569
FXUS65 KFGZ 152255
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
355 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 16/00Z through Thursday 17/00Z...Scattered
-SHRA/-TSRA likely to continue through 06Z, primarily along and
 east of a KPGA-KGCN-KPRC line. A few stray showers could continue
 beyond 06Z, mostly south of I-40. Additional widespread SHRA/TSRA
 forecast after 18Z. VFR conditions forecast outside of brief MVFR
 conditions in heavier storms. Gusty/erratic winds 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 17/00Z through Saturday 19/00Z...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...
Extreme Heat Warning until 7 PM MST this evening for AZZ006.

&&

$$

PUBLIC...RR
AVIATION...Konieczny
FIRE WEATHER...RR

For Northern Arizona weather information visit
weather.gov/flagstaff