Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 224, NWS Flagstaff, AZ

September 2, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 2, 2021, 1:24 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 2, 2021, 1:24 PM MST (20:24 UTC)
Expired: Sep 2, 2021, 4:30 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 Flagstaff radar (KFSX), 78 km from the middle of the area, began a volume at 20:25 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, 8.4 hours before the alert went out and 66 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: 14 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 833 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 14 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

102 
WGUS55 KFGZ 022024
FFWFGZ
AZC025-022330-
/O.NEW.KFGZ.FF.W.0224.210902T2024Z-210902T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
124 PM MST Thu Sep 2 2021

The National Weather Service in Flagstaff has issued a

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

* Until 430 PM MST.

* At 121 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 0.75 to 1.5 
  inches 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...
  Cottonwood, Verde Village and Mingus Mountain Campground.

This includes the following highways...
	State Route 260 between mile markers 207 and 211.

This includes the following creeks, washes and rivers...
  Oak Wash and nearby washes to the south of Oak Wash down to the 
  Verde River.

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.

Remain alert for flooding even in locations not receiving rain. 
Normally dry washes, slot canyons and creeks can become raging 
killer currents in a matter of minutes, even from distant rainfall.

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

&&

LAT...LON 3472 11200 3468 11195 3464 11197 3461 11203
      3462 11205 3464 11211 3465 11216 3469 11215
      3472 11203

FLASH FLOOD...RADAR INDICATED

$$

DB

2 follow-up statements

127 
WGUS75 KFGZ 022243
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
343 PM MST Thu Sep 2 2021

AZC025-022330-
/O.CON.KFGZ.FF.W.0224.000000T0000Z-210902T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
343 PM MST Thu Sep 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 342 PM MST, Doppler radar indicated heavy rain has moved out of 
the area. Earlier heavy rain between 1 and 1.5 inches is expected to 
cause Flash flooding.

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...
  Cottonwood, Verde Village and Mingus Mountain Campground.

This includes the following highways...
	State Route 260 between mile markers 207 and 211.

This includes the following creeks, washes and rivers...
  Oak Wash, Ash Creek, Verde River and Cherry 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.

Remain alert for flooding even in locations not receiving rain. 
Normally dry washes, slot canyons and creeks can become raging 
killer currents in a matter of minutes, even from distant rainfall.

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

&&

LAT...LON 3472 11200 3468 11195 3464 11197 3461 11203
      3462 11205 3464 11211 3465 11216 3469 11215
      3472 11203

FLASH FLOOD...RADAR INDICATED

$$

MCT

058 
WGUS75 KFGZ 022323
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
423 PM MST Thu Sep 2 2021

AZC025-022333-
/O.EXP.KFGZ.FF.W.0224.000000T0000Z-210902T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
423 PM MST Thu Sep 2 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 430 PM MST THIS AFTERNOON FOR 
YAVAPAI COUNTY...

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

LAT...LON 3472 11200 3468 11195 3464 11197 3461 11203
      3462 11205 3464 11211 3465 11216 3469 11215
      3472 11203

$$

MCT

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 5:00 PM MST	Areal Flood Advisory	FGZ	Coconino	2 hr
Sep 1, 5:10 PM MST	Special Weather Statement	FGZ		50 min
Sep 1, 5:42 PM MST	Areal Flood Advisory	FGZ	Apache, Navajo	3 hr
Sep 1, 5:52 PM MST	Special Weather Statement	FGZ		38 min
Sep 1, 6:17 PM MST	Special Weather Statement	FGZ		43 min
Sep 1, 6:52 PM MST	Special Weather Statement	FGZ		38 min
Sep 2, 11:53 AM MST	Special Weather Statement	FGZ	Yavapai	22 min
Sep 2, 1:54 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	51 min
Sep 2, 2:31 PM MST	Areal Flood Advisory	FGZ	Coconino, Gila, Navajo	3 hr
Sep 2, 2:48 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Sep 2, 3:39 PM MST	Areal Flood Advisory	FGZ	Coconino	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.