Alert archive / Arizona / Flash Flood Warnings in 2022

Flash Flood Warning 250, NWS Flagstaff, AZ

August 20, 2022Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 20, 2022, 6:07 PM MST for Yavapai 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 20, 2022, 6:07 PM MST (01:07 UTC)
Expired: Aug 20, 2022, 9:15 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 124 km from the middle of the area, began a volume at 01:09 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 00:00Z, 1.1 hours before the alert went out and 98 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: 150 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 3686 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: -4 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 Aug 20, 1:58 PM MST, 4 hours 9 minutes earlier.

Area forecast discussion, Aug 20, 1:58 PM MST, 4 hours 9 minutes before

Area Forecast Discussion
National Weather Service Flagstaff AZ
158 PM MST Sat Aug 20 2022

.SYNOPSIS...An active monsoon pattern will continue across
northern and central Arizona through Sunday. Heavy rainfall
leading to flash flooding will continue to remain a threat. A
slight downturn in storm activity is forecast early next week,
especially north of the Mogollon Rim. Cooler temperatures are
expected through the weekend before warming up next week.

&&

.DISCUSSION...It has been a slow start to thunderstorm activity
across our CWA today, but we are beginning to see some storms
fire up across northwestern Coconino County and near the White
Mountains. Although our 12Z sounding this morning came in lower
than what has been seen previously this week, there is still good
amounts of moisture in our atmosphere to tap into for the rest of
the afternoon/evening hours.

Sunday...We'll begin to see the northeasterly flow aloft move in
from the high pressure system positioning to our northwest. This
wind pattern will shuffle in drier air to the north/northeast
portion of our state, limiting the potential for thunderstorm
development in these areas. Areas along the Mogollon Rim and
south are still forecast to see isolated to scattered showers for
the afternoon and evening hours.

Monday onward...Storm chances through mid-week will mostly remain
for areas along I-40 and south as we continue to have drier air
for the north/northeastern portion of our CWA. Around Thursday,
model guidance is showing the high pressure system shifting back
toward the Four Corners region. If this movement holds true, we
could see additional active monsoon days toward the end of next
week.

&&

.AVIATION...For the 00Z TAF package...Scattered to numerous TSRA and
SHRA through 02Z along and south of KCMR-KSEZ-KSOW-KJTC line with
isolated TSRA elsewhere. Some areas will see showers and storms
through the evening hours. Light winds away from storms through
tomorrow. Similar conditions are expected Sunday with the most
active areas being over higher terrain. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Scattered showers and thunderstorms Sunday, primarily
along and south of the Mogollon Rim with slightly reduced rain
chances by Monday. Light winds except near storms. Localized flash
flooding will be possible both days.

Tuesday through Thursday...Rain chances remain each day with peak
activity in the afternoons. Light winds will persist away from
storms.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 11 PM MST this evening for AZZ008-011-013>018-
037-038-108-111-113>118-137-138.

&&

PUBLIC...Swenson
AVIATION...JM
FIRE WEATHER...JM

For Northern Arizona weather information visit
weather.gov/flagstaff

In the hours before

Special weather statement, Aug 20, 4:28 PM MST, 1 hour 39 minutes before

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Local storm report, Aug 20, 4:56 PM MST, 1 hour 11 minutes before

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Local storm report, Aug 20, 5:40 PM MST, 27 minutes before

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Special weather statement, Aug 20, 5:57 PM MST, 10 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 5:17 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	43 min
Aug 20, 5:57 PM MST	Special Weather Statement	FGZ		33 min
Aug 20, 6:25 PM MST	Special Weather Statement	FGZ	Yavapai	50 min
Aug 20, 7:13 PM MST	Special Weather Statement	FGZ		47 min
Aug 20, 7:57 PM MST	Special Weather Statement	FGZ		33 min
Aug 21, 1:11 AM MST	Special Weather Statement	FGZ	Yavapai	34 min
Aug 21, 1:39 AM MST	Special Weather Statement	FGZ	Yavapai	36 min
Aug 21, 2:44 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Aug 21, 3:16 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	4 hr
Aug 21, 7:01 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	4 hr
Aug 21, 12:35 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	25 min
Aug 21, 12:58 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Aug 21, 1:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Aug 21, 1:49 PM MST	Special Weather Statement	FGZ		26 min
Aug 21, 2:16 PM MST	Special Weather Statement	FGZ		29 min
Aug 21, 2:42 PM MST	Special Weather Statement	FGZ		33 min
Aug 21, 2:50 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Aug 21, 2:56 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 21, 3:15 PM MST	Special Weather Statement	FGZ		30 min
Aug 21, 3:38 PM MST	Special Weather Statement	FGZ		37 min
Aug 21, 3:43 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Yavapai	3 hr
Aug 21, 3:50 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	40 min
Aug 21, 3:56 PM MST	Severe Thunderstorm Warning	FGZ	Gila	49 min
Aug 21, 4:18 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 21, 4:27 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	33 min
Aug 21, 4:34 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 21, 4:36 PM MST	Special Weather Statement	FGZ	Yavapai	54 min
Aug 21, 4:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	5 hr
Aug 21, 4:41 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Aug 21, 4:46 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	4 hr
Aug 21, 4:52 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 21, 4:54 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	6 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.