


Area Forecast Discussion
Issued by NWS Flagstaff, AZ
Issued by NWS Flagstaff, AZ
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734 FXUS65 KFGZ 160521 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 1021 PM MST Tue Jul 15 2025 .SYNOPSIS...Hot temperatures to continue through today, with isolated to scattered showers and thunderstorms bringing gusty winds, but mostly light rainfall. An uptick in monsoonal moisture is forecast Wednesday through Friday, with widespread showers and thunderstorms expected each day. && .DISCUSSION...Storm activity is forecast to continue through the afternoon and evening hours, likely becoming quiet across northern Arizona after midnight. The main hazards from today`s storms will be strong outflow winds and lightning. There is only a minor risk of flash flooding today, but that is going to change over the coming days. Wednesday through Friday...We are still on track to see increasing chances for showers and thunderstorms across northern Arizona. High pressure to the east of the state and a weak tropical disturbance near the Gulf of California will combine to transport a deep plume of tropical moisture into the area. In fact, we are expecting unusually high atmospheric moisture, with PWATs forecast to be near the 90th percentile for this time of year. It continues to look like the most widespread activity will occur on Thursday, as added upper-level dynamics from the approaching trough interact with the deep moisture to aid in upscale growth for the storms. With this transition to more wet conditions, the risk of flash flooding will increase. Along with this uptick in storms will come noticeably cooler weather. Afternoon highs from Wednesday onward look to be around 5-10 degrees below normal for this time of year. As a result, the Extreme Heat Warning for the Grand Canyon will expire this evening. Saturday through Monday...Over the weekend the aforementioned trough begins to propagate eastward, ushering in drier air behind it (especially across the western-half of the state). Global ensembles do point to a downward trend in PWATs as a result. However, with the ridge still in place to the east, the monsoonal flow looks to keep enough moisture remaining in place to keep isolated to scattered activity in the forecast. && .AVIATION...Wednesday 16/06Z through Thursday 17/06Z...A line of -SHRA/-TSRA continues along and north of a KFLG-KSOW line this evening. Expect isolated to scattered showers to continue through 12Z, before more widespread SHRA/TSRA returns after 18Z. VFR conditions forecast outside of brief MVFR conditions in heavier storms. Gusty/erratic winds (35-45 kts) likely near TS. HZ/FU likely near KGCN from local wildfires. Outside of storm driven winds, look for SW-NW winds 10-20 kts. OUTLOOK...Thursday 17/06Z through Saturday 19/06Z...Widespread SHRA/TSRA forecast to continue through the period, with strongest storms likely between 18Z-04Z each afternoon/evening. VFR conditions will persist outside of brief MVFR conditions in heavier SHRA/TSRA. Gusty/erratic winds, heavy rain, and hail will be possible each day. Outside of storm driven outflow winds, look for W-SW winds 5-15 mph. && .FIRE WEATHER...Wednesday and Thursday...Increasing monsoon moisture will bring scattered thunderstorms Wednesday, becoming more widespread Thursday. These storms will be capable of producing a wetting rainfall. Gusty outflow winds and flash flooding will be the primary hazards. Otherwise, daytime winds are southwest through west 5-10 mph with gusts 10-20 mph each day. Friday through Sunday...Widespread shower and thunderstorm activity Friday, beginning to decrease in coverage on Saturday. Wetting rains are likely within any stronger storms. Winds west/southwest 5-10 mph with gusts 10-20 mph each day. Gusty, erratic winds possible in and around thunderstorms. && .FGZ WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...RR AVIATION...Konieczny FIRE WEATHER...RR For Northern Arizona weather information visit weather.gov/flagstaff