930 FXUS65 KFGZ 052054 AFDFGZArea Forecast Discussion National Weather Service Flagstaff AZ 154 PM MST Fri Sep 5 2025
.SYNOPSIS...Scattered showers and thunderstorms are expected through Saturday. Dry air starts to move in on Sunday delivering isolated activity through early next week. Fall-like weather is expected to set in mid to late next week with the a potential return of the chances for showers and thunderstorms.
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.DISCUSSION...Monsoon moisture will hang around through Saturday with decent chances for showers and thunderstorms continuing. A drier westerly flow will develop on Sunday and last through at least Tuesday. Enough moisture will linger for a slight chance of showers and thunderstorms but our expectation is that it will remain mainly dry. By mid to late next week forecast models diverge, and to put it simply, they range from wet to dry to severe thunderstorm potential. We`ll need to get closer in time to start making that call.
For tonight...Diminishing showers and thunderstorms but with isolated activity continuing through the night. The thunderstorm complex we saw Friday morning through the early afternoon will squash most daytime heating across northwest Arizona and from Interstate-40 southward, so any activity in these locations will be low key. Further north there`s just not enough moisture for more than a stray shower or two.
On Saturday...Monsoon moisture will remain in place. We will see the more typical daytime heating and midday through early evening thunderstorm development. Activity will start mainly over the high terrain first then progress to the lower elevations. No widespread flash flood or severe weather threat is anticipated.
For Sunday through Tuesday...A drier westerly flow will develop across northern Arizona. The result will be some drying but with enough moisture lingering for isolated showers and thunderstorms, mainly toward the Arizona/New Mexico border. Turning a bit warmer. In general, winds will remain on the light side as pressure gradients will remain weak.
From Wednesday onward...Revisit the end of the first paragraph in this discussion, forecast chaos. We have fair confidence that breezes will strengthen and temperatures will cool resulting in a fall-like feel as a trough moves across the western states. But as far as the remainder of the forecast, please check back. The position of the eventual trough will be critical as to how much moisture, if any, gets pulled across Arizona.
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.AVIATION...Friday 05/18Z through Saturday 06/18Z...Mainly VFR expected, brief MVFR in SHRA/TSRA. Scattered SHRA/TSRA between 18Z and 03Z. Gusty outflow winds 20-40kts ahead of TSRA as well as localized gusty erratic wind in immediate vicinity of TSRA. Otherwise expect winds W 5-15 kts daytime with light and variable or terrain driven winds overnight.
OUTLOOK...Saturday 06/18Z through Monday 08/18Z...Mainly VFR expected with brief MVFR in SHRA/TSRA. Scattered SHRA/TSRA after 18Z on Saturday, only isolated SHRA/TSRA over higher terrain on Sunday. Expect gusty outflows 20-40 kts ahead TSRA as well as localized gusty erratic wind in immediate vicinity of TSRA. Otherwise expect S-W winds 5-15 kts daytime, light and variable or terrain driven overnight.
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.FIRE WEATHER...Saturday and Sunday...Scattered showers and thunderstorms expected on Saturday, however things become more isolated and confined to the higher terrain Sunday as a trough moving in from the West Coast dries things out. Main hazards will be heavy rainfall, frequent lightning, and gusty/erratic winds. Outside of storms, expect westerly winds at 10-20 mph. Min RH`s Saturday 25- 35% high deserts, 45-55% mountains and forests. Min RH`s Sunday drop to 25-35% area-wide.
Monday through Wednesday...No showers or thunderstorms expected on Monday as dry air moves into the area. A little more moisture moves in on Tuesday and Wednesday and may produce an isolated storm over the Mogollon Rim and White Mountains. Winds S-SW at 10-20 mph on Monday and Tuesday, increasing S-SW 15-25 mph on Wednesday. Minimum RH values drop to the 15-30% range each day.
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.FGZ WATCHES/WARNINGS/ADVISORIES...None.
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PUBLIC...McCollum AVIATION...Bernhart FIRE WEATHER...Bernhart
For Northern Arizona weather information visit weather.gov/flagstaff
NWS FGZ Office Area Forecast Discussion