Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 37, NWS Flagstaff, AZ

July 16, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 16, 2021, 1:20 PM MST for Coconino County, Arizona. It was in force for 115 min. 3 reports 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: Jul 16, 2021, 1:20 PM MST (20:20 UTC)
Expired: Jul 16, 2021, 3:15 PM MST
In force: 115 min
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), 85 km from the middle of the area, began a volume at 20:20 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
Jul 16, 2:04 PM MST	FLASH FLOOD	2 Ne Downtown Flagstaff, AZ	SPRUCE AVE. WASH NEAR LINDA VISTA GAGE INDICATED A 1.85 FT. RISE BETWEEN 1:56PM AND 2:04PM.
Jul 16, 2:07 PM MST	FLASH FLOOD	3 Nw Flagstaff Mall, AZ	SPRUCE AVE WASH UPPER DRY LAKES STREAM GAGE INDICATED A 1.5 FT. RISE FROM 11:46AM TO 2:07PM.
Jul 16, 2:13 PM MST	FLASH FLOOD	2 Wsw Flagstaff Mall, AZ	2.5 FT. FLOWS WERE OBSERVED AT THE DORTHA CROSSING, AND WATERS HAVE OVERTOPPED THE ROADWAY.

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 12:00Z, 8.3 hours before the alert went out and 16 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: 487 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 1090 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

590 
WGUS55 KFGZ 162020
FFWFGZ
AZC005-162115-
/O.NEW.KFGZ.FF.W.0037.210716T2020Z-210716T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
120 PM MST Fri Jul 16 2021

The National Weather Service in Flagstaff has issued a

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

* Until 215 PM MST.

* At 120 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Museum Fire scar. Between 0.5 and 0.75 inches 
  of rain have fallen. Flash flooding is ongoing or expected to 
  begin shortly.

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

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Flagstaff.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Residents in the warned area should shelter in place, and stay away 
from creeks and local drainages. Flood waters and debris from the 
Museum Fire scar will affect Mount Elden Estates, with lesser 
impacts downstream. The Paradise and Grandview Drive neighborhoods 
may see elevated flows in local drainages.

&&

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3522 11163

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

$$

ET

2 follow-up statements

459 
WGUS55 KFGZ 162054
FFWFGZ
AZC005-162215-
/O.EXT.KFGZ.FF.W.0037.000000T0000Z-210716T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
154 PM MST Fri Jul 16 2021

The National Weather Service in Flagstaff has extended the

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

* Until 315 PM MST.

* At 152 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Museum Fire scar earlier today. The heavy rain 
  has ended over the scar for the time being. Between 0.75 and 1.5 
  inches of rain have fallen. Flash flooding is occurring along the 
  drainage as viewed by cameras.

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

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Flagstaff.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Residents in the warned area should shelter in place, and stay away 
from creeks and local drainages. Flood waters and debris from the 
Museum Fire scar will affect Mount Elden Estates, with lesser 
impacts downstream. The Paradise and Grandview Drive neighborhoods 
may see elevated flows in local drainages.

&&

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3522 11163

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

$$

ET

841 
WGUS75 KFGZ 162207
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
307 PM MST Fri Jul 16 2021

AZC005-162217-
/O.EXP.KFGZ.FF.W.0037.000000T0000Z-210716T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
307 PM MST Fri Jul 16 2021

...FLASH FLOOD WARNING FOR THE MUSEUM FIRE SCAR WILL EXPIRE AT 315 
PM MST THIS AFTERNOON FOR COCONINO COUNTY...

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

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3522 11163

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 5:20 PM MST	Areal Flood Advisory	FGZ	Yavapai	115 min
Jul 15, 6:33 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	27 min
Jul 15, 6:55 PM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Jul 15, 8:21 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	114 min
Jul 16, 11:56 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 16, 12:03 PM MST	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 16, 12:36 PM MST	Areal Flood Advisory	FGZ	Coconino	2 hr
Jul 16, 12:52 PM MST	Special Weather Statement	FGZ		23 min
Jul 16, 1:16 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	29 min
Jul 16, 1:24 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	51 min
Jul 16, 1:44 PM MST	Special Weather Statement	FGZ		46 min
Jul 16, 2:13 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	32 min
Jul 16, 2:25 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 16, 2:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	61 min
Jul 16, 3:14 PM MST	Special Weather Statement	FGZ		31 min
Jul 16, 3:43 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	32 min
Jul 16, 4:18 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	12 min
Jul 16, 4:34 PM MST	Severe Thunderstorm Warning	FGZ	Gila	41 min
Jul 16, 4:41 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Jul 16, 4:48 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila	20 min
Jul 16, 4:59 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Yavapai	15 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.