Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 105, NWS Flagstaff, AZ

July 25, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 25, 2021, 1:51 PM MST for Coconino 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 25, 2021, 1:51 PM MST (20:51 UTC)
Expired: Jul 25, 2021, 5:00 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 102 km from the middle of the area, began a volume at 20:51 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, 8.9 hours before the alert went out and 32 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: 4 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 803 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -30 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

550 
WGUS55 KFGZ 252051
FFWFGZ
AZC005-260000-
/O.NEW.KFGZ.FF.W.0105.210725T2051Z-210726T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
151 PM MST Sun Jul 25 2021

The National Weather Service in Flagstaff has issued a

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

* Until 500 PM MST.

* At 150 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.75 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.75 to 1.25 
  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...
  White Horse Lake Campground.

This includes the following swimming holes...
Sycamore Falls, Lower Sycamore Falls "The Golden Pond" and Paradise 
Forks.

This includes the following streams and drainages...
  Grindstone Wash, Rattlesnake Wash, Sycamore Creek, JD Dam Wash, 
  Hell Canyon, Bear Canyon and Tule Tank Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3516 11205 3510 11198 3499 11221 3510 11230

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

$$

TPS

1 follow-up statement

561 
WGUS75 KFGZ 252359
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
459 PM MST Sun Jul 25 2021

AZC005-260009-
/O.EXP.KFGZ.FF.W.0105.000000T0000Z-210726T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
459 PM MST Sun Jul 25 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 5 PM MST THIS AFTERNOON FOR 
COCONINO COUNTY...

The heavy rain has ended over the Rafael Fire Scar. Flooding is no 
longer expected to pose a threat. Please heed any road closures.

A Flash Flood Watch remains in effect until 1200 AM MST Monday for 
portions of east central Arizona, north central Arizona, northeast 
Arizona and west central Arizona.

LAT...LON 3516 11205 3510 11198 3499 11221 3510 11230

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 24, 5:30 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	30 min
Jul 24, 7:12 PM MST	Areal Flood Advisory	FGZ	Coconino, Navajo	3 hr
Jul 24, 7:50 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 24, 8:49 PM MST	Areal Flood Advisory	FGZ	Coconino, Yavapai	3 hr
Jul 24, 9:32 PM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Jul 24, 10:47 PM MST	Areal Flood Warning	FGZ	Navajo	6 hr
Jul 24, 11:06 PM MST	Areal Flood Advisory	FGZ	Apache, Coconino, Navajo	12 hr
Jul 25, 2:30 AM MST	Areal Flood Advisory	FGZ	Coconino, Navajo	24 hr
Jul 25, 2:51 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	6 hr
Jul 25, 4:58 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 25, 9:15 AM MST	Areal Flood Warning	FGZ	Apache, Coconino, Navajo	13 hr
Jul 25, 11:05 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	11 hr
Jul 25, 12:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Gila, Yavapai	3 hr
Jul 25, 2:27 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	108 min
Jul 25, 2:52 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 25, 3:28 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr

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.