167
FXUS65 KFGZ 012104
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
204 PM MST Mon Sep 1 2025

.SYNOPSIS...Daily chances for showers and thunderstorms are
forecast this week, mainly along and south of the Mogollon Rim,
with activity spreading northward later in the week. Strong
outflow winds and localized flash flooding will be the primary
hazards.

&&

.DISCUSSION...High pressure is centered over central Arizona this
afternoon and will drift northward over the next few days, placing
northern Arizona in a general southeasterly flow aloft. This will
allow for a gradual increase in precipitable water values and
thunderstorm coverage through the week. An outflow boundary moved
northwestward across the region last night through early this
morning, bringing slightly higher low level moisture values as far
northwest as Flagstaff and Seligman. This has allowed for
isolated to scattered showers and a few thunderstorms to develop
early this afternoon along the Mogollon Rim and White Mountains.
These storms are drifting slowly toward the southwest. There is a
chance that some of these storms will move into Yavapai/Gila
counties later this afternoon and evening, but instability and
moisture profiles in those areas aren`t impressive so chances are
only 20-30% at this time. The main threats with this activity
will be lightning and gusty outflow winds to 40 mph.

This general pattern is forecast to persist through the coming
week, with moisture being enhanced further due to surges up the
Gulf of California late week, induced by a possible tropical
system off the Baja coast. Daily storm chances go up to 40-70%
from the Mogollon Rim southward, with 10-40% north of the rim. As
precipitable water values increase late in the week, the chance
for locally heavy rain and localized flash flooding will increase
as well. With the added cloud cover and precipitation, afternoon
high temperatures will show a decreasing trend this week, falling
a few degrees below normal by the end of the week. Model guidance
indicates some increasing westerly flow sometime late in the
weekend or early next week as a trough approaches from the west.
There is still uncertainty on the timing of this trough, but it
would act to push moisture east and out of the region and decrease
storm chances.

&&

.AVIATION...Monday 01/18Z through Tuesday 02/18Z...Primarily VFR
conditions. Isolated to scattered SHRA/TSRA begins after 18Z.
Activity initiates along the higher terrain KFLG and southward,
then spreads south into the lower valleys through 02Z. Winds are
N-NE 5-15 kts, then light and VRB overnight. Gusty and erratic
outflow winds 30-40 kts are possible near storms.

OUTLOOK...Tuesday 02/18Z through Thursday 04/18Z...VFR conditions
expected, brief MVFR possible near stronger SHRA/TSRA. Chances
for showers and thunderstorms increase gradually each day
throughout the period over Northern Arizona. Outside of any
erratic outflow winds from storms, anticipate SE-SW winds 5-15kts
for Tuesday, SW-W 5-15kts Wednesday. Winds are light and VRB
during the overnight periods.

&&

.FIRE WEATHER...Tuesday and Wednesday...Scattered showers and
thunderstorms each afternoon. Best chances for storms are along and
south of the Grand Canyon, Mogollon Rim, and White Mountains on
Tuesday. Shower and thunderstorm chances spread northward on
Wednesday with scattered activity up to the Kaibab Plateau. Gusty
and erratic outflow winds 35 to 45 mph are possible near
thunderstorms. Away from storms, winds are south through southwest 5
to 15 mph each day.

Thursday through Saturday...Scattered to numerous showers and
thunderstorms are expected each afternoon. Activity is most
widespread along/south and west of the Kaibab Plateau, Mogollon Rim,
and White Mountains. The primary hazards are lightning, gusty
outflow winds, and elevated risk for flash flooding over sensitive
terrain and recently burned areas. Outside of any erratic outflow
gusts near storms, expect west through southwest winds 5 to 15 mph
each day.

&&

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

&&

$$

PUBLIC...JJ
AVIATION...Lewandowski
FIRE WEATHER...Lewandowski

For Northern Arizona weather information visit
weather.gov/flagstaff