Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 97, NWS Flagstaff, AZ

July 23, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 23, 2021, 6:00 PM MST for Coconino 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 23, 2021, 6:00 PM MST (01:00 UTC)
Expired: Jul 23, 2021, 8:47 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 87 km from the middle of the area, began a volume at 01:01 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, 1.0 hours before the alert went out and 10 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: 111 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 613 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 185 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

401 
WGUS55 KFGZ 240100
FFWFGZ
AZC005-240400-
/O.NEW.KFGZ.FF.W.0097.210724T0100Z-210724T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Flagstaff has issued a

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

* Until 900 PM MST.

* At 559 PM 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.

  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...
  Flagstaff and Fort Valley.

This includes the following highways...
	Highway 180 between mile markers 218 and 224.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3528 11165 3522 11166 3519 11169 3522 11178
      3530 11172

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

$$

McCollum

1 follow-up statement

973 
WGUS75 KFGZ 240347
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
847 PM MST Fri Jul 23 2021

AZC005-240357-
/O.CAN.KFGZ.FF.W.0097.000000T0000Z-210724T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
847 PM MST Fri Jul 23 2021

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

The heavy rain has ended in the Fort Valley area. Flooding is no 
longer expected to pose a threat. Please heed any road closures and 
avoid driving through water on roads.

A Flash Flood Watch remains in effect until 1200 AM MST Monday for 
portions of east central Arizona, north central Arizona, northeast 
Arizona and west central Arizona.

LAT...LON 3528 11165 3522 11166 3519 11169 3522 11178
      3530 11172

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 5:56 PM MST	Severe Thunderstorm Warning	FGZ	Apache	34 min
Jul 23, 11:13 PM MST	Areal Flood Advisory	FGZ	Apache, Coconino, Gila, Navajo	5 hr
Jul 24, 7:22 AM MST	Areal Flood Advisory	FGZ	Apache, Coconino, Navajo	16 hr
Jul 24, 1:28 PM MST	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 24, 1:56 PM MST	Severe Thunderstorm Warning	FGZ	Apache	34 min
Jul 24, 2:16 PM MST	Severe Thunderstorm Warning	FGZ	Apache	29 min
Jul 24, 2:43 PM MST	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 24, 4:01 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	119 min
Jul 24, 4:05 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 24, 4:18 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Jul 24, 4:20 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	25 min
Jul 24, 4:51 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	39 min
Jul 24, 4:58 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	32 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.