997
FXUS65 KFGZ 132031
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
131 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.

&&

.DISCUSSION...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...Saturday 13/18Z through Sunday 14/18Z...Mainly VFR
conditions. SCT-WDSPRD SHRA/TSRA with MVFR or lower possible,
mainly between 19Z-03Z. Gusty and erratic outflow winds in
vicinity of storms. Otherwise, winds 5-15 kts.


OUTLOOK...Sunday 14/18Z through Tuesday 16/18Z...Mainly VFR
conditions. SCT-WDSPRD SHRA/TSRA with MVFR or lower possible,
mainly between 19Z-03Z each day. Gusty and erratic outflow winds
in vicinity of storms. Otherwise, west winds 10-20 kts.

&&

.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...McCollum
AVIATION...MAS
FIRE WEATHER...MAS

For Northern Arizona weather information visit
weather.gov/flagstaff