Tucson, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

653
FXUS65 KTWC 052037
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
137 PM MST Fri Sep 5 2025

.SYNOPSIS...With considerable moisture in place, expect scattered
showers and thunderstorms through Saturday. The main threat from
these storms will be areas of locally heavy rain producing
isolated flash flooding. Below normal high temperatures through
Saturday. Drier conditions return starting Sunday with a return to
near to slightly above normal temperatures next week.

&&

.DISCUSSION...Post tropical cyclone Lorena continues to be sheared
and enveloped by a broad high pressure system located over
central Mexico. High clouds quickly dissipated this morning
replaced by a field of cumulus clouds. Isolated, weak storms and
showers have begun to develop in far western Pima county. Chances
for storms and showers will continue into the afternoon still
focused to areas west and north of Tucson. Models suggest that
most of the heavy rain will stay to the south of the International
Border but it has crept northward to areas from Nogales where a
few showers have developed. Temperatures will stay at or just
below normal today with Minor HeatRisk. Highs will be in the upper
70s to upper 80s in the lower elevations and in the upper 50s to
low 60s in the higher elevations. For tonight, we can`t rule out
nocturnal activity with scattered showers and thunderstorms. Given
the moisture in place, a small scale lifting mechanism during the
evening or overnight hours will be enough to result in elevated
precipitation chances compared to a more typical monsoon nighttime
scenario.

For Saturday, with plenty of moisture in place (PWAT`s 120 to 140
percent above normal at 1.1 inches eastern areas to 1.6 inches
western deserts), there is certainly potential for thunderstorms
to develop. The CAMs continue to show more activity compared to
today as the combination of greater solar insolation with increased
instability and perhaps some weak lifting mechanisms, will help
to initiate greater convective coverage. WPC has kept us in a
marginal risk for excessive rainfall through tomorrow. Even though
the Flash Flood Watch has been cancelled for both Friday and
Saturday, the threat for localized flash flooding still persists
Saturday. The HREF 12Z 3hr QPF shows there is at least a 50%
chance for greater than 1 inch of rain tomorrow for areas Tucson
southwards with a 10% chance of greater than 3 inches along the
International border. Temperatures on Saturday will be about 8 to
12 degrees below normal.

As westerly flow starts to kick in on Sunday the atmosphere will
undergo a drying process. Still a slight chance of showers and
thunderstorms mainly in the White Mountains but most locales stay
dry. West to southwest flow continues next week as temperatures warm
to near or slightly above normal levels. We`re continuing to see
hints in the ensembles of a bit of a northward moisture push
especially near the AZ/NM border mid to late next week. The
current official forecast is still dry Tuesday and Wednesday with
slight chances east of Tucson Thursday.

&&

.AVIATION...Valid through 07/00Z.

SCT-BKN 6k-10k feet with pockets down to 4k feet mainly near KDUG
for much of the forecast period. Otherwise, especially from KTUS
and points west and north, expect ISOLD to SCT -SHRA/-TSRA with
gusts up to 40 kts this afternoon into evening. Confidence is too
low for anything more than a VCSH mention in TAFs. Surface winds
less than 10 kts and variable outside any thunderstorm activity.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Minimum relative humidities well above 30
percent through the weekend. Scattered showers and thunderstorm
chances each day through Saturday, with drier conditions Sunday
onwards. Surface winds mainly light through the forecast period,
except gusty and erratic in or near any thunderstorms. High
temperatures will be below normal through the weekend then warming
back to near to slightly above normal next week.

&&

&&

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

$$

Malarkey

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson