898
FXUS65 KPSR 031753
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1053 AM MST Fri Oct 3 2025

.UPDATE...Updated 18Z Aviation Discussion.

&&

.KEY MESSAGES...

- Low pressure will brush the Desert Southwest today and bring a dry
cold front through the region tomorrow morning leading to breezy to
locally windy conditions and cooling temperatures heading into the
weekend.

- A gradual warming trend will commence once again for the first
half of next week.

- Increasing rain chances late next week with impactful rainfall
possible, but forecast confidence is very low at this time.


&&

.SHORT TERM /TODAY THROUGH SUNDAY/...
Upper level water vapor satellite imagery and objective analysis
early this morning reveal a closed low over northern CA with high
pressure over SE AZ. The aforementioned low will slowly move
east/southeastward over the next two days and push a dry cold front
through the region early Saturday morning. This will lead to
lowering heights aloft and thus will lead to a cooling trend across
the region. Afternoon high temperatures will be in the mid 90s
across SE CA and SW AZ, in the upper 90s to low 100s across south-
central AZ, and in the low-to-mid 90s across the higher terrain.
Temperatures will cool 5-10 degrees tomorrow, with highs falling
into the mid-to-upper 80s to near 90 degrees across the lower
deserts and in the low-to-mid 80s across the higher terrain. This
morning low temperatures will be in the upper 60s to low 70s across
the lower deserts and in the mid 70s in more urban areas (central
Phoenix) and in the mid 60s across the higher terrain. Low
temperatures will cool into the upper 50s to 60s (near 70 degrees in
central Phoenix) tomorrow morning.

In addition to the cooling temperatures the aforementioned low
pressure system and associated cold front will bring breezy to
locally windy conditions to the region today and tomorrow. WIndy
conditions already exist across the far SW corner of Imperial
County, where winds of 40-45 mph have already been observed early
this morning. Gusty winds will continue for this area through early
Saturday morning, where wind gusts up to 55 mph are possible. A wind
advisory is in effect for the far SW corner of Imperial County
through 5am PDT Saturday morning. Wind speeds will increase
elsewhere across the CWA late this morning through this evening. The
rest of western Imperial County (just west of Imperial Valley) will
be in a Wind Advisory from 3pm PDT this afternoon through midnight
PDT tonight, where wind gusts up to 40 mph are possible. Wind gusts
of 20-30 mph are expected across central and eastern AZ, with gusts
of 25-35 mph are expected across SW AZ and the rest of SE CA. Winds
will subside after sunset across south-central and eastern AZ,
but will continue into the overnight hours across SE CA and
portions of SW AZ. Breezy conditions (20-25 mph) are then again
expected across the higher terrain of eastern AZ Saturday
afternoon and early evening.

Saturday night into Sunday the closed low will open up and move into
the northern Plains as a shortwave trough with a secondary trough
digging into the Intermountain West Region. This secondary trough
will help to keep temperatures below normal on Sunday. Cooler
morning lows will continue on Sunday. Morning lows will range from
the upper 50s to mid 60s across the lower deserts, with most areas
seeing lows in the low 60s. Higher terrain areas will see Sunday
morning lows in the mid 50s. High temperatures on Sunday are
forecasted to be very similar to those on Saturday. Lower desert
high temperatures are forecasted to be in the upper 80s to low 90s,
with higher terrain areas forecasted to be in the mid 80s. Dry
conditions will continue into next week.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
The trough that will be bringing below normal temperatures to the
region this weekend will move into the Plains on Monday with broad
troughing left in its wake across Western CONUS. A subtropical high
will also be trying to build back into the Desert Southwest early
next week. This subtropical high will be battling another low
pressure system that will be in the Gulf of Alaska at the start of
the workweek and will push southward into the Pacific NW by the
middle of the week. As the high pressure tries to build into our
region heights aloft will rise. This will lead to gradually warming
temperatures through the middle of next week. Temperatures are
currently forecasted to be in the upper 80s to low 90s across the
lower deserts to start the week and warm into the mid 90s by
Wednesday. Temperatures across the higher terrain will be in the mid
to upper 80s. Morning low temperatures will continue to be in the
60s across the lower deserts, with the exception of some areas of
near 70 degree morning lows on Wednesday around the Phoenix Metro.
Morning lows in the higher terrain will be in the upper 50s to start
the workweek, warming to the low 60s. Dry conditions will also
continue through at least the middle of next week.

