Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 221, NWS Flagstaff, AZ

September 1, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 1, 2021, 11:22 AM MDT for Navajo 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: Sep 1, 2021, 11:22 AM MDT (17:22 UTC)
Expired: Sep 1, 2021, 2:10 PM MDT
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 117 km from the middle of the area, began a volume at 17:25 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 12:00Z, 5.4 hours before the alert went out and 127 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 611 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

658 
WGUS55 KFGZ 011722
FFWFGZ
AZC017-012030-
/O.NEW.KFGZ.FF.W.0221.210901T1722Z-210901T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1022 AM MST Wed Sep 1 2021

The National Weather Service in Flagstaff has issued a

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

* Until 130 PM MST.

* At 1021 AM MST, local law enforcement reported water across SR87 
  near Coyote Wash in Dilkon at MM373 the warned area. Flash 
  flooding is already occurring. Do not attempt to cross flooded 
  roadways or enter into flowing washes.

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

  SOURCE...Law enforcement reported.

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

* Some locations that will experience flash flooding include...
  Dilkon, Hopi Reservation and Navajo Reservation.

This includes the following highways...
	State Route 87 between mile markers 372 and 378.

This includes the following creeks, washes and rivers...
  Jeddito Wash, Tees Toh Wash, Coyote Wash and Bidahochi Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3538 11075 3540 11071 3539 11063 3537 11052
      3541 11043 3541 11036 3542 11031 3545 11029
      3548 11029 3552 11029 3552 11023 3551 11020
      3546 11019 3541 11019 3538 11022 3536 11028
      3533 11035 3527 11056 3537 11075

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

ET

1 follow-up statement

822 
WGUS75 KFGZ 012010
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
110 PM MST Wed Sep 1 2021

AZC017-012020-
/O.CAN.KFGZ.FF.W.0221.000000T0000Z-210901T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
110 PM MST Wed Sep 1 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NAVAJO COUNTY...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Road crews are still in the area repairing road damage and 
clearing debris. Please use caution driving in this area and 
continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 500 AM MST Thursday for 
portions of north central Arizona and northeast Arizona.

LAT...LON 3538 11075 3540 11071 3539 11063 3537 11052
      3541 11043 3541 11036 3542 11031 3545 11029
      3548 11029 3552 11029 3552 11023 3551 11020
      3546 11019 3541 11019 3538 11022 3536 11028
      3533 11035 3527 11056 3537 11075

$$

DB

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 11:31 AM MDT	Areal Flood Advisory	FGZ	Apache, Navajo	4 hr
Sep 1, 2:59 PM MDT	Severe Thunderstorm Warning	FGZ	Yavapai	31 min
Sep 1, 3:12 PM MDT	Areal Flood Advisory	FGZ	Coconino	2 hr
Sep 1, 4:03 PM MDT	Special Weather Statement	FGZ		27 min
Sep 1, 4:13 PM MDT	Special Weather Statement	FGZ		32 min
Sep 1, 4:23 PM MDT	Severe Thunderstorm Warning	FGZ	Coconino	37 min
Sep 1, 4:33 PM MDT	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	42 min
Sep 1, 4:49 PM MDT	Flash Flood Warning	FGZ	Yavapai	3 hr
Sep 1, 5:11 PM MDT	Flash Flood Warning	FGZ	Coconino	3 hr
Sep 1, 5:21 PM MDT	Special Weather Statement	FGZ		24 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.