Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 100, NWS Flagstaff, AZ

July 24, 2021Apache County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 24, 2021, 4:18 PM MST for Apache County, Navajo County, Arizona. It was in force for 3 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: Jul 24, 2021, 4:18 PM MST (23:18 UTC)
Expired: Jul 24, 2021, 7:15 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Apache County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 188 km from the middle of the area, began a volume at 23:19 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 24, 7:10 PM MST	FLASH FLOOD	1 Wsw Pinon, AZ	PUBLIC REPORTS FLASH FLOOD ALONG NAVAJO ROUTE 4 WEST OF PINON RODEO. FLOOD WATER WAS ACROSS ROAD ESTIMATED 6 IN - 1 FT DEEP. REPORT VIA VIDEO ON FACEBOOK.

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, 11.3 hours before the alert went out and 180 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1053 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: -9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

158 
WGUS55 KFGZ 242318
FFWFGZ
AZC001-017-250215-
/O.NEW.KFGZ.FF.W.0100.210724T2318Z-210725T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
418 PM MST Sat Jul 24 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Navajo County in north central Arizona...
  Apache County in northeastern Arizona...

* Until 715 PM MST.

* At 415 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of northeast Arizona near Pinon, 
  Polacca, and Keams Canyon. Between 0.75 and 1.5 inches of rain 
  have fallen. Additional rainfall amounts of 0.75 to 1.5 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...
  Keams Canyon, Tselani-Cottonwood, Whippoorwill Chapter House, Blue 
  Gap Chapter House, Salina, Jadito, Jeddito, First Mesa, Navajo, 
  and Pinon.

This includes the following highways...
	State Route 264 between mile markers 387 and 418.

This includes the following streams and drainages...
  Balakai Wash, Black Mountain Wash, Tse Chizzi Wash, Wepo Wash, 
  Oraibi Wash, Cottonwood Wash, Steamboat Wash, Bitter Water Wash, 
  Bluebird Canyon Wash, Polacca Wash, Jeddito Wash, and Keams Canyon 
  Wash.

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 3575 11000 3570 11006 3577 11047 3619 11031
      3635 11012 3616 10970 3610 10963

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

$$

TPS

1 follow-up statement

585 
WGUS75 KFGZ 250215
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
715 PM MST Sat Jul 24 2021

AZC001-017-250225-
/O.EXP.KFGZ.FF.W.0100.000000T0000Z-210725T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Apache AZ-Navajo AZ-
715 PM MST Sat Jul 24 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NAVAJO AND APACHE COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MST Monday for 
portions of east central Arizona, north central Arizona, northeast 
Arizona and west central Arizona.

LAT...LON 3575 11000 3570 11006 3577 11047 3619 11031
      3635 11012 3616 10970 3610 10963

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 5:56 PM MST	Severe Thunderstorm Warning	FGZ	Apache	34 min
Jul 23, 6:00 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 23, 11:13 PM MST	Areal Flood Advisory	FGZ	Apache, Coconino, Gila, Navajo	5 hr
Jul 24, 7:22 AM MST	Areal Flood Advisory	FGZ	Apache, Coconino, Navajo	16 hr
Jul 24, 1:28 PM MST	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 24, 1:56 PM MST	Severe Thunderstorm Warning	FGZ	Apache	34 min
Jul 24, 2:16 PM MST	Severe Thunderstorm Warning	FGZ	Apache	29 min
Jul 24, 2:43 PM MST	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 24, 4:01 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	119 min
Jul 24, 4:05 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 24, 4:20 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	25 min
Jul 24, 4:51 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	39 min
Jul 24, 4:58 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	32 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.