Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 34, NWS Flagstaff, AZ

July 15, 2021Coconino County, Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 15, 2021, 3:51 PM MST for Coconino County, Yavapai 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 15, 2021, 3:51 PM MST (22:51 UTC)
Expired: Jul 15, 2021, 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, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 143 km from the middle of the area, began a volume at 22:50 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, 10.9 hours before the alert went out and 63 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1408 m above ground
0-6 km bulk shear: 0 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

137 
WGUS55 KFGZ 152251
FFWFGZ
AZC005-025-160200-
/O.NEW.KFGZ.FF.W.0034.210715T2251Z-210716T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
351 PM MST Thu Jul 15 2021

The National Weather Service in Flagstaff has issued a

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

* Until 700 PM MST.

* At 348 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in Martin Dam Draw, Ash Fork Draw, Partridge Creek 
  drainages from Ash Fork northward. Between 1 and 2 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...
  Ash Fork.

This includes the following highways...
	Business Interstate 40 near mile marker 146.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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.

&&

LAT...LON 3529 11253 3543 11253 3544 11246 3532 11235
      3519 11242 3522 11256

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

$$

JJ

2 follow-up statements

075 
WGUS75 KFGZ 160003
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
503 PM MST Thu Jul 15 2021

AZC005-025-160200-
/O.CON.KFGZ.FF.W.0034.000000T0000Z-210716T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Yavapai AZ-
503 PM MST Thu Jul 15 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 PM MST THIS EVENING 
FOR COCONINO AND YAVAPAI COUNTIES...

At 500 PM MST, Doppler radar indicated heavy rain has moved south of 
the warning area. Previous heavy rain fell in Martin Dam Draw, Ash 
Fork Draw, Partridge Creek drainages from Ash Fork northward. 
Between 1 and 3.5 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...
  Ash Fork.

This includes the following highways...
	Business Interstate 40 near mile marker 146.
	State Route 89 near mile marker 363.
	Interstate 40 between mile markers 142 and 150.

This includes the following streams and drainages...
  Ash Fork Draw, Martin Dam Draw, Pineveta Wash, Johnson Creek and 
  Partridge Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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.

&&

LAT...LON 3529 11253 3543 11253 3544 11246 3532 11235
      3519 11242 3522 11256

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

$$

MCT

460 
WGUS75 KFGZ 160157
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
657 PM MST Thu Jul 15 2021

AZC005-025-160207-
/O.EXP.KFGZ.FF.W.0034.000000T0000Z-210716T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Yavapai AZ-
657 PM MST Thu Jul 15 2021

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

The heavy rain has ended with only scattered light rain showers 
continuing at this time. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3529 11253 3543 11253 3544 11246 3532 11235
      3519 11242 3522 11256

$$

MCT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 14, 6:29 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	2 hr
Jul 14, 7:40 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	2 hr
Jul 14, 10:39 PM MST	Areal Flood Advisory	FGZ	Coconino	5 hr
Jul 15, 12:41 AM MST	Special Weather Statement	FGZ		49 min
Jul 15, 1:38 AM MST	Special Weather Statement	FGZ	Navajo	37 min
Jul 15, 3:52 AM MST	Special Weather Statement	FGZ	Yavapai	38 min
Jul 15, 1:15 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 15, 4:55 PM MST	Special Weather Statement	FGZ		35 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.