Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 64, NWS Flagstaff, AZ

July 21, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 21, 2021, 10:48 AM MST for Yavapai County, Arizona. It was in force for 2 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
Jul 21, 2021, 10:48 AM MST (17:48 UTC)
Expired
Jul 21, 2021, 1:10 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), 118 km from the middle of the area, began a volume at 17:51 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
Jul 21, 12:30 PM MSTFLASH FLOOD2 E Ponderosa Park, AZWATER OVER THE ROAD AT STAGECOACH WHERE IT CROSSES GROOM CREEK. ESTIMATED 2 FT DEEP.

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, 5.8 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 2021-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 77 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 2021-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
77 J/kg
Mixed-layer CIN
-129 J/kg
Mixed-layer LCL
1785 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

607 
WGUS55 KFGZ 211748
FFWFGZ
AZC025-212100-
/O.NEW.KFGZ.FF.W.0064.210721T1748Z-210721T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1048 AM MST Wed Jul 21 2021

The National Weather Service in Flagstaff has issued a

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

* Until 200 PM MST.

* At 1048 AM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  0.5 and 1 inch of rain has fallen. Additional rainfall amounts of 
  0.75 to 1 inch 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 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...
  Prescott, Prescott Valley, Oak Knoll Village, Downtown Prescott, 
  Indian Hill West Prescott, Ponderosa Park, Groom Creek 
  Subdivision, Prescott Gateway Mall, White Spar Campground, Lower 
  Wolf Creek Campground, Upper Wolf Creek Group Campground and Lynx 
  Lake Dam.

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

This includes the following highways...
	State Route 69 between mile markers 293 and 296.
	State Route 89 between mile markers 300 and 316.

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 3454 11258 3460 11242 3448 11234 3442 11253

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

$$

EL
4 follow-up statements
058 
WGUS75 KFGZ 211814
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1114 AM MST Wed Jul 21 2021

AZC025-212100-
/O.CON.KFGZ.FF.W.0064.000000T0000Z-210721T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
1114 AM MST Wed Jul 21 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 1112 AM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. The 
heaviest rainfall has shifted a few miles southeast of Ponderosa 
Park. Between 0.75 and 1.5 inches of rain have fallen. Additional 
rainfall amounts of 0.75 to 1 inch 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 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...
  Prescott, Prescott Valley, Oak Knoll Village, Downtown Prescott, 
  Indian Hill West Prescott, Ponderosa Park, Groom Creek 
  Subdivision, Prescott Gateway Mall, White Spar Campground, Lower 
  Wolf Creek Campground, Upper Wolf Creek Group Campground and Lynx 
  Lake Dam.

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

This includes the following highways...
	State Route 69 between mile markers 293 and 296.
	State Route 89 between mile markers 300 and 316.

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 3454 11258 3460 11242 3448 11234 3442 11253

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

$$

EL
996 
WGUS75 KFGZ 211856
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1156 AM MST Wed Jul 21 2021

AZC025-212100-
/O.CON.KFGZ.FF.W.0064.000000T0000Z-210721T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
1156 AM MST Wed Jul 21 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 1152 AM MST, the rainfall intensity has begun to decrease in the 
warned area with the heaviest rain remaining a few miles 
east-southeast of Ponderosa Park. Between 1 and 2.25 inches of rain 
have fallen, according to multiple Yavapai County automatic rain 
gauges. Additional rainfall amounts of 0.25 to 0.75 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 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...
  Prescott, Prescott Valley, Oak Knoll Village, Downtown Prescott, 
  Indian Hill West Prescott, Ponderosa Park, Groom Creek 
  Subdivision, Prescott Gateway Mall, White Spar Campground, Lower 
  Wolf Creek Campground, Upper Wolf Creek Group Campground and Lynx 
  Lake Dam.

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

This includes the following highways...
	State Route 69 between mile markers 293 and 296.
	State Route 89 between mile markers 300 and 316.

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 3454 11258 3460 11242 3448 11234 3442 11253

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

$$

EL
947 
WGUS75 KFGZ 211924
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1224 PM MST Wed Jul 21 2021

AZC025-212100-
/O.CON.KFGZ.FF.W.0064.000000T0000Z-210721T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
1224 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 1222 PM MST, Doppler radar indicated the heavy rainfall has ended 
across the warned area, however flooding is expected to continue 
being an issue as water drains. Between 1 and 2 inches of rain have 
fallen.

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...
  Prescott, Prescott Valley, Oak Knoll Village, Downtown Prescott, 
  Indian Hill West Prescott, Ponderosa Park, Groom Creek 
  Subdivision, Prescott Gateway Mall, White Spar Campground, Lower 
  Wolf Creek Campground, Upper Wolf Creek Group Campground and Lynx 
  Lake Dam.

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

This includes the following highways...
	State Route 69 between mile markers 293 and 296.
	State Route 89 between mile markers 300 and 316.

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 3454 11258 3460 11242 3448 11234 3442 11253

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

$$

EL
392 
WGUS75 KFGZ 212010
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
110 PM MST Wed Jul 21 2021

AZC025-212020-
/O.CAN.KFGZ.FF.W.0064.000000T0000Z-210721T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
110 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING IS CANCELLED NEAR PONDEROSA PARK IN 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 3454 11258 3460 11242 3448 11234 3442 11253

$$

EL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 6:16 PM MSTSpecial Weather StatementFGZ29 min
Jul 20, 7:32 PM MSTSevere Thunderstorm WarningFGZNavajo28 min
Jul 20, 7:55 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo2 hr
Jul 20, 8:33 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo117 min
Jul 21, 12:17 AM MSTFlash Flood Warning Considerable damage threatFGZGila118 min
Jul 21, 2:38 AM MSTFlash Flood WatchFGZApache, Coconino, Gila, Navajo, Yavapai5 days
Jul 21, 10:19 AM MSTSpecial Weather StatementFGZYavapai26 min
Jul 21, 12:03 PM MSTSpecial Weather StatementFGZYavapai42 min
Jul 21, 12:13 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai56 min
Jul 21, 12:20 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai114 min
Jul 21, 12:35 PM MSTSpecial Weather StatementFGZ40 min
Jul 21, 12:47 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino118 min
Jul 21, 12:54 PM MSTSpecial Weather StatementFGZ36 min
Jul 21, 1:06 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino92 min
Jul 21, 1:24 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino110 min
Jul 21, 1:27 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai74 min
Jul 21, 1:57 PM MSTSpecial Weather StatementFGZYavapai48 min
Jul 21, 2:01 PM MSTAreal Flood AdvisoryFGZYavapai119 min
Jul 21, 2:05 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Jul 21, 2:22 PM MSTAreal Flood AdvisoryFGZCoconino3 hr
Jul 21, 2:30 PM MSTSpecial Weather StatementFGZ45 min
Jul 21, 2:36 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai54 min
Jul 21, 2:53 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino82 min
Jul 21, 2:57 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai60 min
Jul 21, 2:59 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai60 min
Jul 21, 3:21 PM MSTSevere Thunderstorm WarningFGZCoconino26 min
Jul 21, 3:34 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino98 min
Jul 21, 3:49 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 21, 4:35 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino115 min

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.