659
FXUS65 KFGZ 121102
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
402 AM MST Mon Aug 12 2024

.SYNOPSIS...Daily chances for showers and thunderstorms continue
through Tuesday, before drier conditions set in for the middle of
the week. Monsoonal moisture then looks to gradually return by
the end of the week. Temperatures will be near-normal, along with
generally light winds.

&&

.DISCUSSION...Today and Tonight...Another round of showers and
thunderstorms are expected later this morning and into this
afternoon, with ample monsoonal moisture in place. Storms look to
initially develop over the higher terrain later this morning and
early this afternoon, then gradually pushing northward off the
terrain into the lower elevations through the early evening hours.

00Z HREF guidance forecasts around 1000 J/Kg from northwest AZ and
eastward along the Mogollon Rim, thus we`ll likely see the greatest
coverage over these areas. With amble moisture in place (PWATs
around 0.90-1.10 inches) and slow moving storms (~5-10 kts), flash
flooding will continue to be the main threats with any storms that
develop today. A couple strong to severe storms can`t be ruled out,
but any organized severe weather seems unlikely given a weakly
sheared environment with 0-6 km bulk shear around 0-6km bulk shear
< 20 kts.

Latest hi-res and U of A WRF guidance do show a complex of storms
moving northward from the Lower Deserts later this evening, which
may continue showers and storms into the overnight across central
AZ. Confidence isn`t all that high given that this will be highly
dependent upon the progression of today`s storms, but we`ll maintain
a slight chance through the early part of the overnight. Additionally,
some guidance suggests the resulting outflow from this complex
may make it further north into northeastern AZ by the early
morning hours on Tuesday.

Tuesday...Showers and thunderstorms look to return on Tuesday,
although coverage may be a bit less and mainly focused to areas
along and north of the Mogollon Rim. Flash flooding will continue to
be the main threat with any storm.

Wednesday through Sunday...Global ensemble continue to get into
better agreement with a decrease in monsoonal moisture by mid-week as
the upper-level jet becomes wavier and high pressure weakens. As
flow shifts more northerly, drier air is advected into northern AZ.
Thus, any preciptation chances mainly look to be near the White
Mountains each afternoon. Slightly warmer, near-normal temperatures
return for Wednesday and Thursday as well.

This downward trend however looks to be short-lived. Most of the
guidance is in agreement with moisture gradually retuning to the
High Country as the high shifts into a more typical position, and
subsequently a better flow regime. Thus, cooler than normal
temperatures and daily chances for showers and thunderstorms look
to gradually return by the end of the week.

&&

.AVIATION...Monday 12/12Z through Tuesday 13/12Z...SCT SHRA/TSRA
is expected 19Z-03Z, mainly N/E of a P23-KPAN-E24 line. Some
lingering SHRA is possible near KPAN/KSOW through 10Z. Gusty winds
and MVFR conditions expected near +RA/TS. Otherwise, VFR
conditions with W/SW winds around 10 kts.

OUTLOOK...Tuesday 13/12Z through Thursday 15/12Z...MVFR conditions
possible in SHRA/TSRA on Tuesday 19Z-03Z. VFR conditions are otherwise
expected with daytime winds W/SW around 10 kts.

&&

.FIRE WEATHER...Today and Tuesday...Scattered to widespread showers
and thunderstorms each afternoon and evening. Heavy rainfall and
gusty, erratic winds will be the main threats each day. Otherwise,
expected west/southwest winds around 10 mph along with slightly
below-normal temperatures.

Wednesday through Friday...Mainly dry conditions, outside of a few
isolated showers in the White Mountains. West/southwest winds 10-15
mph each afternoon and near-normal temperatures.

&&

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

&&

$$

PUBLIC...Humphreys
AVIATION...Humphreys
FIRE WEATHER...Humphreys

For Northern Arizona weather information visit
weather.gov/flagstaff