Flash Flood Warning 64, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
945 AM MST Wed Sep 13 2023

.SYNOPSIS...Areas of showers and thunderstorms will continue through
Thursday. Drier weather will develop by Friday and continue over the
weekend, however, isolated showers and thunderstorms cannot be ruled
out. Temperatures remain seasonable, with generally light winds.

&&

.DISCUSSION...Moisture and instability continue to be present
across Arizona, especially central Arizona. This moisture is a
combination of several sources, former Hurricane/TS Jova continues
to inject some mid-level moisture and is responsible for initiating
this convection a few days ago. Also, there remains residual Monsoon
moisture south of the Mogollon Rim and over the deserts, as well as
recycled moisture and ground moisture from days of activity.

This moisture will interact with cool temperatures aloft, much of
our CWA is around -10C, which makes up for dwindling PW values by
providing instability. There are also a series of weak troughs in
the eastern Great Basin that will provide occasional lift through
Friday, before a ridge sets up next weekend.

We expect a fairly active day today as a result, especially south of
the I-40 corridor, where the deeper moisture exists. By no means are
we ruling anywhere out, all zones carry at least scattered coverage
today. The 12Z KFGZ sounding has some potential for isolated severe
and training of cells may lead to isolated flooding issues.

On Thursday, we start to see some decrease in activity as PW values
continue to fade, however, enough dynamics and instability remains
for scattered coverage, isolates stronger cells. Similar trends on
Friday, but still not enough to remove all activity.

Morning grids/forecasts look good, no updates.

&&

.AVIATION...For the 18Z TAF Package...VFR for most areas and the
majority of the time frame, except in and near convective activity.
Convective activity may cause brief MVFR. SCT-NMRS SHRA/TSRA with
ISOLD +TSRA today, especially AFT 19Z-20Z, fading coverage AFT 03Z.
Sfc winds generally light and from the SW, outside of storms.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Wednesday and Thursday...Scattered showers and
thunderstorms will stick around today and tomorrow. Gusty outflow
winds from storms will be possible, with southwesterly winds 10 to
20 mph elsewhere.

Friday through Sunday...Isolated showers and thunderstorms remain
possible through this period, but generally, expect drier and warmer
conditions will develop through the weekend. Westerly winds 5 to 15
mph Friday, before shifting southwesterly Saturday and Sunday.

&&

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

&&

PUBLIC...Peterson
AVIATION...Peterson
FIRE WEATHER...Peterson

For Northern Arizona weather information visit
weather.gov/flagstaff