336
FXUS65 KFGZ 270831
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
131 AM MST Fri Jun 27 2025

.SYNOPSIS...Warming temperatures and mainly dry conditions continue
through the weekend. Isolated showers around the White Mountains
today, then more widespread shower and thunderstorm activity sets in
through the week.

&&

.DISCUSSION...Today through Monday...The weak troughing we have
seen across the west lately has weakened and will give way to a
building ridge. This pattern will keep us mostly dry across the
region with gradually warming temperatures through the weekend. As
the temperatures warm we will start to see the potential for extreme
heat in parts of the area, especially in the lower elevations of the
Grand Canyon and Yavapai county. The peak of the heat looks to
arrive for Sunday-Monday, with temperatures at Phantom Ranch
expected to exceed 110 degrees. Saturday looks more marginal for
extreme heat with it more likely to occur for Sunday and Monday.
heat headlines will likely be needed but with some uncertainty as to
whether or not Saturday will reach criteria, we will hold off
issuing any with this forecast package. Regardless of whether there
is a headline, it will be hot and you will need to take precautions
if spending time outside.

Aside from the heat, there is some moisture that will work its way
in from the east and keep slight chances for some high-based showers
or thunderstorms over the White Mountains this afternoon. Moisture
advection looks to be less over the weekend but a stray shower
cannot be ruled out.

Tuesday through the end of the week...As the ridge takes hold, it
will shift and settle towards the Four Corners early in the week.
Meanwhile, another trough digs down along the California coast and a
potential tropical system will move bear the southern tip of the
Baja California peninsula. All of these features will help to put a
more southerly flow across the region and will allow for better
moisture advection into the state, with deeper moisture pushing
northward through the week. This will bring increased chances for
showers and thunderstorms through much of the week and it certainly
looks like it is finally the onset of the monsoon! We will need to
see what happens with the trough/low to our west as it may try to
make a push eastward and this could impact how far west the moisture
and storms make it through the week. For now, we will be optimistic
and be glad we are seeing moisture return to the region as we head
into July.

&&

.AVIATION...Friday 27/06Z through Saturday 28/06Z...Expect VFR
conditions. Areas CU/TCU over southern Apache County redeveloping by
18Z-20Z Friday, with ISOLD high-based -SHRA/-TSRA possible INVOF the
White Mtns for the same time frame. Daytime sfc winds S-SW10-20kts.

OUTLOOK...Saturday 28/06Z through Monday 30/06Z...Expect VFR
conditions. Areas CU/TCU over southern Apache County each afternoon
with ISOLD high-based -SHRA/-TSRA possible over the White Mtns. This
daytime convective activity may push westward a bit each day, due to
outflows, but confidence is low. Daytime sfc winds S-SW10-20kts.

&&

.FIRE WEATHER...Today and Saturday...Mainly dry and warm conditions,
outside of a slight chance for high-based showers and thunderstorms
near the White Mountains each afternoon. Southwest to west winds 5-
15 mph with gusts to 20-25 mph each afternoon. Afternoon minimum RH
values 5-15% both days. Gusty, erratic winds possible in and around
thunderstorms.

Sunday through Tuesday...Warmer and mainly dry conditions on Sunday.
Monsoon moisture starts to build in with daily chances for showers
and thunderstorms. Afternoon minimum RH values 5-15% through Monday,
increasing to 15-25% on Tuesday. Westerly winds 5-15 mph with gusts
of 20-25 mph Sunday, becoming southwest on Monday, then more
southerly on Tuesday. Gusty, erratic winds possible in and around
thunderstorms.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

PUBLIC...Meola
AVIATION...Peterson
FIRE WEATHER...Meola

For Northern Arizona weather information visit
weather.gov/flagstaff