520
FXUS65 KTWC 040829
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
129 AM MST Wed Nov 4 2026

.SYNOPSIS...Dry conditions are expected across southeast
Arizona through Thursday, then a weak weather system brings the
potential for a few showers mainly east of Tucson Friday into
Saturday with dry conditions resuming thereafter. High temperatures
will be below normal through the forecast period.

&&

.DISCUSSION...Clear skies this morning across southeast Arizona as
dry westerly flow prevails. Latest WV satellite imagery shows an
upper low across Nevada that will scoot east across Utah today but
remain far enough north that it won`t have any impact on our
weather. Another shortwave trough will then drop southeast from the
Pacific NW into the Great Basin Thursday into Friday. This is the
point where we start to see some differences within the model
envelope. The EPS/ECMWF is more aggressive on the southern and
western extent of jet energy which results in the upper low cutting
off Friday over Arizona with the GFS/GEFS/GEPS much more progressive
depicting an open wave pattern as a benign positively tilted
shortwave trough moves through. Given the increasing trends of the
potential for a cut-off low in the past day or so, it`s reasonable
to start introducing PoPs especially later Friday into Saturday and
the NBM has done so east of Tucson. If the trends continue with a
cut-off low, PoPs will need to continue be adjusted higher, though
even with that said it`s not shaping up to be a high impact event.

Once the aforementioned system moves to the east, dry weather will
return this weekend into early next week. Meanwhile, high
temperatures will remain about 3 to 8 degrees below normal through
the forecast period.

&&

.AVIATION...Valid through 05/12Z. Mainly SKC conditions thru the
forecast period. SFC wind 12 kts or less at most locations thru the
forecast period, favoring a WLY/NWLY direction during the late
afternoon/early evening hours and variable in direction at other
times. Aviation discussion not updated for TAF amendments.

&&


.FIRE WEATHER...Dry conditions are expected across southeast
Arizona through Thursday, then slight chances of showers mainly east
of Tucson Friday into Saturday. High temperatures will be below
normal and 20-foot winds will be less than 15 mph through the work
week. Breezy easterly winds are possible this weekend, though should
generally remain below critical levels. Minimum RH values in the
valleys will be in the 35-50 percent range this week (and higher in
the mountains).

&&

.HYDROLOGY...Rainfall from this past Friday into early
Monday continues to result in significant flows on the Gila River
and Vamori Wash. While these flows are forecast to gradually recede,
the Gila River at Duncan is forecast to crest near action stage
early this morning. Further downstream, the Gila River at Calva has
risen above action stage and is expected to remain at these levels
into Thursday. Flood Advisories are now in effect for those stream
reaches in Graham and Greenlee counties. Minor flooding also
continues at the Vamori Wash on the Tohono O`odham Nation in central
Pima County where a Flood Warning remains in effect.

&&

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

&&

$$


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