Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 232, NWS Flagstaff, AZ

September 27, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 27, 2021, 5:29 PM MST for 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: Sep 27, 2021, 5:29 PM MST (00:29 UTC)
Expired: Sep 27, 2021, 8:30 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 121 km from the middle of the area, began a volume at 00:33 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 00:00Z, 0.5 hours before the alert went out and 67 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: 177 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 849 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 125 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

452 
WGUS55 KFGZ 280029
FFWFGZ
AZC025-280330-
/O.NEW.KFGZ.FF.W.0232.210928T0029Z-210928T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
529 PM MST Mon Sep 27 2021

The National Weather Service in Flagstaff has issued a

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

* Until 830 PM MST.

* At 523 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain extending from Paulden northward about 5 miles. Between 
  1 and 2 inches of rain have fallen with additional rainfall 
  expected. 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...
  Paulden

This includes the following highways...
	State Route 89 between mile markers 338 and 343.

This includes the following creeks, washes and rivers...
  Hell Canyon, Verde River and Big Chino Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 3499 11245 3496 11239 3489 11239 3490 11245
      3490 11248 3491 11251 3499 11248

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

$$

McCollum

2 follow-up statements

232 
WGUS75 KFGZ 280139
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
639 PM MST Mon Sep 27 2021

AZC025-280330-
/O.CON.KFGZ.FF.W.0232.000000T0000Z-210928T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
639 PM MST Mon Sep 27 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM MST THIS 
EVENING FOR YAVAPAI COUNTY...

At 634 PM MST, Doppler radar indicated that thunderstorms had 
dissipated across the area north of Paulden. Earlier, between 1 and 
2 inches of rain were estimated by radar. Areas of flash flooding 
are expected for the next hour with water levels receding after that 
point.

HAZARD...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...
  Paulden

This includes the following highways...
	State Route 89 between mile markers 339 and 343.

This includes the following creeks, washes and rivers...
  Hell Canyon, Verde River and Big Chino Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3499 11245 3496 11239 3489 11239 3490 11245
      3490 11248 3491 11251 3499 11248

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

$$

McCollum

238 
WGUS75 KFGZ 280324
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
824 PM MST Mon Sep 27 2021

AZC025-280334-
/O.EXP.KFGZ.FF.W.0232.000000T0000Z-210928T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
824 PM MST Mon Sep 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 830 PM MST THIS EVENING FOR 
YAVAPAI COUNTY...

Flood waters in the vicinity of Paulden are receding. Flash flooding 
is no longer expected to pose a threat. Please heed any road 
closures.

LAT...LON 3499 11245 3496 11239 3489 11239 3490 11245
      3490 11248 3491 11251 3499 11248

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 27, 5:41 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	34 min
Sep 27, 6:10 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	18 min
Sep 27, 6:14 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	2 hr
Sep 28, 2:35 PM MST	Special Weather Statement	FGZ		25 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.