199
FXUS65 KFGZ 240522
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1022 PM MST Thu Jul 23 2026

.SYNOPSIS...High pressure will build into the area through the weekend.
This will lead to a slight decrease in monsoonal moisture, though
expect continued showers and thunderstorms each day. Also expect hotter
temperatures. A return to increased monsoon moisture is possible
by the beginning of next week.

&&

.DISCUSSION...The easterly wave that rippled through our area over
the past few days has fully departed. Heights aloft are quickly
building today as the ridge strengthens and expands westward. The
location of the ridge is less optimal for moisture advection into
Northern Arizona, however plenty of moisture still lingers with
dewpoints in the 50s and PW near the 90th percentile. Surface
heating has been uninhibited this morning under clear skies, and
scattered showers thunderstorms are firing along terrain features
as of 1230 MST. The flash flooding threat is lesser than previous
days, but still remains the primary hazard given the moist
profile, saturated ground conditions, and very slow storm motion.

The ridge remains strong while moisture continues to trend downward
on Friday. Monsoon activity will be more low-medium grade with
isolated to scattered storms in the forecast. By late Saturday into
Sunday, the ridge begins to back of a bit and center towards the
Four Corners. Another complicating factor will be the potential
arrival of an easterly wave associated with the remains of Tropical
Storm Bertha, though this may follow a trajectory too far south.
With heights at 500 mb reaching well above normal through the
period, hot temperatures are expected over the the lower elevations
of our forecast area. An Extreme Heat Warning will be in effect
Friday through Sunday for the lower elevations of the Grand Canyon
and Marble/Glen Canyons.

On Monday through the middle of next week, the ridge looks to stay
centered to our east and the door remains open for good moisture
advection into northern AZ.

&&

.AVIATION...Friday 24/06Z through Saturday 25/06Z...Mainly VFR
expected. ISO-SCT SHRA/TSRA between 18Z-03Z. Brief MVFR/IFR
conditions, gusty/erratic winds, and hail possible in stronger
storms. Outside of storms, expect light and variable or terrain
driven winds.

OUTLOOK...Saturday 25/06Z through Monday 27/06Z..Mainly VFR
expected. ISO-SCT SHRA/TSRA, mainly between 18Z-03Z each day.
Brief MVFR/IFR conditions, gusty/erratic winds, and hail possible
in stronger storms. Outside of storms, expect light and variable
or terrain driven winds.

&&

.FIRE WEATHER...Friday through Saturday...Scattered afternoon and
evening showers and thunderstorms are expected over the higher
terrain, with only isolated activity at lower elevations. High
temperatures warm close to 10 degrees above average. Winds are
generally light through the period outside of outflow and
thunderstorm activity. Minimum RH`s 15-20% in the lower deserts to
35% higher terrain.

Sunday through Tuesday...Monsoon trends upward Sunday through
Tuesday with scattered showers and thunderstorms expanding coverage
outside the higher terrain and into the deserts. Temperatures 5-10
degrees above average Sunday trend back towards average Monday and
tuesday. Generally light winds outside of outflow and thunderstorm
activity. Minimum RH 15-25% lower deserts to 40-50% higher terrain.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning from 10 AM MST /11 AM MDT/ Friday to 8 PM
MST /9 PM MDT/ Sunday for AZZ005-006.

&&

$$

PUBLIC...Lewandowski
AVIATION...Meola
FIRE WEATHER...Bernhart

For Northern Arizona weather information visit
weather.gov/flagstaff