Flash Flood Warning 147, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
435 PM MST Fri Sep 11 2026

.SYNOPSIS...Expect an active Monsoon pattern today, likely
extending into the night as deep moisture moves across the region.
Activity tapers off a bit for Saturday, but daily chances continue
through the weekend and into at least early next week, as favorable
flow and moisture patterns continue.

&&

.DISCUSSION...Moisture values rose dramatically overnight as a
series of weak s/wvs, located well to our north, induced a surge
over the southern deserts. The 18Z sounding from KFGZ indicated
robust moisture and instability values, along with some shear. We
expect a very active day as a result. Back-building storms may
prolong the activity well into the night, especially south and
east of Flagstaff.

In the wake of the convection today and tonight, we expect a quiet
start for Saturday, due to debris cloud and cooler temperatures.
However, convection south of our CWA SAturday may push into the
area Saturday evening, mainly the southern and southeastern zones.

This pattern continues off and on for the reminder of the forecast
period. Occasional surges of moisture and s/wvs to our north will
basically alternate active and suppressed days through next Friday.

&&

.AVIATION...Saturday 12/00Z through Sunday 13/00Z...Mainly VFR
conditions, MVFR possible near +TS. SCT-NMRS SHRA/TSRA continue
across much of northern AZ through the late evening then a slight
chance to continue overnight. Stronger storms may contain hail
and gusty/erratic winds to 40 kts. ISOLD-SCT storms return mostly
along the higher terrain after 18Z. Winds SW-W 10-20kts with gusts
to 25kts through 03Z, becoming light and VRB or terrain driven
overnight, then SW-W 10-20 kts after 18Z.

OUTLOOK...Sunday 13/00Z through Tuesday 15/00Z...Mainly VFR
conditions, brief MVFR near heavier thunderstorms. ISOLD-SCT
storms each day between 18Z and 03Z. Winds SW-W 10-20kts daytime,
light and variable or terrain driven overnight.

&&

.FIRE WEATHER...Saturday and Sunday...Daily chances of showers and
thunderstorms will continue, but will likely not be as active as
Friday. Storms will favor the central and east-central portions of
the district, but will not be solely limited to those areas. Expect
daily southwest winds 10 to 20 mph and daytime temperatures around
normal.

Monday through Wednesday...Daily chances for showers and
thunderstorms continue, especially Monday and Tuesday. Expect
afternoon southwest winds from 10 to 20 mph, with gusts to near 25
mph each day.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

PUBLIC...Peterson
AVIATION...Lewandowski
FIRE WEATHER...Peterson

For Northern Arizona weather information visit
weather.gov/flagstaff

Preliminary Local Storm Report
National Weather Service Flagstaff AZ
157 PM MST Fri Sep 11 2026

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

0135 PM     Flash Flood      4 NE Linden             34.32N 110.11W
09/11/2026                   Navajo             AZ   Law Enforcement

            Lone Pine Dam Rd at Linden Draw is closed
            due to flooding.

&&

JJ