Flash Flood Warning 73, NWS Phoenix, AZ

044 
WGUS75 KPSR 170319
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
819 PM MST Wed Sep 16 2026

AZC013-170329-
/O.EXP.KPSR.FF.W.0073.000000T0000Z-260917T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
819 PM MST Wed Sep 16 2026

...FLASH FLOOD WARNING HAS EXPIRED FOR MARICOPA COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 1100 PM MST for a portion of
south central Arizona.

&&

LAT...LON 3388 11328 3382 11333 3364 11333 3363 11329
      3374 11326 3379 11317 3387 11323 3387 11324

$$

TW

Area Forecast Discussion
National Weather Service Phoenix AZ
415 PM MST Wed Sep 16 2026

.UPDATE...00Z Aviation Discussion

&&

.KEY MESSAGES...

- Scattered to widespread showers and storms are forecast to
  continue today across Arizona, with areas of high rainfall
  amounts leading to flash flooding.

- A Flood Watch remains in effect through early tonight across
  much of southern Arizona.

- Shower and thunderstorm chances will greatly diminish by
  Thursday and come to an end starting Friday with much drier
  air moving in and lasting through at least this weekend.

- Below normal temperatures are expected today across south-
  central Arizona, before warming back to to slightly above
  normal levels by the weekend.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...

RAP40 500mb height analysis shows broad troughing over Western
CONUS, with the low centered over Northern California, and ridging
over the southern Gulf States. This places the Desert SW sandwiched
between these two larger features, keeping flow aloft mostly out of
the south-southwest, advecting moisture into the region from Northern
Mexico. More impactful, a well defined low pressure circulation is
seen on satellite along the west coast of Sonora, MX. This feature
is forecasted to continue moving straight north up through AZ likely
this afternoon through tonight and help provide the lift that has
been somewhat lacking. The atmosphere is primed with ample moisture,
with 1000-700mb mixing ratios from this morning's 12Z sounding at 14
g/kg and PWATs at 1.90", upwards of 200% of normal. With this
moisture in place the lift from the previously mentioned low will be
be strengthened by the upper level jet to the region's north
providing extra support. Models are forecasting MUCAPE to be
generally between 1500-2000 J/kg this afternoon, however, some
models are showing support for upwards of 2500 J/kg, with CIN below
-100 J/kg. With any decent lift, this would make for a favorable
environment for storms to develop and continue, possible even
training leading to heavy rainfall, especially this afternoon and
into the later evening hours.

A Flood Watch is currently in effect for south-central AZ and will
continue through 11 PM MST tonight. The watch was issued largely due
to the synoptic and mesoscale setup being supportive of scattered to
widespread showers and storms capable of producing 1-hr rain rates
up around 1-2" and higher over shorter time frames, especially in
the eastern high terrain. So far this morning, localized areas in
the eastern Phoenix, the northern Foothills and eastern high terrain
have received between 1.5"-2.75". Hi-res modeling continues to show
additional QPF upwards of 1-2.5" over a large portion of south-
central AZ, and there are even high end amounts up to around 3"-4",
although chances are limited, and isolated in nature. With
everything coming together and starting to develop as we head into
the afternoon hours WPC Day 1 ERO guidance remains as a Moderate
risk for all of Gila County and most of Maricopa County. A Slight
ERO risk remains from far western Maricopa and westwards near to
AZ/CA state border. The last time a Moderate Risk covered this area
was back in 2022.

Today will be the peak of the activity as the low circulation will
move north of the area by late tonight, but a narrow axis of showers
and storms may linger into the overnight hours, most likely toward
eastern AZ. Once the system fully exits the region the environment
will be too overworked, and subsidence increases on the back side of
the low. This will result in drier air beginning to advent into the
reign with west to southwesterly flow aloft. These conditions will
limit showers and storms mostly to northern AZ high terrain on
Thursday, fallowed by further drying by Friday, limiting showers
across even the higher terrain, and 1000-700 mb mixing ratios drop
to 8 g/kg or below, and PWATs will also decrease to sub 1.00".

Temperatures this afternoon may struggle to reach 90 degrees across
south-central AZ, with ample cloud cover and rain around, while
areas further west, with more sun, still warm into the middle 90s to
around 100 degrees. Temperatures will warm back up by the end of the
week, but only back to around seasonal levels, with highs around 100
degrees across the lower deserts, as broad troughing remain in place
across much of the west.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...

The monsoon pattern may be done after today, shifting into the
transitional season with more frequent troughs. Dry air will
continue to spread across the region through this weekend with
PWATs forecast to drop below normal, as low as 0.4-0.7" across the
lower deserts. The will inhibit any chance at rain. The broad
trough moving through the West, helping drive the westerly flow
and dry air, is expected to shift east into the Plains by the
start of next week. Global ensemble guidance then shows an upper
low moving out of the Pacific toward the SoCal coast by the end of
the day Monday. There is still plenty of uncertainty regarding
this low this far out, but it may be what helps eventually drive
moisture back up in the deserts and drive the next chance at rain.
Average to slightly above average temperatures are forecast this
weekend through the first half of next week with this forecast,
with afternoon highs around to slightly above 100 degrees. With
the drier air coming in, the morning lows will finally be more
pleasant, consistently dropping into the 70s for most lower
desert locations.

