Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 199, NWS Flagstaff, AZ

August 17, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 17, 2021, 10:42 PM MST for Coconino County, Arizona. It was in force for 11 hr. 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
Aug 17, 2021, 10:42 PM MST (05:42 UTC)
Expired
Aug 18, 2021, 9:30 AM MST
In force
11 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), 125 km from the middle of the area, began a volume at 05:42 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 18, 7:00 AM MSTFLASH FLOOD1 Nw Lees Ferry, AZUSGS GAGE FOR THE PARIA RIVER AT LEES FERRY INDICATED A 4 FT. RISE BETWEEN 6AM-7AM.

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 00:00Z, 5.7 hours before the alert went out and 190 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 00:00Z on 2021-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 284 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 00:00Z on 2021-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.193958Sfc1 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
284 J/kg
Mixed-layer CIN
-89 J/kg
Mixed-layer LCL
1301 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

257 
WGUS55 KFGZ 180542
FFWFGZ
AZC005-181430-
/O.NEW.KFGZ.FF.W.0199.210818T0542Z-210818T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1042 PM MST Tue Aug 17 2021

The National Weather Service in Flagstaff has issued a

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

* Until 730 AM MST Wednesday.

* At 1036 PM MST, Heavy rain fell Tuesday evening over the Paria 
  River drainage in Utah. A flood wave along the Paria River will 
  enter Arizona by midnight, and continue down the river to Lees 
  Ferry after sunrise Wednesday morning.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Paria
           River.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Paria River.

* Some locations that will experience flash flooding include...
  Lees Ferry, Glen Canyon National Recreation Area, Grand Canyon 
  National Park and Navajo Reservation.

This includes the following slot canyons...
	Paria River upstream of Lees Ferry.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get out of the Paria River slot canyon! Flood waters will flow down 
the Paria River, reaching the confluence with the Colorado River at 
Lees Ferry between 5 and 7 AM Wednesday.

&&

LAT...LON 3694 11166 3686 11157 3685 11159 3690 11166
      3693 11172 3696 11180 3697 11186 3700 11188
      3700 11170

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

$$

JJ
3 follow-up statements
422 
WGUS75 KFGZ 181222
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
522 AM MST Wed Aug 18 2021

AZC005-181430-
/O.CON.KFGZ.FF.W.0199.000000T0000Z-210818T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
522 AM MST Wed Aug 18 2021

...FLASH FLOOD WARNING FOR THE PARIA RIVER REMAINS IN EFFECT UNTIL 
730 AM MST THIS MORNING FOR COCONINO COUNTY...

At 520 AM MST, Heavy rain fell Tuesday evening over the Paria River 
drainage in Utah. A flood wave along the Paria River will continue 
down the river to Lees Ferry after sunrise this morning.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding in and around the Paria River.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of areas in and around
         the Paria River.

Some locations that will experience flash flooding include...
  Lees Ferry, Glen Canyon National Recreation Area, Grand Canyon 
  National Park and Navajo Reservation.

This includes the following slot canyons...
	Paria River upstream of Lees Ferry.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get out of the Paria River slot canyon! Flood waters will flow down 
the Paria River, reaching the confluence with the Colorado River at 
Lees Ferry between now and 7 AM MST this morning.

&&

LAT...LON 3694 11166 3686 11157 3685 11159 3690 11166
      3693 11172 3696 11180 3697 11186 3700 11188
      3700 11170

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

$$

MCT
703 
WGUS55 KFGZ 181421
FFWFGZ
AZC005-181630-
/O.EXT.KFGZ.FF.W.0199.000000T0000Z-210818T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
721 AM MST Wed Aug 18 2021

The National Weather Service in Flagstaff has extended the

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

* Until 930 AM MST.

* At 716 AM MST, Flood waters have reached Lees Ferry with a stream 
  gauge there indicating a 3.95 foot rise in water. Water levels 
  continue to rise and the Flash Flood Warning has been extended 
  until 9:30 AM MST.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Paria
           River.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Paria River.

* Some locations that will experience flash flooding include...
  Lees Ferry, Glen Canyon National Recreation Area, Grand Canyon 
  National Park and Navajo Reservation.

This includes the following slot canyons...
	Paria River upstream of Lees Ferry.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Get out of the Paria River slot canyon! Flood waters will flow down 
the Paria River flooding the slot canyon.

&&

LAT...LON 3694 11166 3686 11157 3685 11159 3690 11166
      3693 11172 3696 11180 3697 11186 3700 11188
      3700 11170

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

$$

MCT
461 
WGUS75 KFGZ 181633
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
933 AM MST Wed Aug 18 2021

AZC005-181643-
/O.EXP.KFGZ.FF.W.0199.000000T0000Z-210818T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
933 AM MST Wed Aug 18 2021

...FLASH FLOOD WARNING FOR THE PARIA RIVER HAS EXPIRED FOR COCONINO 
COUNTY...

Flood waters are receding according to the river gauge at Lees 
Ferry. Flooding is no longer expected to pose a threat. Please 
continue to heed remaining road closures.

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

LAT...LON 3694 11166 3686 11157 3685 11159 3690 11166
      3693 11172 3696 11180 3697 11186 3700 11188
      3700 11170

$$

EL

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 5:02 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 17, 6:23 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Aug 17, 8:30 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Aug 17, 8:42 PM MSTSevere Thunderstorm WarningFGZCoconino33 min
Aug 17, 9:07 PM MSTFlash Flood WatchFGZApache, Coconino, Gila, Navajo, Yavapai26 hr
Aug 18, 8:43 AM MSTSpecial Weather StatementFGZ47 min
Aug 18, 9:29 AM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 18, 9:44 AM MSTFlash Flood Warning Considerable damage threatFGZGila7 hr
Aug 18, 10:37 AM MSTSpecial Weather StatementFGZ38 min
Aug 18, 10:47 AM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 18, 11:11 AM MSTSpecial Weather StatementFGZ34 min
Aug 18, 11:54 AM MSTSpecial Weather StatementFGZ36 min
Aug 18, 12:01 PM MSTSpecial Weather StatementFGZ44 min
Aug 18, 12:07 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Navajo3 hr
Aug 18, 12:24 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 18, 12:31 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 18, 12:51 PM MSTFlash Flood Warning Considerable damage threatFGZGila, Yavapai4 hr
Aug 18, 1:05 PM MSTSevere Thunderstorm WarningFGZGila, Yavapai40 min
Aug 18, 1:09 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 18, 1:37 PM MSTSevere Thunderstorm WarningFGZCoconino38 min
Aug 18, 1:47 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino118 min
Aug 18, 2:19 PM MSTAreal Flood AdvisoryFGZNavajo3 hr
Aug 18, 2:44 PM MSTSpecial Weather StatementFGZYavapai31 min
Aug 18, 2:52 PM MSTFlash Flood WarningFGZNavajo3 hr
Aug 18, 3:32 PM MSTFlash Flood WarningFGZCoconino, Yavapai3 hr
Aug 18, 3:45 PM MSTSpecial Weather StatementFGZ30 min
Aug 18, 4:12 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.