902
FXUS65 KTWC 172100
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
200 PM MST Thu Jul 17 2025

.SYNOPSIS...Low-grade monsoon pattern through the weekend with
high temperatures around normal.

&&

.KEY MESSAGES...
- Very slight chance for isolated showers and storms today mainly
  south and east of Tucson.

- Near normal temperatures today with highs in the upper 90s.
  Temperatures will gradually increase over the next 7 to 10
  days.

- Low-grade monsoon pattern returns this tomorrow into the weekend.

&&

.DISCUSSION... Partly cloudy skies this afternoon with lots of
cumulus clouds forming. The passing upper level low will draw
moisture out of our area pushing it into northern Arizona keeping
PWATs between 0.9 to 1.2 inches this afternoon here in southern
Arizona. Although the 18Z upper air sounding launched at Tucson
observed 1.46 inches of PWATs, throughout nearly the entire
atmosphere winds are from the south indicating that this moisture
will move northward. Today, very slight chance (15 to 30 percent)
for isolated showers and thunderstorms. As of writing this
discussion, some cumulus are gaining height and light showers are
developing. High temperatures this afternoon will be around 95 to
100 degrees, 4 to 9 degrees warmer than yesterday.

Tomorrow: Moisture returns, raising PWATs to 1.1 to 1.3 inches
areas south and east of Tucson. Tucson northwestward PWATs will
be around 0.9 to 1.1 inches. The chance for showers and
thunderstorms (50 to 60 percent) is focused to areas south and
east of Tucson mainly along the higher terrain of Cochise, Graham
and Greenlee counties. Local probability matched means for 24 hr
precipitation show a bullseye along the Chiricahuas tomorrow and
flood indication products are also highlighting the Chiricahuas,
thus there is a Slight Risk for excessive rainfall noted by the
Weather Prediction Center. Otherwise, Tucson eastward has a
marginal risk for excessive rainfall. Temperatures increase
tomorrow to 97 to 103 degrees with widespread Minor HeatRisk and
localized pockets of Moderate HeatRisk mostly contained to the
Gila River Valley.

The Weekend: As more substantial moisture continues to move back
into the area the chances for showers and thunderstorms increases.
Both Saturday and Sunday, the best chance for storms and showers
will be Tucson eastward. The upper level low continues to move
northward out of the area over the weekend, replaced by
intensifying, broad high pressure centered over southern
Louisiana. This high pressure will lead to winds from the south to
southwest in our area and gently rising temperatures. Over the
weekend, high temperatures will be around 97 to 104 degrees with
widespread Minor HeatRisk and localized Moderate HeatRisk mostly
contained to the Gila River Valley with pockets in eastern and
central Pima county.

Next Week: The aforementioned high pressure will continue to
intensify raising temperatures to 98-106 by the middle of next
week. No particular day sticks out to be a up day for
thunderstorms though moisture will stick around next week,
leading to daily chances.

&&

.AVIATION... Valid 19/00Z.
SCT to BKN cloud cover across most of southern Arizona AOA 6 to
10k ft AGL. Clouds will continue to increase throughout the
afternoon into the early evening. By 18/02Z, low level clouds will
dissipate and be replaced by FEW to SCT mid level clouds AOA 10
to 15k ft AGL. These mid level clouds will stick around for the
rest of the forecast period. SFC winds will be light at around 5
to 10 kts from the west each afternoon with gusts to 20 kts.
Overnight, winds will be light and variable generally less than 10
kts. There are a few showers popping up near KFHU and KALK and
along higher terrain in Santa Cruz and Cochise counties. Slight
chance for isolated showers and storms across the area today. With
stronger storms expect outflow winds around 25 to 35 kts with
locally moderate rainfall. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...Temperatures today cooler than normal than near
normal this weekend into early next week. Low grade monsoon
pattern for much of the next 7 days with day-to-day variability in
thunderstorm coverage. Afternoon winds will remain westerly from
10-15 mph, with occasional gusts at or above 25 mph. Afternoon RH
values in the low lying areas will be 20-30% through Friday
decreasing to 17-25% over the weekend. In the higher terrain, RH
will be around 30 to 50%.

&&

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Malarkey

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