Flash Flood Warning 39, NWS Flagstaff, AZ

332 
WGUS75 KFGZ 190253
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
753 PM MST Sat Jul 18 2026

AZC005-190500-
/O.CON.KFGZ.FF.W.0039.000000T0000Z-260719T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
753 PM MST Sat Jul 18 2026 /853 PM MDT Sat Jul 18 2026/

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 10 PM MST /11 PM MDT/
THIS EVENING FOR COCONINO COUNTY...

At 753 PM MST /853 PM MDT/, Doppler radar indicated thunderstorms
were weakening. Heavy rain that fell earlier across the warned area
produced between 2.0 and 3.0 inches in about and hours. As a result,
flash flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding.

SOURCE...Radar indicated.

IMPACT...Life threatening flash flooding of creeks and streams,
         normally dry washes and roads.

Some locations that will experience flash flooding include...
  Grand Falls and Wolf Crossing.

This includes the following creeks, washes and rivers...
  Little Colorado River and San Francisco Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding of washes and creeks will occur, some dirt roads will become
muddy and impassable.

&&

LAT...LON 3529 11129 3528 11119 3538 11108 3540 11109
      3539 11113 3541 11116 3542 11119 3543 11119
      3543 11123

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

McCollum

669 
WGUS75 KFGZ 190452
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
952 PM MST Sat Jul 18 2026

AZC005-190502-
/O.EXP.KFGZ.FF.W.0039.000000T0000Z-260719T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
952 PM MST Sat Jul 18 2026 /1052 PM MDT Sat Jul 18 2026/

...FLASH FLOOD WARNING WILL EXPIRE AT 10 PM MST /11 PM MDT/ THIS
EVENING FOR COCONINO COUNTY...

The heavy rain has ended. Earlier flash flooding located 10 to 15
miles northwest of Leupp has ended and is no longer expected to pose
a threat. Please heed any road closures.

&&

LAT...LON 3529 11129 3528 11119 3538 11108 3540 11109
      3539 11113 3541 11116 3542 11119 3543 11119
      3543 11123

$$

McCollum

Area Forecast Discussion
National Weather Service Flagstaff AZ
337 PM MST Sat Jul 18 2026

.SYNOPSIS...Deep monsoonal moisture will remain over the area
through this weekend and well into next week. With this moisture
comes the daily threat of thunderstorms, along with the risk for
locally heavy rainfall and flooding. With the added moisture and
cloud cover, daytime temperatures will remain below normal.

&&

.DISCUSSION...We are locked in a pattern that shows no signs of
changing and considering how badly the region needs water, this is
largely a good thing. The region will remain in a very moist air
mass, even with respect to the Monsoon Season, with both PW and
surface dew point values about as high as is possible. Northeast
through easterly steering flow will also persist, at least into
early next week. This steering flow may transition to more of a
southeasterly direction later next week.

The current steering flow heavily favors locations just to the
southwest, south and west of the central Mogollon Rim. A secondary
area usually forms later each day across Apache and Navajo counties
or over western New Mexico. These secondary areas are what supports
nocturnal convection, which should be more active tonight than
last night. This is evident in the latest model guidance aided by
increased sun over northeast AZ this morning.

Despite all the favorable mechanisms to produce heavy rain, we are
also seeing large areas of rain-cooled air, rain-cooled ground and
extensive debris cloud cover each day/night. These factors can
prevent stronger and more widespread convection from forming and
therefore limit the amount of storms that can produce flash
flooding. This and the lack of any clear forcing mechanism will
keep FFA issuances away for another day, at least. By early next
week, an easterly wave may improve shear and storm motion,
potentially raising the risk for flash flooding and hail
production.

&&

.AVIATION...Sunday 19/00Z through Monday 20/00Z...Rounds of
SHRA/TSRA will continue through the evening hours becoming
isolated after 06Z. Stronger storm cells will produce brief MVFR
and IFR conditions.  Outside of thunderstorms, expect light winds
5-10 kts. Another active day of monsoon storms is in store on
Sunday. Expect scattered to numerous SHRA/TSRA with isolated +TSRA
from late Sunday morning through the afternoon. The primary
threat will be MVFR to IFR conditions in heavy rain. Gusty outflow
winds up to 40 kts and hail are also possibilities.

OUTLOOK...Monday 20/00Z through Wednesday 22/00Z...Expect
scattered to numerous SHRA/TSRA and isolated +TSRA each day,
storms most numerous in the afternoon hours. Any stronger storms
will produce brief MVFR to IFR conditions. Some IFR low clouds
and fog possible, mainly for overnight hours. Outside of storms,
expect light winds around 5-10 kts.

&&

.FIRE WEATHER...Sunday and Monday...Expect a continuation of the
active monsoon pattern into next week with rounds of showers and
thunderstorms each day. Primary storm concerns will be heavy rain
and flash flooding, though erratic outflow winds are also possible.
Outside of storms activity, expect light winds.

Tuesday through Thursday...Active monsoon conditions continue with
daily chances for showers and thunderstorms, Expect generally light
winds outside of any storms. Most storms will produce wetting rain
with isolated to scattered flash flooding.

&&

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

&&

PUBLIC...Zanker
AVIATION...McCollum
FIRE WEATHER...MCT

For Northern Arizona weather information visit
weather.gov/flagstaff