738 FXUS65 KFGZ 121751 AFDFGZArea Forecast Discussion National Weather Service Flagstaff AZ 1051 AM MST Fri Sep 12 2025
.SYNOPSIS...Windy conditions will continue today, with lighter winds and cooler temperatures arriving over the weekend. Scattered showers and thunderstorms are forecast through this evening, mainly across eastern Arizona. Most locations will see dry conditions over the weekend but a few showers could linger over far eastern Arizona into Saturday.
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.DISCUSSION...A fairly strong closed low for this time of year was centered over western Nevada this morning. Increasing pressure gradients ahead of the low will continue to bring windy conditions for one more day, with gusts in the 30-40 mph range developing by mid to late morning and continuing through around 7 PM. Daytime temperatures will be a couple degrees cooler today through Saturday as well. With the increased south-southwest flow aloft, deeper moisture located over Sonora continues to be pulled northward into eastern Arizona. This will persist through this evening, with the best chance of showers and thunderstorms east of a Heber to Kayenta line affecting Apache and portions of Navajo and eastern Gila counties. Farther west, a few showers or storms can`t be ruled out, but chances are only 10-20%. In Apache County, storm chances today are 50-70% this afternoon, decreasing by sunset. With deep layer wind shear present due to the approaching low, and increased instability in the moisture plume, there is a chance of a few strong to severe thunderstorms primarily in Apache County and southern Navajo County. The most favorable timing for the stronger storms appears to be later this morning and afternoon as daytime heating increases instability, though there is a lower chance even early this morning if storms manage to develop (an isolated strong storm has developed south of Payson as of 3 AM). Both damaging winds and large hail (1" or greater diameter) will be possible in isolated storms, and the SPC has placed all of Apache County in a marginal risk for severe weather today.
By the weekend - much drier air is forecast to sweep eastward as the low advances into our region, ending the chance of storms. This will also cause southwest winds to diminish to 10-20 mph Saturday and even lighter on Sunday. Saturday is currently forecast to be the coolest day of the forecast period, with highs around 5 degrees below normal. With the drier air and lighter winds, overnight lows will be the coolest we have seen in some time, likely into the 30s Sunday and Monday mornings for many locations above 6500 feet. The usual cold pockets (Bellemont, Tusayan, Window Rock) may approach the freezing mark. Seasonable temperatures are forecast to return next week, with some indications that another moisture plume will move northward into the state and bring a chance of showers and storms back to the area. Still quite a bit of uncertainty in this scenario, so precip chances are only in the 10-20% range beginning Tuesday, and mainly for the eastern half of the state.
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.AVIATION...Friday 12/18Z through Saturday 13/18Z...Mainly VFR conditions, but brief drops to MVFR in heavier SHRA/TSRA. Scattered SHRA/TSRA primarily east of KOV7-KINW-KPAN line, becoming isolated after 06Z Saturday. Winds S-SW 10-20 kts gusting to 30-35 kts then diminishing to 10 kts or less after 02Z.
OUTLOOK...Saturday 13/18Z through Monday 15/18Z...VFR conditions. Isolated SHRA/TSRA possible along the NM and UT state lines on Saturday, dry on Sunday. Winds SW 10-15kts with gusts 20-25kts Saturday, SW 5-10 kts Sunday. Light and variable or terrain driven wind during the overnight.
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.FIRE WEATHER...Friday and Saturday...Slightly cooler. Southwest winds 15 to 20 mph with gusts 30 to 35 mph Friday, then southwest through west 10 to 15 mph with gusts to 20 to 25 mph Saturday. There is a chance of showers and thunderstorms in eastern AZ through Friday evening, some storms could be strong. Storms will become much more isolated on Saturday and confined to areas right along the UT and NM state lines.
Sunday through Tuesday...Much drier with a return to seasonal daytime temperatures. Minimum RH is generally 10-20%, locally higher in the White Mountains. Daytime winds are south through southwest 5 to 15 mph. Slight chance for showers and thunderstorms return to the White Mountains on Tuesday.
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.FGZ WATCHES/WARNINGS/ADVISORIES...None.
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PUBLIC...JJ AVIATION...Lewandowski FIRE WEATHER...JJ
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NWS FGZ Office Area Forecast Discussion