979
FXUS65 KFGZ 032056
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
156 PM MST Mon Jun 3 2024

.SYNOPSIS...Much warmer temperatures and dry conditions are
expected this week as high pressure builds over the Southwest.
Temperatures begin to cool gradually for this weekend with the
potential for a few showers and thunderstorms.

&&

.DISCUSSION...Breezy southwest winds with scattered to broken mid
to upper-level clouds and near average temperatures are taking
place this afternoon across much of northern Arizona. Conditions
remain dry with current humidity at or below 15% across the
region. Cloud cover will continue from north to south through this
evening as a storm system makes its way through the Pacific
Northwest. Expect cool, near average temperatures overnight with
light and variable winds.

The forecast remains on track with a high pressure ridge building
over the Southwest beginning on Tuesday. From then through Friday,
anticipate a warming and drying trend to persist with daytime high
temperatures peaking on Thursday and into Friday, roughly 10-15
degrees above average for this time of year. These forecast high
temperatures are flirting with record highs on Thursday and Friday
as heights maximize. Confidence has grown in the potential for
this early season heat to develop which is why the Excessive Heat
Watches have been upgraded to Heat Warnings, mainly focused on
the lower valleys of Yavapai County and the Grand Canyon to Page
from Thursday through Friday. The heat is on and can be dangerous
for most. Don`t be a jabroni!

With potentially record heat during the day, the question
is...will we see any relief at night? Even though overnight lows
through the remainder of the week will also be 10-15 degrees above
average, given how early it is in the heat season and with dry
conditions present, expect a cool down into the low 50s/60s with
the warmest low temperatures in the low 70s for our lower valley
locations.

Besides for temperatures, expect mostly dry conditions to persist
with west-northwest breezes, 10-20 mph, for Tuesday and
Wednesday, followed by a return of west-southwest winds, 15-25
mph, for Thursday and Friday.

As for precipitation chances through this week, things look glum
at this time. Both GEFS and EPS ensemble guidances have PWAT
values gradually increasing each afternoon this week with even the
slightest chance of a shower/thunderstorm to develop along the
high terrain on Thursday as the ridge axis begins to shift
eastward, allowing more of a southerly flow. Confidence remains
very low in regards to any precipitation during this time as
conditions at the surface will remain quite dry (i.e. virga
showers). Ensemble guidance does continue to suggest additional
shower and thunderstorm chances for this weekend and into next
week, however moisture looks to be limited with any storms being
high-based, hybrid type storms with little rainfall (<0.10") and
the chance for dry lightning and gusty outflow winds. Will have
to keep our eye on the potential for a pesky, cut-off low to form
off the Baja coast later this week and into the weekend, which
could influence moisture availability in a positive way. However,
this will all depend on the overall strength of the already in
place ridge.

&&

.AVIATION...Monday 03/18Z through Tuesday 04/18Z...VFR conditions
will continue under increasing high clouds tonight into Tuesday.
SW to WSW winds today 10-15 kts gusting 20-25 kts through 03Z,
decreasing to near and below 10 kts overnight.

OUTLOOK...Tuesday 04/18Z through Thursday 06/18Z...VFR conditions
will continue through the outlook period. Look for W-NW winds 5-15
kts on Tuesday, becoming more variable in direction on Wednesday.
Overnight winds are forecast to be light and variable.

&&

.FIRE WEATHER...Today through Wednesday...Expect warming
temperatures each day with minimum RH dropping to 10-20%. Overnight
recover will be moderate ranging from 30-70%. Winds become west to
northwest 10-20 mph Tuesday, and then become lighter and more
variable on Wednesday.

Thursday through Saturday...The hottest weather yet this season is
expected on Thursday and Friday when temperatures will near record
heat. Southwest to west-southwest winds 10-20 mph each afternoon. A
20-30% chance for dry thunderstorms develops over the White
Mountains Thursday through Saturday, which could lead to new
wildfire starts.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

Excessive Heat Warning from 10 AM MST /11 AM MDT/ Thursday to 8
PM MST /9 PM MDT/ Friday for AZZ005-006-037.

&&

$$

PUBLIC...LaGuardia
AVIATION...MCT
FIRE WEATHER...MCT

For Northern Arizona weather information visit
weather.gov/flagstaff