Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 86, NWS Flagstaff, AZ

July 22, 2021Apache County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 22, 2021, 8:08 PM MST for Apache County, 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: Jul 22, 2021, 8:08 PM MST (03:08 UTC)
Expired: Jul 22, 2021, 11:15 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Apache County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 117 km from the middle of the area, began a volume at 03:11 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, 3.1 hours before the alert went out and 172 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: 1033 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1131 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

976 
WGUS55 KFGZ 230308
FFWFGZ
AZC001-017-230615-
/O.NEW.KFGZ.FF.W.0086.210723T0308Z-210723T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
808 PM MST Thu Jul 22 2021

The National Weather Service in Flagstaff has issued a

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

* Until 1115 PM MST.

* At 807 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 3 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...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...
  Holbrook and Woodruff.

This includes the following highways...
	State Route 77 between mile markers 381 and 388.
	Highway 180 between mile markers 308 and 330.
	Business Interstate 40 between mile markers 286 and 289.
	State Route 377 between mile markers 30 and 33.
	Interstate 40 between mile markers 279 and 292.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3470 10985 3486 11037 3500 11021 3495 11003
      3497 10984 3499 10972 3469 10983

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

$$

McCollum

2 follow-up statements

376 
WGUS75 KFGZ 230402
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
902 PM MST Thu Jul 22 2021

AZC001-017-230615-
/O.CON.KFGZ.FF.W.0086.000000T0000Z-210723T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Apache AZ-Navajo AZ-
902 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM MST THIS 
EVENING FOR NAVAJO AND APACHE COUNTIES...

At 900 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain had weakened. Additional rainfall amounts of 0.25 to 0.5 inches 
are possible in the warned area. Flash flooding is ongoing.

HAZARD...Thunderstorms producing flash flooding.

SOURCE...Radar.

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

Some locations that will experience flash flooding include...
  Holbrook and Woodruff.

This includes the following highways...
	State Route 77 between mile markers 381 and 388.
	Highway 180 between mile markers 308 and 330.
	Business Interstate 40 between mile markers 286 and 289.
	State Route 377 between mile markers 30 and 33.
	Interstate 40 between mile markers 280 and 292.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3470 10985 3486 11037 3500 11021 3495 11003
      3497 10984 3499 10972 3469 10983

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

$$

McCollum

202 
WGUS75 KFGZ 230609
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1109 PM MST Thu Jul 22 2021

AZC001-017-230619-
/O.EXP.KFGZ.FF.W.0086.000000T0000Z-210723T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Apache AZ-Navajo AZ-
1109 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1115 PM MST THIS EVENING FOR 
NAVAJO AND APACHE COUNTIES...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a threat across the area south of Holbrook to Woodruff. Please 
heed any road closures and be on the lookout for roadways that may 
still be flooded in this area the remainder of the night.

A Flash Flood Watch remains in effect until 1100 PM MST Saturday for 
portions of east central Arizona, north central Arizona, northeast 
Arizona and west central Arizona.

LAT...LON 3470 10985 3486 11037 3500 11021 3495 11003
      3497 10984 3499 10972 3469 10983

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 7:01 PM MST	Areal Flood Warning	FGZ	Navajo	5 min
Jul 22, 7:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Jul 22, 10:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Gila, Navajo	4 hr
Jul 23, 12:57 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	4 hr
Jul 23, 1:50 AM MST	Areal Flood Advisory	FGZ	Coconino, Gila, Yavapai	3 hr
Jul 23, 4:07 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	4 hr
Jul 23, 11:21 AM MST	Areal Flood Warning	FGZ	Gila	6 hr
Jul 23, 11:38 AM MST	Special Weather Statement	FGZ	Coconino	37 min
Jul 23, 12:07 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	4 hr
Jul 23, 12:14 PM MST	Special Weather Statement	FGZ	Coconino	46 min
Jul 23, 12:19 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	2 hr
Jul 23, 12:51 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	114 min
Jul 23, 1:17 PM MST	Special Weather Statement	FGZ		43 min
Jul 23, 1:31 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Jul 23, 2:12 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	2 hr
Jul 23, 2:24 PM MST	Special Weather Statement	FGZ	Yavapai	36 min
Jul 23, 2:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	7 hr
Jul 23, 3:26 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Jul 23, 3:43 PM MST	Special Weather Statement	FGZ	Navajo	47 min
Jul 23, 4:01 PM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Jul 23, 4:28 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr

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.