961
FXUS65 KFGZ 021015
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
315 AM MST Thu May 2 2024

.SYNOPSIS...Warm, dry, and breezy conditions continue through the
end of the week. More unsettled weather and strong winds will
impact the area this weekend into the start of next week.

&&

.DISCUSSION...Tranquil weather conditions are taking place across
northern Arizona early this morning with clear skies, little to no
wind, and near average temperatures. Zonal flow will develop this
afternoon and continue through Friday resulting in mild, daytime
temperatures, dry conditions, and westerly winds of 10-20 mph. A
weak trough looks to pass by from the southwest Friday evening
into early Saturday, however, little to no impacts besides for
some increasing cloud cover, should take place.

For this weekend, the synoptic weather pattern becomes unsettled
as a strong, Pacific low pressure system looks to make its way
through much of the West. The majority of the moisture associated
with this system will likely be confined to north-central
California, Nevada and into Utah for Saturday into Sunday. Much of
the Southwest will have to deal with the strong southwest winds on
Sunday as a result of a passing cold front with strong upper-level
jet support.

By Saturday afternoon, southwest winds begin to increase in
strength with widespread gusts of 25-35 mph. Winds are forecast to
remain elevated Saturday night and into early Sunday morning
across much of the High Country leading to relatively mild
overnight low temperatures without full decoupling taking place.
Then, the southwest winds become strong and widespread by Sunday
afternoon with gusts of 35-55 mph and localized gusts as high as
65 mph in wind prone locations. Global models indicate 700 mb
winds of 50-65 kts on Sunday along with excellent agreement in
regards to the ECMWF Ens with peak wind gusts of 45-55 mph for the
Flagstaff region, White Mountains region, and much of the Little
Colorado River Valley and into the Navajo/Hopi Nation.

Went ahead and added in areas of blowing dust mainly across
northeast Arizona for Sunday afternoon with impacts likely along
I-40, from Twin Arrows to the New Mexico border. Afternoon
humidity will be greater (25-35%) along and west of the Mogollon
Rim during this time, however, is expected to remain quite low
(10-15%) across the Little Colorado River Valley and the Navajo
Nation, leading to heightened concerns for critical fire weather
conditions. Having said that, from personal experience driving
around these portions of the state last week, much of the limited
vegetation was still in "green up" with decent flows in the Little
Colorado River and Chinle Wash. Even with the strong winds and low
humidity, fuels look to be not quite there yet for any fire
weather products at this time.

The strong winds look to decrease after sunset on Sunday,
remaining breezy (15-30 mph) from the west for much of next week.
Daytime temperatures will be "cool" on Sunday followed by a
warming trend for next week. As for chances of precipitation on
Sunday, much of northern Arizona looks to remain dry, however,
have decided to add in mentionable POPs (15-20%) along the Kaibab
Plateau and the western Mogollon Rim due to the slight increase in
moisture along the higher terrain (upslope flow) and presence of
strong forcing along the frontal boundary. Other than that,
anticipate dry conditions for the rest of next week.

&&

.AVIATION...Thursday 02/06Z through Friday 03/06Z...VFR under
mostly clear skies. Light W-SW surface winds overnight will become
breezy W-SW winds by 17Z with gusts generally below 20 kts from
19Z onward. FEW to SCT clouds in the afternoon will dissipate
shortly after sunset as winds weaken once again.

OUTLOOK...Friday 03/06Z through Sunday 05/06Z...VFR conditions
persist with minimal cloud cover. Afternoon W-SW winds at 10-15
Friday will shift to more S-SW and strengthen Saturday to 15-20
kts, gusting near 30 kts. Expect winds to remain breezy overnight
Saturday into Sunday.

&&

.FIRE WEATHER...Today and Friday...Mild temperatures and dry
conditions. Winds west/southwest winds 10-20 mph with afternoon
minimum RH around 10-20%.

Saturday through Monday...Cooling temperatures, with mainly dry
conditions outside of stray shower on Sunday over the high terrain.
Southwest winds gusting 30-40 mph on Saturday, then increasing to 50-
60 mph on Sunday. Near-critical to critical fire weather conditions
are likely from the Little Colorado River Valley into the Chinle
Valley and Chuska Mountains.

&&

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

&&

$$

PUBLIC...LaGuardia
AVIATION...Mazon
FIRE WEATHER...Humphreys

For Northern Arizona weather information visit
weather.gov/flagstaff