Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 146, NWS Flagstaff, AZ

August 1, 2021Gila County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 1, 2021, 7:55 PM MST for Gila County, Arizona. It was in force for 2 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, 7:55 PM MST (02:55 UTC)
Expired: Aug 1, 2021, 10:20 PM MST
In force: 2 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Gila County, AZ

The radar

The Flagstaff radar (KFSX), 44 km from the middle of the area, began a volume at 02:56 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 00:00Z, 2.9 hours before the alert went out and 111 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.

864 
WGUS55 KFGZ 020255
FFWFGZ
AZC007-020600-
/O.NEW.KFGZ.FF.W.0146.210802T0255Z-210802T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
755 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...

* Until 1100 PM MST.

* At 754 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 of 0.25 to 0.75 
  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...
  mainly rural areas of Gila County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 3424 11127 3423 11110 3412 11104 3411 11111
      3414 11117 3415 11128

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

$$

DB

1 follow-up statement

322 
WGUS75 KFGZ 020520
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1020 PM MST Sun Aug 1 2021

AZC007-020530-
/O.CAN.KFGZ.FF.W.0146.000000T0000Z-210802T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
1020 PM MST Sun Aug 1 2021

...FLASH FLOOD WARNING IS CANCELLED FOR GILA COUNTY...

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

LAT...LON 3424 11127 3423 11110 3412 11104 3411 11111
      3414 11117 3415 11128

$$

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, 5:28 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Navajo	5 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, 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.