595
FXUS65 KFGZ 290518
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1018 PM MST Fri Jun 28 2024

.SYNOPSIS...A lull in shower and thunderstorm development will
arrive today and Saturday, before moisture returns and brings an
active pattern back to the area by early next week.

&&

.UPDATE...Showers continue to diminish across Navajo and Apache
counties this evening. Even less coverage is expected on
Saturday...limited to areas south and east of Happy Jack. Current
forecast covers this well.

&&

.PREV DISCUSSION /441 PM MST/...A drier southwest flow will be over
northern Arizona the next couple of days, thanks to persistent
troughing across the northwestern U.S. The FGZ sounding this
morning showed a decrease in precipitable water with drying in the
mid and upper levels. This will lead to a downturn in daytime
convection today and Saturday. However, there is still enough low
level moisture to fuel isolated storms as far west as Flagstaff
today, and mostly near the White Mountains on Saturday. Expect
enhanced afternoon breezes today with gusts up to 25 mph. With
less convective activity and more sunshine, expect daytime
temperatures to increase through the weekend, reaching a few
degrees above late June normals.

Subtropical high pressure over the southern plains will gradually
build west later this weekend, leading to a transition back to
south/southeasterly flow. This in conjunction with active
monsoonal activity forecast in northern Mexico will bring monsoon
moisture back to the area. By Sunday, rain and thunderstorm
chances return to all of northern Arizona. A moderate monsoon
pattern with daily thunderstorm chances will continue through the
middle of next week.

By late next week, operational and ensemble runs of the GFS and EC
continue to forecast a strong high pressure circulation setting up
over the west coast and migrating into the Great Basin. This is a
day and hot pattern for much of northern Arizona. Expect a
decreasing trend in preciptation chances Thursday onward. The
caveat is the moisture pool south of the Mogollon Rim. The drier
northerly flow that develops may not be strong enough to push
across the Rim. This means the valleys below the Rim could see
thunderstorms chances continue while the remainder of the area
dries out. Heat will become more of a concern under this pattern,
and our temperatures and Heat Risk guidance show us nearing
thresholds by Thursday/Friday of next week.

&&

.AVIATION...Saturday 29/06Z through Sunday 30/06Z...Expect mainly
VFR conditions. Isolated showers and thunderstorms developing
Saturday afternoon along and south of a KPAN-KRQE line.
Gusty/erratic winds to 40 kts in the vicinity of storms. Away from
storms, southwest winds 5-15 kts with gusts up to 25 kts.

OUTLOOK...Sunday 30/06Z through Tuesday 02/06Z...Moisture and
storm chances increasing and spreading north Sunday and Monday.
Afternoon southwest winds 10-20 kts becoming light during the
overnight hours.

&&

.FIRE WEATHER...Today through Sunday...Notably drier weather is
expected through Saturday, though isolated thunderstorms are still
possible. The lowest RH is expected Saturday when it drops to
between 15-30%. Southwest to west winds 10-15 mph with afternoon
gusts up to 25 mph. Stronger outflow winds possible near any
storms.

Monday through Wednesday...Moisture and thunderstorm chances
begin to increase again from Sunday through the middle of next
week. Southwest to west winds 10-20 mph each day.

&&

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

&&

$$

PUBLIC...MAS/MCT
AVIATION...McCollum
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff