987
FXUS65 KFGZ 290340
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
840 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 29/00Z through Sunday 30/00Z...Isolated
SHRA/TSRA this evening from around KSEZ to KPGA and eastward.
Brief reductions down to MVFR possible in any stronger storm,
along with outflow wind gusts up to 35 kts. Outside of storms, SW
to W winds 10-15 kts with gusts up to 25 kts.


OUTLOOK...Sunday 30/00Z through Tuesday 02/00Z...SHRA/TSRA
confined to the White Mountains Saturday, with moisture and storm
chances increasing and spreading north Sunday and Monday. SW winds
through the weekend 10-20 kts or less, 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...MAS
FIRE WEATHER...MCT

For Northern Arizona weather information visit
weather.gov/flagstaff