Wind Advisory 11, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1036 AM MST Thu Apr 4 2024

.SYNOPSIS...Unsettled weather will impact northern Arizona
Thursday afternoon into Friday, bringing strong winds, cold
temperatures, and a chance of rain and snow early Friday morning
into Saturday morning. Another chance of rain and snow returns
next week.

&&

.UPDATE...A few high clouds are beginning to stream in from the
west this morning. South and southwest winds will strengthen today
ahead of the approaching system and become quiet breezy by the
afternoon. Today will be the last warm day until perhaps the
middle of next week, so enjoy it while it lasts. The current
forecast is in good shape and no updates are needed at this time.

&&

.PREV DISCUSSION /443 AM MST/...A longwave trough is approaching the
coast of California this morning with the low pressure center
expected to push inland and over the Great Basin area by Friday.
This system will bring colder temperatures along with a chance of
rain and snow to the region. But the most impactful change in the
weather will be blustery winds. Models have been mostly consistent
on the position of this trough. However, as more Hi-Res models
are factored into the NBM, both the wind speed forecast and QPF
are trending downward slightly.

That said, expect breezy conditions in northwest Arizona beginning
this afternoon with south winds at 15 to 25 mph, gusting 30 to 40
mph. Winds will increase significantly overnight and spread
further eastward with strong south-southwest winds all day
Friday. Models indicate 700 mb winds peaking at 65 to 75 mph
north of the Mogollon Rim on Friday with the GFS being on the
higher end compared to the ECMWF. Expect sustained winds between
20 and 40 mph with gusts ranging from 35 to 55 mph across much of
the region. Even stronger winds are possible over and immediately
downslope of the highest terrain, including the San Francisco
Peaks, White Mountains, Black Mesa, Chuska Mountains, and Kaibab
Plateau with gusts of 60+ mph. A High Wind Watch remains in place
from Thursday evening through Friday evening.

Temperatures will drop rapidly as the cold front moves eastward
across the state with afternoon highs roughly 20 degrees cooler
on Friday compared to today. A slight chance (10-20%) of rain and
snow showers begins Friday morning as precipitation chances are
expected a tad earlier now. Showers will continue as chances
increase (30-55%) by the late afternoon into the evening, especially
for the Flagstaff area and along the Mogollon Rim. There is limited
atmospheric moisture associated with this system with the GFS and
ECMWF precipitable water briefly reaching 0.25", which is average
for this time of year. Snow levels will be near 6000' to 6500'
initially, dropping to near 4000' overnight. A fresh 1-2" of snow
is forecast for some areas above 6000' with slightly more accumulation
above 7500'. Generally less than an inch can be expected below
6000'. The combination of strong winds with slick roads and
localized blowing dust will create adverse driving conditions
Friday. Prepare accordingly.

There will be a break in precipitation and strong winds Sunday,
but colder than average temperatures will remain through the
weekend. Another trough will impact northern Arizona towards the
start of next week with models currently indicating the best
chance of rain/snow occurring from late Monday into Tuesday
afternoon. At this time, widespread precipitation is not expected
with minimal to no snow accumulation. Models indicate a weaker
low and relatively warmer conditions compared to Friday's system.
However, temperatures will remain below our seasonal average. By
midweek, a ridge will begin bringing improved conditions and
warmer temperatures to the region. Unfortunately, it is unclear
how long these improved conditions will last.

&&

.AVIATION...Thursday 04/18Z through Friday 05/18Z...VFR conditions
through 15Z Fri, then lowering ceilings from KFLG-KGCN westward with
rain/snow showers developing and MVFR/localized IFR at the higher
elevations. Winds 15-25 kts G25-40 kts through tonight, with locally
higher gusts downstream (northeast) of terrain features. Wind gusts
35-50 kts becoming more widespread from KGCN-KFLG-KSOW north and
east after 15Z.

OUTLOOK...Friday 05/18Z through Sunday 07/18Z...Snow/rain showers
and lowering ceilings increasing from west to east Friday afternoon
and evening, ending by around 09Z-12Z Sat. MVFR and localized IFR
conditions. Conditions quickly improve Saturday morning with VFR
conditions after 13Z-15Z. Friday, expect SW winds 20-35 kts, gusting
40-50 kts, strongest along and NE of a KGCN-KFLG-KSOW line. Winds
decrease after the arrival of precip Friday evening. Winds Saturday
remain breezy from the west with gusts above 30 knots likely in
eastern AZ.

&&

.FIRE WEATHER...Today through Friday...Increasing SW winds today
with 15-25 mph sustained and gusts 30-40 mph. Many lower elevation
locations will have min RHs fall into the teens this afternoon.
Stronger winds Friday at 20-30 mph with gusts 40-60 mph.
Temperatures turn cooler with precipitation arriving during the
afternoon into Friday night.

Saturday through Monday...Precipitation chances end Saturday morning
with cold conditions and west winds 15-25 mph gusting 30-40 mph.
Drier weather with lighter winds for Sunday before the next system
brings breezy winds and a slight chance of precipitation Monday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from this evening through Friday evening for
AZZ004>007-009>017-039-040.

&&

PUBLIC...Benji/JM
AVIATION...JJ
FIRE WEATHER...RKR

For Northern Arizona weather information visit
weather.gov/flagstaff