Fountain Hills Arizona Weather Forecast Discussion

564
FXUS65 KPSR 132030
AFDPSR
Area Forecast Discussion
National Weather Service Phoenix AZ
130 PM MST Mon Oct 13 2025
.KEY MESSAGES...
- A Flood Watch remains in effect for south-central Arizona through
Monday evening.
- Scattered showers and thunderstorms will affect south-central
Arizona through early this evening with the heaviest rainfall
potential and greatest flood threat over the foothills and higher
terrain areas north and east of Phoenix.
- Below normal temperatures will be common throughout the week.
&&
.SHORT TERM /Today through Tuesday/...
Early afternoon Water Vapor satellite imagery shows a large upper-
level trough centered off the northern CA coastline with cyclonic
flow encompassing most of the western CONUS with an upper-level jet
streak downstream, providing large scale ascent across most of
central and southern AZ. This ascent will combine with the the
remnant energy from what was once Tropical Storm Raymond to result
in widespread shower and thunderstorm activity across much of south-
central AZ, mainly from the Phoenix area and points eastward through
this afternoon. Even though the thunderstorm activity will be quick
moving, they will be very efficient rain producers, capable of
producing rainfall in excess of one inch in less than a hour. Given
the very saturated grounds in place as a result of the heavy
rainfall over the weekend, it will not take that much rainfall to
produce flash flooding where in some areas it could just take a half
an inch in less than one hour. A Flood Watch remains in effect
across south-central AZ through early this evening. In addition to
the flood threat, there will also be a risk of strong to locally
damaging winds and marginally severe hail (1"+ diameter) given that
there is currently 40+ kts of 0-6 km bulk shear supporting the
potential for some organized storm clusters.
Heading into this evening through Tuesday, the strong southwesterly
flow aloft out ahead of the upper-level trough will eventually scour
out most of the boundary layer moisture with PWATs plummeting well
below one inch. This should essentially end all rain chances across
the region, with some lingering isolated light showers possible
across the higher terrain areas later this evening through early
Tuesday morning. With the height falls associated with the incoming
trough, strong gusty winds are likely across western Imperial County
this evening with widespread gusts of 30-40 mph and in excess of 40
mph across the southwest corner of Imperial County where a Wind
Advisory is in effect.
&&
.LONG TERM /Wednesday through Sunday/...
Deep negative height anomalies will be lifting and filling into the
Great Basin and northern Rockies during the middle of the week
bringing pronounced, dry westerly flow into the forecast area.
Forecast soundings suggest boundary layer moisture rapidly
deteriorating during the middle of the week with mixing ratios
falling to 5-6 g/kg as early as Wednesday, then never recovering
thereafter. Ensemble membership remains in excellent agreement that
energy lifting north will leave a trailing, weak trough axis over
the SW Conus with H5 heights stuck mostly in a 572-578dm range.
Ensemble numerical spread has widened slightly during this period,
however still indicates temperatures hovering 4F-8F below normal for
much of the latter half of the week. By the weekend, there is good
model agreement that some form of shortwave ridging will build into
the SW Conus with H5 heights spiking closer to 585dm and
temperatures rebounding into a near normal range.
&&
.AVIATION...Updated at 1800Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
A period of CIGs below 6 kft AGL, and the potential for MVFR or
lower visibilities and gusty, erratic winds during SHRA/TSRA this
afternoon will be the greatest concerns during the TAF period.
Expect current SE winds to veer out of the S over the next few
hours and increase to around 8-12 kts.
Models remain consistent in developing TSRA around the terminals
early/mid afternoon, then lifting activity to the north and east
late in the afternoon. Confidence in TS coverage is low to
moderate, but any storm will be capable of producing heavy
rainfall incurring brief IFR/MVFR visibilities and erratic wind
directions. During rain, confidence is moderate that a SCT deck as
low as 3-4 kft AGL could develop across the Phoenix Metro.
Outside the influence of TSRA, winds will tend to veer out of the
SSW for the evening before returning to SE during the overnight
hours.
Southeast California/Southwest Arizona including KIPL and KBLH:
Gusty winds will be the main weather issue through Tuesday morning
under clear skies. West winds will be preferred at KIPL while a S/SW
component should be more common at KBLH. Gusts 20-30kt will develop
mid/late afternoon and persist through the evening before relaxing
overnight. Lofted dust may be generated causing slantwise vsby
issues towards sunset.
&&
.FIRE WEATHER...
Wetting rain chances will continue today over eastern districts with
locally heavy amounts and flooding possible. Drier air across
western districts will begin sweeping through the entire region
Tuesday. Elevated moisture levels will keep humidity levels in
eastern districts above 50% today, then minimum values falling
closer to a 40-50% range during the middle of the week and drying
further to 25-35% by the weekend. Western districts will generally
experience afternoon humidity values 25-35% early this week, then
closer to 15-25% late in the week. Erratic and locally gusty winds
will common around showers and thunderstorms with more widespread
gusty winds affecting the region Tuesday afternoon/evening. Very
tranquil conditions will be common late in the week.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Flood Watch until 8 PM MST this evening for AZZ534-537>563.
CA...Wind Advisory until 11 AM PDT Tuesday for CAZ562.
&&
$$
SHORT TERM...Lojero
LONG TERM...18
AVIATION...Whittock/18
FIRE WEATHER...18

NWS PSR Office Area Forecast Discussion