095
FXUS65 KTWC 130900
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
200 AM MST Mon Oct 13 2025

.SYNOPSIS...Deep tropical moisture will remain over the area today
with continued widespread shower and thunderstorm chances. Flooding
will continue to be a concern, especially with any stronger storms
today. Drier conditions return for the region on Tuesday and
continue through the remainder of the week. High temperatures will
be below normal this week.

&&

.DISCUSSION...Today will be the last day of our prolonged active
weather period across southeast Arizona. Deep tropical moisture
remains over southeast Arizona with an amplifying west coast trough
and southwesterly flow aloft for our area. The combination of ascent
from the right entrance region of an upper level jet and disturbances
within the broader mid level southwest flow will continue to result
in widespread shower and thunderstorm chances today. Current KEMX
radar does have a few showers and embedded thunderstorms mainly from
Tucson north and westward continuing to move north-northeast with
just some isolated shower activity elsewhere. The early morning
hours should be fairly quiet. Thereafter, HREF/CAMs do show showers
and thunderstorms increasing in coverage by mid morning and peaking
through the midday into the mid afternoon with the best chances
moving up into Graham and Greenlee County as the afternoon
progresses. Modest instability and lapse rates should allow for a
few stronger storms capable of producing some gusty winds and small
hail. SPC has highlighted locales east of an Eloy-Three Points-
Nogales line in a marginal risk for severe thunderstorms. Meanwhile,
given the continued anomalously high moisture, we`ll continue to have
some flooding concerns, especially for locales that were previously
harder hit over the past couple of days and thus more susceptible to
quicker runoff. Additional rainfall amounts today will generally be
0.10 inches to 0.50 inches but some of the stronger storms and any
training storms would result in localized areas of 1 inch or more.
WPC continued to highlight locales from Tucson eastward in a slight
risk for excessive rainfall. Will keep the flood watch in place as
is, though the flood threat will decrease significantly by midday
for the western deserts.

Drier air will overspread the area Tuesday and remain in place for
the rest of the week. As dewpoints lower and the drier air settles
in with the trough moving through the western US, it will really
feel like autumn. Thursday will be the coolest day of the week with
highs temperatures in the 70s for all valley locations or about 6 to
12 degrees below normal. Morning lows later in the week in the low
to mid 50s from Tucson westward and in the 40s in the valley south
and east of Tucson. Temperatures will eventually moderate to near
normal levels by around Sunday and Monday.

&&

.AVIATION...Valid through 15/12Z.
Generally BKN-OVC clouds at 5K-8K ft AGL thru about 15/00Z, becoming
SCT-BKN through the remainder of the valid period. SCT-NMRS
-SHRA and ISOLD-SCT -TSRA are also expected, mainly before 14/22Z.
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 8-16 kts and gusts 20-25 kts this
afternoon. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Scattered to numerous showers and isolated to
scattered thunderstorms are expected today. Drier conditions move in
on Tuesday and continue through the weekend. Minimum RH values will
be at least 30+ percent in the valley`s through Wednesday, with
higher values in the mountains. Min RH values lower into the 20-30
percent range in the valleys Thursday into the weekend. 20-foot wind
speeds will be around 15 mph especially from Tucson southward today
with gusts to 20-25 mph. Otherwise, 20-foot winds mainly 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 weekend rain and additional
rainfall today will result in continued flow across many of the main
stem rivers/creeks across southeast Arizona. The latest river
forecasts from the CBRFC keep all of our major rivers below bankfull
stages. A Flood Warning is in effect for the Vamori Wash at Kom Vo
on the Tohono O`odham Nation with local impacts on Highway 21. A few
thunderstorms may also produce areas of flash flooding today.
Normally dry washes and low water crossings will have water flowing
through them.

&&

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

&&

$$

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