Heading into the end of next week models start to differ on what
exactly will happen. Models are in fairly good agreement that the
aforementioned low, that will be pushing into the Pacific NW by
the middle of next week, will continue to push southward into
northern CA and stall there heading into the weekend. Where the
models differ is what to do with the remnants of a tropical system
that will be moving northwestward during the same timeframe. If
the remnants of the tropical system phase with the trough/low off
the Pacific Coast, then an abundance of moisture would be pulled
up into our region. Ensembles currently show around 200% of normal
PWATs for the end of next week and heading into next weekend. The
GEFS and EPS tend to favor this solution. The Canadian Ensemble
has a subtropical ridge building across the Baja keeping the
remnants of this system well south of our area. Outlying members
of the GEFS and EPS bring the circulation associated with the
tropical system itself into our region, resulting in really high
rainfall amounts. While it is looking more likely that our region
will see an increase in moisture by the end of next week, the
question though is how much and will there be enough forcing to
produce showers and storms to capitalize on the increase in
moisture. Impactful rainfall is possible, however with all the
uncertainty forecast confidence is low at this time. With all the
forecast uncertainty there is a large range of possible
temperatures for the end of next week, however it does look like
there will be a cooling trend. The question is how cool will
temperatures get. Stay tuned for future forecast updates.

&&

.AVIATION...Updated at 1744Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation concerns this TAF period. Current S`rly winds
will slowly go SSW`rly early this afternoon, then fully settle out
of the W by early evening. During this time gusts can be expected
between 15-20kts, but will relax by sunset, through the overnight
hours where winds will struggle to go E`rly until near sunrise.
Skies will remain mostly clear with FEW cumulus clouds with bases
aoa 9 kft expected tomorrow afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH:
Winds at KIPL will predominantly favor the W. At KBLH, SW to W
winds will continue. Gusty winds will develop this afternoon with
gusts climbing upwards of 25-30kts at both terminals. At KIPL,
gusts may climb up to around 35 kts at times this evening evening,
this can lead to restrictions in visibility from blowing dust.
Gusty conditions will continue into the overnight hours at KIPL
but will start to taper off around 09Z. Gusty conditions at KBLH
will start to taper off late this evening ~06Z. Mostly clear skies
will prevail through the TAF period.

&&

.FIRE WEATHER...
Temperatures will start to cool out west today, but remain above
normal across the central and eastern districts, with some south-
central AZ lower desert locations seeing tripple digits again today.
Further cooling is expected this weekend region wide, thanks to a
dry cold front, with temperatures falling below normal. This cold
front will bring breezy to locally windy conditions to the region.
Gusts of 20-30 mph are expected across south-central and eastern
AZ this afternoon and evening. Gusts in excess of 40 mph are
possible across western Imperial County, otherwise gusts of 25-35
mph are expected across SE CA and SW AZ. The gusty winds will
continue through early Saturday morning across SE CA and SW AZ.
Gusty winds (20-25 mph) are expected Saturday afternoon and early
evening across the eastern AZ higher terrain. MinRHs will be in
the 15-25% range through the middle of next week, with overnight
recoveries in the 30-60% range. Gradually warming temperatures
and dry conditions are expected for the first half of next week.
There is increasing chances for wetting rainfall by the end of
next week, however, forecast confidence is low at this time. With
the increasing rain chances MinRHs currently look to increase to
30-40% for the end of next week.

&&

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

     Wind Advisory from 3 PM this afternoon to midnight PDT tonight
     for CAZ566.

&&

$$

SHORT TERM...Berislavich
LONG TERM...Berislavich
AVIATION...Ryan
FIRE WEATHER...Berislavich