267
FXUS65 KFGZ 122319
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
419 PM MST Fri Jul 12 2024

.SYNOPSIS...Hot temperatures will continue today, with a slight
cooling trend over the weekend. Increasing moisture each day with
widespread chances for afternoon showers and thunderstorms
continuing into early next week.

&&

.DISCUSSION...High pressure in the mid-levels of the atmosphere
was centered over southern Utah midday, continuing to make slow
progress eastward. The high will then settle in over Colorado and
the Four Corners area through the weekend. By Tuesday a trough
diving over the eastern states in combination with a separate
trough moving across the Pacific Northwest will squeeze our high
pressure system pushing it westward. At this time the high looks
to be a strong one and will become centered over northern Arizona.
This is not the pattern for widespread thunderstorm activity,
especially over northeast portions of the state. The result,
likely a downturn in activity Tuesday potentially lasting into
Friday.

Today through Monday...Look for increasing shower and
thunderstorm activity as monsoon moisture increases. The deepest
moisture will be located from the Mogollon Rim southward and where
storms are expect to be most numerous this afternoon and on
Saturday with east to southeast steering slow. On Sunday and
Monday the flow turns more southerly with a random wobble of the
high leading to a somewhat better chances shifting northward. For
today and Saturday the main threat from storms will be wind gusts
in excess of 45 mph, half inch hail and cloud-to-ground
lightning. As moisture increase localized flash flooding could be
come a threat on Sunday and Monday.

From Tuesday onward...The high moves over Arizona. Moisture will
remain although in reduced amounts as a slightly drier north to
northeast flow develops. We are looking for a downturn in activity
for the second half of next week 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.

&&

.AVIATION...Saturday 13/00Z through Sunday 14/00Z...VFR conditions
will persist outside of heavier SHRA/TSRA. Showers/thunderstorms
will greatly decrease after 06Z, before another round of SHRA/TSRA
begins after 18Z Saturday. Gusty and erratic winds are likely near
storms, with winds 10-20 kts varying in directions otherwise.


OUTLOOK...Sunday 14/00Z through Tuesday 16/00Z...Widespread
SHRA/TSRA forecast each afternoon/evening, with quieter weather
anticipated overnight. VFR conditions expected outside of MVFR
ceilings/visibilities from heavier storms. Gusty and erratic
winds likely with storm development, but west winds 10-20 kts
expected otherwise.

&&

.FIRE WEATHER....FIRE WEATHER...Saturday and Sunday...Monsoon moisture
will increase each day with showers and thunderstorms becoming
more widespread, most numerous from the Grand Canyon, Mogollon Rim
and White Mountains southward. Isolated activity further north.
Outside of gusty/erratic outflow winds to 35-45 mph from storms,
anticipate a return of southerly winds at 5 to 15 mph each
afternoon. Turning a bit cooler.

Monday through Wednesday...Widespread showers and thunderstorms will
continue on Monday with the greatest chances along and south of the
Mogollon Rim and the White Mountains. Coverage becomes more
scattered on Tuesday and Wednesday as moisture decreases slightly.
Afternoon west-northwest winds at 5 to 15 mph are forecast. Warming
by a few degrees each day.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 8 PM MST /9 PM MDT/ this evening
for AZZ005-006.

&&

$$

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

For Northern Arizona weather information visit
weather.gov/flagstaff