speeds will remain
elevated out of the west through the overnight period. At KBLH,
S-SW winds will persist through the period with gusts upwards of
25-30 kts this afternoon and evening. Otherwise, mostly clear
skies will persist with perhaps a few afternoon CU and a few
passing high clouds.

&&

.FIRE WEATHER...
Breezy to windy conditions will continue to impact the region
today, where higher terrain areas could experience gusts 30-40
mph. This will result in an elevated fire danger, particularly
for higher elevation of eastern districts. Temperatures cooling
below normal will allow an increase in humidity levels, and in
combination with some fuels not quite fully cured should preclude
critical fire weather conditions. Otherwise, afternoon minRHs will
generally fall into a 15-25% range through the first part of next
week before return to a 10-15% range by the middle of the week.
Fair to good overnight recovery of 30-60% will retreat towards
poor to fair (20-40%) during the middle of next week as
temperatures warm back towards the seasonal normal.

&&

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

&&

$$


DISCUSSION...Young
AVIATION...Smith
FIRE WEATHER...Young/18