Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 123, NWS Flagstaff, AZ

July 29, 2021Apache County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 29, 2021, 12:57 PM MST for Apache County, Navajo 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 29, 2021, 12:57 PM MST (19:57 UTC)
Expired: Jul 29, 2021, 4:00 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), 201 km from the middle of the area, began a volume at 19:59 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, 8.0 hours before the alert went out and 200 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: 156 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 1821 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 37 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

252 
WGUS55 KFGZ 291957
FFWFGZ
AZC001-017-292300-
/O.NEW.KFGZ.FF.W.0123.210729T1957Z-210729T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1257 PM MST Thu Jul 29 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 400 PM MST.

* At 1255 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain near Salina. 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...
  Tselani-Cottonwood, Salina, Burnside, Blue Gap Chapter House, 
  Whippoorwill Chapter House, Nazlini.

This includes the following highways...
	Highway 191 between mile markers 418 and 439.
	State Route 264 between mile markers 434 and 442.

This includes the following streams and drainages...
  Balakai Wash, Cottonwood Wash, Tse Chizzi Wash, Burnt Corn Wash, 
  Nazlini Wash, Steamboat Wash, Lone Tule Wash, Polacca Wash, Bis Ii 
  Ah Wash, Jeddito Wash, Keams Canyon Wash, Tse Deeshzhaai Wash, 
  Pueblo Colorado Wash, Beshbito Wash and Tse Ba Ni Zi Ni Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3586 11000 3588 11006 3604 11014 3613 11012
      3617 11002 3618 10982 3614 10968 3605 10960
      3599 10947 3595 10935 3583 10941 3573 10955
      3578 10979

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

$$

Peterson

1 follow-up statement

873 
WGUS75 KFGZ 292253
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
353 PM MST Thu Jul 29 2021

AZC001-017-292303-
/O.EXP.KFGZ.FF.W.0123.000000T0000Z-210729T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Apache AZ-Navajo AZ-
353 PM MST Thu Jul 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 4 PM MST THIS AFTERNOON FOR 
NAVAJO AND APACHE COUNTIES...

At 355 PM MST, National Weather Service Flagstaff Doppler radar 
indicated that widespread heavy rain was no longer falling southwest 
of Chinle, near Salina.

No reports of flooding have been received, however, area washes, 
creeks and streams are likley running high. Please continue to heed 
remaining road closures.

LAT...LON 3586 11000 3588 11006 3604 11014 3613 11012
      3617 11002 3618 10982 3614 10968 3605 10960
      3599 10947 3595 10935 3583 10941 3573 10955
      3578 10979

$$

Peterson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 6:47 PM MST	Special Weather Statement	FGZ		28 min
Jul 28, 7:06 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Jul 28, 7:18 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Jul 29, 11:48 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 29, 11:57 AM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	33 min
Jul 29, 12:21 PM MST	Severe Thunderstorm Warning	FGZ	Apache	24 min
Jul 29, 12:36 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	24 min
Jul 29, 12:44 PM MST	Severe Thunderstorm Warning	FGZ	Apache	31 min
Jul 29, 12:53 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 29, 1:07 PM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	38 min
Jul 29, 1:10 PM MST	Severe Thunderstorm Warning	FGZ	Apache	50 min
Jul 29, 1:13 PM MST	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 29, 1:23 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	37 min
Jul 29, 2:05 PM MST	Flash Flood Watch	FGZ	Apache, Coconino, Navajo, Yavapai	31 hr
Jul 29, 2:09 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 29, 2:16 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Jul 29, 2:41 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Jul 29, 3:03 PM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	27 min
Jul 29, 3:41 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Navajo	3 hr
Jul 29, 4:03 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr

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.