Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 58, NWS Flagstaff, AZ

July 20, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 20, 2021, 1:23 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 20, 2021, 1:23 PM MST (20:23 UTC)
Expired: Jul 20, 2021, 4:15 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 Cedar City radar (KICX), 113 km from the middle of the area, began a volume at 20:24 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 166 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: 396 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 1392 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 5 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

780 
WGUS55 KFGZ 202023
FFWFGZ
AZC005-202315-
/O.NEW.KFGZ.FF.W.0058.210720T2023Z-210720T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
123 PM MST Tue Jul 20 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  The Mangum Fire scar in...
  Coconino County in north central Arizona...

* Until 415 PM MST.

* At 123 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Mangum Fire scar. Between 0.5 and 1 inch of 
  rain has fallen. Additional rainfall amounts of 0.25 to 0.5 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 in and around the Mangum Fire
           scar.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Mangum Fire scar.

* Some locations that will experience flash flooding include...
  mainly rural areas of Coconino County

This includes the following streams and drainages...
  Warm Springs Canyon, Jacob Canyon, Jumpup Canyon and Snake Gulch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flash flooding is occurring or imminent! Debris is expected to 
inundate Forest Service Roads 22 (Ryan Road) and 461. The Warm 
Springs Canyon water storage tank and pump house located along 
Forest Service Road 461 may also be affected.

Flooding and debris may also affect the Big Springs Cabin Site and 
structures within Mangum Canyon.

&&

LAT...LON 3672 11244 3673 11225 3668 11224 3662 11222
      3660 11232 3659 11243 3662 11244

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

$$

JJ

2 follow-up statements

485 
WGUS75 KFGZ 202214
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
314 PM MST Tue Jul 20 2021

AZC005-202315-
/O.CON.KFGZ.FF.W.0058.000000T0000Z-210720T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
314 PM MST Tue Jul 20 2021

...FLASH FLOOD WARNING FOR THE MANGUM FIRE SCAR REMAINS IN EFFECT 
UNTIL 415 PM MST THIS AFTERNOON FOR COCONINO COUNTY...

At 313 PM MST, Rain has ended over the Mangum Fire scar. Between 0.5 
and 1.50 inches of rain fell earlier this afternoon. Flash flooding 
is ongoing or expected to begin shortly.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding in and around the Mangum Fire scar.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of areas in and around
         the Mangum Fire scar.

Some locations that will experience flash flooding include...
  mainly rural areas of Coconino County

This includes the following streams and drainages...
  Warm Springs Canyon, Jacob Canyon, Jumpup Canyon and Snake Gulch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flash flooding is occurring or imminent! Debris is expected to 
inundate Forest Service Roads 22 (Ryan Road) and 461. The Warm 
Springs Canyon water storage tank and pump house located along 
Forest Service Road 461 may also be affected.

Flooding and debris may also affect the Big Springs Cabin Site and 
structures within Mangum Canyon.

&&

LAT...LON 3672 11244 3673 11225 3668 11224 3662 11222
      3660 11232 3659 11243 3662 11244

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

$$

JJ

756 
WGUS75 KFGZ 202311
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
411 PM MST Tue Jul 20 2021

AZC005-202321-
/O.EXP.KFGZ.FF.W.0058.000000T0000Z-210720T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
411 PM MST Tue Jul 20 2021

...FLASH FLOOD WARNING FOR THE MANGUM FIRE SCAR WILL EXPIRE AT 415 
PM MST THIS AFTERNOON FOR COCONINO COUNTY...

The heavy rain has ended over the Mangum Fire scar. High flows 
through washes or creeks that run westward off of the fire scar 
should continue to decrease into early evening. Please continue to 
heed any remaining road closures and turn around if water is 
encountered on a roadway.

LAT...LON 3672 11244 3673 11225 3668 11224 3662 11222
      3660 11232 3659 11243 3662 11244

$$

JJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 6:31 PM MST	Severe Thunderstorm Warning	FGZ	Gila	29 min
Jul 20, 11:44 AM MST	Severe Thunderstorm Warning	FGZ	Yavapai	35 min
Jul 20, 11:53 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 20, 1:14 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 20, 1:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 20, 3:45 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 20, 4:57 PM MST	Special Weather Statement	FGZ		48 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.