Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 162, NWS Flagstaff, AZ

August 10, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 10, 2021, 2:43 PM MST for Yavapai County, Arizona. It was in force for 3 hr. 4 reports 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 10, 2021, 2:43 PM MST (21:43 UTC)
Expired
Aug 10, 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), 114 km from the middle of the area, began a volume at 21:44 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 10, 2:52 PM MSTFLASH FLOOD1 Nw Prescott Courthous, AZROAD CLOSED AT LINCOLN AVE AND GROVE AVE DUE TO FLOODING. OTHER ROAD CLOSURES AROUND TOWN BETWEEN 2:50 AND 3:50 PM INCLUDED 1ST ST. SOUTH OF MERRITT, HILLSIDE AND 2ND ST., AND S. RUSH ST.
Aug 10, 3:49 PM MSTFLASH FLOOD2 Ne Prescott Courthous, AZA STREAM GAUGE ON GRANITE CREEK NORTHEAST OF DOWNTOWN PRESCOTT (GRCA3) REPORTED A 6.7 FT RISE WITH A PEAK FLOW OF 3,558 CUBIC FT PER SECOND.
Aug 10, 3:51 PM MSTFLASH FLOOD1 Nne Prescott Courthou, AZA STREAM GAUGE ON GRANITE CREEK NEAR DOWNTOWN PRESCOTT (GCRA3) REPORTED A 4.4 FOOT RISE WITH A PEAK FLOW OF 1,595 CUBIC FT PER SECOND.
Aug 10, 4:39 PM MSTFLASH FLOOD1 Nnw Paulden, AZTWO CARS WERE STUCK IN WASHES NEAR CHINO VALLEY/PAULDEN DUE TO HIGH WATER. WATER WAS BEGINNING TO MOVE THE VEHICLES AND LAW ENFORCEMENT WAS CALLED TO THE SCENE.

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 83 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 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 609 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.1939Sfc1 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
609 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
962 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

331 
WGUS55 KFGZ 102143
FFWFGZ
AZC025-110045-
/O.NEW.KFGZ.FF.W.0162.210810T2143Z-210811T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
243 PM MST Tue Aug 10 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 242 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 2 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...
  Chino Valley, Prescott, Prescott Valley, Williamson Valley, 
  Paulden, Yavapai Campground, Indian Hill West Prescott, Oak Knoll 
  Village, Groom Creek Subdivision, Ponderosa Park, Lynx Lake Dam, 
  White Spar Campground, Upper Wolf Creek Group Campground and Lower 
  Wolf Creek Campground.

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

This includes the following highways...
	State Route 69 between mile markers 283 and 296.
	State Route 89 between mile markers 301 and 349.
	State Route 89A between mile markers 318 and 327.

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 3453 11257 3465 11257 3490 11257 3505 11262
      3507 11248 3502 11237 3493 11234 3474 11234
      3467 11227 3456 11223 3454 11227 3447 11237
      3444 11246 3444 11253

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

$$

Humphreys
2 follow-up statements
395 
WGUS75 KFGZ 102231
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
331 PM MST Tue Aug 10 2021

AZC025-110045-
/O.CON.KFGZ.FF.W.0162.000000T0000Z-210811T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
331 PM MST Tue Aug 10 2021

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

At 329 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain. Between 1 and 2.25 inches of 
rain have fallen. Additional rainfall amounts of 0.5 to 1.5 inches 
are possible in the warned area. Flooding is already ongoing along 
Granite Creek near Prescott.

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

SOURCE...Radar and automated gauges.

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

Some locations that will experience flash flooding include...
  Chino Valley, Prescott, Prescott Valley, Williamson Valley, 
  Paulden, Yavapai Campground, Indian Hill West Prescott, Oak Knoll 
  Village, Groom Creek Subdivision, Ponderosa Park, Lynx Lake Dam, 
  White Spar Campground, Upper Wolf Creek Group Campground and Lower 
  Wolf Creek Campground.

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

This includes the following highways...
	State Route 69 between mile markers 283 and 296.
	State Route 89 between mile markers 301 and 349.
	State Route 89A between mile markers 318 and 327.

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 3453 11257 3465 11257 3490 11257 3505 11262
      3507 11248 3502 11237 3493 11234 3474 11234
      3467 11227 3456 11223 3454 11227 3447 11237
      3444 11246 3444 11253

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

$$

Humphreys
395 
WGUS75 KFGZ 110037
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
537 PM MST Tue Aug 10 2021

AZC025-110047-
/O.EXP.KFGZ.FF.W.0162.000000T0000Z-210811T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
537 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 545 PM MST THIS AFTERNOON FOR 
PAULDEN, CHINO VALLEY, AND PRESCOTT IN YAVAPAI COUNTY...

Flood waters have receded and the heavy rain has ended. Flooding is 
no longer expected to pose a threat. A few area creeks and washes 
may remain high, so continue to use caution. Please continue to heed 
remaining road closures.

LAT...LON 3453 11257 3465 11257 3490 11257 3505 11262
      3507 11248 3502 11237 3493 11234 3474 11234
      3467 11227 3456 11223 3454 11227 3447 11237
      3444 11246 3444 11253

$$

Humphreys

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 5:19 PM MSTSpecial Weather StatementFGZ41 min
Aug 9, 6:17 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 9, 6:56 PM MSTSevere Thunderstorm WarningFGZYavapai34 min
Aug 9, 7:27 PM MSTSpecial Weather StatementFGZ33 min
Aug 9, 7:50 PM MSTSpecial Weather StatementFGZGila25 min
Aug 9, 8:44 PM MSTSpecial Weather StatementFGZGila46 min
Aug 9, 9:18 PM MSTAreal Flood AdvisoryFGZGila, Navajo3 hr
Aug 9, 9:32 PM MSTSpecial Weather StatementFGZGila43 min
Aug 10, 11:35 AM MSTSpecial Weather StatementFGZ25 min
Aug 10, 11:55 AM MSTSevere Thunderstorm WarningFGZCoconino15 min
Aug 10, 12:02 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 10, 12:14 PM MSTSpecial Weather StatementFGZ31 min
Aug 10, 12:46 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 10, 12:59 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 10, 1:22 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai53 min
Aug 10, 2:22 PM MSTSpecial Weather StatementFGZYavapai23 min
Aug 10, 2:26 PM MSTSevere Thunderstorm WarningFGZYavapai32 min
Aug 10, 2:35 PM MSTSevere Thunderstorm WarningFGZYavapai40 min
Aug 10, 2:52 PM MSTSevere Thunderstorm WarningFGZCoconino, Yavapai38 min
Aug 10, 3:11 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 10, 3:46 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 10, 4:13 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 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.