073
FXUS65 KFGZ 231120
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
420 AM MST Sat Aug 23 2025

.SYNOPSIS...Afternoon and evening showers and thunderstorms
will continue into the middle of next week, before a drying trend
develops later in the week. Some thunderstorms have the potential to
produce enough heavy rain, that localized flash flooding is possible
each day. Daytime temperatures continue to fall, reaching below
normal values by early next week.

&&

.DISCUSSION...Mid-level high pressure over south-central Utah will
migrate toward the Four Corners on Sunday. Then, as we head into
next week, the high center will slowly retreat southeastward through
New Mexico, in response to a trough approaching the west coast. By
the end of next week, it looks like the west coast trough will win
again, forcing a drying trend across our area.

The high center today is why we have been having all this easterly
steering flow. Easterly steering flow favors storms development
moving westward, away from the higher terrain it formed on. In the
Flagstaff area, that means storms form over the San Francisco Peaks
and then move toward Williams, usually leaving Flagstaff high and
dry. To our southeast, the higher terrain of the eastern Mogollon
Rim and White Mountains see storms form there first and then move
into Yavapai County.

We expect this pattern again today, but with even more moisture in
place, things could get vigorous. Even the Chuska Mountains will get
into the action, possibly sending long-lived outflows back across
central Arizona deep into the night.

By Sunday, so much debris cloud will be around, it could be down a
bit from Saturday. Additionally, the flow starts to change and we
will see more traditional and slower storm movement. This is where
storms form over higher terrain and move northward, but may back
build into the southerly flow as well, prolonging the time they
spend in one place.

By Monday, southerly steering flow becomes more pronounced and
moisture really ramps up into Tuesday and Wednesday. This will be
another active period, enhanced by shear and colder temperatures
aloft, as the west coast trough exerts itself on the Monsoonal
plume.

Finally, later in the week, the westerlies win and storm activity
should rapidly drop off from west to east heading into next weekend.

Our Flood Watch remains in effect and this may need to be extended
into the second active period of Tuesday and Wednesday. That`s all
for now!

&&

.AVIATION...Saturday 23/12Z through Sunday 24/12Z...From about 19Z
Saturday until 02Z-04Z Sunday, expect areas of SHRA/TSRA and ISOLD
+TSRA producing localized MVFR. Otherwise, mainly VFR with remnant
light showers and considerable middle and high level debris clouds.
Winds away from storms/outflows are not expected to impact flight
operations.

OUTLOOK...Sunday 24/12Z through Tuesday 26/12Z...Daily areas of
SHRA/TSRA and ISOLD +TSRA producing localized MVFR. Mainly VFR
overnight and early mornings, with remnant light showers and
considerable middle and high level debris clouds. Winds away from
storms/outflows are not expected to impact flight operations.

&&

.FIRE WEATHER...Saturday through Sunday...Temperatures remain
just a bit above normal, especially at lower elevations. Expect an
active day today and into this evening. There is a potential for
slightly less activity Sunday, due to debris clouds. All areas will
see minimum relative humidity values above 15 percent, the lowest
readings below 5000 feet. Winds away from storms and outflows will
be light.

Monday through Wednesday...Numerous showers and thunderstorms each
day. Temperatures continue to trend downward and will fall below
average Tuesday and Wednesday. Winds away from storms and outflows
will be light, but will start to trend southwesterly by Wednesday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

Flood Watch from Saturday morning through Monday evening for
AZZ004>006.

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff