Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 233, NWS Flagstaff, AZ

September 27, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 27, 2021, 6:14 PM MST for Coconino County, Arizona. It was in force for 2 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 27, 2021, 6:14 PM MST (01:14 UTC)
Expired: Sep 27, 2021, 8:15 PM MST
In force: 2 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), 115 km from the middle of the area, began a volume at 01:17 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.

What was reported inside it

Time	Report	Where	Remark
Sep 27, 7:30 PM MST	FLASH FLOOD	9 Sw Jacob Lake, AZ	THIS IS A POST EVENT REPORT FROM MONDAY EVENING. KAIBAB NATIONAL FOREST REPORTS ROAD CLOSURES DUE TO FLOODING AND DEBRIS ALONG FOREST ROAD 22 FROM FOREST ROAD 422A TO BIG SPRINGS. TIME OF REPORT IS AN ESTIMATE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 1.2 hours before the alert went out and 165 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: 177 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 849 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 125 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

246 
WGUS55 KFGZ 280114
FFWFGZ
AZC005-280315-
/O.NEW.KFGZ.FF.W.0233.210928T0114Z-210928T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
614 PM MST Mon Sep 27 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 815 PM MST.

* At 614 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Mangum Fire scar. 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 creeks, washes and rivers...
  Jacob Canyon and Warm Springs Canyon.

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 3669 11235 3671 11229 3669 11229 3662 11230
      3660 11232 3659 11235 3662 11236

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

$$

McCollum

2 follow-up statements

368 
WGUS75 KFGZ 280238
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
738 PM MST Mon Sep 27 2021

AZC005-280315-
/O.CON.KFGZ.FF.W.0233.000000T0000Z-210928T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
738 PM MST Mon Sep 27 2021

...FLASH FLOOD WARNING FOR THE MANGUM FIRE SCAR REMAINS IN EFFECT 
UNTIL 815 PM MST THIS EVENING FOR COCONINO COUNTY...

At 734 PM MST, Doppler radar indicated thunderstorms that earlier 
produced heavy rain over the Mangum Fire scar have moved to the 
south. A few light showers will continue but the threat for heavy 
rain has ended for now.

HAZARD...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 creeks, washes and rivers...
  Jacob Canyon and Warm Springs Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3669 11235 3671 11229 3669 11229 3662 11230
      3660 11232 3659 11235 3662 11236

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

$$

McCollum

332 
WGUS75 KFGZ 280316
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
816 PM MST Mon Sep 27 2021

AZC005-280326-
/O.EXP.KFGZ.FF.W.0233.000000T0000Z-210928T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
816 PM MST Mon Sep 27 2021

...FLASH FLOOD WARNING FOR THE MANGUM FIRE SCAR HAS EXPIRED FOR 
COCONINO COUNTY...

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

LAT...LON 3669 11235 3671 11229 3669 11229 3662 11230
      3660 11232 3659 11235 3662 11236

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 27, 5:29 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Sep 27, 5:41 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	34 min
Sep 27, 6:10 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	18 min
Sep 28, 2:35 PM MST	Special Weather Statement	FGZ		25 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.