657
FXUS65 KFGZ 121120
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
420 AM MST Wed Aug 12 2026

.SYNOPSIS...Expect very active Monsoon conditions for the rest of
this week, but especially for Wednesday and Thursday. A downturn in
Monsoon activity is possible by the weekend, as drier air moves into
the region. Temperatures will move lower, even below normal in some
spots, as cloud cover and precipitation persist.

&&

.DISCUSSION...High pressure will slowly and grudgingly retreat
eastward over the next several days, as a long-wave trough forms
over the eastern Pacific. In fact, much of the next 10 days looks
like an ongoing battle between the high pressure to our east and
the troughing to our northwest.

What does this do? Well, in the short term, it allows capping to
weaken and southerly flow to increase across the region. As long as
the moisture remains in place, this is a very good recipe for active
weather. Today looks like the most active day, with slight downturns
and a eastward shift in activity afterwards. We expect moderate to
high grade Monsoon conditions today as a result and a Flash Flood
Watch has been issued.

Why has a Flash Flood Watch been issued? Many locations are quite
saturated at this point and when combined with increased instability
values, shear and PW values over the 90th percentile, the chances
for flooding are greatly increased.

By the end of the week and into next weekend, there is potential for
some drying, as the west coast trough attempts to move inland. This
could bring drier, mid-level air and effectively reduce convection
over our state. However, if the trough does not move inland as much
or if it ejects farther north, it may just keep our active weather
going. For now, we have tapered off PoPs a little bit, but we will
need to watch this pattern closely, as any change on the trough
position could make a big difference.

Temperatures will continue to trend down with the cloud cover and
precipitation, heat related headlines will not be needed.

&&

.AVIATION...Wednesday 12/12Z through Thursday 13/12Z...Mainly VFR
conditions away from thunderstorms. SCT-NMRS SHRA/TSRA and ISOLD
+TSRA through the period, but especially in the afternoon/evening
hours. Stronger storms may produce brief MVFR/IFR and wind gusts as
high as 45kts. Sfc winds are not anticipated to affect flight
operations, but will trend W-SW10-15kts Wednesday afternoon.

OUTLOOK...Thursday 13/12Z through Saturday 15/12Z...Mainly VFR
conditions away from thunderstorms. SCT SHRA/TSRA and ISOLD +TSRA
through the period, but especially in the afternoon hours. Storm
trends shift eastward by Friday. Stronger storms may produce brief
MVFR/IFR and wind gusts as high as 45kts. Expect daytime sfc winds
W-SW10-15kts.

&&

.FIRE WEATHER...Wednesday and Thursday...Expect active Monsoon
conditions for each day, with numerous showers and thunderstorms.
Outside of thunderstorms, expect southwest winds from 10 to 15 mph.
Daytime temperatures will keep decreasing as cloud cover and
rainfall increase.

Friday through Sunday...Some drying develops during this forecast
period, with the emphasis for activity shifting eastward. Daytime
temperatures will continue to trend downward. Expect southwesterly
winds at 10 to 15 mph each afternoon.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

Flood Watch from Noon MST Wednesday through Midnight MST Wednesday
evening for AZZ004>018-037>040.

&&

$$

PUBLIC...Peterson
AVIATION...Peterson
FIRE WEATHER...Peterson

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