031
FXUS65 KFGZ 140512
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1012 PM MST Sat Jul 13 2024

.SYNOPSIS...Scattered showers and thunderstorms are expected each
day through next week as we enter into an active monsoon pattern.
Temperatures will remain near average during this time with
typical afternoon winds.

&&

.UPDATE...Made some adjustments for POPs for this evening as most
activity is already over for the night. Likewise, looking at
latest CAMs and WRF guidance for tomorrow, much of the activity
from Flagstaff west looks to be more isolated/subdued compared to
today. Meanwhile, from Flagstaff down south along the Rim,
activity will increase for tomorrow afternoon and evening, which
is a flip from today where most activity was to the west and the
eastern half of the area was far more tame. It does still looks
like showers and storms will push of the Rim, traveling southwest
into part so of Gila and Yavapai Counties. Timing could be pretty
late in the afternoon/evening for Yavapai county when instability
would be decreasing.

&&

.PREV DISCUSSION /427 PM MST/...High pressure in the mid-levels
of the atmosphere was centered over southwest Colorado and the
Four Corners midday Saturday, forecast to remain in place through
Monday. By Tuesday a trough diving over the eastern states in
combination with a separate trough moving across the Pacific
Northwest will cause the high center to move westward and amplify.
It`s looking like the high will become centered over northern
Arizona on Tuesday and Wednesday then gradually shift further
north later in the week. In any case, monsoon moisture will remain
over the state with chances for showers and storms continuing.

For the remainder of Today...Looks like the target zone for
showers and thunderstorms remains from about Prescott northward
toward the Grand Canyon and northwest portion of Coconino County.
The flow has shifted to more southeasterly helping to deliver
additional moisture to central and western portions of Arizona. In
addition, the southeast flow will tend to push storms toward the
northwest. Elsewhere, if anything, the southeast flow has moved
drier air from over New Mexico across eastern and northeast
portions of Arizona with isolated thunderstorms anticipated across
those areas.

Sunday and Monday...High pressure will remain in place with
monsoon moisture gradually increasing across northern Arizona
leading to somewhat better chances for showers and thunderstorms.
The steering flow during this period will tend to push any storms
southwestward. Most will form over the high terrain first then
move into the lower elevations. The deepest moisture will remain
from the Mogollon Rim southward where storms will be most
numerous. However, the circulation around the high will allow for
additional moisture to move over the northeast portion of the
state with a slight uptick in storm coverage there.

From Tuesday onward...The high moves over Arizona on Tuesday and
Wednesday. Moisture will remain, although in reduced amounts, as
a slightly drier north to northeast flow develops. We could see a
bit of a downturn in activity over these two days but not a
complete shutdown like we experienced earlier this month. Look for
low grade monsoon activity with the best chances over the higher
terrain. Starting Thursday the high begins to shift northward
toward Utah and Nevada. If this shift occurs the door will open to
a period of very active weather from the Mogollon Rim southward
as thunderstorm outflows from over Mexico and southern Arizona
bank up against the Mogollon Rim. Isolated activity will continue
further to the north where drier air will likely filter in from
the northeast.

&&

.AVIATION...Sunday 14/06Z through Monday 15/06Z...VFR conditions overnight
with a few sprinkles possible mainly north of I-40. Scattered showers
and thunderstorms develop again after 19Z Sunday, first over the higher
terrain and spreading into valleys by mid afternoon. MVFR conditions
briefly in stronger storms. There is a chance that showers or thunderstorms
could last into the late evening hours. Winds in the afternoon and
evening will be highly influenced by outflows, with local gusts
to 35 kts.

OUTLOOK...Monday 15/06Z through Wednesday 17/06Z...Daily SHRA/TS
opportunities will persist, but VFR conditions are expected outside
of those. Winds will remain variable, especially in the afternoons
and evening when outflows will be spread out across the region.

&&

.FIRE WEATHER...Sunday and Monday...Monsoon moisture will continue
to increase. Expect widespread afternoon and evening showers and
thunderstorms, most numerous near the Grand Canyon and along and
south of the Mogollon Rim and White Mountains. Isolated activity
further north. Outside of gusty/erratic outflow winds at 35-45 mph,
winds will be southerly around 5 to 15 mph each afternoon. Slightly
cooler daytime temperatures.

Tuesday through Thursday...Shower and thunderstorm coverage will be
on the decrease coinciding with a bit drier air mass. West to
northwest winds around 5 to 15 mph each day with gradually warming
temperatures.

&&

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

&&

$$

PUBLIC...RKR/McCollum
AVIATION...JJ
FIRE WEATHER...MAS

For Northern Arizona weather information visit
weather.gov/flagstaff