Chandler, Arizona Weather Forecast Discussion

289
FXUS65 KPSR 290517
AFDPSR
Area Forecast Discussion
National Weather Service Phoenix AZ
1017 PM MST Sun Sep 28 2025
.UPDATE...Updated 06Z Aviation Discussion.
&&
.KEY MESSAGES...
- Isolated showers and thunderstorms expected through this
  afternoon across mainly the prominent terrain features, before
  drying out by this evening.
- A dry and tranquil weather pattern expected through the
  upcoming week.
- Below normal temperatures will prevail today before gradually
  warming up to more seasonable levels by the middle of the week.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
Early afternoon water vapor satellite imagery as well as streamline
analysis show the center of the upper-level low that has caused
the very active weather during the last couple of days situated
over the northwestern quadrant of AZ. Shower and thunderstorm
activity once again is developing along the eastern flank of the
low over the AZ High Country. Farther south, across south-central
and southwest AZ, subsidence is in place and will hinder
development across much of the region, with the exception over the
higher terrain features as enough moisture and instability
remains in place to spark activity. The activity that develops
should be short-lived given the subsidence in place, thus any
sort of flooding impacts will be quite limited. Rain chances
should completely end by this evening as the upper-level low
gradually shifts eastward and drier air begins to filter in.
Under the influence of the lowered upper-level heights from the
low, temperatures will once again be below normal for today with
afternoon highs expected to top out in the upper 80s to around 90
degrees across the lower deserts.
Heading into Monday, the upper-level low will finally have exited
the Desert Southwest while weakening and becoming an open wave with
a quasi-zonal flow pattern in place. Much drier air will be in
place and thus rain chances will virtually be nil everywhere along
with mostly clear skies. Afternoon highs will warm by about 3-5
degrees with readings expected to reach the low to mid 90s across
the lower deserts.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A benign and dry weather pattern will take shape through the
middle of this week as ridging aloft begins to build over the
forecast area. 500 mb hghts will gradually increase to around
588-590 dam by the end of the week resulting in highs across the
lower deserts increasing from the mid 90s on Tuesday to the upper
90s to around 100 degrees on Thursday and Friday. Global models do
indicate a shortwave trough diving into the Intermountain West by
next weekend which may result in a slight cool down and breezier
conditions region-wide. Due to the trajectory of this system
remaining well north of the area, dry conditions are expected to
persist across the Desert Southwest.
&&
.AVIATION...Updated at 0515Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation concerns are expected during the TAF period. Winds
will mostly maintain a NW`rly component with periods of VRB. Wind
speeds will remain aob 10kts. Clear skies are expected through
most of the TAF period.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation concerns are expected during the next 24 hours. Winds
will follow light and diurnal trends, with extended periods of
variability. Clear skies are expected through most of the TAF
period.
&&
.FIRE WEATHER...
Temperatures will remain below normal today followed by a gradual
warming trend through the beginning of this week. A low pressure
system will continue to result in shower and thunderstorm
activity, mainly across northern AZ through this afternoon.
Isolated showers and thunderstorms will still be possible over the
high terrain of southwestern and south-central AZ this afternoon.
Rain chances will come to an end across the area by this evening
with dry conditions prevailing everywhere throughout the upcoming
week. MinRHs will range from 30-45% this afternoon, falling to
around 25-35% on Monday and 15-25% on Tuesday along with fair to
good overnight recoveries. Winds will generally be light and
diurnal during the next several days with some modest afternoon
upslope gusts.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
SHORT TERM...Lojero
LONG TERM...Salerno
AVIATION...Ryan
FIRE WEATHER...Salerno/Lojero

NWS PSR Office Area Forecast Discussion