Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 152, NWS Flagstaff, AZ

August 9, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 9, 2021, 2:39 PM MST for Yavapai County, Arizona. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 9, 2021, 2:39 PM MST (21:39 UTC)
Expired
Aug 9, 2021, 5:45 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), 118 km from the middle of the area, began a volume at 21:38 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.

What was reported inside it

TimeReportWhereRemark
Aug 9, 4:05 PM MSTFLASH FLOOD1 Ne Walker, AZTRAINED SPOTTER REPORTED LYNX CREEK IN WALKER WAS RUNNING 4-5 FT DEEP IN SPOTS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.7 hours before the alert went out and 101 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.

189 
WGUS55 KFGZ 092139
FFWFGZ
AZC025-100045-
/O.NEW.KFGZ.FF.W.0152.210809T2139Z-210810T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
239 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 545 PM MST.

* At 237 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain southwest of Prescott to Walker. Between 0.5 and 1.5 
  inches of rain have fallen. Additional rainfall amounts of 0.75 to 
  1.5 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...
  Prescott, Ponderosa Park, Oak Knoll Village, Groom Creek 
  Subdivision, Walker, White Spar Campground, Lower Wolf Creek 
  Campground and Upper Wolf Creek Group Campground.

This includes the following swimming holes...
	Wolf Creek Falls.

This includes the following highways...
	State Route 69 near mile marker 296.
	State Route 89 between mile markers 303 and 312.

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 3460 11253 3447 11233 3437 11242 3454 11261

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

$$

TPS
3 follow-up statements
717 
WGUS75 KFGZ 092247
FFSFGZ

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

AZC025-100045-
/O.CON.KFGZ.FF.W.0152.000000T0000Z-210810T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
347 PM MST Mon Aug 9 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 345 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain have ended from Iron Springs southeast to Walker. Between 1 and 
2 inches of rain have fallen. Additional rainfall amounts up to 0.25 
inches are possible. Flash flooding will remain a concern over the 
next couple hours due to runoff from the heavy rainfall.

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...
  Prescott, Ponderosa Park, Oak Knoll Village, Groom Creek 
  Subdivision, Walker, White Spar Campground, Lower Wolf Creek 
  Campground and Upper Wolf Creek Group Campground.

This includes the following swimming holes...
	Wolf Creek Falls.

This includes the following highways...
	State Route 89 between mile markers 303 and 312.

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 3460 11253 3447 11233 3437 11242 3454 11261

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

$$

TPS
009 
WGUS75 KFGZ 092357
FFSFGZ

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

AZC025-100045-
/O.CON.KFGZ.FF.W.0152.000000T0000Z-210810T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
457 PM MST Mon Aug 9 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 455 PM MST, Doppler radar indicated heavy rain has moved out of 
the warned area. 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...
  Prescott, Ponderosa Park, Oak Knoll Village, Groom Creek 
  Subdivision, Indian Hill West Prescott, Downtown Prescott, Walker, 
  White Spar Campground, Lower Wolf Creek Campground and Upper Wolf 
  Creek Group Campground.

This includes the following swimming holes...
	Wolf Creek Falls.

This includes the following highways...
	State Route 89 between mile markers 303 and 312.

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 3460 11253 3447 11233 3437 11242 3454 11261

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

$$

MCT
673 
WGUS75 KFGZ 100038
FFSFGZ

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

AZC025-100048-
/O.EXP.KFGZ.FF.W.0152.000000T0000Z-210810T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
538 PM MST Mon Aug 9 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 545 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 and use 
caution near any high water.

LAT...LON 3460 11253 3447 11233 3437 11242 3454 11261

$$

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, 2:27 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai2 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.