534
FXUS65 KPSR 100815
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
115 AM MST Fri Oct 10 2025

.KEY MESSAGES...

- A Flood Watch remains in effect for southeast CA and southwest
  AZ through this evening and for all of south-central AZ from
  this afternoon through Saturday.

- Multiple rounds of showers with occasional embedded
  thunderstorms will affect much of the area today into Saturday
  with the heaviest rainfall likely over higher terrain areas to
  the north and northeast of Phoenix. Some locations could
  receive rainfall totals exceeding 2.00" which will promote
  excessive runoff into area watersheds, leading to flooding of
  low lying areas.

- Additional chances for showers and thunderstorms with some
  storms possibly being strong are expected across south-central
  and eastern Arizona for Sunday through early next week.

- Near normal temperatures today and Saturday will cool to below
  normal by Sunday. Expect highs across the lower deserts to lower
  into the 80s by Sunday and persist through all of next week.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...
One day of this weather event is now in the books and the focus
for shower and thunderstorm activity has been more across south-
central Arizona. Some locations across Maricopa County have
already seen over 0.5" with the highest totals of near an inch in
the Camp Creek area. The lack of instability on Thursday
definitely hindered storm development and the higher rainfall
rates. PWATs have increased to between 1.5-1.8" with additional
moisture advection likely pushing PWATs to near 2" across at
least southwest Arizona later today.

Current radar imagery shows a band of fairly persistent showers
and embedded thunderstorms stretching from western Pima County
through Phoenix to well into the high country. This band is likely
to continue for much of the early morning hours while likely
shifting slowly to the northwest. An additional 0.5" or so will be
likely through sunrise within portions of the band, while other
isolated showers across the rest of the area will mostly bring
less than 0.1".

For this afternoon and into tonight, the main area of focus for
shower and thunderstorm activity should mostly be across southwest
and south-central Arizona with rainfall amounts averaging between
0.25-0.75". Localized higher amounts of over 1" are also likely
to occur with the most favored areas being across northeast La
Paz County and northern Maricopa County. Rainfall rates are not
likely to exceed 1" per hour and most heavier showers or
thunderstorms will be moving quickly to the north at around 30
mph. Despite the lack of heavy rainfall rates, we are expecting
training to occur with some areas potentially seeing 1-2" of
rainfall over a period of 6-12 hours. This will likely be enough
to bring some low-land flooding and flooding within area washes
and small streams.

Hi-res CAMs are in fairly good agreement showing the main rainfall
band gradually shifting to the east Saturday morning as mid-level
winds shift more out of the southwest. This should put the best
rain area more into eastern Maricopa, Pinal, and Gila Counties by
around sunrise Saturday, likely lasting through Saturday
afternoon. Drier air aloft will also begin to work into the area
from the west on Saturday which may eventually allow for a few
discrete stronger thunderstorms to form by the afternoon. These
storms will mainly be capable of producing heavy rainfall with
strong gusty winds only a minor threat. The area of focus for
heavy rainfall and flooding potential should shift to the higher
terrain northeast and east of Phoenix on Saturday, but with still
a chance of a few heavy rainfall producing thunderstorms within
the Phoenix area and Pinal County through Saturday afternoon.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Forecast uncertainty remains quite high starting Sunday with any
additional moisture and impacts indirectly associated with TC
Raymond now likely to mostly stay to the south over far southeast
Arizona into Mexico. However, we will still see plenty of upper
level forcing associated with a deepening Pacific trough diving
southward through California later Sunday through Monday. We are
still likely to see fairly good moisture hanging out from around
Phoenix through eastern Arizona during this time with PWATs
anywhere from 0.8-1.1". Plenty of low and mid-level moisture will
be in place for additional shower and thunderstorm chances for
Sunday and Monday, but the chances for heavy rainfall will be more
localized and likely reliant on any potential thunderstorms. WPC
has highlighted a Slight Risk on their Day 4 and Day 5 EROs east
and southeast of Phoenix with a Marginal Risk extending westward
through most of the Phoenix metro. NBM PoPs are mostly between
20-40% for Sunday and Monday across the south-central Arizona
lower deserts to 40-60% across the higher terrain of eastern
Arizona.

Further decreasing of moisture is likely to begin by Tuesday with
rain chances mostly lingering across the eastern Arizona higher
terrain. Drier air is likely to continue to move into the region
from the southwest as the main Pacific low slowly moves southward
along the California coast. The eventual progression of this
Pacific low is still fairly uncertain with guidance suggesting it
may gradually move over at least northwest portions of our region
during the middle of next week with additional slight chances for
rain focused over eastern Arizona. This low may hang out close
enough for additional slight chances for rain even into late next
week, but it should also be in a weakening phase.

Temperatures will definitely be influenced by the Pacific low next
week with highs likely dropping from just shy of normal through
the weekend to around 5-8 degrees below normal for much of next
week. The latest NBM forecast highs show readings dipping into
the low to mid 80s across the lower deserts for much of next week.

&&

.AVIATION...Updated at 0644Z.
South Central Arizona including KPHX,KIWA,KSDL, and KDVT:
Main aviation concern will be thunderstorms and rain. Current band
of thunderstorms looks to pass by 09-10Z and gives the Metro a
break for the overnight period. However, the development of short
lived cells that could bring VCSH/-RA can be possible during this
time, but confidence is low. Starting Friday morning the metro
will see widespread activity, however during this time there is
uncertainty if TS will develop over the terminals, so the TAF
will need to be amended as needed. Wind directions will mostly
favor E`rly to NE`rly with wind speeds being between 05-10kts with
periods of gusty conditions. FEW-BKN clouds will develop to SCT-
BKN by tomorrow evening with bases aob 100kft.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns throughout the TAF period, outside some
SHRA/VCSH. A band of showers look to go over the terminals
starting tomorrow afternoon. Winds will favor the NW shifting out
of the SE tomorrow afternoon. Speeds are expected to remain aob
10kts. SCT-BKN low to mid level clouds with bases near 100kft
will persist.

&&

.FIRE WEATHER...
Wetting rainfall will continue today over much of the area with
more of a focus across southern and central Arizona. Rain may be
moderate to heavy at times leading to localized flooding,
especially over higher terrain areas. Elevated moisture levels
will keep MinRHs above of 30-40% through Saturday with drier air
eventually working into the western districts by Sunday. East
northeasterly winds will persist across the eastern districts with
northerly winds over the western districts today before shifting
to the southwest on Saturday. Occasional wind gusts between 20-30
mph will be possible during the period. Additional chances for
showers and thunderstorms will be possible Sunday through Tuesday
across the eastern districts.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Flood Watch through Friday evening for AZZ530>533-535-536.

     Flood Watch from Friday afternoon through Saturday evening for
     AZZ534-537>563.

CA...Flood Watch through Friday evening for CAZ560>570.

&&

$$

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