Area Forecast Discussion
Issued by NWS Tucson, AZ

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727
FXUS65 KTWC 121015
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
315 AM MST Wed Aug 12 2026

.SYNOPSIS...The combination of a shifting weather pattern aloft
and deep moisture residing across the region will result in
scattered showers and thunderstorms across Southeast Arizona
with the potential for heavy rain the next few days. Although
most of the storms will produce between a half and one inch of
rain, the stronger storms are capable of producing locally
heavier amounts between 1-3 inches. Otherwise, a drier southwest
flow aloft will bring a downturn in daily storm activity Friday
into the weekend. High temperatures will be near normal today,
then 3 to 6 degrees below normal tomorrow and Thursday before
temperatures warm again into the weekend.

&&

.DISCUSSION...Considerable cloud cover over the area as of 3 am
with scattered showers and thunderstorms, some of which have
been rather efficient producing heavy rain with PWATs between
1.30" and 2". Confidence low with forecast evolution as the day
progresses and the extent of flash flooding as any storms will
be efficient rain makers. Current cloud cover, morning
showers/storms and possible MCV may delay the start of afternoon
convection and push it more toward this evening. Another factor
is possible weak upper level disturbance, that was over
southern Sonora MX last night, moving across the area under
southern flow as it shifts today to become more southwesterly.
Per conference call earlier this AM with WPC and the offices
from AZ/NM/UT/NV the SLGT risk for Excessive Rainfall was
expanded at across most of SE AZ and the state. Due to my low
confidence about how today will evolve, all models don`t have
the answer and they muddy the waters, I decided against hoisting
Flash Flood Watch

Tonight: As the southwesterly flow aloft increases as an upper
level trof moves into the west coast, there is the potential for
another overnight period of showers and thunderstorms, with the
focus being across Pinal, Graham and Greenlee counties.

Friday into this weekend: A downturn in daily thunderstorm is
expected as drier air pushes across the area under southwest
flow aloft. Isolated thunderstorms at best, and mostly east and
south of Tucson of Tucson.

Early next week: Possible slight uptick in thunderstorms
associated with easterly wave passing by across northern MX.
Confidence low.

Temperatures will be about 3 to 6 degrees below normal today
and Thursday, with warming thereafter to above normal values
for this weekend.

&&

.AVIATION...Valid thru 13/12Z.
SCT-BKN 8-12k ft AGL thru much of the valid pd. SCTD -SHRA/-TSRA
with isold vsbys 1SM +TSRA. Gusty erratic winds of 35-45 kts
possible with any thunderstorm. Outside of storms SFC winds
WLY/NWLY at 8-12 kts with ocnl gusts to 20 kts this aftn and
evening. SFC winds light and terrain driven after 12/06Z.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...The combination of a shifting weather pattern
aloft and deep moisture residing across the region will result
in scattered to numerous showers and thunderstorms across
Southeast Arizona with the potential for heavy rain the next few
days. Although most of the storms will produce between a half
and one inch of rain, the stronger storms are capable of
producing locally heavier amounts between 1-3 inches. Otherwise,
a drier southwest flow aloft will bring a downturn in daily
storm activity Friday into the weekend. Minimum relative
humidity will be 20-40 percent through Thursday lowering to
around 15-30 percent thereafter. Temperatures will be near
normal through Tuesday, dropping to below normal Wednesday and
Thursday, then warming again next weekend. Outside of
thunderstorms, winds terrain driven to around 10 mph with
occasional afternoon gusts to 20 mph.

&&

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

&&

$$

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