Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 67, NWS Flagstaff, AZ

July 21, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 21, 2021, 12:47 PM MST for Coconino County, Arizona. It was in force for 118 min. 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: Jul 21, 2021, 12:47 PM MST (19:47 UTC)
Expired: Jul 21, 2021, 2:45 PM MST
In force: 118 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 19:48 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 21, 1:30 PM MST	FLASH FLOOD	2 Ne Downtown Flagstaff, AZ	FLOODED WASH ALONGSIDE PARADISE ROAD.

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, 7.8 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: 77 J/kg
Mixed-layer CIN: -129 J/kg
Mixed-layer LCL: 1785 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: -11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

013 
WGUS55 KFGZ 211947
FFWFGZ
AZC005-212045-
/O.NEW.KFGZ.FF.W.0067.210721T1947Z-210721T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1247 PM MST Wed Jul 21 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 145 PM MST.

* At 1247 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Museum Fire scar. Between 0.25 and 0.75 inches 
  of rain have fallen. The expected rainfall rate is 1 to 2 inches 
  in 1 hour. 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
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

EL

5 follow-up statements

769 
WGUS75 KFGZ 211959
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1259 PM MST Wed Jul 21 2021

AZC005-212045-
/O.CON.KFGZ.FF.W.0067.000000T0000Z-210721T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
1259 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING FOR THE MUSEUM FIRE SCAR REMAINS IN EFFECT 
UNTIL 145 PM MST THIS AFTERNOON FOR COCONINO COUNTY...

At 1257 PM MST, Doppler radar indicated thunderstorms producing 
heavy rain over the Museum Fire scar. Highest rain rates are taking 
place on the western side of the scar with an automatic rain gauge 
reporting 0.98 inches of rain in the last 30 minutes in that area. 
Between 0.5 and 1 inch of rain has fallen. The expected rainfall 
rate is 1 to 2 inches in 1 hour. 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
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

EL

126 
WGUS75 KFGZ 212019
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
119 PM MST Wed Jul 21 2021

AZC005-212045-
/O.CON.KFGZ.FF.W.0067.000000T0000Z-210721T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
119 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING FOR THE MUSEUM FIRE SCAR REMAINS IN EFFECT 
UNTIL 145 PM MST THIS AFTERNOON FOR COCONINO COUNTY...

At 116 PM MST, Doppler radar indicated the rain intensity has 
decreased to a more moderate rainfall with the heaviest rain 
occurring on the northern portions of the Museum Fire scar. Between 
0.5 and 1.25 inches of rain have fallen with 1.26 inches measured on 
the scar. The expected rainfall rate is 0.5 to 1 inch in 1 hour. 
Heavy rainfall could move onto the scar from the east-northeast 
within the hour. 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
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

EL

640 
WGUS55 KFGZ 212032
FFWFGZ
AZC005-212145-
/O.EXT.KFGZ.FF.W.0067.000000T0000Z-210721T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
132 PM MST Wed Jul 21 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 245 PM MST.

* At 129 PM MST, Doppler radar indicated the rainfall intensity has 
  decreased across the Museum Burn Scar with the heaviest rates 
  north and east of the scar. Light to moderate rain is possible 
  within the next hour with flooding likely. Between 0.5 and 1.25 
  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

$$

EL

635 
WGUS75 KFGZ 212113
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
213 PM MST Wed Jul 21 2021

AZC005-212145-
/O.CON.KFGZ.FF.W.0067.000000T0000Z-210721T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
213 PM MST Wed Jul 21 2021

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

At 211 PM MST, Doppler radar indicated the heavy rainfall has moved 
off the Museum Burn Scar, however flooding is still likely as rain 
water drains. 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

$$

EL

225 
WGUS75 KFGZ 212136
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
236 PM MST Wed Jul 21 2021

AZC005-212146-
/O.EXP.KFGZ.FF.W.0067.000000T0000Z-210721T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
236 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING FOR THE MUSEUM FIRE SCAR WILL EXPIRE AT 245 
PM MST THIS AFTERNOON FOR COCONINO COUNTY...

Flood waters have receded. 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

$$

EL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 6:16 PM MST	Special Weather Statement	FGZ		29 min
Jul 20, 7:32 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	28 min
Jul 20, 7:55 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	2 hr
Jul 20, 8:33 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	117 min
Jul 21, 12:17 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	118 min
Jul 21, 2:38 AM MST	Flash Flood Watch	FGZ	Apache, Coconino, Gila, Navajo, Yavapai	5 days
Jul 21, 10:19 AM MST	Special Weather Statement	FGZ	Yavapai	26 min
Jul 21, 10:48 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	2 hr
Jul 21, 12:03 PM MST	Special Weather Statement	FGZ	Yavapai	42 min
Jul 21, 12:13 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	56 min
Jul 21, 12:20 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	114 min
Jul 21, 12:35 PM MST	Special Weather Statement	FGZ		40 min
Jul 21, 12:54 PM MST	Special Weather Statement	FGZ		36 min
Jul 21, 1:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	92 min
Jul 21, 1:24 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	110 min
Jul 21, 1:27 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	74 min
Jul 21, 1:57 PM MST	Special Weather Statement	FGZ	Yavapai	48 min
Jul 21, 2:01 PM MST	Areal Flood Advisory	FGZ	Yavapai	119 min
Jul 21, 2:05 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	2 hr
Jul 21, 2:22 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 21, 2:30 PM MST	Special Weather Statement	FGZ		45 min
Jul 21, 2:36 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	54 min
Jul 21, 2:53 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	82 min
Jul 21, 2:57 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	60 min
Jul 21, 2:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	60 min
Jul 21, 3:21 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	26 min
Jul 21, 3:34 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	98 min
Jul 21, 3:49 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 21, 4:35 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	115 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.