883
FXUS65 KFGZ 200943
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
243 AM 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...Thunderstorm activity remains pretty active over the
southern part of our CWA this morning, but slowly this activity is
dissipating and will likely end by sunrise. This may slow the
onset of convection a couple hours, but overall its expected to
be an active day. 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 today and lasting through the weekend.
For today short term models are showing the potential for two
waves of thunderstorms. First wave develops along the Mogollon Rim
and pushes to the west and southwest during the early to late
afternoon out into Yavapai County. The second wave develops over
the northeast mountains and mountains of western New Mexico in the
mid to late afternoon and pushes to the west through eastern and
northeastern Arizona during the evening and early nighttime hours
making it as far as central Arizona before dissipating during the
early morning 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 may become briefly severe with strong winds and
quarter sized hail.

Friday`s activity will be dependent on how badly 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 an active monsoon pattern for
the higher terrain with lower POPs for the lower deserts as
steering flow remains unfavorable for storms to move off the
higher terrain.

Models are split for next week. GFS wants to keep monsoon
moisture in while the ECMWF wants to bring in drier air from the
west. Right now from Tuesday onward the forecast is for low grade
monsoon with only the high terrain seeing a slight chance of
storms. Temperatures may also tick back up a few degrees with the
drier air in place with highs rising about 5 degrees above
average.

&&

.AVIATION...Thursday 20/06Z through Friday 21/06Z...Primarily
VFR conditions. ISOLD-SCT SHRA/TSRA along/south of a KPRC-KRQE
line through 07Z-09Z. Stronger storms may bring brief MVFR/IFR
conditions. Storm activity increases again after 18Z Thursday and
continues well into the evening. Highest coverage Thursday
along/south of a KGCN-KFLG-KSJN line, with isolated storms
farther north. Winds SW-NW 5-15kts daytime, light and variable or
terrain driven overnight. Gusty and erratic winds near storms.

OUTLOOK...Friday 21/06Z through Sunday 23/06Z...Primarily VFR
conditions. SCT-NMRS SHRA/TSRA each afternoon and evening, with
the highest coverage on Friday. Stronger storms may bring brief
MVFR/IFR conditions. Winds W-NW 5-15kts each day, light and
variable or terrain driven overnight. Gusty and erratic winds near
storms.

&&

.FIRE WEATHER...Today and Friday...Expect temperatures to be 5 to 10
degrees above average. Scattered to numerous showers and
thunderstorms each day area wide. Nocturnal storms are also possible
over the time period. The primary hazards are lightning, gusty and
erratic winds, and heavy rain. Winds variable 5-15 mph on today,
becoming SW-W 5-15 mph on Friday. Minimum RH`s 15-35% each day.

Saturday through Monday...Expect temperatures 0-5 degrees above
average through the weekend. Scattered to numerous showers and
thunderstorms area wide each day, with nocturnal showers and
thunderstorms also possible. Winds 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...Bernhart
AVIATION...JJ
FIRE WEATHER...Bernhart

For Northern Arizona weather information visit
weather.gov/flagstaff