Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 187, NWS Flagstaff, AZ

August 17, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 17, 2021, 12:41 PM MST for Coconino County, Arizona. It was in force for 3 hr. 4 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
Aug 17, 2021, 12:41 PM MST (19:41 UTC)
Expired
Aug 17, 2021, 3:45 PM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Emergency
Flash flood emergency
Damage threat
Catastrophic
Flood severity
None

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 84 km from the middle of the area, began a volume at 19:44 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

TimeReportWhereRemark
Aug 17, 12:46 PM MSTFLASH FLOODMt. Elden Estates At La, AZTREES, LOGS, AND OTHER DEBRIS ARE NOW IN THE FLOW, WATER IS APPROXIMATELY 60-70’ WIDE OVERTOPPING THE ROAD, AND DEPTH IS ABOUT 2.5 - 3 FEET.
Aug 17, 12:55 PM MSTFLASH FLOODLinda Vista Drive, AZWATER HAS OVERTOPPED ROADWAY WITH DEBRIS.
Aug 17, 1:00 PM MSTFLASH FLOODDortha Ave., AZWATER HAS OVERTOPPED THE BARRIERS AND OVERTOPPED THE ROADS WITH GREATER THAN 1.5 FEET WATER DEPTH.
Aug 17, 1:10 PM MSTFLASH FLOODCedar Ave. And West St., AZSIGNIFICANT FLOODING NEAR SAFEWAY. CEDAR AVE. CLOSED BY THE CITY OF FLAGSTAFF.

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, 7.7 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-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 12:00Z on 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 984 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 135 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
984 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
829 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

Open this sounding in Storm Lab

The text

As transmitted.

771 
WGUS55 KFGZ 171941
FFWFGZ
AZC005-172145-
/O.NEW.KFGZ.FF.W.0187.210817T1941Z-210817T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1241 PM MST Tue Aug 17 2021

...FLASH FLOOD EMERGENCY FOR MUSEUM FIRE SCAR AREA...

The National Weather Service in Flagstaff has issued a

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

* Until 245 PM MST.

* At 1241 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain over the Museum Fire scar area. 
  Up to 2 inches of rain have fallen. Additional rainfall amounts of 
  1 to 2 inches are possible in the warned area. Flash flooding is 
  ongoing or expected to begin shortly.

  This is a FLASH FLOOD EMERGENCY for Museum Fire scar area. This is 
  a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!

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

  SOURCE...Radar and automated gauges.

  IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK
           HIGHER GROUND NOW! IMMEDIATE EVACUATION for areas in
           and around the Museum Fire scar area.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now! This is an extremely dangerous and 
life-threatening situation. Do not attempt to travel unless you are 
fleeing an area subject to flooding or under an evacuation order.

Residents in the warned area should shelter in place, and stay away 
from creeks and local drainages.

Do not drive across flooded streets. Flood waters and debris from 
the Museum Fire scar will affect Mount Elden Estates, the Paradise 
and Grandview Drive neighborhoods, as well as the Sunnyside 
neighborhood of Flagstaff. The flood waters may include ash and 
debris.

&&

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3521 11161 3520 11162 3522 11163 3524 11164

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC

$$

DB
3 follow-up statements
457 
WGUS75 KFGZ 172055
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
155 PM MST Tue Aug 17 2021

AZC005-172145-
/O.CON.KFGZ.FF.W.0187.000000T0000Z-210817T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
155 PM MST Tue Aug 17 2021

...FLASH FLOOD EMERGENCY FOR MUSEUM FIRE SCAR AREA...

...FLASH FLOOD WARNING FOR THE MUSEUM FIRE SCAR AREA REMAINS IN 
EFFECT UNTIL 245 PM MST THIS AFTERNOON FOR COCONINO COUNTY...

At 153 PM MST, Doppler radar indicates heavy rain has ended over the 
Museum Fire scar area. Between 2 and 3 inches of rain have fallen. 
Additional rainfall amounts up to 0.25 inches are possible in the 
warned area. Local law enforcement reports flash flooding is ongoing 
with several road closures north of Route 66 in Flagstaff.

This is a FLASH FLOOD EMERGENCY for Museum Fire scar area. This is a 
PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!

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

SOURCE...Radar and automated gauges.

IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
         GROUND NOW! IMMEDIATE EVACUATION for areas in and around
         the Museum Fire scar area.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now! This is an extremely dangerous and 
life-threatening situation. Do not attempt to travel unless you are 
fleeing an area subject to flooding or under an evacuation order.

Residents in the warned area should shelter in place, and stay away 
from creeks and local drainages.

Do not drive across flooded streets. Flood waters and debris from 
the Museum Fire scar will affect Mount Elden Estates, the Paradise 
and Grandview Drive neighborhoods, as well as the Sunnyside 
neighborhood of Flagstaff. The flood waters may include ash and 
debris.

