Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 30, NWS Flagstaff, AZ

July 14, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 14, 2021, 5:54 PM MDT for Navajo County, Arizona. It was in force for 111 min. 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 14, 2021, 5:54 PM MDT (23:54 UTC)
Expired: Jul 14, 2021, 7:45 PM MDT
In force: 111 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 53 km from the middle of the area, began a volume at 23:58 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, 11.9 hours before the alert went out and 134 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: 17 J/kg
Mixed-layer CIN: -187 J/kg
Mixed-layer LCL: 1682 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

779 
WGUS55 KFGZ 142354
FFWFGZ
AZC017-150145-
/O.NEW.KFGZ.FF.W.0030.210714T2354Z-210715T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
454 PM MST Wed Jul 14 2021

The National Weather Service in Flagstaff has issued a

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

* Until 645 PM MST.

* At 452 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...
  mainly rural areas of Navajo County within the Wyrick burn scar.

This includes the following streams and drainages...
  Brookbank Canyon, Potato Wash and Black Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid recently burned areas and downstream locations. 
Life-threatening flooding of creeks, roads and normally dry washes 
will occur. Rockslides and mudslides will likely occur in steep 
terrain.

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

&&

LAT...LON 3449 11070 3455 11059 3454 11053 3444 11056
      3446 11070

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

$$

MCT

2 follow-up statements

537 
WGUS75 KFGZ 150045
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
545 PM MST Wed Jul 14 2021

AZC017-150145-
/O.CON.KFGZ.FF.W.0030.000000T0000Z-210715T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
545 PM MST Wed Jul 14 2021

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

At 543 PM MST, Doppler radar indicated heavy rain has moved south of 
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. 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 Navajo County including the Wyrick burn scar.

This includes the following streams and drainages...
  Brookbank Canyon, Potato Wash and Black Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid recently burned areas and downstream locations. 
Life-threatening flooding of creeks, roads and normally dry washes 
will occur. Rockslides and mudslides will likely occur in steep 
terrain.

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

&&

LAT...LON 3449 11070 3455 11059 3454 11053 3444 11056
      3446 11070

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

$$

MCT

809 
WGUS75 KFGZ 150135
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
635 PM MST Wed Jul 14 2021

AZC017-150145-
/O.EXP.KFGZ.FF.W.0030.000000T0000Z-210715T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
635 PM MST Wed Jul 14 2021

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

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures and be 
cautious near any elevated water.

LAT...LON 3449 11070 3455 11059 3454 11053 3444 11056
      3446 11070

$$

MCT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 6:20 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Gila, Yavapai	3 hr
Jul 13, 8:23 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 3:39 AM MDT	Special Weather Statement	FGZ	Yavapai	36 min
Jul 14, 4:06 AM MDT	Areal Flood Advisory	FGZ	Yavapai	111 min
Jul 14, 4:24 AM MDT	Special Weather Statement	FGZ	Yavapai	36 min
Jul 14, 4:38 AM MDT	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 14, 4:59 AM MDT	Special Weather Statement	FGZ	Yavapai	46 min
Jul 14, 5:24 AM MDT	Areal Flood Advisory	FGZ	Yavapai	74 min
Jul 14, 5:30 AM MDT	Special Weather Statement	FGZ		45 min
Jul 14, 5:45 AM MDT	Special Weather Statement	FGZ		45 min
Jul 14, 6:23 AM MDT	Special Weather Statement	FGZ		37 min
Jul 14, 10:53 AM MDT	Flash Flood Watch	FGZ	Apache, Coconino, Navajo	17 hr
Jul 14, 2:47 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Jul 14, 3:13 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 3:39 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 3:57 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 14, 4:36 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 5:02 PM MDT	Severe Thunderstorm Warning	FGZ	Coconino	31 min
Jul 14, 5:24 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	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.