Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 14, NWS Flagstaff, AZ

July 9, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 9, 2021, 3:59 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
Jul 9, 2021, 3:59 PM MST (22:59 UTC)
Expired
Jul 9, 2021, 7:00 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), 124 km from the middle of the area, began a volume at 22:59 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 9, 4:45 PM MSTFLASH FLOOD1 Sw Prescott Courthous, AZTWO USGS RIVER GAUGES ON GRANITE CREEK MEASURED A 4 FOOT RISE DUE TO HEAVY RAINFALL WITHIN THE AREA.

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, 11.0 hours before the alert went out and 90 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 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 115 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 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 74 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
115 J/kg
Mixed-layer CIN
-284 J/kg
Mixed-layer LCL
2249 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

584 
WGUS55 KFGZ 092259
FFWFGZ
AZC025-100200-
/O.NEW.KFGZ.FF.W.0014.210709T2259Z-210710T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
359 PM MST Fri Jul 9 2021

The National Weather Service in Flagstaff has issued a

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

* Until 700 PM MST.

* At 357 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain from Prescott to Iron Springs to the northwest along 
  Mint Wash and Williamson Valley Wash. Between 0.75 and 1.75 inches 
  of rain have fallen. Additional rainfall amounts of 0.5 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.

  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, Williamson Valley, Yavapai Campground, 
  Iron Springs, Prescott Airport, Indian Hill West Prescott, 
  Downtown Prescott, Prescott Gateway Mall, Oak Knoll Village, White 
  Spar Campground, Lynx Lake Dam and Prescott Valley Event Center.

This includes the following highways...
	State Route 69 between mile markers 288 and 296.
	State Route 89 between mile markers 309 and 324.
	State Route 89A between mile markers 318 and 322.

This includes the following streams and drainages...
  Mud Tank Wash, Bannon Creek, Miller Creek, Dillon Wash, Willow 
  Creek, Butte Creek, Humphrey Wash, Spence Creek, Strickland Wash, 
  Horse Wash, Hitt Wash, Lynx Creek, Agua Fria River, Granite Creek, 
  Iron Springs Wash, Bottleneck Wash, Mint Wash, Butte Wash, Cooper 
  Wash, Little Chino Valley, Skull Valley Wash and Williamson Valley 
  Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3488 11269 3472 11251 3470 11239 3465 11234
      3455 11232 3448 11240 3454 11258 3468 11269
      3482 11281

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

$$

JJ
1 follow-up statement
053 
WGUS75 KFGZ 100156
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
656 PM MST Fri Jul 9 2021

AZC025-100206-
/O.EXP.KFGZ.FF.W.0014.000000T0000Z-210710T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
656 PM MST Fri Jul 9 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 7 PM MST THIS EVENING FOR 
YAVAPAI COUNTY...

The heavy rain has ended. Minor flooding in portions of the Prescott 
area will continue to recede and flooding is no longer expected to 
pose a threat.

LAT...LON 3488 11269 3472 11251 3470 11239 3465 11234
      3455 11232 3448 11240 3454 11258 3468 11269
      3482 11281

$$

JJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 5:13 PM MSTSpecial Weather StatementFGZYavapai32 min
Jul 8, 5:28 PM MSTSevere Thunderstorm WarningFGZYavapai19 min
Jul 8, 6:25 PM MSTSpecial Weather StatementFGZYavapai50 min
Jul 8, 7:03 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 9, 3:02 PM MSTSevere Thunderstorm WarningFGZYavapai28 min
Jul 9, 3:22 PM MSTSevere Thunderstorm WarningFGZGila23 min
Jul 9, 3:33 PM MSTSevere Thunderstorm WarningFGZYavapai27 min
Jul 9, 3:42 PM MSTSevere Thunderstorm WarningFGZYavapai48 min
Jul 9, 3:45 PM MSTAreal Flood AdvisoryFGZYavapai2 hr
Jul 9, 4:26 PM MSTAreal Flood AdvisoryFGZYavapai2 hr
Jul 9, 4:48 PM MSTSevere Thunderstorm WarningFGZGila42 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.