Flash Flood Warning 20, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
413 PM MST Tue Jul 14 2026

.SYNOPSIS...Monsoon moisture will return to the area through the
coming week with daily storm chances, along with the risk for
heavy rainfall and localized flooding. With the added moisture,
temperatures will trend toward normal and even dropping below
normal by late week.

&&

.DISCUSSION...Northern Arizona will remain in an active monsoon
pattern as the general flow remains favorable for the continued
movement of monsoon moisture to the area.

For Today...Monsoon moisture has made its way across all of
northern Arizona. As a result, almost any location could see a
shower or thunderstorms. The odds at any single location will
30-50% percent for this afternoon through this evening. As usual,
the higher terrain locations will likely get hit first with storms
then wandering into the lower elevations from the late afternoon
into the evening. Isolated thunderstorms could even continue
through the night as outflow boundaries running across the area
encounter any remaining pockets of instability. The highest CAPE
values will be south of the Mogollon Rim where pockets of 200-500
J/kg will exist. Isolated storm will be capable of producing
localized flash flooding, wind gust 30-40 mph and hail up to
around nickle size. From the Mogollon Rim northward CAPE values
of 100-200 J/kg will be the norm with garden variety thunderstorms
anticipated capable of producing locally heavy downpours and
small hail but with a limited flash flood threat.

For the remainder of the week...The high aloft will remain over
the north-central United States into Wednesday before an inverted
trough moves across Arizona from the east. The arrival of the
trough will place northern Arizona under a weak northeast to
southwest steering flow aloft. However, moisture in the low levels
will remain ample due to flow from over the Gulf of
California/northwest Mexico and daily recycling of rainfall
through evapostranspiration. The interesting aspect of this
pattern is that there will be the typical afternoon development of
showers and thunderstorms over the higher terrain followed by
storm outflow in the evening from over New Mexico then later in
the night from over Colorado. This will likely result in
continued chances for showers and storms through the overnight
periods. In other words, look for active monsoon weather through
the weekend.

The weekend and beyond...High pressure becomes reestablished over
a favorable position to the north and east of Arizona for active
monsoon weather to continue.

&&

.AVIATION...Wednesday 15/00Z through Thursday 16/00Z...VFR mainly
expected. Isolated to scattered -SHRA/-TSRA possible through 12Z,
becoming more widespread after 18Z. Brief MVFR conditions possible
throughout the afternoon/evening hours on Wednesday from heavier
showers/storms. Gusty/erratic winds possible from outflows, with
W-SW winds 10 kts or less otherwise forecast.

OUTLOOK...Thursday 16/00Z through Saturday 18/00Z...Continuous
-SHRA/-TSRA expected, with greatest coverage generally between
 18Z-04Z each day. Gusty/erratic winds possible near/around
 storms, with generally S-W winds 10 kts or less otherwise. VFR
 conditions expected outside of brief MVFR conditions in heavier
 storms.

&&

.FIRE WEATHER...Wednesday and Thursday...Daily chances for showers
and thunderstorms, with the greatest chances over the higher
terrain. Some activity may last into the overnight hours. Wetting
rains and gusty outflow winds possible with any stronger storm.
Outside of storm activity, winds south through west 5-15 mph.

Friday through Sunday...Daily chances for showers and thunderstorms
continue, with the best chances over the higher terrain. Wetting
rains and and gusty outflow winds possible with any stronger storm.
Outside of storm activity, winds south through west 5-15 mph.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

PUBLIC...McCollum
AVIATION...Konieczny
FIRE WEATHER...Humphreys

For Northern Arizona weather information visit
weather.gov/flagstaff