Alert archive / Arizona / Flash Flood Warnings in 2020

Flash Flood Warning 13, NWS Flagstaff, AZ

August 1, 2020Coconino County, Gila County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 1, 2020, 3:38 PM MST for Coconino County, 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, 2020, 3:38 PM MST (22:38 UTC)
Expired: Aug 1, 2020, 7:00 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Coconino County, AZ, Gila County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 50 km from the middle of the area, began a volume at 22:38 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.6 hours before the alert went out and 140 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: 12 J/kg
Mixed-layer CIN: -237 J/kg
Mixed-layer LCL: 3175 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: -97 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

686 
WGUS55 KFGZ 012238
FFWFGZ
AZC005-007-017-020200-
/O.NEW.KFGZ.FF.W.0013.200801T2238Z-200802T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
338 PM MST Sat Aug 1 2020

The National Weather Service in Flagstaff has issued a

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

* Until 700 PM MST.

* At 337 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 3 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

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

  SOURCE...Doppler radar.

  IMPACT...Life-threatening flash flooding of low-water
           crossings, creeks, normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Forest Lakes, Fort Apache Reservation, Black Canyon Rim 
  Campground, Gentry Campground, Canyon Creek Fish Hatchery, 
  Airplane Flat Campground, Canyon Point Campground and Forest Road 
  237 Camping Area.

This includes the following highways...
	State Route 260 between mile markers 286 and 295.

This includes the following streams and drainages...
  Carrizo Creek, Sheep Creek, Canyon Creek, Chevelon Canyon, 
  Brookbank Canyon, Wildcat Canyon, Mule Creek, Cibecue Creek and 
  Black Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3430 11083 3432 11086 3436 11087 3439 11077
      3435 11063 3424 11064 3423 11073 3424 11075

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

$$

KD

1 follow-up statement

594 
WGUS75 KFGZ 020156
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
656 PM MST Sat Aug 1 2020

AZC005-007-017-020206-
/O.EXP.KFGZ.FF.W.0013.000000T0000Z-200802T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Gila AZ-Navajo AZ-
656 PM MST Sat Aug 1 2020

...FLASH FLOOD WARNING WILL EXPIRE AT 7 PM MST THIS EVENING FOR 
GILA, COCONINO AND NAVAJO COUNTIES...

At 650 PM MST, National Weather Service Doppler radar indicated that 
rain has ended in the Flash Flood Warning area near Forest Lakes. 
Any additional rainfall this evening is expected to be light. No 
reports of flooding were received by the National Weather Service.

Please continue to heed remaining road closures.

Visit weather.gov/Flagstaff for more information on northern Arizona 
weather conditions.

LAT...LON 3430 11083 3432 11086 3436 11087 3439 11077
      3435 11063 3424 11064 3423 11073 3424 11075

$$

BEP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 1:11 PM MST	Special Weather Statement	FGZ	Gila	49 min
Aug 1, 2:07 PM MST	Special Weather Statement	FGZ		23 min
Aug 1, 2:24 PM MST	Severe Thunderstorm Warning	FGZ	Gila	36 min
Aug 1, 2:31 PM MST	Severe Thunderstorm Warning	FGZ	Apache	29 min
Aug 1, 2:40 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila, Navajo	35 min
Aug 1, 2:57 PM MST	Severe Thunderstorm Warning	FGZ	Apache	17 min
Aug 1, 3:07 PM MST	Areal Flood Advisory	FGZ	Coconino, Navajo	32 min
Aug 1, 3:59 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	46 min

Nearby

Flash Flood Warnings in Arizona, 2020 Every flash flood warning in 2020

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.