Alert archive / Arizona / Flash Flood Warnings in 2026

Flash Flood Warning 102, NWS Flagstaff, AZ

August 10, 2026Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 10, 2026, 7:31 PM MDT for Navajo County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 10, 2026, 7:31 PM MDT (01:31 UTC)
Expired
Aug 10, 2026, 10:30 PM MDT
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 122 km from the middle of the area, began a volume at 01:31 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 1.5 hours before the alert went out and 266 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2026-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 484 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2026-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
484 J/kg
Mixed-layer CIN
-154 J/kg
Mixed-layer LCL
2675 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Flagstaff, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 10, 5:00 PM MDT, 2 hours 31 minutes earlier.

Area forecast discussion, Aug 10, 5:00 PM MDT, 2 hours 31 minutes before
Area Forecast Discussion
National Weather Service Flagstaff AZ
400 PM MST Mon Aug 10 2026

.SYNOPSIS...Cooler temperatures and scattered to widespread showers
and thunderstorms are expected through much of this week.

&&

.DISCUSSION...High pressure will sit over the Four Corners over
the next few days. This puts Arizona in a favorable spot for
increased moisture flow into the area which will lead to more
widespread shower and thunderstorm activity. With PWAT's hitting
1.0-1.5", storms will be able to put down more rain and as the
soil saturates throughout the week, flash flooding will definitely
be a concern. With the higher moisture and likely increased cloud
cover, high temperatures will also drop below average for the
first time in awhile.

Moisture and POPs are expected to peak around Thursday. By Friday
a weak West Coast trough begins to move into the area which will
push our high pressure center to the east, as well as introduce
some drier air across the region. By Saturday storm chances will
be confined mainly over the White Mountain region and the very
highest terrain. High temperatures will begin to recover back to
mid August averages by Saturday or Sunday.

&&

.AVIATION...Tuesday 11/00Z through Wednesday 12/00Z...SCT-NRMS
SHRA/TSRA expected through 10Z. Another round of SHRA/TSRA possible
after 19Z, mainly near and north of a KGCN-KSEZ-KJTC line. Periods
of MVFR/IFR conditions and gusty outflow winds in excess of 40 kts
possible in and around +TS. Otherwise, VRB conditions with light and
VRB winds overnight, becoming SW/W 5-15 kts after 18Z.

OUTLOOK...Wednesday 12/00Z through Friday 14/00Z...SCT-NRMS
SHRA/TSRA each day from 19Z-03Z, most likely over the higher
terrain. Some SHRA may linger into the overnight periods. Brief
MVFR/IFR conditions and gusty outflow winds in excess of 40 kts
possible in and around +TS. Otherwise, daytime winds W/SW 5-15 kts,
becoming light and VRB overnight.

&&

.FIRE WEATHER...Tuesday and Wednesday...Daily max temps will be
near north to slightly above normal Tuesday, falling to below
normal Wednesday, with daily chances for showers and
thunderstorms. Greatest coverage across the higher terrain.
Stronger storms may contain heavy rain, hail, and gusty/erratic
winds. Outside of storms, expect variable winds around 5-15 mph
Tuesday, becoming west to southwest Wednesday.

Thursday through Saturday...Below normal temperatures with scattered
to widespread showers and thunderstorms Through at least Friday.
Potential for drying trend starting Saturday. Outside of storms,
expect west to southwest winds around 5-15 mph.

&&

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

&&

PUBLIC...Bernhart
AVIATION...Humphreys
FIRE WEATHER...Schank

For Northern Arizona weather information visit
weather.gov/flagstaff

In the hours before

Local storm report, Aug 10, 7:14 PM MDT, 17 minutes before
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The office that day

Everything else NWS Flagstaff, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 10, 6:20 PM MDTSevere Thunderstorm WarningFGZYavapai25 min
Aug 11, 3:03 PM MDTSevere Thunderstorm WarningFGZApache18 min
Aug 11, 3:59 PM MDTSpecial Weather StatementFGZ31 min
Aug 11, 4:21 PM MDTAreal Flood AdvisoryFGZCoconino114 min
Aug 11, 5:37 PM MDTFlash Flood Warning Considerable damage threatFGZGila, Navajo3 hr

Nearby

Flash Flood Warnings in Arizona, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.