Severe Thunderstorm Warning 270, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
114 PM MST Sat Sep 12 2026

.SYNOPSIS...A more typical isolated to scattered coverage of storms
is forecast this weekend into next week. Daily high temperatures
will fluctuate between near normal and a few degrees below
normal.

&&

.DISCUSSION...Scattered storms already ongoing and continue to fill
into the Tucson Metro which is no surprise given the moisture
profile in place today in conjunction with sufficient instability.
We'll mainly be monitoring for heavy rainfall this afternoon as
scattered storms with frequent lightning continue to evolve, but
can't rule out strong gusty outflow winds. With very weak flow in
the atmosphere, the storms that do form have the potential to dump
an impactful amount of rain over the same spot resulting in water
flowing in normally dry washes and low water crossings becoming
inundated with swift moving water. HREF depicts a slight chance
(10%) for rainfall totals exceeding 3 inches. If storms do gradually
evolve into the Tucson Metro proper, we could see urban street
flooding with ponding of water on roadways and in poor drainage
areas. This weekend chances for isolated to scattered storms
continues, again with the moisture we have in place the primary
concern continues to lean toward heavy rainfall and localized
flash flooding.

Monday still looks to be a bit more active as a weak disturbance
moves across southeast Arizona. Combined with the additional
moisture we have in place, any lifting mechanism can help provide
confidence in a heavy rainfall event. QPF continues to trend up
with WPC placing portions of the forecast area under slight
risk for excessive rainfall with the potential for stronger
storms producing rainfall rates of 1-2"/hr leading to the
increased risk of localized flash flooding. Time will tell as
its difficult to time disturbances this far out.

&&

.AVIATION...Valid thru 14/00Z.
SCT SHRA/TSRA thru 13/04Z. SFC winds WLY/NWLY 6-10 kts thru 13/05
becoming terrain driven and less than 10 kts thereafter. Tomorrow,
ISOLD-SCT SHRA/TSRA aft 13/17Z. SFC winds WLY/NWLY at 6-10 kts.
Visibility 1-3 SM possible in TSRA. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...A typical isolated to scattered coverage of storms
is forecast this weekend into next week. High temperatures will will
fluctuate between near normal and a few degrees below normal.
Min RH values mainly 20 to 45 percent in the valleys and 35 to 65
percent in the mountains over the next week. RH recoveries will
continue to be excellent overnight. Winds will generally remain less
than 15 mph and terrain driven. Gusty and erratic winds will
accompany thunderstorms.

&&

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

&&

DVS

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Preliminary Local Storm Report
National Weather Service Tucson AZ
109 PM MST Sat Sep 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1255 PM     Flash Flood      2 S Picture Rocks       32.31N 111.24W
09/12/2026                   Pima               AZ   Fire Dept/Rescue

            Swift water rescue on W Rudasill rd and N
            Chaparral Rd.

&&

AJE

Preliminary Local Storm Report
National Weather Service Tucson AZ
118 PM MST Sat Sep 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0107 PM     Flash Flood      4 SSE Picture Rocks     32.29N 111.22W
09/12/2026                   Pima               AZ   Fire Dept/Rescue

            Swift water rescue on W Manville Rd and N
            Sandario Rd.

&&

AJE

Preliminary Local Storm Report
National Weather Service Tucson AZ
150 PM MST Sat Sep 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0146 PM     Flash Flood      15 SE Tucson            32.03N 110.72W
09/12/2026                   Pima               AZ   Fire Dept/Rescue

            Swift water rescue on Wentworth near I10.

&&

AJE

Preliminary Local Storm Report
National Weather Service Tucson AZ
227 PM MST Sat Sep 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0219 PM     Flash Flood      15 SE Tucson            32.03N 110.72W
09/12/2026                   Pima               AZ   Fire Dept/Rescue

            Swift water rescue on E Colossal Cave Rd and
            E Dawn Rd.

&&

AJE