Peridot, Arizona Weather Forecast Discussion

937
FXUS65 KPSR 262303
AFDPSR
Area Forecast Discussion
National Weather Service Phoenix AZ
400 PM MST Fri Sep 26 2025
.UPDATE...
Updated Aviation
&&
.KEY MESSAGES...
- Widespread shower and thunderstorm activity will continue through
this evening across much of central and eastern AZ. Some of the
thunderstorms will be capable of producing strong to locally
damaging wind gusts, large hail, and heavy rainfall leading to flash
flooding.
- Shower and thunderstorm chances will continue this weekend,
particularly on Saturday across southwest AZ and southeast CA where
a few strong storms and locally heavy rainfall may occur.
- Below normal temperatures will prevail through the weekend before
gradually warming up to near normal by the middle of next week.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
A very active late morning through early afternoon has been observed
across much of south-central AZ with widespread thunderstorm
activity erupting across much of the Phoenix metro area with large
hail in excess of 1" in diameter, heavy rainfall leading to
instances of flash flooding, and strong winds observed. This entire
weather situation unfolding is due to a potent upper-level low
situated across southern CA, imparting strong upper-level ascent in
the form of strong divergence aloft across much of central and
eastern AZ. The ascent, in combination with deep subtropical
moisture with low-level mixing ratios of 10-13 g/kg will continue to
support additional shower and thunderstorm development through the
rest of this afternoon and early this evening. The latest SPC
mesoanalysis shows MLCAPE values in excess of 1000-1500 J/KG along
with 0-6km shear values in excess of 25-35 kts. Therefore, strong to
severe thunderstorms with strong to locally damaging winds along
with severe hail (1+" in diameter) due to cold 500 mb temperatures
of around -10C will continue to remain a threat. In addition to the
severe weather potential, the potential for flash flooding will also
continue, especially if there are training thunderstorm cells,
resulting in rainfall amounts of 1-2"+ in a very short amount of
time. A Flood Watch remains in effect from the Phoenix metro area
east to southeastward through much of Pinal, eastern Maricopa and
southern Gila County through this evening.
Heading into Saturday, the upper-level low is depicted by guidance
to stall over southern CA. Therefore, additional shower and
thunderstorm activity is likely with the latest guidance depicting
the greater convective coverage across southeast CA and southwest AZ
where the better moisture and instability will be focused with CAPE
values upwards of 500-1000 J/KG. The thunderstorm activity could
produce strong gusty winds as well as locally heavy rainfall leading
to localized flash flooding. Further east, across south-central AZ,
the moisture and instability is expected to be more meager and thus
any convective activity is expected to be more isolated and focused
across the higher terrain areas to the north and east of Phoenix. A
few isolated showers and storms cannot be completely ruled out
across portions of the Phoenix metro area.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Ensembles continue to advertise the upper low lifting northeast of
the area during the day Sunday. Lingering moisture and  favorable
(albeit less robust) dynamics ahead of the low are expected to allow
for continued scattered showers and isolated afternoon
thunderstorms, though likely focused over the AZ high terrain.
By Sunday night into Monday, our region will transition more into
zonal flow to weak ridging as a deep Pacific low moves southward to
off the Pacific Northwest coast. This will help to usher in dry air
across the region ending any rain chances by Sunday night.
Temperatures will take a dive today into the weekend with the help
of the cut-off low and the rain cooled air. Forecast highs this
weekend are currently only in the upper 80s across the bulk of the
lower deserts, or 5-8 degrees below normal. Once we start to see
weak ridging back into our region early next week, highs should
creep up into the low to mid 90s by Monday or Tuesday.
&&
.AVIATION...Updated at 2300Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Multiple weather hazards associated with clusters of TSRA will
continue through early evening before a tendency for storms to exist
the area beyond mid evening. Erratic, gusty winds and briefly
reduced visibilities and lowered cigs into at least MVFR category
will be likely. Conditions should begin to improve around a 01-03Z
time frame, though cloud decks around 050-060 AGL may linger into
the overnight. Confidence is moderate that east winds will prevail
through Saturday morning, though some variability may be common
around SHRA/TSRA.
Another round of SHRA will be possible Saturday mid-morning with
cigs potentially hovering around 060. However, confidence is rather
low regarding timing and cloud heights with any of these SHRA.
Thereafter, a period of southerly cross runway winds will be
possible through much of the afternoon before attempting to veer
westerly around sunset. While another round of TSRA is possible
later Saturday afternoon, probabilities are too low to include in
this TAF package as activity may stay relegated to SW Arizona.
Southeast California/Southwest Arizona including KIPL and KBLH:
Developing SHRA/TSRA Saturday will be the primary weather issue as
cigs in a 080-100 AGL develops over the region. Winds should become
more variable in direction overnight with some SHRA likely
developing around KBLH. By mid/late afternoon, scattered TSRA should
begin to erupt over SE California/SW Arizona though exact coverage
and timing are more uncertain. Gusty winds and lowered visibilities
would be common with any TSRA directly impacting an aerodrome.
&&
.FIRE WEATHER...
Expect fairly widespread showers and thunderstorms across the
eastern districts today with strong outflow winds, hail, and heavy
rainfall likely in some areas. MinRHs will range from 25-45% through
the weekend. Outside of thunderstorm impacts, winds will be breezy
at times with occasional gusts around 20-25 mph today. The slow-
moving low pressure system impacting the region should continue to
bring chances for wetting rains areawide on Saturday before drying
conditions begin Sunday into early next week. Below normal
temperatures will persist through at least Monday.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Flood Watch until 11 PM MST this evening for AZZ537-540>553-
     555>558-560>563.
CA...None.
&&
$$
SHORT TERM...Lojero
LONG TERM...Whittock
AVIATION...18
FIRE WEATHER...Whittock/Smith

NWS PSR Office Area Forecast Discussion