849
FXUS65 KFGZ 211656 AAC
AFDFGZ

Area Forecast Discussion...UPDATED
National Weather Service Flagstaff AZ
956 AM MST Fri Aug 21 2026

.SYNOPSIS...Thunderstorm chances will continue with an active
monsoon pattern expected through early next week. Daytime
temperatures generally remaining above average through the
period.

&&

.DISCUSSION...High pressure aloft centered over the Four Corners
early Friday morning will slowly drift to the south and east over
the coming days becoming centered over New Mexico toward the end
of next week. The net result will be daily chances for showers and
thunderstorms across northern Arizona as the position of the high
all but guarantees monsoon moisture will remain entrenched across
Arizona.

For Today...Monsoon moisture will remain in place. However, the
combination of morning cloudiness and some stabilization due to
all the low-level cooling from outflows on Thursday looks to
result in a downturn in overall coverage of storms. We`re still
looking at isolated to scattered showers and thunderstorms but
not as much larger-scale organization as was seen on Thursday. In
addition, southeast flow aloft will tend to favor development over
the Grand Canyon, Mogollon Rim, White mountains and Chuska
Mountains then moving to the north and east. Otherwise, light
winds and just a bit cooler high temperatures.

From Saturday into Tuesday...Monsoon moisture remain in place with
daily chances for showers and thunderstorms. Which days will be
the most active? We`ll let you know when we get there. One thing
is for sure, monsoon moisture isn`t going anywhere. Roughly, with
the flow aloft from the southeast, it appears the bulk of
activity will be from the Mogollon Rim northward. Also worth
noting, a bit drier air looks to make it`s way across the
northwest corner of Arizona on Saturday, so a brief downturn in
activity is possible across that portion of Arizona. Otherwise,
with the high remaining over the southwest, light winds will
continue along with above normal temperatures.

Looking from Wednesday onward...Monsoon moisture will remain
available but the exact position of the high will be critical.
The GFS is currently placing the high center far enough north that
the flow aloft remains primarily south to southeast which would
spell a continuation of low to moderate levels of monsoon
activity. However, the ECMWF moves the high further south, partly
in response to a Pacific trough. This solution would bring in
southwest flow aloft which usually delivers a capping layer aloft
having origins in the subsiding branch of the Hadley circulation.

&&

.AVIATION...Friday 21/18Z through Saturday 22/18Z...Mainly VFR,
with brief periods of MFR with scattered showers and
thunderstorms developing after 18Z and winding down by 03Z.
Daytime winds southwest to northwest at 5-15 kts, light and
variable overnight. Localized/brief MVFR conditions and
gusty/erratic winds up to 40 kts in stronger storms.

OUTLOOK...Saturday 22/18Z through Monday 24/18Z...Scattered
thunderstorm activity becomes more focused on the higher terrain
areas for Saturday and Sunday afternoons. Daytime winds southwest
to west at 5-15 kts. Light and variable or terrain driven winds
overnight. Gusty and erratic winds near thunderstorms.

&&

.FIRE WEATHER...Today and Saturday...Look for isolated to scattered
showers and thunderstorms each afternoon and evening across northern
Arizona with the main focus located from the Mogollon Rim northward.
Stronger storms will bring hail, gusty and erratic winds, and localized
heavy rainfall. Away from storms, winds look to be variable 5-15 mph
each day.

Sunday through Tuesday...Expect scattered showers and thunderstorms
on Sunday and Monday, becoming more isolated on Tuesday. Stronger
storms will bring hail, gusty and erratic winds, and localized heavy
rainfall. Winds southwest to west at 5-15 mph each day, with gusty
and erratic winds possible near storms.

&&

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

&&

$$

PUBLIC...McCollum
AVIATION...Schank
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff