904
FXUS65 KTWC 101531
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
831 AM MST Sat Oct 10 2026

.SYNOPSIS...

Temperatures will lower to near normal today and then below
normal through most of next week. Slight chances for
precipitation this morning. Thereafter, expect a longer
duration period of precipitation chances for our area today
through Tuesday. Gusty winds are also expected, especially
Sunday and Monday.

&&

.UPDATE...

Light showers are moving across portions of central Cochise
county into Graham county this morning with some embedded
thunderstorms. This early morning development is likely due to
a pocket of elevated moisture around 700 mb combined with a
small disturbance at 500 mb. These showers and thunderstorms
will continue throughout the day becoming widespread by the
afternoon hours. Thunderstorms have the potential to become
severe with the main threats remaining damaging wind gusts(4060
mph), small hail, and localized heavy downpours. The non-zero
threat for tornadoes in far western Pima county remains due to
the combination of modest instability, low-level helicity and
strong deep layer shear. Greatest chance for severe
thunderstorms will start this afternoon and potentially go into
the overnight hours.

&&

.DISCUSSION...

Overnight, showers and perhaps a rumble of thunder continue as a
weak disturbance interacts with increasing moisture and elevated
instability. Rainfall amounts overnight will remain light, but
some localized areas could pick up a quick 0.25" or so through
the morning. Over the past hour, lightning has picked up just
south of the border, with these isolated storms moving into
southern AZ.

Tropical Storm Rachel continues to track northeastward toward
Baja, bringing tropical moisture and dynamic forcing into
Southern Arizona. While gradient winds have lessened slightly in
recent guidance, strong, gusty winds are still expected. A Wind
Advisory remains in place from Tucson westward for Sunday.
Expect south to southwest winds of 2535 mph with gusts of
4555+ mph, with localized higher gusts possible near any
convective activity. For the Wind Adv east for eastern Pima,
portions of Santa Cruz, and SE Pinal COs, S/SW sustained winds
of 25-35 mph, with gusts around 45 mph likely. Once again,
localized wind gusts to 60 mph will be possible due to a threat
for isolated strong to severe thunderstorms.

While there could be a brief lull from mid morning into early
afternoon, increasing moisture transported north into AZ from
Rachel`s interaction with an upper level trof will increase
coverage of showers and storms.

Severe potential exists this afternoon/evening and possibly into
Sunday morning. The main threats remain damaging wind gusts
(4060 mph), small hail, and localized heavy downpours. Modest
instability paired with favorable 01km/03km helicity and
moderate to strong deep layer shear maintains a non-zero
tornado threat (2% risk per SPC) primarily across western Pima
County (including Ajo, Lukeville, and Why) from Saturday
afternoon through early Sunday morning. Looking over some of the
CAMs, the greatest severe threat would be later in the
afternoon, the evening, and possibly overnight. There are
solutions that bring one or two broken lines of convection
through the western third of the CWA in the E/SE quadrant of
Rachel as she makes landfall in northern Baja. Given the shear,
supercells are possible, even as far east as of Tucson. However,
any tornado threat should remain confined to far western Pima
and perhaps into central Pima County.

As for the rain an possible flash flood risk, scattered to
numerous showers and storms will pick up this afternoon into
Sunday. Storm total rainfall averages 0.25" to 0.75" west of
Tucson and 0.10" to 0.25" east of Tucson, with 1 to 2+ inches
possible in mountain locations or under localized training
cells. While widespread flooding is not expected, localized
quick bursts of a half-inch to an inch could yield an isolated
flash flood threat. Southerly flow ahead of the longwave trough
keeps lingering rain/thunderstorm chances (2050%) going Monday
and Tuesday. Drier air returns by Wednesday, clearing out shower
activity across the area. Expect an extended period of below-
normal temperatures starting Sunday and persisting through mid-
week.

While its fairly early, there is an increasing signal for
another east wind event late week. Just something to keep on
your radar as winds could be fairly strong in the usual easterly
wind even prone areas.

&&

.AVIATION /14Z SATURDAY THROUGH 14Z SUNDAY/...

SCT-BKN clouds 9-12k ft AGL this morning with VCSH and
possible VCTS. Renewed development of SCT SHRA/TSRA is expected
for much of the area aft 10/19Z through end of valid pd. Brief
MVFR possible under heavier showers/storms. Gusty winds to 45
kts possible around convection later this afternoon. SFC winds
S/SW around 8-15 kts with gusts to 25kts this afternoon.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...

The combination of a low pressure system and the remnants of
Tropical Storm Rachel will bring breezy to windy southwest winds
Sunday and Monday with wind gusts of 35 to 45+ mph on Sunday for
much of southeast Arizona. Highest wind potential will be from
central Pima County west. Breezy winds continue on Monday as well
with winds 15 to 25 mph with gusts around 35 mph. This weather
system will bring a 30-70 percent chance for rain Saturday and
Sunday, lowering to 20 to 50 percent Monday and Tuesday. Minimum
relative humidity values will remain 15-30 percent in lower
elevations and above 40 percent in high elevation terrain through
Saturday.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 2 AM to 11 PM MST Sunday for AZZ501-502-505.
Wind Advisory from 7 AM to 11 PM MST Sunday for AZZ503-504-506-
514-515.

&&

$$

Update...Malarkey
Previous...Michael

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