840
FXUS65 KFGZ 202341
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
441 PM MST Thu Aug 20 2026

.SYNOPSIS...Expect temperatures 5-10 degrees above average today
and Friday, with temperatures cooling back to near normal over the
weekend. Thunderstorm coverage increases today with an active
monsoon pattern expected through the weekend.

&&

.DISCUSSION...High pressure has shifted to the east and is
centered over the Four Corners which is a good position to import
more moisture into the area through the weekend. The first wave of
thunderstorms today has developed along the Mogollon Rim and
pushes westward to Yavapai County. Short term models show a
second wave developing over the northeast mountains and mountains
of western New Mexico in the mid to late afternoon pushing to the
west through eastern and northeastern Arizona during the evening hours.
With plenty of moisture to work with and some wet soils in parts
of the area from yesterday`s activity, will definitely have to
watch for the potential for some flash flooding. A few storms will
likely become briefly severe with strong winds and quarter sized
hail.

Friday`s activity will be dependent on how Thursday`s activity
works over the atmosphere. It looks like storm motion may be
towards the northwest which often means lower POPs for the middle
and lower elevations as storms are not as likely to move off the
Rim and that`s reflected in the forecast at this time. POPs for
the northern half of the state remain elevated as storms may move
off the higher terrain into the northern deserts.

Saturday through Monday looks like a moderately active monsoon
pattern for the higher terrain with lesser chances for the lower
deserts as steering flow remains unfavorable for storms to move
off the higher terrain. Model suites are split for next week. The
GFS ensemble wants to keep monsoon moisture in, while the ECMWF
wants to bring in drier air from the west by midweek. Temperatures
will also tick back up a few degrees if drier air is in place
with highs rising about 5 degrees above average.

&&

.AVIATION...Friday 21/00Z through Saturday 22/00Z...Isolated to scattered
thunderstorms will continue through the evening, as late as
07Z-09Z. Otherwise, VFR conditions with MVFR/brief IFR in
thunderstorm activity along with locally heavy rainfall and gusty
and erratic winds up to 40 kts. Showers and storms will diminish
after 09Z. Another round of scattered to numerous thunderstorms
developing after 18Z Friday. Daytime winds SW-NW 5-15 kts Friday.


OUTLOOK...Saturday 22/00Z through Monday 24/00Z...Scattered to
numerous thunderstorms through 03Z Saturday. Thunderstorm activity
becomes more focused on the higher terrain areas for Saturday and
Sunday afternoons. Daytime winds SW-W 5-15 kts Saturday and Sunday.
Light and variable or terrain driven wind overnight. Gusty and
erratic winds near thunderstorms.

&&

.FIRE WEATHER...Today through Saturday...Scattered to numerous
showers and thunderstorms each day across northern AZ. Storms may
continue into the late evening/overnight hours tonight and Friday
night. Stronger storms will bring hail, gusty and erratic winds, and
localized heavy rainfall. Away from storms, winds are variable 5-15
mph each day.

Sunday through Tuesday...Scattered showers and thunderstorms on
Sunday and Monday, becoming isolated on Tuesday. Stronger storms
will bring hail, gusty and erratic winds, and localized heavy
rainfall. Winds are SW-W 5-15 mph each day, with gusty and erratic
winds possible near storms.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM MST this evening for AZZ006.

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff