338 
FXUS65 KFGZ 042100
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
200 PM MST Sun Apr 4 2021

.SYNOPSIS...Warm, dry and windy weather is expected through this
week. A passing dry trough will create the strongest winds of the
week on Monday and Tuesday. A Red Flag Warning and Wind Advisory
are in effect Monday afternoon for parts of Coconino, Navajo and
Apache counties, along with much of the Navajo Nation. A low heat
risk continues Monday for elevations below 4000 feet in the Grand
Canyon and across the valleys and basins in Yavapai County.

&&

.DISCUSSION...The main weather hazards and resulting impacts of
this forecast will be centered on Monday and Tuesday with much 
quieter typical springtime weather through the rest of the week.

Visible satellite imagery this afternoon is showing mostly sunny 
skies across northern Arizona. The exception is residual mid-level
cumulus clouds over high terrain areas of far eastern Arizona and
the Navajo Nation. Cloud cover in these areas is expected to 
decrease quickly after sunset.

Seasonally very warm temperatures are being observed on surface
stations this afternoon in the valleys of Yavapai County and in
the bottom of the Grand Canyon. Although a few degrees of cooling
is expected on Monday, another very warm day is in store for the 
lower elevations. Bring extra water if you are working or recreating
outdoors and come prepared again for afternoon temperatures anywhere
from 85-93 F in Yavapai County and closer to 97 F at Phantom Ranch.

Beyond warm temperatures again Monday afternoon, there is also the
risk for critical fire weather conditions and driving impacts for
high profile vehicles Monday afternoon in the high country. A dry
trough passing over the Great Basin will tighten the lower and 
mid-level gradients by Monday morning. Daytime mixing heights are
progged to reach upwards of 550 mb tomorrow afternoon. The result
will be daytime winds of 15-25 mph and gusts of 35-45 mph. A Wind
Advisory was issued for much of eastern Coconino County and the
Black Mesa as a result of these wind gusts. These strong winds
will also combine with very low dewpoints and increasingly drier
fuels for critical fire weather conditions. The previous Fire
Weather Watch has been upgraded to a Red Flag Warning for Monday 
afternoon and early evening. Any fires that do start tomorrow have
the potential to rapidly spread. Do not drag chains if towing 
anything or park on very dry grasses!

Winds are expected to remain gusty northeast of high terrain 
areas Monday night. There is good operational agreement the 
trough will pass over northern Arizona by Tuesday morning and
produce slightly cooler temperatures for Tuesday. Persistent gusty
westerly to northwesterly winds could create near-critical fire 
weather conditions in far eastern Arizona Tuesday afternoon.

Deterministic operational and ensemble guidance is progging a
return to a ridge building again over the state on Wednesday. Flow
aloft will remain very dry so the forecast continues with no
chances of mentionable precipitation over the next seven days.

&&

.AVIATION...For the 00Z package...Expect VFR conditions and mostly
clear skies for the 24 hour TAF forecast period. Surface winds 
today at SW10-20 knots until 02Z then light overnight. Southwesterly
winds increase again after 16z with afternoon winds 15-25 knots 
and gusts 30-40 knots. Aviation discussion not updated for TAF 
amendments.

&&

.FIRE WEATHER...Much windier and drier weather arrives Monday, 
with continued well above normal temperatures. A Red Flag Warning
has been issued for far southeastern Coconino County and much of 
Navajo and Apache counties for Monday afternoon and evening. 
Gusty westerly to northwesterly winds continue Tuesday with near- 
critical fire weather conditions possible in far eastern Arizona.

Wednesday through Friday...Above normal daytime temperatures and 
continued dry conditions persist, with typical springtime westerly
breezes each afternoon.


&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Wind Advisory from noon to 7 PM
MST (1 PM - 8 PM Navajo Nation) Monday FOR AZZ012-015-039.

Red Flag Warning from noon to 7 PM MST (1 PM - 8 PM Navajo Nation)
Monday FOR AZZ110-111-113- 114-116-140.


&&

$$

PUBLIC...NL
AVIATION...NL
FIRE WEATHER...NL


For Northern Arizona weather information visit weather.gov/flagstaff