621
FXUS65 KFGZ 221617
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
917 AM MST Fri Nov 22 2024

.SYNOPSIS...Dry and unusually warm weather is forecast today and
Saturday. Beginning Sunday, a pattern shift will bring cooler
weather, along with chances for light rain and mountain snow on
Tuesday and Wednesday.

&&

.UPDATE...The cold temperatures from earlier this morning have
begun to warm up across northern Arizona. Today is forecast to be
the warmest day of the week with afternoon temperatures reaching
10-15 degrees above average for most locations. High pressure
remains in place for today along with dry conditions. Taking a
look at current water vapor imagery, much of Arizona continues to
be in a dry slot, sandwiched between a sub-tropical jet towards
the south and the polar jet towards the north. The ongoing
atmospheric river event, along the northern portions of the West
Coast, continues to dump rain and snow into northern California
and the Sierra. Unfortunately, much of that moisture will remain
confined towards the north through this weekend with chances for
showers for northern Arizona by next week. Not looking too
impactful at this time as confidence remains on the high side in
regards to no significant weather disruptions for next week`s
holiday travel outlook for Arizona. The current forecast remains
on track with no changes needed at this time.

&&

.PREV DISCUSSION /357 AM MST/...For today and Saturday, high
pressure remains in place across northern Arizona leading to a
continuation of unusually warm and dry weather. Otherwise, expect
mostly sunny skies both days, but with breezier southwest winds on
Saturday. In terms of creating the forecast, low temperatures
predicted by the National Blend of Models continue to be several
degrees too warm. This trend will likely persist through Saturday
morning.

On Sunday and Monday, the upper-level weather pattern becomes
more zonal as a broad long-wave trough develops across the
western United States. Atmospheric moisture begins to increase
during this time, with a few ensemble members predicting light
precipitation associated with a fast-moving short-wave trough
near the Arizona/Utah border. The current forecast is calling for
a 5-15% chance of light rain and mountain snow showers, with the
higher chances over the Kaibab Plateau. Otherwise, confidence is
high that this pattern shift will bring cooler weather, along with
a round of gusty southwest winds on Sunday.

Tuesday and Wednesday, nearly all clusters predict that a low-
pressure system will influence northern Arizona`s weather;
however, uncertainty with regard to the timing and overall
strength remain. The current forecast calls for a 10-50% chance of
rain and mountain snow showers on Tuesday and Wednesday, with the
higher chances north of Interstate 40. Little to no snow
accumulations are forecast, although a few ensemble members
predict localized pockets up to 2-3 inches over higher terrain
along the Arizona/Utah border.

From Thursday onward, uncertainty is high with regards to the
evolution of the upper-level weather pattern.

&&

.AVIATION...Friday 22/12Z through Saturday 23/12Z...VFR conditions
will persist under varying amounts of high clouds. Look for light
and variable winds generally less than 10 kts.

OUTLOOK...Saturday 23/12Z through Monday 25/12Z...VFR conditions
are forecast except late Sunday into Monday from KGCN northward
where isolated -SHRA and MVFR conditions will be possible. Winds
becoming southwest at 15-25 kts after 18Z both Saturday and
Sunday.

&&

.FIRE WEATHER...Today and Saturday...Little change to the dry and
mild pattern across northern Arizona. Light, terrain driven winds
are forecast for today, followed by southwest winds at 15 to 25 mph
on Saturday.

Sunday through Tuesday...An approaching Pacific low will deliver
increasing moisture and cooler daytime temperatures. It will remain
dry through Sunday but with increasing chances for rain and snow
showers on Monday and Tuesday, especially along and north of I-40.
Southwest winds gusting to 20 to 35 mph are likely on Sunday,
becoming lighter at 10 to 20 mph for Monday and Tuesday.

&&

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

&&

$$

PUBLIC...LaGuardia/RR
AVIATION...McCollum
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff