165
FXUS65 KFGZ 201121
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
421 AM MST Sun Sep 20 2026

.SYNOPSIS...Expect a sunny and warm day today, ahead of another low
pressure set to arrive by early next week. This low pressure system
will draw moisture back into Arizona, with shower and thunderstorm
chances arriving late Monday and Tuesday. Chances will then linger
for the remainder of the week, especially for eastern Arizona.

&&

.DISCUSSION...A s/wv ridge and relatively high hghts will bring
warm and stable conditions to the region today, after a cool start
to the morning. This is in advance of a low pressure system that
will enter the SOCAL area early Monday morning, ejecting through
southern Nevada and into Utah by Tuesday. This low will draw
Monsoonal moisture back northward, allowing for showers and
thunderstorms to redevelop over Arizona.

This moisture may lead to shower development as nearly as Monday
afternoon, but is more likely to just result in increased CU/TCU
development, rather than QPF. The main chances will arrive Tuesday
as the trough axis moves through northern Arizona. This will not be
a full blown convective pattern and the moisture will not be as deep
as last week, but a few stronger cells may produce up to a half inch
of rainfall.

For the remainder of the week, persistent southerly flow will keep
moisture and shower chances going, but mainly for eastern Arizona as
the western zones continue to fight the intrusion of drier air.

Late in the period, models suggest that a pair of sub-tropical
systems could inject more significant moisture into our area.
However, confidence is low at this time.

&&

.AVIATION...Sunday 20/12Z through Monday 21/12Z...Expect VFR
conditions. Sfc winds S-SW5-15g20kts from 18Z-02Z.

OUTLOOK...Monday 21/12Z through Wednesday 23/12Z...Expect mainly VFR
conditions. ISOLD-SCT SHRA/-TSRA from late Monday onward, especially
Tuesday. Daytime sfc winds S-SW10-15g20kts Monday, SW10-20g25kts on
Tuesday.

&&

.FIRE WEATHER...Sunday and Monday...Sunny and dry conditions are
anticipated for Sunday. Dry weather continues for Monday, with
slight chances for showers and thunderstorms developing late, as
moisture returns to the district. Expect afternoon southwesterly
winds 10 to 15 mph each day.

Tuesday through Thursday...Chances for showers and thunderstorms
continue each day, with the best chances across eastern Arizona.
Southwesterly winds 10 to 20 mph, with gusts to 25 mph on Tuesday.
Winds then becoming generally light, but trending southeast through
easterly on Wednesday and Thursday.

&&

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

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff