032
FXUS65 KFGZ 221120
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
420 AM MST Fri Aug 22 2025

.SYNOPSIS...Chances for showers and thunderstorms increase over
the next severals days. Scattered to widespread storms, some with
heavy rain and localized flash flooding, are expected each day.
Daytime temperatures will still remain quite hot at lower
elevations today, with gradual cooling into the weekend.

&&

.DISCUSSION...Favorable moisture transport into Arizona, along
with the erosion of our mid-level cap, will allow for increasing
storm activity over the next several days.

Steering flow favors areas along and west of the Mogollon Rim
through the weekend, with drier conditions for northeastern Arizona.
By early next week, flow becomes more southerly and moisture should
get into most locations.

The erosion of the mid-level cap means stronger storms and an
increased likelihood of locally heavy rain. We have a number of new
burn scars this year, along with our usual washes and creeks. Pay
attention to warnings when out and about.

Things that can ruin chances for rainfall? Well, there will be a
persistent one during this frame. Considerable debris cloud each
night may suppress convection from time to time, but elevated
heating and clearing skies from the east each day should help.

Temperatures will decrease as the convection increases, today will
be the last day for the EHW at the Grand Canyon.

&&

.AVIATION...Friday 22/12Z through Saturday 23/12Z...From about 19Z
Friday until 02Z-04Z Saturday, 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...Saturday 23/12Z through Monday 25/12Z...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...Friday and Saturday...Very warm conditions will
continue, although temperatures will trend downward each day as
storm activity picks up. Expect storms to form over higher terrain
and move west or southwest each afternoon, becoming more showery at
night. Minimum relative humidity values will still drop below 15
percent northeast of the Mogollon Rim Friday, but all locations will
be above 15 percent by Saturday. Winds will generally be terrain or
outflow driven.

Sunday through Tuesday...Expect an active Monsoon period for these
days, with temperatures continuing to trend downward and relative
humidity trending upward. Winds will generally be terrain or outflow
driven.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

Extreme Heat Warning until 8 PM MST Friday for AZZ006.

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff