Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 30, NWS Phoenix, AZ

July 12, 2021Gila County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 12, 2021, 8:29 PM MST for Gila 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 12, 2021, 8:29 PM MST (03:29 UTC)
Expired: Jul 12, 2021, 11:15 PM MST
In force: 3 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Gila County, AZ

The radar

The Phoenix radar (KIWA), 102 km from the middle of the area, began a volume at 03:29 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, 3.5 hours before the alert went out and 130 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: 523 J/kg
Mixed-layer CIN: -351 J/kg
Mixed-layer LCL: 2953 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

430 
WGUS55 KPSR 130329
FFWPSR
AZC007-130615-
/O.NEW.KPSR.FF.W.0030.210713T0329Z-210713T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
829 PM MST Mon Jul 12 2021

The National Weather Service in Phoenix has issued a

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

* Until 1115 PM MST.

* At 829 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 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.

Excessive rainfall including over the Mescal burn scar will result 
in debris flow moving through the Mescal burn scar basins. The 
debris flow can consist of rock, mud, vegetation and other loose 
materials.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar and automated gauges.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Mescal burn scar, San Carlos, Cutter and Peridot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3316 11079 3321 11079 3327 11076 3335 11071
      3341 11064 3345 11063 3352 11058 3356 11042
      3340 11040 3338 11044 3336 11045 3330 11045
      3329 11046 3320 11040 3319 11050 3315 11056

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

$$

JS

2 follow-up statements

402 
WGUS75 KPSR 130432
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
932 PM MST Mon Jul 12 2021

AZC007-130615-
/O.CON.KPSR.FF.W.0030.000000T0000Z-210713T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
932 PM MST Mon Jul 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM MST THIS 
EVENING FOR GILA COUNTY...

At 932 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms had produced heavy rain across the warned area. 
Between 1 and 2 inches of rain have fallen. Flash flooding is 
ongoing.

Excessive rainfall over the burn scars will result in debris flow 
moving through the Mescal and east Telegraph burn scars. The debris 
flow can consist of rock, mud, vegetation and other loose materials.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar and automated gauges.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
Mescal and east Telegraph burn scars, San Carlos, Cutter and Peridot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3316 11079 3321 11079 3327 11076 3335 11071
      3341 11064 3345 11063 3352 11058 3356 11042
      3340 11040 3338 11044 3336 11045 3330 11045
      3329 11046 3320 11040 3319 11050 3315 11056

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

$$

JS

989 
WGUS75 KPSR 130612
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1112 PM MST Mon Jul 12 2021

AZC007-130622-
/O.EXP.KPSR.FF.W.0030.000000T0000Z-210713T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
1112 PM MST Mon Jul 12 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1115 PM MST THIS EVENING FOR 
GILA COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat but some washes may still be running. Please continue to heed 
remaining road closures.

LAT...LON 3316 11079 3321 11079 3327 11076 3335 11071
      3341 11064 3345 11063 3352 11058 3356 11042
      3340 11040 3338 11044 3336 11045 3330 11045
      3329 11046 3320 11040 3319 11050 3315 11056

$$

AD

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 7:37 PM MST	Special Weather Statement	PSR	Gila	38 min
Jul 12, 8:17 PM MST	Severe Thunderstorm Warning	PSR	Gila, Pinal	43 min
Jul 12, 9:18 PM MST	Special Weather Statement	PSR		42 min
Jul 12, 9:40 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	35 min
Jul 12, 10:05 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	25 min
Jul 12, 10:14 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	2 hr
Jul 12, 10:28 PM MST	Special Weather Statement	PSR	Maricopa	32 min
Jul 12, 11:35 PM MST	Special Weather Statement	PSR		40 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.