Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 151, NWS Flagstaff, AZ

August 9, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 9, 2021, 2:27 PM MST for Yavapai County, Arizona. It was in force for 2 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 9, 2021, 2:27 PM MST (21:27 UTC)
Expired
Aug 9, 2021, 4:30 PM MST
In force
2 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), 147 km from the middle of the area, began a volume at 21:28 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, 9.5 hours before the alert went out and 86 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-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 12:00Z on 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
2142 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
-74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

623 
WGUS55 KFGZ 092127
FFWFGZ
AZC025-092330-
/O.NEW.KFGZ.FF.W.0151.210809T2127Z-210809T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
227 PM MST Mon Aug 9 2021

The National Weather Service in Flagstaff has issued a

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

* Until 430 PM MST.

* At 226 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts of 0.25 to 0.5 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...
  Walnut Creek Ranger Station.

This includes the following streams and drainages...
  Mud Tank Wash, Indian Springs Wash, Antelope Wash, Apache Creek, 
  Pine Creek, Williamson Valley Wash, Round Valley Wash, Graver 
  Wash, Quartz Lead Wash, Big Chino Wash and Walnut Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3514 11279 3510 11271 3497 11256 3490 11258
      3489 11286

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

$$

TPS
2 follow-up statements
405 
WGUS75 KFGZ 092238
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
338 PM MST Mon Aug 9 2021

AZC025-092330-
/O.CON.KFGZ.FF.W.0151.000000T0000Z-210809T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
338 PM MST Mon Aug 9 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 337 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain have ended in portions of northern Yavapai County. Between 1 
and 2 inches of rain have fallen. Additional light rainfall amounts 
up to 0.25 inches are possible. 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...
  Walnut Creek Ranger Station.

This includes the following streams and drainages...
  Mud Tank Wash, Indian Springs Wash, Antelope Wash, Apache Creek, 
  Pine Creek, Williamson Valley Wash, Round Valley Wash, Graver 
  Wash, Quartz Lead Wash, Big Chino Wash and Walnut Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3514 11279 3510 11271 3497 11256 3490 11258
      3489 11286

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

$$

TPS
342 
WGUS75 KFGZ 092323
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
423 PM MST Mon Aug 9 2021

AZC025-092333-
/O.EXP.KFGZ.FF.W.0151.000000T0000Z-210809T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
423 PM MST Mon Aug 9 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 430 PM MST THIS AFTERNOON FOR 
YAVAPAI COUNTY...

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

LAT...LON 3514 11279 3510 11271 3497 11256 3490 11258
      3489 11286

$$

MCT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 5:16 PM MSTSpecial Weather StatementFGZ44 min
Aug 9, 12:30 PM MSTSpecial Weather StatementFGZYavapai30 min
Aug 9, 2:39 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 9, 3:42 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 9, 3:53 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 9, 4:15 PM MSTSpecial Weather StatementFGZ30 min
Aug 9, 4:21 PM MSTSevere Thunderstorm WarningFGZCoconino24 min
Aug 9, 4:42 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Gila3 hr
Aug 9, 4:51 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr

Nearby

Flash Flood Warnings in Arizona, 2021Every 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.