First Mesa, Arizona Weather Forecast Discussion

515
FXUS65 KFGZ 192114
AFDFGZ
Area Forecast Discussion
National Weather Service Flagstaff AZ
215 PM MST Fri Sep 19 2025
.SYNOPSIS...Chances for showers and thunderstorms diminish over the
weekend, especially Saturday, with a bit warmer temperatures. A new
low pressure system forming near San Diego on Sunday will continue
shower and thunderstorm chances into early next week.
&&
.DISCUSSION...Storm activity has actually decreased though the day
as subsidence behind this mornings s/wv and a heavily rain-cooled
air mass governed our convection. We expect activity to decrease
fairly quickly tonight, as the flow aloft becomes anti-cyclonic and
warms a bit.
Nonetheless, despite a less favorable environment Saturday, so much
moisture is still around, we put isolated to scattered PoPs back
into the forecast.
By Sunday and into early next week, it now looks like a closed low
will form near San Diego. This will keep the moisture stream over
Arizona for several more days, along with introducing some shear and
cooler mid-level temperatures. We have begun increasing shower and
thunderstorm chances as a result.
&&
.AVIATION...Friday 19/18Z through Saturday 20/18Z...Expect mainly
VFR conditions. Areas SHRA/-TSRA could cause brief MVFR conditions
through 02Z, then clearing. Sfc winds not expected to impact flight
operations.
OUTLOOK...Saturday 20/18Z through Monday 22/18Z...Expect mainly VFR
conditions. Isolated -SHRA/-TSRA from 19Z-02Z Saturday, mainly south
of the I-40 corridor. Coverage potentially increasing during the
daytime hours Sunday and Monday. Sfc winds not expected to impact
flight operations.
&&
.FIRE WEATHER...Saturday and Sunday...Scattered showers and
thunderstorms will diminish overnight as high pressure strengthens
over the district. More isolated coverage, mainly south of I-40 is
expected Saturday, with a slight increase for Sunday. Winds will
mainly be light, trending southwest through west.
Monday through Wednesday...A chance of showers and thunderstorms
will persist through the period, especially Monday, as a new low
pressure system forms off the southern California coast. Winds will
remain mainly light.
&&
.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