Tempe, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

542
FXUS65 KPSR 250552
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1052 PM MST Thu Apr 24 2025

.UPDATE...
06Z Aviation Discussion.

&&

.SYNOPSIS...
Near to slightly above normal temperatures will persist over the
next few days ahead of an approaching area of the low pressure.
Noticeable cooling and breezy to locally windy conditions will
accompany this system as it traverses the Great Basin this
weekend. A quick rebound temperatures, along with the return of
more tranquil conditions, are expected next week as high pressure
builds over the western United States.

&&

.DISCUSSION...
Current atmospheric analysis reveals persistent quasi-zonal flow
stretched out over much of the Desert Southwest, resulting in a
prolonged period of little day-to-day regional condition variations.
However, it looks like this quiet flow regime will begin to break as
an Eastern Pacific area of low pressure begins its advance toward
the western CONUS. Before this pattern shift takes place,
temperatures will continue to run near to slightly above normal for
this time of year, with lower desert highs ranging generally in the
upper 80s to lower 90s this afternoon.

The influence of the above-mentioned low will begin to be felt as
early as Friday with cooling temperatures, mostly over the
western deserts of SE California and SW Arizona, and increasing
winds for portions of the region. In terms of temperatures, the
initial cooldown will not be very pronounced as temperatures fall
only a few degrees into the middle and upper 80s for the areas
mentioned above. Elsewhere across the desert of south-central
Arizona, temperatures will continue the status-quo that has been
observed over the past several days with temps in the upper 80s to
lower 90s. With cooler air beginning to filter in, a tightening
of the regional thermal and pressure gradient will help generate
breezy to locally windy conditions for parts of our forecast
area, particularly the typical downsloping areas of western
Imperial County, portions of the Lower Colorado River Valley, and
the high terrain areas east of the Phoenix metro. Due to the high
probabilities (>90% chance) of gusts reaching or exceeding 40 mph
in western Imperial County, a Wind Advisory has been posted and
will go into effect Friday afternoon. Elsewhere, gusts 20-30 mph
will be common, with locally higher gusts at times.

The closed-low will eventually make landfall on Saturday, and some
of the greatest impacts associated with will be felt, from more
noticeable cooling temperatures, to a continuation of enhanced
breeziness. Saturday looks to be the windiest day this weekend, with
widespread 25-35 mph gusts, with the potential for higher gusts
across the most wind prone areas. As of now, no wind advisories have
been issued outside of the one for far western Imperial County.
However, it would not be surprising if that advisory is extended
eastward to encompass the Imperial Valley, and a separate advisory is
issued for the Arizona high terrain over the next day or so. On both
Friday and Saturday, the enhanced breeziness, combined with a very
dry air mass in place, will result in periods of elevated to locally
critical fire weather conditions across portions of the region. As
for temperatures, this system will funnel unseasonably cool air over
the Desert Southwest (though there likely will not be too many
complaints about that) dropping temperatures a good 5-10 degrees
below normal, with initial cooling over the western deserts
Saturday before spreading further east by Sunday. Widespread temps
in the middle to upper 70s are expected by Sunday, with just a
few spots making into the lower 80s. Lingering breeziness is
likely on Sunday as the system weakens, but gusts should remain
below the advisory level threshold.

Heading into the start of next week, models depict the weekend low
splitting into two separate systems, with one ejecting toward the
Plains, while the other hangs back over the Southwestern CONUS and
Northern Sonora. The general consensus is that this secondary
system will not be as strong as its predecessor, so little in the
way of impacts are anticipated. At the most, periods of elevated
winds and maybe a delay in a more noticeable warming trend will be
the main impacts. Beyond that, clusters indicate the return of
high pressure to the western CONUS by the middle of next week,
ushering in the return of benign conditions and above-normal
temperatures.

&&

.AVIATION...Updated at 0550Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
The main aviation concern this forecast period will be a gusty
southerly crosswind Friday morning through the early afternoon.
Until then, winds will remain light and variable before settling
out of the ESE overnight. Winds will become elevated and begin to
shift more out of the S-SE early Friday morning, creating a cross-
runway component at KPHX for at least 3-4 hrs until finally
shifting out of the SW in the late afternoon. Gusts around 20-25
kts can be expected through tomorrow afternoon before diminishing
after sunset. Skies will remain mostly clear aside from a few
passing high clouds.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather concerns will exist through the forecast period
under mostly clear skies. Winds at KIPL will remain out of the west
tonight with intermittent gusts up to 20 kts possible. There will be
a period of lighter speeds early Friday morning before winds
increase again out of the west. Stronger gusts up to 30 kts will
materialize starting around 23Z-00Z tomorrow evening. At KBLH,
expected winds to remain generally out of the S-SW through Friday
with gusts reaching 20-25 kts by the early afternoon.

&&

.FIRE WEATHER...
Dry conditions will persist through the next 7 days, with seasonably
warm temperatures through the end of the workweek. Expect diurnally
driven and generally light winds today, with typical afternoon
upslope breeziness. An approaching low pressure system late week
into this weekend will increase winds Friday for the western
districts and areawide by Saturday, leading to locally elevated to
near critical fire weather conditions for the typically prone areas,
such as the Arizona high terrain east of Phoenix. Temperatures will
also cool below normal this weekend as a result of the low pressure
system. Afternoon minRHs will generally fall into the upper single
digits to lower teens through the end of the workweek before rising
slightly this weekend, in the middle to upper teens, thanks to the
cooler temperatures. Overnight recoveries will be poor to fair,
generally between 25-45% through Friday night, increasing to 30-50%
for the eastern districts by Saturday night and slightly higher (45-
60%) for the western districts.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 2 PM Friday to 5 AM PDT Sunday for CAZ562.

&&

$$


DISCUSSION...RW
AVIATION...Salerno
FIRE WEATHER...Whittock