Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 139, NWS Flagstaff, AZ

August 1, 2021Gila County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 1, 2021, 4:51 PM MST for Gila 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: Aug 1, 2021, 4:51 PM MST (23:51 UTC)
Expired: Aug 1, 2021, 7:45 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Flood severity: None

Counties Gila County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 114 km from the middle of the area, began a volume at 23:56 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

Phoenix, AZ (KPSR), launched 12:00Z, 11.9 hours before the alert went out and 174 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: 445 J/kg
Mixed-layer CIN: -135 J/kg
Mixed-layer LCL: 2155 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

742 
WGUS55 KFGZ 012351
FFWFGZ
AZC007-017-020045-
/O.NEW.KFGZ.FF.W.0139.210801T2351Z-210802T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
451 PM MST Sun Aug 1 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Gila County in east central Arizona...
  Navajo County in north central Arizona...

* Until 545 PM MST.

* At 450 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts up to 0.5 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of low-water crossings, creeks,
           normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Fort Apache Reservation and White Mountain Apache Reservation.

This includes the following highways...
	State Route 73 between mile markers 314 and 317.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid recently burned areas and downstream locations. 
Life-threatening flooding of creeks, roads and normally dry washes 
will occur. Rockslides and mudslides will likely occur in steep 
terrain.

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

Report any flooding to local law enforcement and the NWS Flagstaff 
when you can do so safely.

&&

LAT...LON 3400 11021 3413 11010 3403 11003 3395 11010
      3393 11019 3392 11024 3385 11032 3386 11036
      3394 11026

FLASH FLOOD...RADAR INDICATED

$$

DB

3 follow-up statements

414 
WGUS55 KFGZ 020040
FFWFGZ
AZC007-017-020245-
/O.EXT.KFGZ.FF.W.0139.000000T0000Z-210802T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
540 PM MST Sun Aug 1 2021

The National Weather Service in Flagstaff has extended the

* Flash Flood Warning for...
  Gila County in east central Arizona...
  Navajo County in north central Arizona...

* Until 745 PM MST.

* At 539 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.25 and 2.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.25 to 0.75 
  inches are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of low-water crossings, creeks,
           normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Fort Apache Reservation and White Mountain Apache Reservation.

This includes the following highways...
	State Route 73 between mile markers 314 and 316.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid recently burned areas and downstream locations. 
Life-threatening flooding of creeks, roads and normally dry washes 
will occur. Rockslides and mudslides will likely occur in steep 
terrain.

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

Report any flooding to local law enforcement and the NWS Flagstaff 
when you can do so safely.

&&

LAT...LON 3400 11021 3413 11010 3403 11003 3395 11010
      3393 11019 3392 11024 3385 11032 3386 11036
      3394 11026

FLASH FLOOD...RADAR INDICATED

$$

DB

673 
WGUS75 KFGZ 020202
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
702 PM MST Sun Aug 1 2021

AZC007-017-020245-
/O.CON.KFGZ.FF.W.0139.000000T0000Z-210802T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Navajo AZ-
702 PM MST Sun Aug 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MST THIS 
EVENING FOR GILA AND NAVAJO COUNTIES...

At 657 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1.25 and 2.5 inches of rain 
have fallen. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of low-water crossings, creeks, normally
         dry washes and roads.

Some locations that will experience flash flooding include...
  Corduroy Creek and Carrizo Creek south to the Salt River on Fort 
  Apache Reservation and White Mountain Apache Reservation.

This includes the following highways...
	State Route 73 between mile markers 314 and 316.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Avoid recently burned areas and downstream locations. 
Life-threatening flooding of creeks, roads and normally dry washes 
will occur. Rockslides and mudslides will likely occur in steep 
terrain.

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

Report any flooding to local law enforcement and the NWS Flagstaff 
when you can do so safely.

&&

LAT...LON 3400 11021 3413 11010 3403 11003 3395 11010
      3393 11019 3392 11024 3385 11032 3386 11036
      3394 11026

FLASH FLOOD...RADAR INDICATED

$$

DB

735 
WGUS75 KFGZ 020239
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
739 PM MST Sun Aug 1 2021

AZC007-017-020249-
/O.EXP.KFGZ.FF.W.0139.000000T0000Z-210802T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Navajo AZ-
739 PM MST Sun Aug 1 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 745 PM MST THIS EVENING FOR 
GILA AND NAVAJO COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures. Do not 
attempt to cross flooded roads. Turn around, don't drown when 
encountering flooded roads. Most flood deaths occur in vehicles.

Report any flooding to local law enforcement and the NWS Flagstaff 
when you can do so safely.

LAT...LON 3400 11021 3413 11010 3403 11003 3395 11010
      3393 11019 3392 11024 3385 11032 3386 11036
      3394 11026

$$

DB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 5:22 PM MST	Areal Flood Advisory	FGZ	Yavapai	113 min
Jul 31, 6:08 PM MST	Areal Flood Advisory	FGZ	Apache, Navajo	3 hr
Aug 1, 12:03 PM MST	Special Weather Statement	FGZ		27 min
Aug 1, 12:15 PM MST	Special Weather Statement	FGZ		30 min
Aug 1, 12:53 PM MST	Special Weather Statement	FGZ	Coconino	22 min
Aug 1, 1:08 PM MST	Special Weather Statement	FGZ		22 min
Aug 1, 1:14 PM MST	Special Weather Statement	FGZ		31 min
Aug 1, 1:30 PM MST	Special Weather Statement	FGZ	Navajo	30 min
Aug 1, 1:38 PM MST	Special Weather Statement	FGZ	Coconino	22 min
Aug 1, 1:53 PM MST	Special Weather Statement	FGZ		37 min
Aug 1, 2:03 PM MST	Special Weather Statement	FGZ	Navajo	27 min
Aug 1, 2:26 PM MST	Special Weather Statement	FGZ	Navajo	34 min
Aug 1, 2:55 PM MST	Special Weather Statement	FGZ		35 min
Aug 1, 3:12 PM MST	Special Weather Statement	FGZ		33 min
Aug 1, 3:15 PM MST	Special Weather Statement	FGZ		30 min
Aug 1, 3:21 PM MST	Special Weather Statement	FGZ		24 min
Aug 1, 3:58 PM MST	Flash Flood Warning	FGZ	Gila, Navajo	3 hr
Aug 1, 4:18 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Aug 1, 4:24 PM MST	Special Weather Statement	FGZ		51 min
Aug 1, 4:38 PM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	37 min
Aug 1, 4:52 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Coconino, Navajo	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.