Flash Flood Warning 12, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1204 PM MST Sun Jul 12 2026

.SYNOPSIS...Monsoon moisture will return to the area through the
coming week bringing better storm chances, especially for areas
along and south of the Mogollon Rim. With the added moisture,
hot temperatures begin to trend downward Monday ending up towards
seasonal averages later in the week.

&&

.DISCUSSION...A strong high pressure system aloft was in the
process of building over the north-central United States. The
position of the high will place much of Arizona in a favorable
position for increasing monsoon moisture over the coming week.

For today...Thunderstorm complexes over southern Arizona and
northwest Mexico last night collapsed pushing moisture northward
across portions of south and central Arizona. The result, deep
moisture is in place from about the Mogollon Rim southward. Model
sounding CAPE values range from around 200 J/kg across the
Mogollon Rim to 400-600 J/kg at lower elevation south of the
Rim. As storms build over the higher terrain of the Mogollon Rim,
White Mountains and San Francisco Peaks with daytime heating storm
motion to the west and southwest is expected (a combination of
steering flow aloft and downslope moving outflow). The strongest
storms are expected to be toward the southern edge of the Mogollon
Rim southward across Yavapai and Gila counties where the highest
CAPE values will be found. With hot temperatures continuing at the
lower elevations any thunderstorm downpours will be capable of
producing 45-60 mph winds gusts, the result of evaporational
cooling. As usual, localized downpours in excess of 1.0 inch in
less than an hour are likely. Values of CAPE south of the Rim are
such that an isolated storm or two will be capable of producing
nickle size hail. Elsewhere, further north and east weaker and
more isolated storms are expected as moisture is laking further
north.

For the remainder of the week...The high aloft will remain over
the north-central United States into Wednesday before an inverted
trough moving from east to west (south of the high center)
dominates the weather across the southwest United States through
next weekend. The net result is the door will remain open to the
continued intrusion of moisture from over the Gulf of California
and northwest Mexico, gradually working it's way further north.
Look for active monsoon weather to continue with the chances for
daily showers and thunderstorms continuing through into next
weekend.

&&

.AVIATION...Sunday 12/18Z through Monday 13/18Z...VFR with MVFR
possible near heaviest storms. Scattered showers/storms expected
between 18Z-04Z today, mainly south and west of a KGCN-KFLG-KJTC
line. Winds SW- SE 5-15kts daytime, light and variable or terrain
driven overnight. Gusty and erratic winds up to 30-40kts possible
in vicinity of storms.

OUTLOOK...Monday 13/18Z through Wednesday 15/18Z...VFR with MVFR
possible near heaviest storms. Scattered showers/storms each
afternoon mainly between 18Z-04Z throughout most of the area.
Winds SW-SE 5-15kts daytime, light and variable or terrain driven
overnight. Gusty and erratic winds up to 30-40kts possible in
vicinity of storms.

&&

.FIRE WEATHER...Monday and Tuesday...Temperatures trending back
towards normal as monsoon moisture increases across the area.
Showers and thunderstorms likely each afternoon along the higher
elevations with a 10-30% chance of showers or thunderstorms in the
high desert regions. Winds S-SE 5-15 mph Monday, S-W 5-15 mph
Tuesday.  Min RH's 15% deserts to 35% mountains Monday, 15% deserts
to 40% mountains Tuesday.

Wednesday through Friday...Afternoon and evening showers and
thunderstorms likely across most of the region each day with the
best chances over the higher elevations. Temperatures near seasonal
averages. Winds S-SW 5-15 mph. Min RH's 15-30% deserts to 50-60%
mountains.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM MST /9 PM MDT/ this evening for
AZZ005-006.

&&

PUBLIC...McCollum
AVIATION...Bernhart
FIRE WEATHER...Bernhart

For Northern Arizona weather information visit
weather.gov/flagstaff