Flash Flood Warning 117, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
332 PM MST Thu Aug 23 2018

.SYNOPSIS...Deep monsoon moisture will bring another round of
afternoon and evening thunderstorms Friday. Drier air advecting
into the region will lead to a downturn in shower and
thunderstorm activity over the weekend into early next week.

&&

.DISCUSSION...Scattered to numerous shower and thunderstorm
activity is ongoing across northern Arizona this afternoon. Storms
have been most numerous across Coconino and Yavapai counties with
more isolated activity over eastern portions of the Rim. Latest
hi-res guidance indicates storm activity will diminish through the
evening hours with little in the way of overnight convection.

Another active monsoon day looks to be on tap for Friday. Moisture
will slightly decrease over northern portions of the area so
expect thunderstorms to be more focused along the Rim from roughly
Flagstaff to the White Mountains with more isolated activity to
the north. Drier air will continue to slowly advect into the
region over the weekend resulting in a continued decrease in
convection. However, enough moisture will remain in the White
Mountains for scattered to numerous storms each afternoon.

A drier airmass will remain in place early next week so we are
only expecting isolated monsoon activity each afternoon. Long
range model guidance indicates these drier conditions could last
well into next week.

&&

.AVIATION...For the 00Z package...Sct-nmrs shra/tsra and isold +tsra
diminishing after 02z. Most active areas along and west of a KPGA-
KGCN-FLG-KSOW line. Brief MVFR/IFR possible in the strongest cells.
Light winds, except for thunderstorm outflows. Shower and
thunderstorm activity decreases Friday with the most active areas
along the Rim from KFLG southeast to the White Mountains. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Monsoon moisture will remain over the district
with good chances for showers and thunderstorms again Friday. Drier
air will slowly move in beginning Saturday resulting in a downturn
in shower and thunderstorm activity for areas north and east of the
Mogollon Rim.

Sunday through Tuesday...Drier air will remain over the region
leading to decreased shower and thunderstorm activity. Scattered
showers and thunderstorms are still expected in the White
Mountains region each afternoon.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

PUBLIC...TPS
AVIATION...TPS
FIRE WEATHER...TPS

For Northern Arizona weather information visit
weather.gov/flagstaff