Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 142, NWS Flagstaff, AZ

August 1, 2021Gila County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 1, 2021, 5:28 PM MST for Gila County, Navajo County, Arizona. It was in force for 5 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, 5:28 PM MST (00:28 UTC)
Expired: Aug 1, 2021, 10:32 PM MST
In force: 5 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Gila County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 100 km from the middle of the area, began a volume at 00:28 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 00:00Z, 0.5 hours before the alert went out and 164 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: 748 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 2842 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

830 
WGUS55 KFGZ 020028
FFWFGZ
AZC007-017-020615-
/O.NEW.KFGZ.FF.W.0142.210802T0028Z-210802T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
528 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 along the Carrizo Creek...
  Navajo County in north central Arizona 5-10 miles north of Cibeque 
  over the Carrizo Creek basin...

* Until 1115 PM MST.

* At 520 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.5 to 1.5 inches 
  are possible in the warned area. Flash flooding is ongoing or 
  expected to begin shortly in the Carrizo Creek Basin and along the 
  Carrizo Creek south to the Salt River.

  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...
  Carrizo and Fort Apache Reservation.

This includes the following highways...
	Highway 60 between mile markers 315 and 316.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

Remain alert for flooding even in locations not receiving rain. 
Normally dry washes, slot canyons and creeks can become raging 
killer currents in a matter of minutes, even from distant rainfall.

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

&&

LAT...LON 3417 11048 3424 11043 3421 11033 3410 11034
      3407 11030 3394 11025 3389 11026 3382 11028
      3380 11029 3381 11031 3385 11029 3397 11028
      3406 11032 3410 11040 3412 11049

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

$$

DB

1 follow-up statement

696 
WGUS75 KFGZ 020532
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1032 PM MST Sun Aug 1 2021

AZC007-017-020542-
/O.CAN.KFGZ.FF.W.0142.000000T0000Z-210802T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Navajo AZ-
1032 PM MST Sun Aug 1 2021

...FLASH FLOOD WARNING IS CANCELLED FOR GILA AND NAVAJO COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat, but high water will flow in Carrizo Creek through the night.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding. Do not attempt to cross flooded roads. Turn 
around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles. Please continue to heed any remaining road 
closures.

LAT...LON 3417 11048 3424 11043 3421 11033 3410 11034
      3407 11030 3394 11025 3389 11026 3382 11028
      3380 11029 3381 11031 3385 11029 3397 11028
      3406 11032 3410 11040 3412 11049

$$

DB

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 5:05 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Aug 1, 5:11 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	49 min
Aug 1, 5:22 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 1, 5:49 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Aug 1, 5:49 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Aug 1, 6:04 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 1, 6:20 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Navajo	3 hr
Aug 1, 7:55 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	2 hr
Aug 1, 8:26 PM MST	Flash Flood Warning	FGZ	Gila	115 min
Aug 1, 8:59 PM MST	Flash Flood Warning	FGZ	Gila	85 min
Aug 1, 9:47 PM MST	Special Weather Statement	FGZ		28 min
Aug 2, 1:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Aug 2, 2:23 PM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	22 min
Aug 2, 2:44 PM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	31 min
Aug 2, 4:06 PM MST	Special Weather Statement	FGZ	Apache	39 min
Aug 2, 4:14 PM MST	Special Weather Statement	FGZ		31 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.