Red Flag Warning 1, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
928 AM MST Sun May 17 2020

.SYNOPSIS...A strong, late season low pressure system will bring
windy conditions to Arizona Sunday through Tuesday, the windiest
weather is set for Tuesday. A brief cool down will also occur on
Tuesday and Wednesday, before warmer weather and less wind
develops Wednesday and Thursday. Windy weather is expected again
late in the week and into next weekend.

&&

.UPDATE...Southwest winds have begun to increase over northern
Arizona both at the surface and aloft. This is in response to a
large area of low pressure off the Pacific Northwest Coast moving
towards our area. Current forecast is on track for the windy to
very windy conditions through Tuesday.

&&

.PREV DISCUSSION /420 AM MST/...A deep upper low approaching the
northern California coastline remains on track to bring a series
of windy days to much of Arizona. Warm conditions remain today
and Monday as a ridge axis develops to our east, but winds begin
as early as this afternoon.

Expect southwest winds ranging from 10 to 20 mph, with gusts
around 30 mph this afternoon.

Expect southwest winds ranging from 15 to 25 mph, with gusts
around 40 mph by Monday afternoon.

Expect southwest winds ranging from 20 to 30 mph, with gusts from
35 to 50 mph by Tuesday afternoon.

Winds will peak Tuesday as the low moves onshore and then into the
Great Basin Tuesday night. A potent dry cold front and crashing
surface pressures in eastern Utah will aid the development of
locally strong winds north of the Mogollon Rim. Headlines will
likely be needed Tuesday, we are holding off for Monday.

A dry boundary layer today and Monday will also contribute to
potentially critical fire weather conditons. A Fire Weather Watch
has been issued for portions of northern Arizona for Monday, when
the best combination of winds, low Rh and fire danger coexist. Rh
values will likely be higher on Tuesday, due to the arrival of
colder air.

Considerably less wind and a warming trend develop Wednesday and
Thursday, in the wake of the dry cold front. However, this will be
short-lived, as another trough enters the Great Basin late in the
week and next weekend, bringing more wind and some cooling.

&&

.AVIATION...For the 18Z package...VFR conditions will prevail for
the next 24 hours. Winds today will be southwest at 10-20g20-30 kts
before becoming 5-10 kts after 02Z Monday. Winds will begin to
increase again after 16Z Monday. Expect periods of low level wind
shear tonight after 06Z at high country terminals. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Dry conditions, breezy southwest winds and warm
daytime temperatures will occur today. Southwesterly winds will be
stronger Monday. A Fire Weather Watch remains in place from 11 AM
- 8 PM MST Monday for possible Red Flag conditions.

.Tuesday through Thursday...The strongest winds of the week will
occur Tuesday with near-critical fire weather conditions.
Temperatures will cool about 10 degrees Wednesday. Dry conditions
continue through Thursday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Monday morning through Monday evening
FOR AZZ104-106-107-109-139-140.

&&

PUBLIC...MAS/Peterson
AVIATION...NL
FIRE WEATHER...NL

For Northern Arizona weather information visit
weather.gov/flagstaff