San Tan Valley, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

977
FXUS65 KPSR 302320
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
420 PM MST Sun Mar 30 2025

.Update...00Z Aviation Discussion

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.SYNOPSIS...
Seasonably warm temperatures will continue tomorrow before
temperatures cool to below normal for the remainder of the workweek.
The weather system that will be cooling our temperatures will also
bring breezy to locally windy conditions to the region. The windiest
day will be on Tuesday with the highest winds forecasted to be in
Southeast California and the higher terrain to the north and east of
Phoenix. Slight chances for light showers exist on Wednesday,
Friday, and Saturday, but these chances are confined to the higher
terrain to the north and east of Phoenix.

&&

.DISCUSSION...
This afternoon water vapor imagery and objective analysis show that
the Desert Southwest is still under zonal flow with a weak shortwave
trough in northern Arizona along with a low pressure sitting off the
coast of the Pacific Northwest. The aforementioned shortwave
trough is leading to breezy conditions across the area along with
some upper level cirrus clouds, similar to the weather conditions
the past couple of days. Winds have gusted up around 40-50 mph in
the far SW corner of Imperial County where a Wind Advisory remains
in effect through early Wednesday morning. Temperatures early
this afternoon range from the mid 70s to mid 80s across the lower
deserts and are only expected to rise a few more degrees before
topping out for today. Zonal flow aloft will continue tomorrow,
which will result in very similar weather conditions, with
continued breezy to locally windy conditions and afternoon high
temperatures forecasted to be in the upper 70s to mid 80s.

A big pattern shift will take affect on Tuesday as the
aforementioned low pressure system, currently off the coast of the
Pacific Northwest, pushes onshore and into the Desert Southwest.
With this low pressure system moving into our region we will see
temperatures cool to around 8-12 degrees below normal for this time
of year. The lower deserts are only forecasted to see afternoon high
temperatures in the low to mid 70s. The bigger impact with this
weather system will be in the increase in winds across the region
with widespread breezy to locally windy conditions. The highest wind
speeds are forecasted to be across SE CA and the higher terrain to
the north and east of Phoenix. In addition to the Wind Advisory in
the far SW corner of Imperial County, wind speeds will also be
approaching Wind Advisory criteria in the higher terrain to the
east of Phoenix and a Wind Advisory may need to be issued for this
area for Tuesday.

This weather system will continue to progress eastward with the
low pressure system moving over northern AZ on Wednesday. With the
low overhead on Wednesday temperatures will cool even further
with high temperatures forecasted to be in the low 70s across the
lower deserts in SE CA and SW AZ and only in the mid to upper 60s
across south-central AZ. In addition to the cooler temperatures
there will be a slight chance of light rain showers Wednesday
afternoon across the higher terrain to the north and east of
Phoenix. With the low over northern AZ the best rain chances will
be confined to northern AZ.

A weather pattern resembling a rex block looks to set up for the
latter half of the workweek as high pressure builds over the Eastern
US and Northwest US/Western Canada and keeping the trough over the
SW US. This will keep temperatures below normal through at least
Saturday, with a gradual warming trend with afternoon high
temperatures warming back into the mid to upper 70s to near 80
degrees across the lower deserts on Saturday. Despite the trough
overhead rain chances, at least for the lower deserts, are not great
due to the limited amount of moisture. Slight chances for light
rainfall exist on Friday and Saturday for the higher terrain to the
north and east of Phoenix.

Global ensemble guidance indicate that the blocking pattern will
start to break up by the end of next weekend and early next week.
This will allow for the low pressure system to finally advect into
the Plains and allow for high pressure start to build back over the
region. There is some disagreement among the global ensembles on
when exactly the blocking pattern will start to break up, however,
once it does that will lead to further warming as the ridge builds
back in and further promote dry conditions. Ensembles currently show
temperatures returning to near normal (low to mid 80s) by next
Sunday.

&&

.AVIATION...Updated at 2320Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation concerns are expected during the TAF period.
Winds will follow familiar diurnal trends with some occasional
breeziness in the mid-teens to around 20 kts prior to sunset.
Conditions tomorrow will follow similar trends as today, with
breeziness returning once W`rly winds become established in the
afternoon. High cirrus will stick around through most of the
forecast, with a FEW cumulus around 5-6k ft popping up Monday
afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH:
Breezy to windy conditions will continue to be the main aviation
impact during the next 24 hours. Gusts between 25-30 kts are
expected at IPL through this evening before speeds relax tonight.
Relatively elevated sustained speeds between 10-15 kts will
persist overnight, with some occasional gusts 20-25 kts at times,
At BLH, SW breezes 20-25 kts will be observed through this evening
before a downtrend in wind magnitude takes place, with even some
variability taking place overnight. High cirrus decks will stream
over the region through most of the forecast window.

&&

.FIRE WEATHER...
Seasonal temperatures are expected through tomorrow with
temperatures cooling below normal by Tuesday and remaining below
normal through the workweek. Mostly dry conditions are expected
throughout the week as well, with the exception of slight chances
for rain on Wednesday afternoon/evening and again Friday and
Saturday, but these chances will be confined to the higher terrain
to the north and east of Phoenix. Each day will get progressively
windier through Tuesday. The strongest winds are expected on Tuesday
with the highest winds across SE CA, mainly Imperial County, and
across the higher terrain of Maricopa and Gila Counties, where
elevated fire weather concerns will exist. Minimum relative humidity
is expected to range from 15-25% most afternoons through the week,
and overnight recoveries will be fair and generally around 40-60%.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory until 2 AM PDT Wednesday for CAZ562.

&&

$$

DISCUSSION...Berislavich
AVIATION...RW
FIRE WEATHER...Berislavich/Whittock