Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 28, NWS Flagstaff, AZ

July 14, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 14, 2021, 3:36 PM MST for Coconino County, Arizona. It was in force for 3 hr. 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 14, 2021, 3:36 PM MST (22:36 UTC)
Expired: Jul 14, 2021, 6:45 PM MST
In force: 3 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), 180 km from the middle of the area, began a volume at 22:39 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, 10.6 hours before the alert went out and 104 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: 17 J/kg
Mixed-layer CIN: -187 J/kg
Mixed-layer LCL: 1682 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

211 
WGUS55 KFGZ 142236
FFWFGZ
AZC005-150145-
/O.NEW.KFGZ.FF.W.0028.210714T2236Z-210715T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
336 PM MST Wed Jul 14 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Coconino County in north central Arizona...

* Until 645 PM MST.

* At 335 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.5 to 1 inch are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life-threatening flash flooding of low-water
           crossings, creeks, normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Cape Royal At Grand Canyon and Grand Canyon National Park.

This includes the following streams and drainages...
  Chuar Creek, Sixtymile Creek, Clear Creek, Little Colorado River, 
  West Fork Carbon Creek, Kwagunt Creek, Cardenas Creek, Comanche 
  Creek, Nankoweap Creek, Bright Angel Creek, Unkar Creek and 
  Colorado River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

Stay away or be swept away! The banks of creeks and washes are 
unstable and unsafe during any flooding event.

&&

LAT...LON 3622 11199 3623 11188 3618 11179 3607 11181
      3608 11194 3611 11204

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

$$

MCT

2 follow-up statements

429 
WGUS75 KFGZ 142344
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
444 PM MST Wed Jul 14 2021

AZC005-150145-
/O.CON.KFGZ.FF.W.0028.000000T0000Z-210715T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
444 PM MST Wed Jul 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MST THIS 
EVENING FOR COCONINO COUNTY...

At 442 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 2 and 4.5 inches of rain have 
already fallen. Additional thunderstorms are moving into the area 
from the northwest and will bring additional rainfall over the next 
hour. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads.

Some locations that will experience flash flooding include...
  Cape Royal At Grand Canyon and Grand Canyon National Park.

This includes the following streams and drainages...
  Chuar Creek, Sixtymile Creek, Clear Creek, Little Colorado River, 
  West Fork Carbon Creek, Kwagunt Creek, Cardenas Creek, Comanche 
  Creek, Nankoweap Creek, Bright Angel Creek, Unkar Creek and 
  Colorado River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

Stay away or be swept away! The banks of creeks and washes are 
unstable and unsafe during any flooding event.

&&

LAT...LON 3622 11199 3623 11188 3618 11179 3607 11181
      3608 11194 3611 11204

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

$$

MCT

722 
WGUS75 KFGZ 150139
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
639 PM MST Wed Jul 14 2021

AZC005-150149-
/O.EXP.KFGZ.FF.W.0028.000000T0000Z-210715T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
639 PM MST Wed Jul 14 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM MST THIS EVENING FOR 
COCONINO COUNTY...

The heavy rain has ended with only areas of light rain continuing at 
this time. Flooding is no longer expected to pose a threat. Please 
continue to heed remaining road closures and use caution near any 
elevated water levels.

A Flash Flood Watch remains in effect until 1200 AM MST for portions 
of north central Arizona and northeast Arizona. Additional heavy 
rainfall is possible.

LAT...LON 3622 11199 3623 11188 3618 11179 3607 11181
      3608 11194 3611 11204

$$

MCT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 5:20 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Yavapai	3 hr
Jul 13, 7:23 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 2:39 AM MST	Special Weather Statement	FGZ	Yavapai	36 min
Jul 14, 3:06 AM MST	Areal Flood Advisory	FGZ	Yavapai	111 min
Jul 14, 3:24 AM MST	Special Weather Statement	FGZ	Yavapai	36 min
Jul 14, 3:38 AM MST	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 14, 3:59 AM MST	Special Weather Statement	FGZ	Yavapai	46 min
Jul 14, 4:24 AM MST	Areal Flood Advisory	FGZ	Yavapai	74 min
Jul 14, 4:30 AM MST	Special Weather Statement	FGZ		45 min
Jul 14, 4:45 AM MST	Special Weather Statement	FGZ		45 min
Jul 14, 5:23 AM MST	Special Weather Statement	FGZ		37 min
Jul 14, 9:53 AM MST	Flash Flood Watch	FGZ	Apache, Coconino, Navajo	17 hr
Jul 14, 1:47 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	5 hr
Jul 14, 2:13 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 2:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 14, 2:57 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 14, 4:02 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	31 min
Jul 14, 4:24 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	111 min
Jul 14, 4:54 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	111 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.