Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 89, NWS Flagstaff, AZ

July 23, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 23, 2021, 4:07 AM MST for Yavapai County, Arizona. It was in force for 4 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 23, 2021, 4:07 AM MST (11:07 UTC)
Expired: Jul 23, 2021, 8:00 AM MST
In force: 4 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 102 km from the middle of the area, began a volume at 11:06 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 00:00Z, 11.1 hours before the alert went out and 80 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: 1155 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 2803 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: -22 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

336 
WGUS55 KFGZ 231107
FFWFGZ
AZC025-231415-
/O.NEW.KFGZ.FF.W.0089.210723T1107Z-210723T1415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
407 AM MST Fri Jul 23 2021

The National Weather Service in Flagstaff has issued a

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

* Until 715 AM MST.

* At 406 AM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly along Black Canyon Creek.

  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...
  mainly rural areas of Yavapai County

This includes the following streams and drainages...
  Agua Fria River, Black Canyon Creek, Antelope Creek, Sycamore 
  Creek, Castle Creek, Slate Creek, North Fork Rock Creek, Rock 
  Creek and Black Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3419 11224 3422 11216 3418 11215 3415 11215
      3410 11215 3407 11216 3405 11216 3404 11218

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

$$

MCT

3 follow-up statements

182 
WGUS75 KFGZ 231306
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
606 AM MST Fri Jul 23 2021

AZC025-231415-
/O.CON.KFGZ.FF.W.0089.000000T0000Z-210723T1415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
606 AM MST Fri Jul 23 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 AM MST THIS 
MORNING FOR YAVAPAI COUNTY...

At 605 AM MST, Doppler radar indicated heavy rain has moved out of 
the warned area, but previous heavy rain between 1 and 2 inches is 
expected to cause flooding along Black Canyon Creek.

HAZARD...Life-threatening flash flooding. Heavy rain 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...
  mainly rural areas of Yavapai County

This includes the following streams and drainages...
  Agua Fria River, Black Canyon Creek, Antelope Creek, Sycamore 
  Creek, Castle Creek, Slate Creek, North Fork Rock Creek, Rock 
  Creek and Black Canyon.

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.

&&

LAT...LON 3419 11224 3422 11216 3418 11215 3415 11215
      3410 11215 3407 11216 3405 11216 3404 11218

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

$$

MCT

716 
WGUS55 KFGZ 231351
FFWFGZ
AZC025-231500-
/O.EXT.KFGZ.FF.W.0089.000000T0000Z-210723T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
651 AM MST Fri Jul 23 2021

The National Weather Service in Flagstaff has extended the

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

* Until 800 AM MST.

* At 649 AM MST, local law enforcement reported flooding of Black 
  Canyon Creek across Maren Avenue. Flash flooding is already 
  occurring. The flash flood warning has been extended through 8:00 
  AM MST.

  HAZARD...Life-threatening flash flooding. Heavy rain 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...
  mainly rural areas of Yavapai County

This includes the following streams and drainages...
  Agua Fria River, Black Canyon Creek, Antelope Creek, Sycamore 
  Creek, Castle Creek, Slate Creek, North Fork Rock Creek, Rock 
  Creek and Black Canyon.

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.

&&

LAT...LON 3419 11224 3422 11216 3418 11215 3415 11215
      3410 11215 3407 11216 3405 11216 3404 11218

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

$$

MCT

161 
WGUS75 KFGZ 231501
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
801 AM MST Fri Jul 23 2021

AZC025-231511-
/O.EXP.KFGZ.FF.W.0089.000000T0000Z-210723T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
801 AM MST Fri Jul 23 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR YAVAPAI COUNTY...

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

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 3419 11224 3422 11216 3418 11215 3415 11215
      3410 11215 3407 11216 3405 11216 3404 11218

$$

MCT

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, 8:08 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, 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, 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.