881
FXUS65 KTWC 121713
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1013 AM MST Sun Oct 12 2025

.SYNOPSIS...Deep tropical moisture will remain over the area into
Monday, along with widespread shower and thunderstorm chances. This
prolonged period of rain along with scattered stronger thunderstorms
will result in the continued potential for flooding and a Flood
Watch remains in effect through Monday afternoon. Rain chances
diminish on Tuesday and dry conditions are expected areawide the
second half of the week. High temperatures will be below normal this
week.

&&

.DISCUSSION...Overall, not much change in the forecast versus 24
hours ago. A trough continues to develop and will dig southward
along the west coast, with a ridge of high pressure extending from
eastern Texas northeast into the Great Lakes region. Moisture from
remnant Raymond continues to push north/northeast through Sonora,
Mexico.

Deep tropical moisture will continue across the forecast area
through Monday, with values of 200-300 percent of normal and daily
record PWAT`s. This moisture will interact with the trough as it
continues to dig south along the west coast, resulting in favorable
dynamics and upper level support for widespread shower activity and
embedded thunderstorms. A Flood Watch remains in effect for most of
southeast Arizona through 5 pm MST Monday. Refer to the PHXFFATWC
product for more information on the Flood Watch and to the HYDROLOGY
section below for hydro concerns.

The CAMs point to widespread showers and embedded thunderstorms
across eastern Santa Cruz, Cochise and southern Graham counties as
the thicker cloud shield from Raymond remnants pushes northeast
across those areas today. For locations west/northwest of this area,
scattered to numerous showers and thunderstorms are expected to
develop from the late morning through the evening hours tonight.
CAM`s show the current line of showers/thunderstorms stretching from
southeast of Yuma, to Gila Bend through Phoenix will continue to
shift slowly southeast and strengthen across our forecast area this
afternoon and tonight. The latest satellite/radar trends support
this scenario, especially given the dynamics/upper level support
that will come into play later today with the approaching trough.
Additional showers and thunderstorms will develop between these two
aforementioned areas with less cloud cover and more than sufficient
instability.

Thunderstorms today, especially west of the Raymond cloud shield,
will have the potential to produce high rainfall rates and have a
higher flash flood potential than those underneath the cloud shield.
WPC has the entire western half of our forecast area highlighted in
a Slight Risk of excessive rainfall today, as well as Santa Cruz and
the southern half of Cochise counties. SPC also has the western two-
thirds of the forecast area (generally west of a Safford, to Benson
to Sierra Vista line) in a Marginal Risk for severe weather, with
hail and gusty winds being the main threats. All things point to an
active day today, with a repeat tomorrow for central and eastern
portions of the forecast area.

Drier conditions then start to return to the forecast area Tuesday
as the trough axis begins to shift east and drier air moves in from
the west/southwest. There will still be a slight chance of showers
and thunderstorms across Graham and Greenlee counties Tuesday, with
dry conditions areawide on Wednesday through next weekend. High
temperatures will be 4-8 degrees below normal through the end of the
work week as the trough axis shifts east across the western United
States.

&&

.AVIATION...Valid through 14/00Z.
Generally BKN-OVC clouds at 5K-8K ft AGL thru the valid period along
with SCT-NMRS -SHRA and ISOLD-SCT -TSRA. Gusts up to 30 kts and GR
with the stronger TSRA. MVFR conditions possible near -SHRA/-TSRA
due to lower VSBYS and CIGS. Outside of -TSRA, SFC wind SELY/SLY at
8-13 kts and occasional gusts to 20-25 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Scattered to numerous showers and isolated to
scattered thunderstorms are expected through Monday. Drier
conditions start to move in on Tuesday with dry conditions area wide
Wednesday into next weekend. Minimum RH values will be at least 35+
percent in the valley`s through Tuesday, with higher values in the
mountains. Min RH values lower into the 18-25 percent range in the
valleys the second half of the week. 20-foot sustained wind speeds
will be 15 mph or less this week, with occasional gusts to 20-25
mph. High temperatures will be below normal into this weekend.

&&

.HYDROLOGY...Runoff from the expected rainfall through Monday
will bring rises to the main stem rivers/creeks across southeast
Arizona, with some of them potentially rising 3 to 8 feet. The main
areas of concern will be the San Pedro River, Nogales Wash and the
Santa Cruz River. The latest river forecasts from the CBRFC keep all
of our major rivers below bankfull stages. A few thunderstorms may
also produce areas of flash flooding today and Monday. Normally dry
washes and low water crossings will have water flowing through them.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Monday afternoon for AZZ501>509-511>515.

&&

$$

Zell

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