233
FXUS65 KFGZ 032208
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
308 PM MST Wed Sep 3 2025

.SYNOPSIS...Daily chances for showers/storms remains in the
forecast through Saturday, before we quickly dry out across the
state Sunday onward. There still remains uncertainty with
available instability and the trajectory of Tropical Storm Lorena,
so confidence is iffy on rainfall amounts especially for later in
the week. Either way, gusty winds and localized flash flooding
will be the primary hazards.

&&

.DISCUSSION...Rest of today...A moist airmass is currently in place
over much of northern AZ after a subtle inverted trough pushed
northward in the past 24 hours. The 18Z sounding at KFGZ measured
a PW of 0.70 inches, which is lower than ensemble guidance was
previously indicating but still above the median for early
September. We are seeing isolated to scattered storms across much
of northern AZ, with the primary threat today being localized
flash flooding. Better moisture is present over the Kaibab, but
residual clouds and light showers have lingered overhead through
the early afternoon. This has subdued convective activity for the
day north of the Grand Canyon.

Thursday through Saturday...Overall we expect an active period of
showers and thunderstorms through the end of the week. Hurricane
Lorena is a potential forecast element during this period, however
the biggest impacts will stay well to the south of our forecast
area. The hurricane currently sits off the southern tip of Baja
California. The official NHC forecast has Lorena briefly moving
northward before taking a turn across the Gulf of California with
the remnants moving inland towards southeastern AZ, but there is
still some uncertainty on the exact track. The primary impact will
be preserving the moist airmass over northern AZ, and there will be
a few more slightly active days with continued enhanced risk of
flash flooding. One conflicting factor could be cloud shielding on
Friday, however there is still much uncertainty in when/if this
will manifest.

Sunday and beyond...After the uncertainty of Lorena, the long term
models are in strong agreement that we will enter a zonal regime.
Shortly thereafter a Pacific trough sweeps through to clear the
moisture. The result is an expected sharp decline in activity
starting Sunday, with things remaining quiet through at least the
middle of next week.

&&

.AVIATION...Wednesday 03/18Z through Thursday 04/18Z...Mainly VFR
conditions persist through Thursday with brief periods of MVFR/IFR
conditions due to scattered TSRA and low CIGS. Greatest chances
will be along and south of a KGCN-KFLG-KSOW line Expect storms to
develop ~18/19Z and continue through 03/05Z each day. -SHRA could
continue for KPRC through 09Z tonight. Outside of erratic outflow
winds of 20-35 kts, plan on light south to west winds, 5-15 kts,
during the day.

OUTLOOK...Thursday 04/18Z through Saturday 06/18Z...Look for
scattered to widespread TSRA coverage each day resulting in
periods of MVFR/IFR conditions and mountain obscuration from low
CIGS. Moderate turbulence is expected due to storms and erratic
outflow winds. Brief +RA, small hail, and lightning are the main
hazards. Anticipate southwest winds, 15-25 kts, Thursday and
Friday, becoming more west-northwest on Saturday.

&&

.FIRE WEATHER...Thursday and Friday...A monsoonal moisture surge
from the south will result in scattered to widespread showers and
thunderstorms across northern Arizona each day. Hazards include
brief heavy rainfall, lightning, and gusty outflow winds of 30 to 40
mph. Flash flooding will be a risk to burn scar areas across the
region. Temperatures will cool to 5 to 10 degrees below average.
Outside of outflow winds, expect southwest winds, 10 to 20 mph.

Saturday through Monday...Scattered to widespread showers and
thunderstorms continue on Saturday before drier conditions set in
for Sunday and Monday. Temperatures look to gradually warm up Sunday
and Monday as winds switch to the west-northwest, 15 to 20 mph.

&&

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

&&

$$

PUBLIC...Lewandowski
AVIATION...LaGuardia
FIRE WEATHER...LaGuardia

For Northern Arizona weather information visit
weather.gov/flagstaff