Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 23, NWS Flagstaff, AZ

July 13, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 13, 2021, 7:23 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: Jul 13, 2021, 7:23 PM MST (02:23 UTC)
Expired: Jul 13, 2021, 10:30 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), 150 km from the middle of the area, began a volume at 02:25 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, 2.4 hours before the alert went out and 142 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: 64 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 1699 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

342 
WGUS55 KFGZ 140223
FFWFGZ
AZC005-140530-
/O.NEW.KFGZ.FF.W.0023.210714T0223Z-210714T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
723 PM MST Tue Jul 13 2021

The National Weather Service in Flagstaff has issued a

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

* Until 1030 PM MST.

* At 720 PM MST, National Weather Service Doppler radar indicated 
  thunderstorms producing heavy rain just west of the Village of 
  Supai. Between 0.5 and 1.25 inches of rain have fallen in Little 
  Coyote Canyon. Additional rainfall amounts of 0.5 to 1 inch are 
  possible.

Flash flooding is ongoing or expected to begin shortly in Little 
Coyote Canyon and Havasu Creek from the Village of Supai northward 
to the confluence of the Colorado River..

  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...
  Supai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away or be swept away! The banks of creeks and washes are 
unstable and unsafe during any flooding event.

Get out of washes and creeks if you are camping or hiking! Flooding 
is occurring or imminent and will inundate area drainages.

&&

LAT...LON 3630 11276 3629 11270 3628 11268 3623 11262
      3615 11271 3617 11282 3625 11284 3626 11279

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

$$

Peterson

1 follow-up statement

082 
WGUS75 KFGZ 140524
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1024 PM MST Tue Jul 13 2021

AZC005-140534-
/O.EXP.KFGZ.FF.W.0023.000000T0000Z-210714T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
1024 PM MST Tue Jul 13 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1030 PM MST THIS EVENING FOR 
COCONINO COUNTY...

At 1020 PM MST, National Weather Service Doppler radar indicated 
that rain was no longer falling in the Supai area. Gage reports on 
Havasu Creek indicated a minor rise at the Village of Supai, but a 
2.9 foot rise at the confluence of Havasu Creek and the Colorado 
River. This indicates that flood waters have moved down Little 
Coyote Canyon and Havasu Creek and levels should be receding.

LAT...LON 3630 11276 3629 11270 3628 11268 3623 11262
      3615 11271 3617 11282 3625 11284 3626 11279

$$

Peterson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 5:20 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Yavapai	3 hr
Jul 14, 2:39 AM MST	Special Weather Statement	FGZ	Yavapai	36 min
Jul 14, 3:06 AM MST	Areal Flood Advisory	FGZ	Yavapai	111 min
Jul 14, 3:24 AM MST	Special Weather Statement	FGZ	Yavapai	36 min
Jul 14, 3:38 AM MST	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 14, 3:59 AM MST	Special Weather Statement	FGZ	Yavapai	46 min
Jul 14, 4:24 AM MST	Areal Flood Advisory	FGZ	Yavapai	74 min
Jul 14, 4:30 AM MST	Special Weather Statement	FGZ		45 min
Jul 14, 4:45 AM MST	Special Weather Statement	FGZ		45 min
Jul 14, 5:23 AM MST	Special Weather Statement	FGZ		37 min
Jul 14, 9:53 AM MST	Flash Flood Watch	FGZ	Apache, Coconino, Navajo	17 hr
Jul 14, 1:47 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Jul 14, 2:13 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 2:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 2:57 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 14, 3:36 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 4:02 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	31 min
Jul 14, 4:24 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	111 min
Jul 14, 4:54 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	111 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.