Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 222, NWS Flagstaff, AZ

September 1, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 1, 2021, 3:49 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 outline as issued.

The facts

Issued: Sep 1, 2021, 3:49 PM MST (22:49 UTC)
Expired: Sep 1, 2021, 6:45 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Flood severity: None

County Yavapai County, AZ

The radar

The Phoenix radar (KIWA), 129 km from the middle of the area, began a volume at 22:49 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

Phoenix, AZ (KPSR), launched 12:00Z, 10.8 hours before the alert went out and 99 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: 117 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 973 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: -40 m²/s²
0-3 km storm-relative helicity: -57 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

633 
WGUS55 KFGZ 012249
FFWFGZ
AZC025-020145-
/O.NEW.KFGZ.FF.W.0222.210901T2249Z-210902T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Yavapai County in west central Arizona...

* Until 645 PM MST.

* At 344 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.5 to 1 inch are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of low-water crossings, creeks,
           normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Wagoner and Walnut Grove.

This includes the following creeks, washes and rivers...
  Spring Creek, Buckhorn Creek, Hamlin Wash, Slim Jim Creek, Ash 
  Creek,  Blind Indian Creek, Mescal Creek, Arrastre Creek, Dead 
  Mexican Creek, Hassayampa River, Oak Creek, Milk Creek, Cherry 
  Creek, Amazon Gulch, Weaver Creek, Cottonwood Creek, Minnehaha 
  Creek and Cellar Springs Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

Report any flooding to local law enforcement and the NWS Flagstaff 
when you can do so safely.

&&

LAT...LON 3400 11277 3416 11270 3429 11260 3431 11249
      3407 11248 3400 11274 3400 11275

FLASH FLOOD...RADAR INDICATED

$$

DB

2 follow-up statements

309 
WGUS75 KFGZ 020057
FFSFGZ

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

AZC025-020145-
/O.CON.KFGZ.FF.W.0222.000000T0000Z-210902T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
557 PM MST Wed Sep 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MST THIS 
EVENING FOR YAVAPAI COUNTY...

At 555 PM MST, Doppler radar indicated rain has moved out of the 
area. Earlier heavy rain of 1 to 1.5 inches will continue to cause 
flash flooding along the Hassayampa River and its tributaries.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of low-water crossings, creeks, normally
         dry washes and roads.

Some locations that will experience flash flooding include...
  Wagoner and Walnut Grove.

This includes the following highways...
	Highway 93 near mile marker 196.

This includes the following creeks, washes and rivers...
  Spring Creek, Buckhorn Creek, Hamlin Wash, Slim Jim Creek, Ash 
  Creek, Whipsaw Creek, Blind Indian Creek, Mescal Creek, East Fork 
  Castle Creek, Arrastre Creek, Dead Mexican Creek, Hassayampa 
  River, Buzzard Roost Creek, Oak Creek, Milk Creek, Cherry Creek, 
  Castle Creek, Amazon Gulch, Weaver Creek, Cottonwood Creek, 
  Minnehaha Creek and Cellar Springs Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

Report any flooding to local law enforcement and the NWS Flagstaff 
when you can do so safely.

&&

LAT...LON 3400 11277 3416 11270 3429 11260 3431 11249
      3407 11248 3400 11274 3400 11275

FLASH FLOOD...RADAR INDICATED

$$

MCT

329 
WGUS75 KFGZ 020136
FFSFGZ

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

AZC025-020146-
/O.EXP.KFGZ.FF.W.0222.000000T0000Z-210902T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
636 PM MST Wed Sep 1 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM MST THIS EVENING FOR 
YAVAPAI COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures and use 
caution near area creeks and streams that may be running high this 
evening.

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

LAT...LON 3400 11277 3416 11270 3429 11260 3431 11249
      3407 11248 3400 11274 3400 11275

$$

MCT

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 10:22 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Sep 1, 10:31 AM MST	Areal Flood Advisory	FGZ	Apache, Navajo	4 hr
Sep 1, 1:59 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	31 min
Sep 1, 2:12 PM MST	Areal Flood Advisory	FGZ	Coconino	2 hr
Sep 1, 3:03 PM MST	Special Weather Statement	FGZ		27 min
Sep 1, 3:13 PM MST	Special Weather Statement	FGZ		32 min
Sep 1, 3:23 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	37 min
Sep 1, 3:33 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	42 min
Sep 1, 4:11 PM MST	Flash Flood Warning	FGZ	Coconino	3 hr
Sep 1, 4:21 PM MST	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.