639
FXUS65 KFGZ 061752
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1052 AM MST Sun Sep 6 2026

.SYNOPSIS...Isolated showers and thunderstorms are expected
today across the area, with scattered activity in northwest
Arizona and the White Mountains. Storm activity will be confined
to far eastern Arizona Monday before spreading back westward
through next week. Temperatures will be close to normal through
Labor Day, warming above normal by mid week.

&&

.DISCUSSION...Today...Sub-tropical moisture has surged northward
as a result of Hurricane Marie (~800 miles W of the tip of the
Baja California peninsula). A band of showers and embedded
thunderstorms has moved northward through northern Arizona at the
leading edge of the moisture surge, largely driven by large-scale
ascent ahead of an approaching shortwave. As the shortwave ejects
off the Pacific, the band begins will stall through the remainder
of the day. Much of the latest hi-res guidance shows it stalling
over northwestern Arizona, largely to the west of our CWA, just
brushing northwestern Coconino County. Elsewhere, mainly dry
conditions are expected, outside of a few isolated showers an
thunderstorms along the higher terrain. Rainfall amounts so far
this morning have been fairly minimal, with only a few hundredths
to a couple tenths in the steadier areas of precipitation.
Therefore, the threat for any strong thunderstorms and flash
flooding remains low.

Monday and Tuesday...With moisture still in place, a few isolated
showers and thunderstorms will be possible again Monday. Activity
looks to however be fairly minimal, as warming aloft will limit the
potential for vertical motion. Drier surface conditions will also
limit how much rain will actually reach the ground.

Coverage for Monday looks to be mainly focused across the eastern
Mogollon Rim, White Mountains, and the Chuska Mountains. A similar
trend looks to follow suit into Tuesday, through potentially
expanding coverage along the remainder of the Mogollon Rim.

Wednesday through Saturday...High pressure over the central US
begins to retrograde back over the southwest over the second-half of
the week. Much of the EPS, GEFS, and CMCE members have PWATs
remaining high enough for continued monsoonal activity through at
least the end of the work week; albeit a slight downward trend. Thus,
continued daily chances for afternoon showers and thunderstorms
seems reasonable. Much of the activity should be fairly isolated to
scattered in nature, and most numerous over the higher terrain.
Temperatures also look to gradually climb each day, as heights
gradually rise over Arizona.

Thereafter, there remains some uncertainty as a trough may descend
through the Great Basin and suppress some of the moisture to the
south. A strengthening ridge behind the trough over Nevada may also
further suppress upward motion, while also ushering in drier air from
the north.

&&

.AVIATION...Sunday 06/18Z through Monday 07/18Z...Mainly VFR
conditions. Expect scattered showers over northwest Arizona today
with KGCN and KPGA terminals potentially seeing a few showers or
thunderstorms today. A few isolated afternoon thunderstorms are
also possible over the White Mountain region. Rest of the state
will be dry. Winds SW-W 10-20kts daytime, light and variable or
terrain driven overnight.

OUTLOOK...Monday 07/18Z through Wednesday 09/18Z...Mainly VFR
conditions. Isolated to scattered showers and thunderstorms possible
over the White Mountains and East Rim Monday afternoon, isolated
to scattered afternoon showers and thunderstorms possible over the
Rim and White Mountains Tuesday afternoon. Winds SW-W 5-15kts
daytime, light and variable or terrain driven overnight.

&&

.FIRE WEATHER...Monday and Tuesday...On Monday, isolated to
scattered afternoon showers and thunderstorms will be confined to
the higher terrain in the eastern third of Arizona. By Tuesday
afternoon showers and thunderstorm chances begin to move westward
along the Mogollon Rim with continued chances over the mountains of
eastern Arizona. High temperatures near normal Monday warming to
about 5 degrees above average Tuesday. Winds SW-W 5-15 mph with
gusts to 25 mph each afternoon, light and variable or terrain driven
overnight. Minimum RH`s each afternoon ranging from 15% in the lower
deserts to 30-40% in the mountains.

Wednesday through Friday...Afternoon showers and thunderstorms
remain primarily over the higher terrain of the Rim and White
Mountains each day. Temperatures warming to 5-10 degrees above
normal. Winds S-SW 5-15 mph each day, light and variable or terrain
driven overnight.

&&

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

&&

$$

PUBLIC...Humphreys
AVIATION...Bernhart
FIRE WEATHER...Bernhart

For Northern Arizona weather information visit
weather.gov/flagstaff