018
FXUS65 KPSR 041042
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
330 AM MST Sun Oct 4 2026

.KEY MESSAGES...

- Temperatures will remain largely unchanged, with a slight
  increase across southeast California and southwest Arizona
  during the middle of the week.

- Periods of breezy to locally windy conditions can be expected
  across south-central and southwestern Arizona through Monday
  with gusts reaching 20-35 mph.

- Dry weather with zero rain chances will persist through the
  upcoming week.

&&

.SHORT TERM /TODAY THROUGH MONDAY/...
The overall synoptic pattern remains largely unchanged with high
pressure stretching across the Desert Southwest and centered over
southern Utah/northern Arizona and a trough centered over the
Midwest. The high is expected to peak this morning around 591-593
dm before gradually weakening into tomorrow. With the high
peaking this morning the increase pressure gradient, between this
high and the low to the east, is also expected to peak this
morning. Easterly/northeasterly winds of 20-35 mph with some
occasional gusts upwards of 40 mph are expected to peak this
morning then gradually decrease through the afternoon and early
evening. The highest gusts are expected across the higher terrain
to the east of Phoenix and across northern and western Yuma
County. As mentioned previously, the pressure gradient will start
to relax tomorrow as the high weakens and the low migrates
eastward. However, there will still be some wind gusts of 20-30
mph across the region during the morning and afternoon hours. Peak
gusts will be across the higher terrain to the east of Phoenix
and southwest AZ.

Temperatures will be fairly similar to yesterday with afternoon
highs above normal. High temperatures are forecasted to be in the
mid to upper 90s across south-central AZ, the upper 90s to low 100s
across SE CA and SW AZ, and in the 80s across the higher terrain
areas. Morning lows will continue to be well above normal (7-12
degrees). Morning lows will be in the 70s to low 80s across the
lower deserts and in the 60s across the higher terrain. As a result
there will be widespread Minor Heat Risk with areas of Moderate Heat
Risk, mainly across western Imperial County, Yuma County, and the
Lower Colorado River Valley.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
On Tuesday, the high pressure system will shift westward as a quasi-
omega block pattern sets. There will be troughing across the eastern
two-thirds of CONUS, a low pressure system in the Pacific, and the
aforementioned high centered over the west Pacific
Ocean/California coast. Forecast confidence is good that this
pattern will hold through the majority of the week. This will
result in temperatures remaining fairly steady across south-
central AZ with afternoon highs in the 95-100 degree range across
the lower deserts and ranging from the mid 80s to lower 90s across
the higher terrain areas. The high across the coast of California
looks to strengthen slightly resulting in a slight increase in
temperatures for SE CA and SW AZ. As a result afternoon highs will
be around 100-106 degrees across the lower deserts in SE CA and
SW AZ on Wednesday and Thursday. With high pressure in place dry
conditions with no chances for rain will continue.

The high pressure system is then expected to start to weaken by the
end of the workweek with a trough moving into western CONUS this
upcoming weekend. However, forecast confidence starts to decrease
this upcoming weekend as the ensemble members differ on the timing
of the high weakening and moving out of the region and the trough
moving in. The ensembles also disagree on the strength of the trough
for this upcoming weekend. Either way temperatures are expected to
gradually decrease back to near to slightly above normal by this
upcoming weekend. Additionally, dry conditions look to continue
through at least Saturday, but this could change depending on when
the aforementioned low moves into the region. Right now better
chances for rain look to arrive by the beginning of next week, with
the best chances across the higher terrain in eastern AZ, but since
we`re still a week out a lot could change. Stay tuned for updates.

&&

.AVIATION...Updated at 0510Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Gusty east winds will be the main weather concern through Sunday
night under clear skies. Confidence is very good that east winds
will maintain modest speeds overnight, falling just short of LLWS
criteria. Wind speeds will rapidly increase mid/late Sunday morning
with a period of 25-35kt gusts possible before gradually weakening
through the afternoon. Forecast uncertainty grows Sunday evening as
gusts may be maintained longer than is typical before weakening
overnight. Depending on wind gust strength Sunday afternoon and
recent land use, lofted dust affecting slantwise visibility may be
an issue Sunday late afternoon/evening around sunset.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather concerns will exist through Sunday night under
clear skies. Confidence is excellent that an E/NE wind component
will be favored, though a light north drift or variable direction
will be possible around sunrise. A few gusts near 20kt may affect
KBLH in the afternoon.

&&

.FIRE WEATHER...
Dry conditions with above normal temperatures will continue
through the upcoming week. A slight increase in temperatures, into
the 100-106 degree range is anticipated across the western
districts during the middle of the workweek. MinRHs will mostly
range from 15-25% over the western districts to 25-35% for the
eastern districts with fair to good overnight recovery area-wide.
A persistent breezy easterly gradient wind will continue through
Monday. Expect winds to remain elevated around 8-12 mph with early
morning and afternoon gusts up to 20-30 mph, with locally higher
gusts of 35-40 mph possible, mainly across SW AZ and the eastern
district. On Tuesday, winds will return to their more typical
diurnal tendencies with only minor afternoon upslope gustiness in
the afternoons.


&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

SHORT TERM...Berislavich
LONG TERM...Berislavich
AVIATION...18
FIRE WEATHER...Berislavich