618
FXUS65 KFGZ 051738
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1038 AM MST Sun May 5 2024

.SYNOPSIS...A strong low pressure will cross the region today
bringing strong, gusty winds and isolated to scattered showers.
Winds will decrease late tonight but remain breezy through much of
the week. Temperatures will remain cool and conditions will remain
dry through the week as several troughs cross through the region.

&&

.UPDATE...The current forecast is on track. Strong winds will be
observed across much of northern Arizona today into this evening.
In addition, some shower activity will move in later this
afternoon with the best chances toward the Utah border.

&&

.PREV DISCUSSION /416 AM MST/...A deep upper level low will dig southward,
crossing the Great Basin and moving through our region today.
This system is anomalously strong for this time of year and is
quite cold aloft. There will be several things to discuss with
this low so we will break it down by hazard.

First, the pressure gradient tightens up and as a result we will see
extremely gusty and strong winds, especially as we move through the
day. While most areas will see winds gusting up to around 40-50 mph,
there will be areas of 55-65 mph, mainly to the north and east of
the Mogollon Rim. Highest gusts are likely to be downwind of the
higher terrain so be prepared for strong winds, especially if out
and about today. No changes were made to the current headlines as
they look well placed based on the latest guidance and expected wind
gusts.

Second, guidance continues to increase the precipitation chances
across the region as the low passes to the north. While we still
aren`t expecting blockbuster amounts of precipitation, it is looking
more likely that we will see some showers as far south as the I-40
corridor through this afternoon. Additionally, as the low pushes to
the east, there will be a good amount of cold air aloft. Even though
we have relatively warm temperatures ahead of the this system, the
cold air will have little preventing it from working its way down to
the surface. This means there is a good chance that the rain will
changeover to snow in some locations. Snow levels that start off
above 8500 feet will drop as the associated cold front moves through
and quickly fall to 5500-6500 feet. While accumulations are not
likely in most locations, could see a few inches accumulate in some
of the higher elevations. Most likely areas are over the Kaibab
Plateau and the San Francisco Peaks. Just don`t be shocked if you
see some flakes falling from the sky as we move through this
evening.

Third, as previously mentioned, there is a good deal of cold air
associated with this system. This will result in temperatures
falling to below normal. Overnight lows tonight will be quite cold
with the typically colder spots dropping down into the low to mid
20s! If you have put any plants out recently, it wouldn`t be a bad
idea to bring them indoors or cover them to protect them from the
freezing temperatures.

Fourth, limited potential for near critical fire weather continues
for today. Strong southwest winds and RH values in the 10-20% range
are expected but fuels remain marginal, outside of the area around
St. Johns, where a Red Flag Warning remains in place.

Once the low passes to the east of the region, we will see things
dry out rather quickly. However, several troughs will cross the
region through the week, keeping temperatures on the cool side and
winds breezy each day. No precipitation is expected through the rest
of the week.

With the strong winds and dry conditions continuing through the
week, we will see afternoon RH values drop in the 5-15% range. While
this raises the potential for near critical fire weather concerns
over the course of the week, it will be the fuels that may end up
being the limiting factor.

&&

.AVIATION...Sunday 05/18Z through Monday 06/18Z...Expect very
strong winds and generally VFR conditions through the TAF period,
with the exception of periods of MVFR ceilings/visibilities
between 21Z-06Z due to -SHRA/SHSN along and north of I-40 as a
cold front moves west to east across the area. Isolated MVFR
conditions from blowing dust near KINW, KSJN, and KRQE will be
possible due to the winds. Look for SW winds 20-35 kts, gusting
40-55 kts. Localized areas may see gusts up to 65 kts. Winds will
decrease west to east after 04Z.

OUTLOOK...Monday 06/18Z through Wednesday 08/18Z...VFR conditions
expected through the outlook period. Look for west winds 15-25
kts, gusting 30-40 kts on both Monday and Tuesday afternoon.
Strongest winds will be along and east of a KGCN-KFLG-KSOW line.

&&

.FIRE WEATHER...Sunday and Monday...Southwest winds will quickly
ramp up today, with sustained speeds between 25-35 mph gusting 40-55
mph. Localized areas downslope of terrain may see gusts upwards of
60 mph. Red Flag conditions expected for portions of Apache County
this afternoon. Rain and snow chances likely across higher terrain
north of I-40 today. Winds will become lighter on Monday out of the
west, gusting 20-30 mph.

Tuesday through Thursday...Breezy west winds, especially along AZ/NM
border, stick around for Tuesday, becoming lighter west through
north winds Wednesday and Thursday. Dry conditions will persist each
day along with temperatures a few degrees below normal.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 9 PM MST /10 PM MDT/ this evening for
AZZ004>007-009>017-039-040.

Wind Advisory until 9 PM MST this evening for AZZ008.

Red Flag Warning until 9 PM MST this evening for AZZ114.

&&

$$

PUBLIC...McCollum/Meola
AVIATION...BAK
FIRE WEATHER...BAK

For Northern Arizona weather information visit
weather.gov/flagstaff