Gray Mountain, Arizona Weather Forecast Discussion

074
FXUS65 KFGZ 251120
AFDFGZ
Area Forecast Discussion
National Weather Service Flagstaff AZ
420 AM MST Thu Sep 25 2025
.SYNOPSIS...Another warm day is expected today, but then scattered
showers and thunderstorms will form by afternoon. These showers and
thunderstorms will become more widespread by tonight and then will
persist through at least Sunday. Some stronger storms may contain
large hail, damaging winds, the threat of flash flooding, and even
the threat for tornadic activity. Please heed any warnings you
receive and take them seriously.
&&
.DISCUSSION...A closed low just south of San Francisco this morning
will slowly move into the Imperial Valley by Friday morning. This
low will then move even slower, reaching Yuma Saturday morning, then
toward Prescott Sunday morning. The low then moves out of the region
by sometime on Monday.
The trajectory of this low will allow another northward incursion of
the Monsoonal moisture pool for most of the state, but especially in
the eastern third of the state. More importantly, the significantly
colder temperatures aloft will destabilize the atmosphere. The days
spent on the eastern side of the low will also have a fair amount of
shear and large helicity values, making for a potentially dangerous
situation.
So, multiple days and nights of showers and thunderstorms are a
given, but the ingredients for severe weather are also present from
about tonight through Saturday night. Isolated storms containing
large hail, damaging winds and even tornadic activity cannot be
ruled out. Training storms will also enhance Flash Flood risk, but
storm motion may minimize that risk for most areas.
Finally, by the start of next week, this low moves away from
Arizona, with warmer and drier conditions taking over.
Again, this is a multiple day period with a moderate threat of
damaging thunderstorms, take any warnings seriously.
&&
.AVIATION...Thursday 25/12Z through Friday 26/12Z...Expect VFR
through 19Z-22Z. Then, SCT-NMRS SHRA/TSRA and ISOLD +TSRA through
the remainder of the period. Storms may produce areas of MVFR. Sfc
winds outside of storms will not affect flight operations.
OUTLOOK...Friday 26/12Z through Sunday 28/12Z...SCT-NMRS SHRA/TSRA
and ISOLD +TSRA through the the period. Storms may produce areas of
MVFR. Sfc winds outside of storms will not affect flight operations.
&&
.FIRE WEATHER...Thursday and Friday...Expect scattered showers and
thunderstorms this afternoon becoming more widespread tonight
through Friday. Some storms may become severe. Winds away from
storms will be southerly at 5 to 15 mph.
Saturday through Monday...Periods of showers and thunderstorms will
continue through Sunday, with coverage becoming isolated on Monday.
Daytime southerly winds at 5 to 15 mph each day.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
PUBLIC...Peterson
AVIATION...Peterson
FIRE WEATHER...Peterson
For Northern Arizona weather information visit
weather.gov/flagstaff

NWS FGZ Office Area Forecast Discussion