&&

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3521 11161 3520 11162 3522 11163 3524 11164

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC

$$

TPS
543 
WGUS55 KFGZ 172140
FFWFGZ
AZC005-172245-
/O.EXT.KFGZ.FF.W.0187.000000T0000Z-210817T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
240 PM MST Tue Aug 17 2021

...FLASH FLOOD EMERGENCY FOR MUSEUM FIRE SCAR AREA...

The National Weather Service in Flagstaff has extended the

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

* Until 345 PM MST.

* At 239 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain over the Museum Fire scar area. 
  Between 2 and 4 inches of rain have fallen. Flash flooding is 
  ongoing.

  This is a FLASH FLOOD EMERGENCY for Museum Fire scar area. This is 
  a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!

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

  SOURCE...Radar and automated gauges.

  IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK
           HIGHER GROUND NOW! IMMEDIATE EVACUATION for areas in
           and around the Museum Fire scar area.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now! This is an extremely dangerous and 
life-threatening situation. Do not attempt to travel unless you are 
fleeing an area subject to flooding or under an evacuation order.

Residents in the warned area should shelter in place, and stay away 
from creeks and local drainages.

Do not drive across flooded streets. Flood waters and debris from 
the Museum Fire scar will affect Mount Elden Estates, the Paradise 
and Grandview Drive neighborhoods, as well as the Sunnyside 
neighborhood of Flagstaff. The flood waters may include ash and 
debris.

&&

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3521 11161 3520 11162 3522 11163 3524 11164

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC

$$

DB
179 
WGUS75 KFGZ 172238
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
338 PM MST Tue Aug 17 2021

AZC005-172248-
/O.EXP.KFGZ.FF.W.0187.000000T0000Z-210817T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
338 PM MST Tue Aug 17 2021

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

Several roadways in Flagstaff are closed especially from Route 66 
northward, but flood waters will continue to recede over the next 
few hours. The heavy rain threat has ended. Please continue to heed 
road closures.

A Flash Flood Watch remains in effect until 1100 PM MST Tuesday for 
portions of north central Arizona, northeast Arizona and west 
central Arizona.

LAT...LON 3526 11165 3527 11163 3528 11162 3527 11160
      3525 11160 3525 11162 3524 11163 3522 11161
      3521 11161 3520 11162 3522 11163 3524 11164

$$

TPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 5:04 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Navajo3 hr
Aug 16, 6:33 PM MSTSevere Thunderstorm WarningFGZYavapai27 min
Aug 16, 7:08 PM MSTSevere Thunderstorm WarningFGZYavapai37 min
Aug 16, 7:37 PM MSTSevere Thunderstorm WarningFGZCoconino23 min
Aug 16, 7:42 PM MSTSevere Thunderstorm WarningFGZYavapai33 min
Aug 16, 7:57 PM MSTSevere Thunderstorm WarningFGZCoconino33 min
Aug 16, 8:04 PM MSTSevere Thunderstorm WarningFGZYavapai26 min
Aug 16, 8:21 PM MSTSevere Thunderstorm WarningFGZCoconino24 min
Aug 16, 9:18 PM MSTSevere Thunderstorm WarningFGZGila42 min
Aug 16, 10:01 PM MSTSevere Thunderstorm WarningFGZYavapai29 min
Aug 16, 10:33 PM MSTSevere Thunderstorm WarningFGZYavapai25 min
Aug 17, 12:04 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Gila, Navajo3 hr
Aug 17, 12:15 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino60 min
Aug 17, 12:22 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 12:29 PM MSTSevere Thunderstorm WarningFGZCoconino, Gila, Navajo46 min
Aug 17, 12:59 PM MSTSevere Thunderstorm WarningFGZCoconino46 min
Aug 17, 1:06 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 1:16 PM MSTSevere Thunderstorm WarningFGZCoconino44 min
Aug 17, 1:21 PM MSTSevere Thunderstorm WarningFGZCoconino39 min
Aug 17, 1:28 PM MSTSevere Thunderstorm WarningFGZCoconino47 min
Aug 17, 1:37 PM MSTFlash Flood WatchFGZApache, Coconino, Navajo9 hr
Aug 17, 2:03 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 2:09 PM MSTSevere Thunderstorm WarningFGZCoconino51 min
Aug 17, 2:15 PM MSTSevere Thunderstorm WarningFGZCoconino45 min
Aug 17, 2:18 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 3:03 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 17, 3:42 PM MSTSevere Thunderstorm WarningFGZCoconino33 min
Aug 17, 3:44 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 17, 4:06 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 17, 4:19 PM MSTSevere Thunderstorm WarningFGZYavapai26 min
Aug 17, 4:22 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 17, 4:46 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr

Nearby

Flash Flood Warnings in Arizona, 2021Every 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.