795
FXUS65 KFGZ 171130
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
430 AM MST Thu Jul 17 2025

.SYNOPSIS...An active monsoonal period is forecast through
Friday, with scattered to numerous showers and thunderstorms
expected today and tomorrow. Low grade monsoon conditions then
set in for the weekend and into next week, with isolated to
scattered storms possible each day. Cooler temperatures are also
expected through the rest of the week and into next week.

&&

.DISCUSSION...Today...Monsoonal moisture remains place today,
leading to another round of showers and thunderstorms this
afternoon. However, debris clouds from overnight convection may
lead to a delayed start to the activity. As a result, coverage
looks to be less than previously thought, with more scattered
coverage of storms expected this afternoon.

Storms look to initially form just south of the Mogollon Rim, where
destabilization is expected to take place initially. With 0-6 km mean
wind from the south, storm are then expected to move northward
through the afternoon as instability increase across the remainder
of the region. Storm motion of 5-15 kts and PWATs 0.80-1.10" will
generally lead to a flash flood risk going into this afternoon.
However, some weak 0-6 km shear (~20-30 kts) and pockets of modest
CAPE (800-1000 J/Kg) could allow for a couple strong to severe
storms this afternoon.

Friday...A weak trough over the northern Baja ejects off the Pacific
and moves into Arizona. This will lead to an increase in large scale
ascent over the region, aiding in storm development. However, hi-res
guidance does continue to back off on the overall coverage on
Friday. As a result, more scattered coverage looks to be most
probable. Given the influence of the trough, a few stronger storms
may be possible, and potentially bring hail and strong winds. Flash
flooding still looks to be the primary threat however.

Saturday through Wednesday...The aforementioned trough looks to move
into the Mojave Desert over the weekend, and eventually become
absorbed into weak longwave trough over the northwestern US. This
looks to usher in drier air to northern Arizona, with flow not
exactly supportive of monsoonal moisture advection. Large-scale
ensemble guidance still shows the vast majority of members
supporting a downward trend in PWATs through at least the middle of
next week. While storms do not look to entirely disappear, coverage
looks to be more isolated. The greatest odds for storms look to
mainly be over the higher terrain into next week, especially across
the Mogollon Rim and White Mountains.

&&

.AVIATION...Thursday 17/12Z through Friday 18/12Z...SCT-WDSPR
SHRA/TSRA after 19Z and before 02Z, with lingering -SHRA possible
through 08Z. Brief MVFR conditions and gusty, erratic winds possible
in and around TS. Otherwise, VFR conditions with daytime winds SW 5-
10 kts.

OUTLOOK...Friday 18/12Z through Sunday 20/12Z...SCT SHRA/TSRA
remains possible each day, mainly 19Z-02Z. Brief MVFR conditions and
gusty, erratic winds possible in and around TS. Otherwise, VFR with
daytime winds W/SW 5-10 kts.

&&

.FIRE WEATHER...Today and Friday...Scattered showers and
thunderstorms are expected each afternoon and evening. Wetting
rains, gusty outflow winds, and flash flooding will be possible.
Daytime winds west/southwest 5-10 mph with gusts 10-20 mph each day.

Saturday through Monday...Scattered to isolated showers and
thunderstorms are expected over the weekend and on Monday, with the
greatest odds over the eastern Mogollon Rim and White Mountains.
Wetting rains are likely within any stronger storms. Daytime winds
west/southwest 5-10 mph with gusts 10-20 mph each day. Gusty,
erratic winds possible in and around thunderstorms.

&&

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

&&

$$

PUBLIC...Humphreys
AVIATION...Humphreys
FIRE WEATHER...Humphreys

For Northern Arizona weather information visit
weather.gov/flagstaff