022 FXUS65 KFGZ 150808 AFDFGZArea Forecast Discussion National Weather Service Flagstaff AZ 108 AM MST Mon Sep 15 2025
.SYNOPSIS...High pressure over the Southwest will result in seasonable temperatures, light winds, and mostly dry conditions through the next few days. Chances for showers and thunderstorms look to return by the second-half of the week.
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.DISCUSSION...Today...Weak ridging remains in place over northern Mexico, keeping cooler temperatures and mainly dry conditions in place across northern Arizona. The only real shot at a couple afternoon showers and storms today look to be over the White Mountains, but even then, activity looks to be minimal.
Tuesday and Wednesday...Tropical Storm Mario off the tip of Baja California looks to initiate a moisture surge up the Gulf, with moisture increasing over southern Arizona each day. While at the same time, the ridge looks to retrograde and become elongated from Nevada across Arizona into New Mexico. These two contradicting forces look to create a sharp moisture souht-north gradient somewhere across northern Arizona, with the drier northwest flow cutting off any sub-tropical moisture advection. Current guidance looks to cut off any of the deeper moisture near the Mogollon Rim, thus any chances for precipitation through the middle of the week will largely be from the Rim and south. Model soundings also show a fairly significant subsidence inversion aloft with the ridge in place, which will also limit the overall coverage of storms. Warmer, but still seasonable temperatures also look to set in through Wednesday.
Thursday through Sunday...By the end of the week, guidances has the remnants of Mario ejecting off the Pacific into southern California, before being absorbed into the mean flow. Flow begins to shift to favor increased moisture advection over a larger portion of the area as a result. There are many moving parts here, and the exact timing and track of each part will greatly impact the extent of the moisture push. The operational guidance still varies greatly on where the low ejects, so confidence remains low, however ensemble members do seem to be favoring an increase in PWAT more so than in previous runs. Outside of the precipitation chances, cooler temperatures look to return to northern Arizona to close out the week.
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.AVIATION...Monday 15/06Z through Tuesday 16/06Z...VFR conditions are forecast. Light and variable winds overnight will become southwest at 5-15 kts on Monday.
OUTLOOK...Tuesday 16/06Z through Thursday 18/06Z...VFR conditions are expected. Look for a 10-20% chance of -SHRA/-TSRA south of a KSOW-KSJN line on Tuesday and Wednesday afternoon. Winds southwest to west at 5-15 kts each day, becoming light and variable during the overnight periods.
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.FIRE WEATHER...Today and Tuesday...Mostly dry with near-average temperatures. Slight chance for showers and thunderstorms in the White Mountains each afternoon. Afternoon winds west/southwest 5-15 mph with minimum RH 10-25% each day.
Wednesday through Friday...Chances for showers and thunderstorms increasing each day, mainly along and south of the Mogollon Rim. Daytime winds west/northwest 5-15 mph, becoming southwest by Friday. Minimum RH 10-25% through Thursday, increasing to 20-40% on Friday.
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.FGZ WATCHES/WARNINGS/ADVISORIES...None.
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PUBLIC...Humphreys AVIATION...McCollum FIRE WEATHER...Humphreys
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NWS FGZ Office Area Forecast Discussion