795
FXUS65 KFGZ 301059
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
359 AM MST Sun Aug 30 2026

.SYNOPSIS...Active monsoon pattern will continue through Monday
night, with flash flooding being a primary concern. Calmer
conditions forecast to return for the middle of the week.
Unsettled weather looks to return by the end of the week/next
weekend.

&&

.DISCUSSION...Isolated to scattered activity remains mostly east
of I-17 and south of I-40, and hi-res guidance suggests this
southeastern portion of our CWA to be the center of attention for
showers/storms through the rest of the overnight period. The
severe threat appears to have dwindled, but there`s plenty of
lightning and brief heavy showers still out there. A Flash Flood
Watch continues through 5 AM MST for Yavapai County, northern Gila
County, and Oak Creek and Sycamore Canyons.

An additional Flash Flood Watch is in place starting at 2 PM MST
today (Sunday) for all of central/northern AZ and continues
through late Monday night. Monsoonal moisture hangs on tight
today and much of Monday. This is reflected in our PWAT values
ranging from an inch towards the AZ/UT border and near 1.5 inches
across the Mogollon Rim southward. Taking a look at the recent U
of A WRF run, activity this afternoon could be slightly delayed
from early morning debris clouds, so expect showers/storms to pick
up closer to noon-1PM. Initially, we`ll see activity fire up
along the Rim and northward, but then the potential for a MCS to
form south of our CWA later in the evening will lead to
widespread showers/storms Sunday night into Monday.

By Tuesday, we`ll see a quick decline in PWATs as a shortwave
trough glides across the Great Basin region and pushes moisture
further south. There is still potential for isolated activity
primarily across the Kaibab Plateau and White Mountains Tuesday
through Thursday, but overall should be much quieter in terms of
active weather for the middle of the week. Not to mention the
westward trajectory of Tropical Storm Karina will not help bring
in any additional moisture during this timeframe.

Friday onward we could return to an active monsoon pattern. Model
guidance suggests high pressure strengthening across the central
US and another tropical system funneling up the western California
Baja Coast. There`s still uncertainty on how everything will pan
out, but for now know we could see a quick return of active
weather Friday and over the upcoming weekend.

&&

.AVIATION...Sunday 30/12Z through Monday 31/12Z...VFR conditions
expected through at least 18Z, with decreasing
ceilings/visibilities likely afterwards due to increasing chances
for SHRA/TSRA. Showers/storms will continue through the end of
the period after 18Z. Gusty/erratic winds likely near storms, with
W-SW winds 10-20 kts otherwise.

OUTLOOK...Monday 31/12Z through Wednesday 02/12Z...MVFR/IFR
conditions may continue through 06Z Tuesday, due to persistent
SHRA/TSRA. Afterwards, expect quickly improving conditions.
Gusty/erratic winds likely near storms, with SW winds 10-20 kts
during the afternoon hours and becoming light and variable
overnight.

&&

.FIRE WEATHER...Sunday and Monday...Active monsoon weather
continues each day, as well as into the overnight hours. Storms will
be capable of producing hail, heavy rain, frequent lightning, and
gusty/erratic winds. As a result of the heavy rain threat, a Flash
Flood Watch is in place for all of central/northern AZ Sunday
afternoon through Monday night. A cooling trend is expected, leaving
daytime highs 5-10 degrees below normal by Monday. Outside of storm
driven outflows, look for southwest winds 5-15 mph Sunday, becoming
lighter out of the south on Monday.

Tuesday through Thursday...Precipitation chances will quickly
decline through the middle of the week, but an isolated shower/storm
across the higher terrain is not completely out of the question.
Daytime highs will slowly warm each day, bringing temperatures
closer to seasonal norms. Look for southwest winds 10-20 mph each
afternoon, becoming light and variable overnight.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 2 PM MST /3 PM MDT/ this afternoon through
Monday evening for AZZ004>018-037>040.

Flood Watch until 5 AM MST early this morning for AZZ008-018-037-
038.

&&

$$

PUBLIC...Konieczny
AVIATION...Konieczny
FIRE WEATHER...Konieczny

For Northern Arizona weather information visit
weather.gov/flagstaff