Rio Verde Arizona Weather Forecast Discussion

701
FXUS65 KPSR 102229
AFDPSR
Area Forecast Discussion
National Weather Service Phoenix AZ
329 PM 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 Sunday.
- Multiple rounds of showers with occasional embedded
  thunderstorms will affect much of the area today through at
  least Sunday morning with the heaviest rainfall likely over
  higher terrain areas to the north and east 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 are expected
  across primarily southeastern Arizona for Monday, but still with
  slight chances in south-central AZ.
- Near to slightly above 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 SUNDAY/... After the first day of this
multi-day rainfall event, upwards of 0.5- 1.5" of rain has
already fallen across parts of south-central AZ, including Phoenix
and the foothills just to the north, while southwest AZ was
mostly missed and southeast CA had a few hundredths. Highest 24-hr
rainfall totals, through this morning, were northwest of Payson
with upwards of 2.0-2.5". Rain continues to fall across the
northern AZ high terrain and some light to moderate rain bands are
seen moving into parts of southwest AZ and southeast CA.
Satellite analysis shows a large cloud shield extending from TC
Priscilla, near the middle of Baja California, all the way through
the Colorado Rockies; being pulled between the subtropical high
over west TX and a deep Pacific low near OR. This record-level
tropical moisture - for this time of year - will continue to
stream up through the Desert Southwest through Saturday. Models
continue to show the remnant vorticity and forcing with Priscilla
moving through the region this evening and through Saturday
morning, from Yuma up through the central portions of AZ.
Scattered showers and isolated thunderstorms are expected to
continue through this afternoon across south-central AZ out through
the Lower Colorado River. Latest HREF, has a low probability of
rainfall reaching 1.00" through this afternoon across the lower
deserts. While chances for flash flooding this afternoon are low out
in southeast CA and southwest AZ, the Flood Watch has been allowed
to continue and will expire at midnight tonight. Heading into this
evening and through Saturday morning, when the remnants of Priscilla
finally move through, a more expansive area of moderate to heavy
rain, with embedded thunder, is expected to move through the central
portions of AZ. Model soundings are showing potential for a deep
warm cloud layer (up to 10K ft) and efficient warm rain processes,
capable of producing widespread high rainfall totals. Highest
rainfall totals this evening through Saturday morning will likely
still favor the upslope foothill areas north and east of Phoenix,
including some of the same areas that have already seen 1+ inches of
rain. HREF probabilities of >0.50" during this period are 50% or
higher to the north and east of Phoenix and closer to 20% in
Phoenix. Rain rates are not expected to be too high with this round
of rain, so slower prolonged runoff leading to rises in dry or
lightly running creeks, streams, and washes is favored more than the
more rapid flash flooding risk.
Models continue to show dry mid and upper level air quickly moving
in from the west through the day Saturday, following passage of
Priscilla`s remnants, while maintaining abundant low level
moisture, at least across most of southern AZ. Drier boundary
layer air is expected to push through southeast CA and into parts
of southwest AZ through Saturday. Models even show somewhat of a
dry line developing by the end of the day Saturday, situated just
east of the Colorado River. This change, with drier air aloft and
less widespread cloud cover, will actually end up leading to
higher instability heading into Saturday afternoon for parts of
AZ, with CAPE up to 1000 J/kg. This increased instability will
transition the environment more to a convective environment with
scattered thunderstorms capable of producing higher rainfall
rates. This is when the flash flood threat will likely become more
of a threat for south-central AZ. Shear magnitudes up around
30-40 kts for sfc-6km will also support some organized stronger
thunderstorms Saturday afternoon. A supercell or two cannot be
ruled out. So, there may also be some strong gusty winds and
small hail risk with storms Saturday.
Heading into Sunday, the environment will remain favorable for
showers and storms across south-central AZ, as the boundary layer
moisture remains elevated. In some ways the environment may
become even more favorable for strong thunderstorms capable of
producing very heavy rainfall, gusty winds, and small hail.
Heading into Sunday, southern AZ will be under the right entrance
region of a strengthening upper level jet, with the phasing of the
subtropical jet and jet with the Pacific low as it progresses
inland through the Great Basin and Intermountain West. This better
upper level support along with remnants of TC Raymond sliding up
through Sonora looks like it may lead to an area of mid-level
convergence somewhere in south-central AZ. Some of the hi-res
models and global models support this, with indications of
potentially a convergent line of showers and thunderstorms
developing as early as Sunday morning. With this in consideration,
the Flood Watch for south-central AZ has been extended through
Sunday.
Temperatures still managed to get into the low to mid 90s in
portions of south-central AZ this afternoon, while areas out west
have reached the mid to upper 80s. Despite all the rainfall tonight
into tomorrow, high temperatures are again forecast to be slightly
above normal for this time of year. The warm air advection from the
south is keeping thing a little warmer than one might expect. It is
not until Sunday that temperatures dip below normal, largely due to
passage of the trough to the north, in addition to the rainfall.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
Forecast uncertainty remains quite high starting heading into the
beginning of next week 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 early
next week. 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 through at least 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 Marginal Risk Day 5 EROs east and southeast of
Phoenix. NBM PoPs are mostly between 20-40% for 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 1715Z.
South Central Arizona including KPHX,KIWA,KSDL, and KDVT:
Main aviation weather concern will be rain with isolated
thunderstorm activity late this afternoon through early Saturday
morning. In the meantime, conditions should remain dry into the
mid afternoon hours before more widespread rainfall activity
materializes after 00z and likely lasting through 13-15z Saturday
morning with visibilities at times reducing to MVFR to lower
conditions with the heavier showers. Thunderstorm coverage during
the main rainfall timeframe is a bit more uncertain so a PROB30
for thunderstorms have been added at this time. Winds will remain
mostly out of the east to northeast through early this afternoon
before shifting out of the north to northwest by the mid-
afternoon hours and persisting through the overnight hours.
However, gusty and erratic winds will be possible with any heavier
SHRA/TSRA activity. SCT-BKN clouds mid-level clouds aoa 10 kft
will persist through this afternoon before becoming BKN-OVC by
late this afternoon as shower coverage increases.
Southeast California/Southwest Arizona including KIPL and KBLH:
Areas of scattered shower activity through this evening will be
the main aviation throughout the TAF period. Expect shower
activity to increase in coverage by early this afternoon with
activity ending by the mid to late evening hours. Winds will
generally be out of an easterly component aob 10 kts through this
evening before becoming more light and variable afterwards. SCT-
BKN low to mid level clouds with bases aoa 8 kft will persist
through tonight.
&&
.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 until midnight MST tonight for AZZ530>533-535-536.
Flood Watch through Sunday evening for AZZ534-537>563.
CA...Flood Watch until midnight PDT tonight for CAZ560>570.
&&
$$
SHORT TERM...Benedict
LONG TERM...Kuhlman/Benedict
AVIATION...Lojero
FIRE WEATHER...Kuhlman

NWS PSR Office Area Forecast Discussion