Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 3, NWS Flagstaff, AZ

June 29, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jun 29, 2021, 3:49 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: Jun 29, 2021, 3:49 PM MST (22:49 UTC)
Expired: Jun 29, 2021, 6:45 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 Cedar City radar (KICX), 126 km from the middle of the area, began a volume at 22:52 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, 10.8 hours before the alert went out and 182 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: 225 J/kg
Mixed-layer CIN: -162 J/kg
Mixed-layer LCL: 1570 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -75 m²/s²
0-3 km storm-relative helicity: -28 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

402 
WGUS55 KFGZ 292249
FFWFGZ
AZC005-300145-
/O.NEW.KFGZ.FF.W.0003.210629T2249Z-210630T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
349 PM MST Tue Jun 29 2021

The National Weather Service in Flagstaff has issued a

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

* Until 645 PM MST.

* At 347 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Paria River. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Paria
           River.

  SOURCE...Doppler radar.

  IMPACT...Life-threatening flash flooding of areas in and around
           the Paria River.

* Some locations that will experience flash flooding include...
  Lees Ferry, Grand Canyon National Park, Glen Canyon National 
  Recreation Area and Navajo Reservation.

This includes the following slot canyons...
Paria River upstream of Lees Ferry and Cathedral Wash near Marble 
Canyon.

This includes the following highways...
	U.S. Highway 89A between mile markers 539 and 561.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get out of the Paria River slot canyon! Flood waters will flow down 
the Paria River, reaching the confluence with the Colorado River at 
Lees Ferry around 9:00 PM MST/10:00 PM MDT.

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

&&

LAT...LON 3694 11165 3686 11156 3685 11158 3686 11161
      3676 11169 3665 11179 3668 11194 3682 11208
      3700 11207 3700 11187 3700 11169

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

$$

ET

2 follow-up statements

463 
WGUS75 KFGZ 300040
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
540 PM MST Tue Jun 29 2021

AZC005-300145-
/O.CON.KFGZ.FF.W.0003.000000T0000Z-210630T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
540 PM MST Tue Jun 29 2021

...FLASH FLOOD WARNING FOR THE PARIA RIVER REMAINS IN EFFECT UNTIL 
645 PM MST THIS EVENING FOR COCONINO COUNTY...

At 540 PM MST, Doppler radar indicated thunderstorms that earlier 
were producing heavy rain over the Paria River have dissipated.

HAZARD...Life-threatening flash flooding is still possible for
         the next hour in and around the Paria River.

SOURCE...Doppler radar.

IMPACT...Life-threatening flash flooding of areas in and around
         the Paria River.

Some locations that will experience flash flooding include...
Grand Canyon National Park, Glen Canyon National Recreation Area and 
Navajo Reservation.

This includes the following slot canyons...
Paria River upstream of Lees Ferry and Cathedral Wash near Marble 
Canyon.

This includes the following highways...
	U.S. Highway 89A between mile markers 539 and 561.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get out of the Paria River slot canyon! Flood waters will flow down 
the Paria River, reaching the confluence with the Colorado River at 
Lees Ferry around 9:00 PM MST/10:00 PM MDT.

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

&&

LAT...LON 3694 11165 3686 11156 3685 11158 3686 11161
      3676 11169 3665 11179 3668 11194 3682 11208
      3700 11207 3700 11187 3700 11169

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

$$

McCollum

864 
WGUS75 KFGZ 300140
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
640 PM MST Tue Jun 29 2021

AZC005-300150-
/O.EXP.KFGZ.FF.W.0003.000000T0000Z-210630T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
640 PM MST Tue Jun 29 2021

...FLASH FLOOD WARNING FOR THE PARIA RIVER WILL EXPIRE AT 645 PM MST 
THIS EVENING FOR COCONINO COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3694 11165 3686 11156 3685 11158 3686 11161
      3676 11169 3665 11179 3668 11194 3682 11208
      3700 11207 3700 11187 3700 11169

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 11:34 AM MST	Severe Thunderstorm Warning	FGZ	Coconino	26 min
Jun 29, 11:56 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Jun 29, 1:05 PM MST	Areal Flood Advisory	FGZ	Coconino, Yavapai	3 hr
Jun 29, 1:58 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	32 min
Jun 29, 2:24 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Jun 29, 3:03 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	42 min
Jun 29, 3:39 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	36 min
Jun 29, 4:07 PM MST	Special Weather Statement	FGZ	Gila	23 min

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.