631 FXUS65 KFGZ 191134 AFDFGZArea Forecast Discussion National Weather Service Flagstaff AZ 434 AM MST Fri Sep 19 2025
.SYNOPSIS...Areas of showers and thunderstorms will continue through the day today, before fading out over the weekend. Unsettled conditions with seasonable temperatures look to continue into early next week.
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.DISCUSSION...Today...As the remnant low from Tropical Storm Mario moves northward through California, sub-tropical moisture continues to be advected northward into Arizona. An area of steady showers with some embed thunder has develop across northern Arizona early this morning as result, and will continue to traverse northeastward through the morning hours. An additional complex of storms over the Phoenix Metro looks to move northward this morning as well, brining another round of showers to the area.
Rainfall rates have largely be 0.10-0.50"/hr this morning, with a few heavier pockets embedded. This along with storm motions around 15 kts should limit the overall flash flood potential, at least outside of any training storms or flood sensitive areas.
A brief lull is expected after daybreak, before another round of scattered showers and thunderstorms develops during the afternoon hours. This activity will likely be delayed given the lingering debris clouds from activity this morning. Flash flooding will continue to be the main threat, especially with training storms. However, a few strong to severe storms will remain possible, mainly over Yavapai and Gila counties where pockets of stronger instability look to be present.
Saturday and Sunday...Heights look to rise slightly into the weekend as high pressure builds to the south, while at the same time, an upper-level low begins to eject off the Pacific. Our unsettled pattern looks to remain as a result, with another surge of moisture ahead of the low. As a result, daily chances for afternoon showers and thunderstorms look to continue over the weekend, along with seasonal temperatures.
Monday through Thursday...Solutions still look to diverge in exactly what happens with the low at the start of next week. Much of the operational guidance seems to stall it out just off the coast, keeping the moisture pipeline into Arizona open. However, just how long it stays stalled out remains in question. Nevertheless, unsettled conditions with seasonable temperatures are expected as a result.
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.AVIATION...Friday 19/12Z through Saturday 20/12Z...Mainly VFR conditions are forecast. Look for isolated SHRA/TSRA before 18Z becoming scattered to numerous after 18Z. Gusty and erratic winds and brief MVFR conditions possible in and around TSRA. Outside of storms, expect daytime southwest to northwest winds at 5-15 kts with a few gusts over 20 kts, becoming light and variable at night.
OUTLOOK...Saturday 20/12Z through Monday 22/12Z...VFR conditions are expected. Isolated -SHRA/-TSRA are forecast mainly along and south of KFLG-KJTC line on Saturday and Sunday. Expect daytime south to southwest winds at 5-15 kts with a few gusts over 20 kts, becoming light and variable at night.
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.FIRE WEATHER...Today and Saturday...Expect thunderstorms to redevelop over much of central and northern Arizona by the afternoon. Wetting rains are likely. Isolated thunderstorms will be possible again on Saturday, but more confined to the higher terrain. Minimum RH values will range between 30-50% today and 25-40% on Saturday. Winds southwest to west at 5-15 mph with a few higher gusts during the afternoon, light and variable or terrain driven overnight.
Sunday through Tuesday...Look for isolated showers and thunderstorms on Sunday and Monday, turning drier on Tuesday. Minimum RH values 20-35% Sunday and Monday dipping to 15-25% on Tuesday. Winds southwest at 5-15 mph gusting to 25 mph on Sunday then turning light at 15 mph or less for Monday and Tuesday.
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.FGZ WATCHES/WARNINGS/ADVISORIES...None.
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PUBLIC...Humphreys AVIATION...McCollum FIRE WEATHER...McCollum
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NWS FGZ Office Area Forecast Discussion