791
FXUS65 KFGZ 131633
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
933 AM MST Tue Aug 13 2024

.SYNOPSIS...The chance of showers and thunderstorms continues
today before drier conditions set in starting Wednesday. Monsoonal
moisture then looks to gradually return by the weekend. Near-
normal temperatures through mid week will become above normal by
late week, along with generally light winds.

&&

.UPDATE...Another day of scattered showers and thunderstorms are
expected for today across northern Arizona. PWATs are a bit lower
this morning, according to the upper air sounding at Bellemont,
however, should be enough to support scattered convective
activity. Storm motion will be towards the north-northeast at
around 10-15 mph for today. With a longwave trough passing through
the Pacific Northwest, anticipate shear to be higher as well,
resulting in greater chances for severe thunderstorms than the
past couple of days. Confidence continues to increase in a
downward trend in moisture and storm activity beginning on
Wednesday and lasting through Friday, thanks to the infiltration
of drier air from the west as the previously mentioned trough
progresses across the Intermountain West. The forecast remains on
track this morning with no changes needed at this time.

&&

.PREV DISCUSSION /343 AM MST/...A few outflow boundaries combined
with elevated moisture values and a weak disturbance are keeping
some showers and thunderstorms going early this morning over
southern Apache and Navajo counties. This activity should
dissipate by around sunrise. The monsoon high has continued to
shift off to the east as a trough moves into the Pac NW. Satellite
estimates of precipitable water are showing some drying moving in
from the west, and this should result in a bit lower coverage of
storms later today compared to the past few days. Storm motion
will also increase as this trough approaches, with today`s storms
moving toward the east-northeast around 10-15 mph, lessening the
overall threat of excessive rainfall in any one location. After
storms end this evening, the decreasing moisture values and a
developing mid-level cap will shut off storms over northern
Arizona on Wednesday and Thursday. Earlier models runs indicated
better moisture returning Friday as the high becomes re-
established over New Mexico, but have backed off on Friday`s storm
chances. The model blend is now indicating only a 20% chance for
the White Mtns Friday with less than 10% elsewhere. By Saturday
and through early next week, with the high center persisting over
New Mexico and west Texas, southerly flow over Arizona should
result in an increase in moisture and storm chances returning to
our region each day. With the high being fairly strong, daytime
highs are likely to be 5-10 degrees hotter than normal especially
in eastern Arizona.

&&

.AVIATION...Tuesday 13/12Z through Wednesday 14/12Z...SCT
SHRA/TSRA expected 19Z-02Z, mainly N/E of a P53-KPAN line. Some
lingering SHRA is possible N/E of a KPGA-KRQE line through 07Z.
Gusty winds up to 40 kts and MVFR conditions expected near +RA/TS.
Otherwise, VFR conditions with W/SW winds around 10 kts.

OUTLOOK...Wednesday 14/12Z through Friday 16/12Z...VFR conditions
with daytime winds W/SW around 10 kts.

&&

.FIRE WEATHER...Today and Wednesday...Scattered showers and
thunderstorms are expected again today, with mostly dry conditions
setting in by Wednesday. Heavy rain and gusty outflow winds will be
the main threats with any thunderstorms. Otherwise, daytime winds
west/southwest around 10 mph with near-normal temperatures.

Thursday through Saturday...Dry conditions remain through Friday,
before chances for showers and storms return by Saturday. Daytime
winds west/southwest around 10 mph with temperatures 5-10 degrees
above normal.

&&

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

&&

$$

PUBLIC...LaGuardia/JJ
AVIATION...Humphreys
FIRE WEATHER...Humphreys

For Northern Arizona weather information visit
weather.gov/flagstaff