Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 38, NWS Flagstaff, AZ

July 16, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 16, 2021, 2:59 PM MST for Coconino County, Arizona. It was in force for 61 min. 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 16, 2021, 2:59 PM MST (21:59 UTC)
Expired: Jul 16, 2021, 4:00 PM MST
In force: 61 min
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), 82 km from the middle of the area, began a volume at 22:03 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, 10.0 hours before the alert went out and 26 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: 487 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 1090 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 77 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

877 
WGUS55 KFGZ 162159
FFWFGZ
AZC005-162300-
/O.NEW.KFGZ.FF.W.0038.210716T2159Z-210716T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
259 PM MST Fri Jul 16 2021

The National Weather Service in Flagstaff has issued a

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

* Until 400 PM MST.

* At 259 PM MST, the public reported flooding along Highway 89 and 
  in Doney Park from thunderstorms producing heavy rain across the 
  warned area earlier. Between 1 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...Public reported.

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

* Some locations that will experience flash flooding include...
  Flagstaff, Doney Park, Hutchison Acres, Flagstaff Mall, Walnut 
  Canyon National Monument and Little Elden Spring Horse Camp.

This includes the following highways...
	U.S. Highway 89 between mile markers 419 and 424.
	Route 66 between mile markers 201 and 204.
	Interstate 40 between mile markers 202 and 207.

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 3530 11148 3525 11146 3520 11148 3522 11160
      3530 11159

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

ET

2 follow-up statements

218 
WGUS75 KFGZ 162233
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
333 PM MST Fri Jul 16 2021

AZC005-162300-
/O.CON.KFGZ.FF.W.0038.000000T0000Z-210716T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
333 PM MST Fri Jul 16 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 4 PM MST THIS 
AFTERNOON FOR COCONINO COUNTY...

At 328 PM MST, the public reported thunderstorms producing heavy 
rain across the warned area earlier. Heavy rain has ended for now. 
Between 1 and 3 inches of rain were reported earlier. Flood waters 
are expected to recede over the next hour. Drive with caution areas 
of ponding and flowing water as well as slick mud still exist on 
area roads including Highway 89.

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

SOURCE...Public reported.

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

Some locations that will experience flash flooding include...
  Flagstaff, Doney Park, Hutchison Acres, Flagstaff Mall, Walnut 
  Canyon National Monument and Little Elden Spring Horse Camp.

This includes the following highways...
	U.S. Highway 89 between mile markers 419 and 424.
	

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 3530 11148 3525 11146 3520 11148 3522 11160
      3530 11159

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

McCollum

840 
WGUS75 KFGZ 162250
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
350 PM MST Fri Jul 16 2021

AZC005-162300-
/O.EXP.KFGZ.FF.W.0038.000000T0000Z-210716T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
350 PM MST Fri Jul 16 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 4 PM MST THIS AFTERNOON FOR 
COCONINO COUNTY...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3530 11148 3525 11146 3520 11148 3522 11160
      3530 11159

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 5:20 PM MST	Areal Flood Advisory	FGZ	Yavapai	115 min
Jul 15, 6:33 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	27 min
Jul 15, 6:55 PM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Jul 15, 8:21 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	114 min
Jul 16, 11:56 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 16, 12:03 PM MST	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 16, 12:36 PM MST	Areal Flood Advisory	FGZ	Coconino	2 hr
Jul 16, 12:52 PM MST	Special Weather Statement	FGZ		23 min
Jul 16, 1:16 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	29 min
Jul 16, 1:20 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	115 min
Jul 16, 1:24 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	51 min
Jul 16, 1:44 PM MST	Special Weather Statement	FGZ		46 min
Jul 16, 2:13 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	32 min
Jul 16, 2:25 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 16, 3:14 PM MST	Special Weather Statement	FGZ		31 min
Jul 16, 3:43 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	32 min
Jul 16, 4:18 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	12 min
Jul 16, 4:34 PM MST	Severe Thunderstorm Warning	FGZ	Gila	41 min
Jul 16, 4:41 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Jul 16, 4:48 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila	20 min
Jul 16, 4:59 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Yavapai	15 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.