Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 20, NWS Flagstaff, AZ

July 13, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 13, 2021, 2:38 PM MST for Coconino County, Arizona. It was in force for 112 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 13, 2021, 2:38 PM MST (21:38 UTC)
Expired: Jul 13, 2021, 4:30 PM MST
In force: 112 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 21:37 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, 9.6 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: 854 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1003 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -72 m²/s²
0-3 km storm-relative helicity: 195 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

247 
WGUS55 KFGZ 132138
FFWFGZ
AZC005-132330-
/O.NEW.KFGZ.FF.W.0020.210713T2138Z-210713T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
238 PM MST Tue Jul 13 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 430 PM MST.

* At 237 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Museum 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 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

$$

JJ

2 follow-up statements

490 
WGUS75 KFGZ 132250
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
350 PM MST Tue Jul 13 2021

AZC005-132330-
/O.CON.KFGZ.FF.W.0020.000000T0000Z-210713T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
350 PM MST Tue Jul 13 2021

...FLASH FLOOD WARNING FOR THE MUSEUM FIRE SCAR REMAINS IN EFFECT 
UNTIL 430 PM MST THIS AFTERNOON FOR COCONINO COUNTY...

At 345 PM MST, Doppler radar indicated that rainfall has diminished 
over the Museum Fire scar. Rainfall amounts of 1 to 2 inches fell 
earlier this afternoon and is leading to flash flooding.

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 flooding 
reported as far south as East Cedar Avenue and Dortha Avenue at 
North Main Street.

&&

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

$$

JJ

367 
WGUS75 KFGZ 132339
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
439 PM MST Tue Jul 13 2021

AZC005-132349-
/O.EXP.KFGZ.FF.W.0020.000000T0000Z-210713T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
439 PM MST Tue Jul 13 2021

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

City of Flagstaff and Coconino County officials report that water 
continues to recede due to runoff from the Museum Fire Scar. The 
threat for heavy rainfall has ended. Flooding is no longer expected 
to pose a threat to life and property. 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

$$

Peterson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 5:40 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	35 min
Jul 12, 5:56 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	34 min
Jul 12, 7:10 PM MST	Areal Flood Advisory	FGZ	Coconino, Yavapai	3 hr
Jul 13, 12:41 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Navajo	3 hr
Jul 13, 1:29 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 13, 1:57 PM MST	Special Weather Statement	FGZ		33 min
Jul 13, 2:25 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	2 hr
Jul 13, 2:54 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	29 min
Jul 13, 3:06 PM MST	Special Weather Statement	FGZ	Yavapai	39 min
Jul 13, 3:27 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	33 min
Jul 13, 4:14 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 13, 4:25 PM MST	Areal Flood Advisory	FGZ	Coconino, Yavapai	3 hr

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.