046
FXUS65 KTWC 312203
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
303 PM MST Mon Aug 31 2026

.SYNOPSIS...Storm chances and coverage decease Tuesday and
Wednesday, then increase again Thursday into the weekend. High
temperature will be below normal to start the week then near normal
Wednesday into the weekend.

&&

.DISCUSSION...It`s been an interesting day with light to moderate,
localized heavy rain occurring across eastern Pinal county, central
and eastern Pima county and Santa Cruz county. CAMs have struggled
all day with areal coverage of storms and how long they would last,
especially across eastern Pima county. Argh. Today is being enhanced
by a shortwave that extended from eastern NV south to northern Baja.
The current showers/embedded thunder will continue to push east
across Graham/Greenlee/Cochise counties into this evening. Out
across western half of Pima county and south of the border, isolated
storms will be around into this evening.

Tuesday and Wednesday: Although PWATs decrease a bit across the area
under southwest flow aloft, there still is enough moisture around
for support daily chances of afternoon and evening showers and
thunderstorms, especially south and east of Tucson. If I had to pick
the most down day, it would be Tuesday.

Thursday into this weekend: Lots of uncertainty during this period
associated with how the upper air pattern evolves. Across the PacNW
there will be a deepening upper level trof. To our east, upper
level high pressure will be building across the central plains.
And well to our south, how does the track of Invest 95E, currently
developing well off the SW Mexican coast and likely becoming a
tropical storm named Marie in the next 18 hours, impact our area
with increased tropical moisture. For now the NBM is showing an
uptick monsoon storms with increased risk in flash flooding,
especially Friday into the weekend. Also it could end up being
hotter than currently forecast.

8-14 day outlooks (Sep 8-14)
Temperature: Likely above normal 50-55%
Precipitation: Leaning above normal 41-47%

&&

.AVIATION...Valid through 02/00Z.
SCT -SHRA/-TSRA east of KTUS thru 01/03z with BKN cigs 7k-12k ft AGL.
Otrw SCT to lcly BKN 9k-12k ft AGL with ISOLD -SHRA/TS. Outflow SFC
winds near TSRA 30-40 kts otherwise SFC winds mostly less than 10
kts and terrain driven. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...Scattered showers and isolated thunderstorms into
this evening. Storms chances decrease a little Tuesday and Wednesday
with activity mainly from Tucson south and eastward. Then expect
another increase in storm chances Thursday into the weekend.
Temperatures will be around normal today through the coming work
week. Minimum relative humidity values mainly 20 to 45 percent in
the valleys and 30 to 60 percent in the mountains over the next
week. Winds will generally remain less than 15 mph and terrain
driven through the week.

&&

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

&&

$$

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