Alert archive / Arizona / Flash Flood Warnings in 2022

Flash Flood Warning 112, NWS Flagstaff, AZ

July 30, 2022Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 30, 2022, 11:37 AM MST for Coconino 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: Jul 30, 2022, 11:37 AM MST (18:37 UTC)
Expired: Jul 30, 2022, 2:45 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 18:39 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 6.6 hours before the alert went out and 68 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 61 J/kg
Mixed-layer CIN: -96 J/kg
Mixed-layer LCL: 2835 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Jul 30, 10:06 AM MST, 1 hour 31 minutes earlier.

Area forecast discussion, Jul 30, 10:06 AM MST, 1 hour 31 minutes before

Area Forecast Discussion
National Weather Service Flagstaff AZ
1006 AM MST Sat Jul 30 2022

.SYNOPSIS...An active monsoon pattern will continue through the
weekend with scattered to widespread showers and thunderstorms
expected. Beginning next week, a slight downward trend in
thunderstorm coverage is expected. Flash flooding will remain the
main threat.

&&

.UPDATE...Showers and some isolated thunderstorms are already
moving through portions of the region. Expect coverage to increase
we head into the afternoon. Heavy rainfall is a big threat this
afternoon and in areas where we have seen less cloud cover this
morning, storms may be a bit stronger and bring some gusty winds and
hail. Stay weather aware today as storms may develop rather
quickly. Updated PoPs but other than that the forecast looks to
be on track.

&&

.PREV DISCUSSION /235 AM MST/...Isolated showers and thunderstorms
are more limited this morning than the past few days. In any case,
be careful with your morning commute as stronger storms, combined
with already overburdened soils, can lead to flooding in a flash!

High Precipitable Water content continues across northern Arizona
with values around 1". This is due to the placement of high
pressure currently residing over the Pacific Northwest allowing
for moisture to advect across our region from the Gulf of
California. This will continue the Flash Flood threat especially
with the flooding we have seen thus far creating saturated soils
that are unable to absorb additional rainfall. The Flash Flood
Watch has been extended through early Sunday morning for all of
northern Arizona. Avoid slot canyons and swimming holes, have a
way to get to higher ground and have more than one way to receive
warnings. Turn around, don't drown!

Beginning Sunday, the high looks to shift to our north and sets up
over the Four Corners region before moving into the Plains on
Monday. This should tamper down some of the moisture propagating
into the region with some chances that we might return to a more
normal looking monsoon - clear at night and in the morning with
thunderstorm activity in the late morning to early evening.
However, since models are showing differing solutions related to
the position of that high, we will have to see if the high
moisture content, and the flooding, will continue. For the end of
next week, some models are showing a return to a wetter pattern.

&&

AVIATION...For the 18Z TAF package...Scattered to
numerous showers and thunderstorms through 02Z then decreasing.
Otherwise, mainly VFR conditions expected with light winds. Gusty,
erratic winds and MVFR or lower conditions possible in and near
thunderstorms. Aviation discussion not updated for TAF amendments.

&&

FIRE WEATHER...Scattered to numerous storms Saturday and Sunday
with flash flooding the main threat. Light winds, seasonally cool
temperatures, and humid both days with gusty, erratic winds in and
near storms.

Monday through Wednesday...Daily showers and thunderstorms will
continue with flash flooding as the main threat.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for AZZ004>018-037>040-104>118-
137>140.

&&

PUBLIC...Meola/Kobold
AVIATION...MAS
FIRE WEATHER...Kobold

For Northern Arizona weather information visit
weather.gov/flagstaff

In the hours before

Local storm report, Jul 30, 6:25 AM MST, 5 hours 12 minutes before

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Local storm report, Jul 30, 6:30 AM MST, 5 hours 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
630 AM MST SAT JUL 30 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0814 PM     FLASH FLOOD      2 NNW DOWNTOWN FLAGSTAF 35.22N 111.66W
07/29/2022                   COCONINO           AZ   PUBLIC

            CORRECTS PREVIOUS FLASH FLOOD REPORT FROM 2
            NNW DOWNTOWN FLAGSTAFF. CORRECTS PREVIOUS
            FLASH FLOOD REPORT FROM 2 NNW DOWNTOWN
            FLAGSTAFF. STEVANNA WAY NEIGHBORHOOD
            FLOODED, VIDEOS FROM PUBLIC AND MEDIA ON
            TWITTER.

&&

Local storm report, Jul 30, 6:35 AM MST, 5 hours 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
635 AM MST SAT JUL 30 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0609 PM     FLASH FLOOD      1 N DOWNTOWN FLAGSTAFF  35.22N 111.65W
07/29/2022                   COCONINO           AZ   COUNTY OFFICIAL

            COCONINO ESTATES FLOODED AS REPORTED BY
            COUNTY IN EMAIL.

&&

Local storm report, Jul 30, 6:36 AM MST, 5 hours 1 minute before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
636 AM MST SAT JUL 30 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0814 PM     FLASH FLOOD      2 NNW DOWNTOWN FLAGSTAF 35.22N 111.66W
07/29/2022                   COCONINO           AZ   PUBLIC

            STEVANNA WAY NEIGHBORHOOD FLOODED, VIDEOS
            FROM PUBLIC AND MEDIA ON TWITTER.

&&

Local storm report, Jul 30, 6:37 AM MST, 5 hours before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
637 AM MST SAT JUL 30 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0609 PM     FLASH FLOOD      1 N DOWNTOWN FLAGSTAFF  35.22N 111.65W
07/29/2022                   COCONINO           AZ   COUNTY OFFICIAL

            COCONINO ESTATES FLOODED AS REPORTED BY
            COUNTY IN EMAIL.

&&

Special weather statement, Jul 30, 9:50 AM MST, 1 hour 47 minutes before

Special Weather Statement
National Weather Service Flagstaff AZ
950 AM MST Sat Jul 30 2022

AZZ008-037-301715-
Yavapai County Valleys and Basins-Yavapai County  Mountains-
950 AM MST Sat Jul 30 2022

...A strong thunderstorm will impact portions of Yavapai County
through 1015 AM MST...

At 950 AM MST, Doppler radar was tracking a strong thunderstorm 8
miles west of Childs Power Plant, or 14 miles south of Camp Verde.
This storm was nearly stationary.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of Yavapai County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3437 11175 3434 11188 3448 11196 3452 11178
TIME...MOT...LOC 1650Z 172DEG 3KT 3439 11184

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

MAS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 5:34 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	2 hr
Jul 29, 5:43 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 29, 6:27 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 29, 7:52 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Jul 29, 10:24 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	7 hr
Jul 30, 9:50 AM MST	Special Weather Statement	FGZ		25 min
Jul 30, 10:33 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 30, 11:00 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 30, 11:49 AM MST	Special Weather Statement	FGZ	Yavapai	41 min
Jul 30, 12:04 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 30, 12:17 PM MST	Special Weather Statement	FGZ	Yavapai	28 min
Jul 30, 12:20 PM MST	Special Weather Statement	FGZ	Yavapai	25 min
Jul 30, 12:55 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 30, 1:24 PM MST	Special Weather Statement	FGZ	Navajo	51 min
Jul 30, 2:36 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Jul 30, 2:43 PM MST	Special Weather Statement	FGZ	Apache	47 min
Jul 30, 3:15 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr

Nearby

Flash Flood Warnings in Arizona, 2022 Every flash flood warning in 2022

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.