Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 163, NWS Flagstaff, AZ

August 10, 2021Coconino County, Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 10, 2021, 3:11 PM MST for Coconino County, Yavapai 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
Aug 10, 2021, 3:11 PM MST (22:11 UTC)
Expired
Aug 10, 2021, 6:15 PM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Coconino County, AZ, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 172 km from the middle of the area, began a volume at 22:14 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, 10.2 hours before the alert went out and 94 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 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 609 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 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 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
609 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
962 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

238 
WGUS55 KFGZ 102211
FFWFGZ
AZC005-025-110115-
/O.NEW.KFGZ.FF.W.0163.210810T2211Z-210811T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
311 PM MST Tue Aug 10 2021

The National Weather Service in Flagstaff has issued a

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

* Until 615 PM MST.

* At 311 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 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.

  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...
  Seligman and Ash Fork.

This includes the following highways...
	Business Interstate 40 between mile markers 140 and 146.
	State Route 89 between mile markers 362 and 363.
	Route 66 between mile markers 135 and 139.
	Interstate 40 between mile markers 117 and 146.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

&&

LAT...LON 3546 11300 3555 11301 3565 11303 3570 11273
      3534 11245 3507 11248 3505 11262 3509 11280
      3523 11299 3537 11297

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

$$

Humphreys
2 follow-up statements
594 
WGUS75 KFGZ 102235
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
335 PM MST Tue Aug 10 2021

AZC005-025-110115-
/O.CON.KFGZ.FF.W.0163.000000T0000Z-210811T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Yavapai AZ-
335 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MST THIS 
EVENING FOR COCONINO AND YAVAPAI COUNTIES...

At 332 PM MST, flash flooding was reported near Seligman. Between 1 
and 2 inches of rain have fallen. Additional rainfall amounts of 0.5 
to 1.5 inches are possible in the warned area. Flash flooding is 
already occurring.

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

SOURCE...Fire department reported.

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

Some locations that will experience flash flooding include...
  Seligman and Ash Fork.

This includes the following highways...
	Business Interstate 40 between mile markers 140 and 146.
	State Route 89 between mile markers 362 and 363.
	Route 66 between mile markers 135 and 139.
	Interstate 40 between mile markers 117 and 146.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

&&

LAT...LON 3546 11300 3555 11301 3565 11303 3570 11273
      3534 11245 3507 11248 3505 11262 3509 11280
      3523 11299 3537 11297

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Humphreys
229 
WGUS75 KFGZ 110110
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
610 PM MST Tue Aug 10 2021

AZC005-025-110120-
/O.EXP.KFGZ.FF.W.0163.000000T0000Z-210811T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Yavapai AZ-
610 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM MST THIS EVENING FOR 
COCONINO AND YAVAPAI COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures and use 
caution near creeks and washes in the area that may be running high 
this evening.

LAT...LON 3546 11300 3555 11301 3565 11303 3570 11273
      3534 11245 3507 11248 3505 11262 3509 11280
      3523 11299 3537 11297

$$

MCT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 5:19 PM MSTSpecial Weather StatementFGZ41 min
Aug 9, 6:17 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 9, 6:56 PM MSTSevere Thunderstorm WarningFGZYavapai34 min
Aug 9, 7:27 PM MSTSpecial Weather StatementFGZ33 min
Aug 9, 7:50 PM MSTSpecial Weather StatementFGZGila25 min
Aug 9, 8:44 PM MSTSpecial Weather StatementFGZGila46 min
Aug 9, 9:18 PM MSTAreal Flood AdvisoryFGZGila, Navajo3 hr
Aug 9, 9:32 PM MSTSpecial Weather StatementFGZGila43 min
Aug 10, 11:35 AM MSTSpecial Weather StatementFGZ25 min
Aug 10, 11:55 AM MSTSevere Thunderstorm WarningFGZCoconino15 min
Aug 10, 12:02 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 10, 12:14 PM MSTSpecial Weather StatementFGZ31 min
Aug 10, 12:46 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 10, 12:59 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 10, 1:22 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai53 min
Aug 10, 2:22 PM MSTSpecial Weather StatementFGZYavapai23 min
Aug 10, 2:26 PM MSTSevere Thunderstorm WarningFGZYavapai32 min
Aug 10, 2:35 PM MSTSevere Thunderstorm WarningFGZYavapai40 min
Aug 10, 2:43 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 10, 2:52 PM MSTSevere Thunderstorm WarningFGZCoconino, Yavapai38 min
Aug 10, 3:46 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 10, 4:13 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.