


Area Forecast Discussion
Issued by NWS Flagstaff, AZ
Issued by NWS Flagstaff, AZ
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883 FXUS65 KFGZ 300506 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 1006 PM MST Sun Jun 29 2025 .SYNOPSIS...Hot temperatures continue through Tuesday, with increasing moisture anticipated each afternoon through the end of the week. Daily chances for showers and thunderstorms increase each day, with the greatest coverage expected on Wednesday and Thursday. && .UPDATE...The isolated showers and thunderstorm activity has begun to decrease over the last couple of hours with the loss of daytime heating. An outflow boundary continues to move off the Rim, with some breezy conditions moving into the Verde Valley. Model soundings show a further increase in mid-level moisture during the afternoon tomorrow. given that the sub-cloud layer still remains very dry, little, if any, precipitation is expected with this activity. Thus, dry lightning and gusty outflow winds look to be the primary threat once again over the High Country. The greatest likelihood looks to remain over the White Mountains, though coverage does look to expand more into the Mogollon Rim and Chuska Mountains. Opted to expand PoPs over the higher terrain during the afternoon tomorrow, based on the latest hi-res guidance and model soundings. && .PREV DISCUSSION /402 PM MST/...High pressure is currently centered across the Arizona/New Mexico border, resulting in hot to dangerously hot temperatures across the state. We have an Extreme Heat Warning in effect through Tuesday evening for the lower elevations of the Grand Canyon. Even if you`re not hiking down into the Canyon, be sure to avoid strenuous activity during the hottest part of the day and stay hydrated! Despite the mostly dry pattern over Arizona today, there is still some lingering moisture aloft. This little bit of moisture is resulting in the increased cloud cover across the higher terrain. The chances of these clouds producing precipitation that reaches the surface is very slim, but we cannot completely rule out a virga shower or a sprinkle this afternoon across the High Country. Monday will look similar to today with hot and mostly dry conditions continuing. Look for daytime highs peaking across much of the state, and just enough moisture to bring in additional cloud cover and a few stray showers. The White Mountains look to be the main location for showers/thunderstorms for tomorrow afternoon. Tuesday through Thursday...This is when our forecast will get a little more exciting. Monsoonal moisture looks to ramp up fairly quickly as the previously mentioned area of high pressure wobbles towards the Four Corners. This pattern will allow moisture to funnel in from the south, which is also shown by elevated PWAT values across central/northern Arizona shown on the recent ensemble runs of both the GFS and the ECMWF. Although afternoon highs will gradually cool through the period, daytime heating will play a big role in the initiation of thunderstorms. It`s worth noting that hi-res guidance does suggest activity continuing during the late evening/overnight hours on Tuesday night/Wednesday morning and Wednesday night/Thursday morning. Friday through the weekend...A low pressure system that is forecast to move in across southern California through the week, will gradually shift the area of high pressure eastward. We could still see a few lingering showers during this transition, but overall moisture looks to decrease through the weekend. Another favorable monsoon pattern could return by next week, but let`s get through this first round before we get into the weeds of the next one. && .AVIATION...Monday 30/06Z through Tuesday 01/06Z...ISO -SHRA/-TSRA possible over the higher terrain 19Z-02Z. Brief MVFR conditions and gusty, erratic winds possible in and around TS. MVFR VIZ possible in HZ/FU possible near KRQE from a nearby wildfire. Otherwise, VFR conditions with winds S-W 5-10 kts. OUTLOOK...Tuesday 01/06Z through Thursday 03/06Z...SCT SHRA/TSRA expected each afternoon, mainly over the higher terrain. Brief MVFR conditions and gusty, erratic winds possible in and around TS. Winds S/SW 5-10 kts with gusts 15-20 kts each afternoon. Winds S/SE 10-20 kts Monday night into Tuesday morning, mainly across eastern Arizona. && .FIRE WEATHER...Monday and Tuesday...Hot and mostly dry weather will continue through Monday. Isolated high-based showers or thunderstorms are possible over the Mogollon Rim and White Mountains through Monday, increasing in coverage and spreading west on Tuesday. The greatest risk for dry thunderstorms will be on Monday and Tuesday. Winds will generally be from the W at about 10-20 mph Monday, shifting to the S on Tuesday. Erratic wind gusts up to 40 mph possible in/near any thunderstorms. Wednesday through Friday...Increasing moisture through Thursday with scattered to widespread showers and thunderstorms. SW through W winds 5-15 mph with gusts to 20-25 mph each day. Gusty and erratic winds are likely in the vicinity of storms. Decreased moisture and thunderstorm chances are forecast Friday into the holiday weekend. && .FGZ WATCHES/WARNINGS/ADVISORIES... Extreme Heat Warning until 7 PM MST Tuesday for AZZ006. && $$ PUBLIC...Humphreys/Konieczny AVIATION...Humphreys FIRE WEATHER...MCT For Northern Arizona weather information visit weather.gov/flagstaff