853
FXUS65 KTWC 292027
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
127 PM MST Fri Aug 29 2025

.SYNOPSIS...

Isolated to scattered showers and thunderstorms through the
weekend with higher chances generally south and east of Tucson.
Increasing moisture by early next week should bring an increase
in thunderstorm chances to southeastern Arizona, with day to day
variability. High temperatures will be near normal through the
weekend, lowering to several degrees below normal by the middle of
next week.

&&

.DISCUSSION...

The upper level pattern has the upper high currently centered over
southeast New Mexico/southwest Texas.  The upper high will shift
northwest into the northern Great Basin by Sunday with the ridge
amplifying across the Intermountain West into southern Canada. The
ridge continues to amplify and shift slowly west/northwest through
much of next week.

Thunderstorm chances today will mainly be confined to south and
southeast of Tucson, with thunderstorm chances east of Tucson on
Saturday.  By Sunday, thunderstorm chances increase across the
forecast area, mainly from the Tucson metro eastward.  High
temperatures warm from near normal today to a couple of degrees
above normal over the weekend as the high shifts northwest across
the state into the Great Basin.

As we work through next week, thunderstorm chances increase across
the entire forecast area, especially mid to late week.  Easterly
flow will keep the moisture tap open across southeast Arizona during
this time frame. There will also be the potential (low confidence)
for some tropical influences late next week, either through moisture
being pushed northward through Mexico, or up the Gulf of California.
Either way, with the deep moisture in place and expected cloud
cover, high temperatures will lower to several degrees below normal
mid to late next week.

The main threat with any of the stronger thunderstorms that develop
today into next week will be heavy rainfall and a localized flash
flooding threat, although an isolated severe storm or two cannot be
ruled out.

&&

.AVIATION...Valid through 31/00Z.

Cloud bases at 8k-11k ft AGL. ISOL-SCT -SHRA/-TSRA thru 30/05Z, then
diminishing thru 30/18Z, and redeveloping again aft 30/18Z. NWLY SFC
wind at 8-12 kts thru 30/03Z across most of southeast Arizona, with
12-16 kts and gusts to around 25 kts in portions of Cochise and
Graham counties, especially in the vicinity of KSAD. Between 30/03Z
and 30/18Z, SFC wind variable in direction and less than 10 kts. Aft
30/18Z, WLY/NWLY SFC wind at 8-12 kts. Gusty and erratic winds
possible with any thunderstorms. Aviation discussion not updated for
TAF Amendments.

&&

.FIRE WEATHER...

Expect daily chances for rain showers and thunderstorms through the
weekend, with the potential for an upswing in thunderstorm activity
next week. High temperatures will be near to slightly above normal
through the weekend, with readings lowering to several degrees below
normal by the middle of next week. Winds will generally remain less
than 15 mph with typical afternoon gustiness. Min RHs will be in the
20-30 percent range in the lower elevations and 35-45 percent in the
mountains.

&&

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

$$

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