&&

.AVIATION...Updated at 2315Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Main aviation concern will be SHRA/TSRA activity this evening and
accompanying low VIS and CIGs, potentially reaching as low as IFR
criteria. Another around of rainfall and embedded convection looks
possible until around 04Z, but uncertainty remains on if window of
activity will come to fruition. If it does, CIGs as low as 3-4
kft, along with VIS falling to around 4-6 miles will be the main
impacts. Winds through tonight look to remain generally out of the
east, but erratic directions may be observed depending on where
convection sets up. Conditions quiet down starting around 04-05Z,
but some lingering SHRA as late as 08Z cannot be ruled out. CIGs
aob 6 kft may also stick around until the morning hours resulting
in some operational impacts, especially at KPHX. East winds look
likely to prevail through Thursday afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected during the next 24 hours.
Winds will favor a southeasterly component at KIPL through
tonight, with some occasional gusts this evening upwards of 20 kt.
At KBLH, southerly to southeasterly winds will be common, with
gusts upwards of 25 kt possible between 03-06Z. Extended periods
of VRB wind directions appear likely at each terminal, especially
overnight into Thursday morning.

&&

.FIRE WEATHER...
Periods of scattered to widespread showers and thunderstorms are
expected to continue today, focusing mostly across the eastern
districts this afternoon through this evening, however widespread
activity over much of the lower deserts can be expected. There
will be a heavy rainfall and flood threat with the activity.
Moisture levels will be elevated most areas, highest across
eastern districts, where minimum RH this afternoon will be around
50-60%. Minimum RHs will be lowest across southeast CA, with
values around 20-30%. A drying trend will begin Thursday with
conditions becoming very dry by this weekend. Minimum RHs by
Saturday dip to 10-25% across the lower deserts (lowest across
western districts). Overnight recoveries will still be good across
eastern districts this weekend at 40-60%, while western districts
hover around 25-45%. The drier air moving in will eliminate rain
chances by Friday, with low chances in Gila County Thursday
afternoon. Winds will favor the south to southeast over much of
the area through Wednesday with gusts of 20-30 mph at times across
southwest AZ and southeast CA. In the following days winds will
return to a more typical diurnal with modest afternoon upslope
gustiness.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Flood Watch until 11 PM MST this evening for AZZ531-533-534-
     536>563.

CA...None.
&&

SHORT TERM...Ryan/Benedict
LONG TERM...Benedict
AVIATION...RW
FIRE WEATHER...Ryan/Benedict

Preliminary Local Storm Report
National Weather Service Phoenix AZ
320 PM MST Wed Sep 16 2026

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

0318 PM     Flash Flood      6 NW Paradise Valley    33.60N 112.01W
09/16/2026                   Maricopa           AZ   County Official

            Maricopa County Flood Control District
            streamflow gauge (IBW @ Sweetwater Rd) is
            indicating water level is at Alarm stage
            (2.05 ft). Gauge is located near E
            Sweetwater Ave and N 36th St.

&&

MS

Preliminary Local Storm Report
National Weather Service Phoenix AZ
322 PM MST Wed Sep 16 2026

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

0321 PM     Flash Flood      4 NNW Paradise Valley   33.58N 111.97W
09/16/2026                   Maricopa           AZ   County Official

            Maricopa County Flood Control District
            streamflow gauge (IBW @ Shea Blvd) is
            indicating water level is above Alarm stage
            (2.00 ft).

&&

MS

Preliminary Local Storm Report
National Weather Service Phoenix AZ
331 PM MST Wed Sep 16 2026

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

0330 PM     Flash Flood      4 NNW North Scottsdale  33.68N 111.93W
09/16/2026                   Maricopa           AZ   Broadcast Media

            Local news reports N Scottsdale Rd closed
            between E Grayhawk Dr and E Deer Valley Rd
            due to flooding.

&&

MS

Special Weather Statement
National Weather Service Phoenix AZ
348 PM MST Wed Sep 16 2026

AZZ531-533-536-162330-
Gila River Valley AZ-Kofa AZ-Central La Paz AZ-
348 PM MST Wed Sep 16 2026

...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL LA PAZ AND
NORTHEASTERN YUMA COUNTIES THROUGH 430 PM MST...

At 348 PM MST, Doppler radar was tracking a strong thunderstorm 22
miles southeast of Kofa Wildlife Refuge, or 41 miles northeast of
Martinez Lake, moving north at 20 mph.

HAZARD...Wind gusts of 50 to 55 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Kofa Wildlife Refuge and Palm Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3301 11362 3322 11411 3351 11408 3339 11351
TIME...MOT...LOC 2248Z 182DEG 17KT 3321 11381

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH

TW

Preliminary Local Storm Report
National Weather Service Phoenix AZ
404 PM MST Wed Sep 16 2026

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

1220 PM     Flash Flood      9 ENE Carefree          33.86N 111.77W
09/16/2026                   Maricopa           AZ   Park/Forest Srvc

            Photo showed several inches of fasting
            moving water along Bartlett Dam Road from a
            wash that intersects the road, forcing the
            closure of the road.

&&

GL

Preliminary Local Storm Report
National Weather Service Phoenix AZ
410 PM MST Wed Sep 16 2026

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

0339 PM     Flash Flood      8 N Deer Valley         33.78N 112.13W
09/16/2026                   Maricopa           AZ   Law Enforcement

            Water rescue along W Dove Valley Rd near N
            32nd Ave due to flash flooding.

&&

MS