Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 191, NWS Flagstaff, AZ

August 17, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 17, 2021, 3:03 PM 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 outline as issued.

The facts

Issued: Aug 17, 2021, 3:03 PM MST (22:03 UTC)
Expired: Aug 17, 2021, 6:15 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), 122 km from the middle of the area, began a volume at 22:04 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, 10.1 hours before the alert went out and 62 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: 984 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 829 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.8

Open this sounding in Storm Lab

The text

As transmitted.

774 
WGUS55 KFGZ 172203
FFWFGZ
AZC005-180115-
/O.NEW.KFGZ.FF.W.0191.210817T2203Z-210818T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
303 PM MST Tue Aug 17 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Coconino County in north central Arizona...

* Until 615 PM MST.

* At 301 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain between Gray Mountain and Wupatki National Monument. 
  Between 0.75 and 1.5 inches of rain have fallen. Additional 
  rainfall amounts of 0.75 to 1.5 inches are possible in the warned 
  area. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life-threatening flash flooding of low-water
           crossings, creeks, normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Wupatki National Monument, Gray Mountain, and Navajo Reservation.

This includes the following highways...
	U.S. Highway 89 between mile markers 444 and 461.

This includes the following streams and drainages...
  Citadel Wash, Jackrabbit Wash, Antelope Wash, Badger Wash, Little 
  Mexican Spring Wash, Deadman Wash, Doney Mountain Wash, Taah Iiti 
  Wash, Sei Haasgaii Wash, Mays Wash, Kish Zhini Wash, Ball Court 
  Wash, White Water Wash, Hulls Wash, Tonahakaad Spring, Tohachi 
  Wash, Haada Is Taani Di Wash, Tse To Baah Naali Wash, Stone House 
  Wash and Kanaa Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

&&

LAT...LON 3582 11144 3564 11102 3544 11136 3559 11158

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

$$

TPS

2 follow-up statements

572 
WGUS75 KFGZ 172313
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
413 PM MST Tue Aug 17 2021

AZC005-180115-
/O.CON.KFGZ.FF.W.0191.000000T0000Z-210818T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
413 PM MST Tue Aug 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MST THIS 
EVENING FOR COCONINO COUNTY...

At 411 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain between Gray Mountain and Wupatki National Monument have 
shifted south. Between 1.25 and 2.25 inches of rain have fallen. 
Only light additional rainfall amounts up to 0.25 inches are 
expected. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads.

Some locations that will experience flash flooding include...
  Wupatki National Monument, Gray Mountain, and Navajo Reservation.

This includes the following highways...
	U.S. Highway 89 between mile markers 444 and 462.

This includes the following streams and drainages...
  Citadel Wash, Jackrabbit Wash, Antelope Wash, Badger Wash, Little 
  Mexican Spring Wash, Deadman Wash, Doney Mountain Wash, Taah Iiti 
  Wash, Sei Haasgaii Wash, Mays Wash, Kish Zhini Wash, Ball Court 
  Wash, White Water Wash, Hulls Wash, Tonahakaad Spring, Tohachi 
  Wash, Haada Is Taani Di Wash, Tse To Baah Naali Wash, Stone House 
  Wash and Kanaa Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

&&

LAT...LON 3582 11144 3567 11113 3544 11136 3559 11158

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

$$

TPS

324 
WGUS75 KFGZ 180114
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
614 PM MST Tue Aug 17 2021

AZC005-180124-
/O.EXP.KFGZ.FF.W.0191.000000T0000Z-210818T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
614 PM MST Tue Aug 17 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM MST THIS EVENING FOR 
COCONINO COUNTY FROM WUPATKI TO GRAY MOUNTAIN...

The heavy rain has ended. Runoff will continue into the evening, but 
additional flooding is no longer expected to pose a threat. Please 
continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1100 PM MST for portions 
of north central Arizona, northeast Arizona and west central Arizona.

LAT...LON 3582 11144 3567 11113 3544 11136 3559 11158

$$

JJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 16, 5:04 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Aug 16, 6:33 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	27 min
Aug 16, 7:08 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	37 min
Aug 16, 7:37 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	23 min
Aug 16, 7:42 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	33 min
Aug 16, 7:57 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	33 min
Aug 16, 8:04 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	26 min
Aug 16, 8:21 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	24 min
Aug 16, 9:18 PM MST	Severe Thunderstorm Warning	FGZ	Gila	42 min
Aug 16, 10:01 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	29 min
Aug 16, 10:33 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	25 min
Aug 17, 12:04 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Gila, Navajo	3 hr
Aug 17, 12:15 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	60 min
Aug 17, 12:22 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Aug 17, 12:29 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila, Navajo	46 min
Aug 17, 12:41 PM MST	Flash Flood Warning EmergencyCatastrophic damage threat	FGZ	Coconino	3 hr
Aug 17, 12:59 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	46 min
Aug 17, 1:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Aug 17, 1:16 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	44 min
Aug 17, 1:21 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	39 min
Aug 17, 1:28 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	47 min
Aug 17, 1:37 PM MST	Flash Flood Watch	FGZ	Apache, Coconino, Navajo	9 hr
Aug 17, 2:03 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Aug 17, 2:09 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	51 min
Aug 17, 2:15 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	45 min
Aug 17, 2:18 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Aug 17, 3:42 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	33 min
Aug 17, 3:44 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Aug 17, 4:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Aug 17, 4:19 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	26 min
Aug 17, 4:22 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 17, 4:46 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr

Nearby

Flash Flood Warnings in Arizona, 2021 Every flash flood warning in 2021

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.