691
FXUS65 KFGZ 231112
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
412 AM MST Sun Aug 23 2026

.SYNOPSIS...Moderate monsoon activity will continue through
Monday, mainly along the higher terrain during the afternoon and
evening hours. Then, as high pressure builds over Arizona, hot and
mainly dry conditions are expected to develop as the flow of
moisture northward into the region diminishes.

&&

.DISCUSSION...High pressure aloft was centered over New Mexico
Sunday morning. It is expected that the high center will slowly
drift southward through about Tuesday then westward becoming
centered over southeast Arizona by Friday/Saturday. Look for
daily chances for showers/thunderstorms across northern Arizona
through Tuesday, with diminished chances later in the week as a
drier and more stable air mass develops over northern Arizona.

For Today...Monsoon moisture will remain in place. As a result,
we`re looking at another round of isolated to scattered showers
and thunderstorms. Much like on Saturday, look for shower and
thunderstorm development over the mountains around midday with
activity then tending to move north and east with the general flow
aloft. Storms during the day will likely be most numerous from
the Mogollon Rim and White Mountains northward. Another aspect to
keep an eye on is the possibility of a convective blowup over
southern Arizona this afternoon and evening. The potential is for
a strong outflow boundary to be sent northward interacting with
moisture and instability across central to northern Arizona. The
result would be a mid to late evening (and even overnight) uptick
in showers and storms across portions of northern Arizona
(especially along and west of the I-17/Highway 89A corridor).
Otherwise, light winds and generally hot conditions.

For Monday and Tuesday...Monsoon moisture remains in place with
daily chances for showers and thunderstorms. The flow aloft will
remain southerly with the bulk of activity expected from the
Mogollon Rim and White Mountains northward. Otherwise, with the
high remaining over the southwest United States, light winds will
continue along with above normal temperatures, turning especially
hot by Tuesday as high pressure begins to strengthen over
Arizona.

Looking from Wednesday onward...Models appear to be trending
toward high pressure aloft becoming centered over southeast
Arizona. This solution would bring in a more southwest to west
flow aloft which would deliver a drier air mass as well as a
capping layer under the influence of weak subsidence. In
addition, daytime temperatures will be on the increase, likely
rising to the upper 80 to lower 90s in the mountains to 105 to
110 degrees at elevations below 4000 feet. A reminder that we
remain in the grips of summer.

&&

.AVIATION...Sunday 23/12Z through Monday 24/12Z...Mainly VFR
conditions. Another round of scattered SHRA/TSRA developing after
18Z and continuing through at least 03Z. Brief MVFR conditions
and gusty/erratic wind possible in heavier SHRA/TSRA. Otherwise,
look for variable winds at 5-15 kts.

OUTLOOK...Monday 24/12Z through Wednesday 26/12Z...Expect mainly
VFR conditions. Scattered afternoon/evening SHRA/TSRA Monday, with
coverage decreasing to isolated by Tuesday. Outside of
gusty/erratic outflow driven winds, look for daytime winds mainly
southwest to west 5-15 kts. Light and variable winds at night.

&&

.FIRE WEATHER...Today and Monday...Expect daily chances for
showers/thunderstorms, with the greatest coverage across the higher
terrain. Activity will ramp up around midday then continue through
the evening hours both days. Outside of gusty and erratic storm
driven winds, look for variable winds generally 10 mph or less.

Tuesday through Thursday...Drier conditions will gradually return,
with activity becoming limited to the White Mountains by Wednesday
and Thursday. Daytime highs are forecast to become quite hot,
reaching 10-15 degrees above normal. Look for southwest winds 5-15
mph each afternoon.

&&

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

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff