Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 172, NWS Flagstaff, AZ

August 12, 2021Gila County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 12, 2021, 5:36 AM 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
Aug 12, 2021, 5:36 AM MST (12:36 UTC)
Expired
Aug 12, 2021, 8:30 AM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Gila County, AZ

The radar

The Phoenix radar (KIWA), 81 km from the middle of the area, began a volume at 12:40 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, 0.6 hours before the alert went out and 97 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-pSkew-T log-p diagram, Phoenix, AZ at 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1266 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1266 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
865 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

691 
WGUS55 KFGZ 121236
FFWFGZ
AZC007-121530-
/O.NEW.KFGZ.FF.W.0172.210812T1236Z-210812T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
536 AM MST Thu Aug 12 2021

The National Weather Service in Flagstaff has issued a

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

* Until 830 AM MST.

* At 535 AM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2.75 inches of 
  rain have fallen. 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 south of Sierra Ancha Wilderness.

This includes the following highways...
	State Route 288 between mile markers 273 and 282.

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.

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

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.

Get out of washes and creeks if you are camping or hiking! Flooding 
is occurring or imminent and will inundate area drainages.

&&

LAT...LON 3379 11112 3384 11111 3382 11095 3375 11090
      3372 11096 3373 11096 3375 11098

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

$$

ET
3 follow-up statements
820 
WGUS75 KFGZ 121249
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
549 AM MST Thu Aug 12 2021

AZC007-121530-
/O.CON.KFGZ.FF.W.0172.000000T0000Z-210812T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
549 AM MST Thu Aug 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 AM MST THIS 
MORNING FOR GILA COUNTY...

At 549 AM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 2.5 inches of rain have 
fallen. 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

This includes the following highways...
	State Route 288 between mile markers 273 and 282.

This includes the following streams and drainages...
  Big Cherry Creek, Workman Creek, Greenback Creek, South Fork 
  Parker Creek, Parker Creek, Dagger Wash, Oak Creek, Coon Creek, 
  Salt River, Pocket Creek, Warm Creek, Deer Creek, Connor Wash, 
  Rose Creek, Salome Creek and Griffin Wash.

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.

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

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.

Get out of washes and creeks if you are camping or hiking! Flooding 
is occurring or imminent and will inundate area drainages.

&&

LAT...LON 3379 11112 3384 11111 3382 11095 3375 11090
      3372 11096 3373 11096 3375 11098

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

$$

ET
652 
WGUS75 KFGZ 121356
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
656 AM MST Thu Aug 12 2021

AZC007-121530-
/O.CON.KFGZ.FF.W.0172.000000T0000Z-210812T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
656 AM MST Thu Aug 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 AM MST THIS 
MORNING FOR GILA COUNTY...

At 656 AM MST, Doppler radar indicated heavy rain had ended across 
the warned area with mainly light to moderate showers ongoing. 
Between 1 and 3.0 inches of rain have fallen. 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

This includes the following highways...
	State Route 288 between mile markers 273 and 282.

This includes the following streams and drainages...
  Big Cherry Creek, Workman Creek, Greenback Creek, South Fork 
  Parker Creek, Parker Creek, Dagger Wash, Oak Creek, Coon Creek, 
  Salt River, Pocket Creek, Warm Creek, Deer Creek, Connor Wash, 
  Rose Creek, Salome Creek and Griffin Wash.

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.

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

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.

Get out of washes and creeks if you are camping or hiking! Flooding 
is occurring or imminent and will inundate area drainages.

&&

LAT...LON 3379 11112 3384 11111 3382 11095 3375 11090
      3372 11096 3373 11096 3375 11098

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

$$

ET
153 
WGUS75 KFGZ 121523
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
823 AM MST Thu Aug 12 2021

AZC007-121533-
/O.EXP.KFGZ.FF.W.0172.000000T0000Z-210812T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
823 AM MST Thu Aug 12 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 830 AM MST THIS MORNING FOR 
GILA COUNTY...

At 820 AM MST, National Weather Service Flagstaff doppler radar 
indicated that rainfall had ended south of Young. River gages on 
Parker Creek showed minor rises of around one foot. Water levels in 
this region should continue to decrease for the remainder of this 
morning and the Flash Flood Warning will be allowed to expire.

Please continue to heed remaining road closures.

LAT...LON 3379 11112 3384 11111 3382 11095 3375 11090
      3372 11096 3373 11096 3375 11098

$$

Peterson

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 5:35 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo3 hr
Aug 12, 12:34 PM MSTSpecial Weather StatementFGZYavapai26 min
Aug 12, 12:43 PM MSTSpecial Weather StatementFGZ32 min
Aug 12, 1:08 PM MSTSpecial Weather StatementFGZ22 min
Aug 12, 1:29 PM MSTSpecial Weather StatementFGZ31 min
Aug 12, 3:21 PM MSTSpecial Weather StatementFGZYavapai24 min
Aug 12, 3:41 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino6 hr

Nearby

Flash Flood Warnings in Arizona, 2021Every 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.