Flash Flood Warning 50, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
1235 PM MST Thu Sep 11 2025

.SYNOPSIS...Scattered afternoon and evening thunderstorms will
continue through Friday, mainly from Tucson south and eastward.
Gusty winds, brief heavy rain, blowing dust and lightning will be
the main hazards. High temperatures will lower several degrees
through Saturday, when highs will top out a couple of degrees below
normal. There will be a slight chance of thunderstorms southeast of
Tucson on Saturday and dry conditions areawide Sunday. Temperatures
warm back up a couple of degrees next week, along with a return of
slight chances of afternoon and evening thunderstorms.

&&

.DISCUSSION...Arizona remains sandwiched between a trough to the
west and high pressure aloft centered over the Texas panhandle.
South to southwest flow continues to advect moisture northward
across the the forecast area. The latest Blended TPW Imagery
indicates PW values around 1 inch across much of southeast Arizona.
However, the 250911/18 KTWC sounding indicates a PW value of 1.30
inches. Overall, plenty of moisture in place for thunderstorm
development. The latest high-res guidance continues to indicate
isolated to scattered thunderstorm coverage east of a Nogales to
Tucson to Oracle line this afternoon and evening. The models have a
similar repeat tomorrow, with the potential for storms starting a
little earlier and coverage clearly in the scattered to numerous
range. With the trough axis shifting slowly eastward into Friday,
convection may continue well into the evening (and even overnight)
hours given the upper level support and dynamics. The main threats
will be gusty outflow winds, areas of blowing dust and lighting.
While heavy rainfall will also be possible with the strongest
thunderstorms, mean flow of around 25 kts should keep this threat on
the minimal side. High temperatures will be within a degree or two
of normal today and Friday.

As the trough axis shifts eastward over the weekend drier air will
move into the region from the west. This will limit thunderstorms
chances to far eastern areas in Cochise, Graham and Greenlee
counties on Saturday and dry conditions areawide on Sunday. High
temperatures will be 3-5 degrees below normal on Saturday, warming
back up to near seasonal normals on Sunday.

The upper high then rebuilds across the western United States early
to mid next week. This will allow moisture to return to southeast
Arizona, with a slight chance of thunderstorms across eastern areas
Monday and Tuesday and across all of southeast Arizona mid to late
next week. High temperatures warm back into the upper 90s across the
lower deserts next week. 100 degrees is not out of the equation for
the latter part of next week, although NBM probabilities of that are
25 percent or less.

&&

.AVIATION...Valid through 13/00Z.
SCT-BKN clouds at 8k-11k ft AGL thru 12/06Z. Decreasing clouds
between 12/06Z and 12/17Z. SCT-BKN clouds again at 8k-11k ft AGL aft
12/17Z. Scattered -SHRA/-TSRA mainly east of KTUS-KOLS-KCGZ line
thru 12/04Z and again aft 12/18Z. Gusty and erratic winds to 45 kts
possible with any thunderstorm. Otherwise, SLY/SWLY SFC wind at 10-
16 kts with gusts to 20-25 kts thru 12/04Z and again aft 12/18Z. SFC
wind less than 10 kts and variable in direction between 12/04Z and
12/18Z.

&&

.FIRE WEATHER...Minimum RH values will be in the 20-35 percent range
through Saturday, lowering into the 15-30 percent range Sunday and
Monday. Scattered showers and thunderstorms are expected from the
Tucson area eastward today and Friday, with a slight chance of
showers and thunderstorms south and east of Tucson on Saturday. Dry
area-wide Sunday, then a slight chance of thunderstorms return again
next week. Gusty and erratic winds are expected with thunderstorms.
Outside of thunderstorm outflows, expect 20-foot winds to be 15 mph
or less, with some afternoon/early evening gusts to around 25 mph.
High temperatures will be near normal the next 7 days, except for
Saturday when they will be slightly below normal.

&&

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

&&

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