Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 219, NWS Flagstaff, AZ

August 29, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 29, 2021, 8:11 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 29, 2021, 8:11 PM MST (03:11 UTC)
Expired: Aug 29, 2021, 10:15 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), 88 km from the middle of the area, began a volume at 03:14 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

Phoenix, AZ (KPSR), launched 00:00Z, 3.2 hours before the alert went out and 103 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 193 J/kg
Mixed-layer CIN: -82 J/kg
Mixed-layer LCL: 3484 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

747 
WGUS55 KFGZ 300311
FFWFGZ
AZC025-300515-
/O.NEW.KFGZ.FF.W.0219.210830T0311Z-210830T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
811 PM MST Sun Aug 29 2021

The National Weather Service in Flagstaff has issued a

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

* Until 1015 PM MST.

* At 810 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain along SR69 from northwest of Mayer to Cordes Junction. 
  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...
  Cordes Junction, Cordes Lakes, Spring Valley, Cordes and Mayer.

This includes the following highways...
	State Route 69 between mile markers 263 and 273.
	Interstate 17 between mile markers 259 and 267.

This includes the following streams and drainages...
  Agua Fria River, Cedar Creek, Mineral Creek, Hackberry Creek, Ash 
  Creek, Antelope Creek, Sycamore Creek, Little Ash Creek, Dry 
  Creek, Brushy Wash, Indian Creek, Turkey Creek, Government Spring 
  Wash, Yarber Wash, Big Bug Creek, Little Sycamore Creek and Badger 
  Spring Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3444 11226 3443 11222 3442 11216 3439 11209
      3439 11206 3437 11194 3435 11194 3431 11195
      3428 11199 3426 11205 3426 11207 3428 11209
      3428 11212 3428 11219 3429 11224 3433 11226
      3439 11227

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

$$

Peterson

1 follow-up statement

703 
WGUS75 KFGZ 300510
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1010 PM MST Sun Aug 29 2021

AZC025-300520-
/O.EXP.KFGZ.FF.W.0219.000000T0000Z-210830T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
1010 PM MST Sun Aug 29 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 PM MST THIS EVENING FOR 
YAVAPAI COUNTY...

At 1010 PM MST, National Weather Service Flagstaff Doppler radar 
indicated that rainfall had ended along SR69 from Mayer to Cordes 
Junction. No reports of Flash Flooding have been received and the 
Flash Flood Warning will expire at 1015 PM MST. Area creeks and 
streams may still have higher than normal flow for the remainder of 
the evening.

Please continue to heed remaining road closures.

LAT...LON 3444 11226 3443 11222 3442 11216 3439 11209
      3439 11206 3437 11194 3435 11194 3431 11195
      3428 11199 3426 11205 3426 11207 3428 11209
      3428 11212 3428 11219 3429 11224 3433 11226
      3439 11227

$$

Peterson

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 30, 2:00 AM MST	Flash Flood Watch	FGZ	Apache, Coconino, Gila, Navajo, Yavapai	67 hr
Aug 30, 1:58 PM MST	Special Weather Statement	FGZ		17 min
Aug 30, 2:10 PM MST	Special Weather Statement	FGZ		20 min
Aug 30, 2:24 PM MST	Special Weather Statement	FGZ		21 min

Nearby

Flash Flood Warnings in Arizona, 2021 Every 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.