030
FXUS65 KTWC 172052
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
152 PM MST Mon Aug 17 2026

.SYNOPSIS...

Hot conditions this week with variable chances for thunderstorms
from day to day. An Extreme Heat Warning is in effect today
through Friday for portions of the area. Strong gusty winds are
possible with any thunderstorm today, especially near the Gila
River and San Simon valleys. Isolated thunderstorms expected on
Tuesday, an uptick in thunderstorm coverage is anticipated the
second half of the week and into next weekend.

&&

.DISCUSSION...

Thunderstorms were developing over areas of high terrain areas
early this afternoon with initial development over the White
and Chiricahua mountains. Available moisture is on the lower
side today with surface dew points mainly 50-55 degrees and
precipitable water 1-1.25 inches across the area. Even with the
lackluster moisture profile, an easterly wave located over south
central New Mexico will be enough to drive today`s scattered
thunderstorm development, with the dry air present posing a
strong to severe wind gust threat. High resolution models
continue to show an isolated risk of 45-50 mph wind gusts,
especially with thunderstorms that move off the White Mountains
late this afternoon. The 12Z HREF painted a very slight chance
of a severe wind gust through the Gila River valley from around
Bylas through Safford, and a 30-50 percent chance of a 50+ mph
wind gust. If outflows can become organized and somewhat
long-lived, then isolated strong wind gusts will be possible
much further south. Otherwise any thunderstorm that forms today
and moves off the higher terrain will pose a strong wind gust
threat. Thunderstorms should mainly take a southwesterly
trajectory today, however any cells that dive south off the
White Mountains may produce a blowing dust threat into the I-10
corridor east of Willcox.

On Tuesday, thunderstorm coverage should decrease a bit as the
easterly wave will be to the south and mostly through the area,
and the upper level ridge center will have made its way west
into the desert southwest. Just isolated activity is forecast in
the afternoon and evening. A gulf surge of moisture late Tuesday
into Wednesday however will likely bring deeper moisture into
the area. This will coincide with the upper high moving north
over the Four Corners to bring a more active monsoon pattern to
southeastern Arizona for the second half of the week.

Temperatures remain hot this week with highs 5 to near 10
degrees above normal. These above normal highs along with warm
overnight lows will produce areas of Major HeatRisk, with the
Extreme Heat Warning in effect through Friday.

&&

.AVIATION...Valid through 19/00Z.

SCT-BKN ceilings 8-12k ft with increasing cumulus development
and scattered -SHRA/-TSRA through 18/03Z. Gusty and erratic winds possible
near TSRA with gusts to 40-45 kts, especially in southern Graham
and northern Cochise counties including KSAD. Winds outside of
thunderstorms mainly light and terrain driven. Isolated
thunderstorms likely Tuesday afternoon and early evening.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...

Hot conditions return this week with temperatures
becoming 5 to 7 degrees above normal across Southeast Arizona.
An Extreme Heat Warning is in effect today through Friday for
portions of the area. Scattered thunderstorms this afternoon,
then isolated coverage on Tuesday. Daily chances of isolated to
scattered thunderstorms expected through the remainder of the
week. Winds mainly light and terrain driven but thunderstorms,
especially near the Gila and San Simon valleys today, may bring
45-50 mph wind gusts. Minimum relative humidities 15-25 percent
in lower elevation areas this week with 25-35 percent in higher
terrain.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM MST Friday for AZZ501-502-
504>506-509.

&&

$$

DISCUSSION...Edwards
AVIATION...Edwards
FIRE WEATHER...Edwards

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