Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 218, NWS Flagstaff, AZ

August 29, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 29, 2021, 2:25 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, 2:25 PM MST (21:25 UTC)
Expired
Aug 29, 2021, 4:31 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 Phoenix radar (KIWA), 143 km from the middle of the area, began a volume at 21:27 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 12:00Z, 9.4 hours before the alert went out and 113 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, Phoenix, AZ at 12:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 122 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
122 J/kg
Mixed-layer CIN
-447 J/kg
Mixed-layer LCL
2496 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
6 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

200 
WGUS55 KFGZ 292125
FFWFGZ
AZC025-300030-
/O.NEW.KFGZ.FF.W.0218.210829T2125Z-210830T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  The Tenderfoot Fire scar in...
  Yavapai County in west central Arizona...

* Until 530 PM MST.

* At 224 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Tenderfoot Fire scar. Between 0.50 and 1.00 
  inches of rain have fallen. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Tenderfoot
           Fire scar.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Tenderfoot Fire scar.

* Some locations that will experience flash flooding include...
  Yarnell and Glen Ilah.

This includes the following highways...
	State Route 89 between mile markers 277 and 278.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall over the Tenderfoot Fire scar will flood 
neighborhoods next to the scar and highway 89A south of Yarnell.

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

&&

LAT...LON 3421 11276 3422 11276 3423 11274 3423 11272
      3421 11274 3421 11275

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

$$

McCollum
1 follow-up statement
832 
WGUS75 KFGZ 292331
FFSFGZ

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

AZC025-292341-
/O.CAN.KFGZ.FF.W.0218.000000T0000Z-210830T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
431 PM MST Sun Aug 29 2021

...FLASH FLOOD WARNING FOR THE TENDERFOOT FIRE SCAR IS CANCELLED FOR 
YAVAPAI COUNTY...

At 430 PM MST, National Weather Service Flagstaff Doppler radar 
indicated that rainfall had ended in the Yarnell area. No reports of 
Flash Flooding have been received and the Flash Flood Warning is 
cancelled. Area creeks and streams may still have higher than normal
flow for the remainder of the afternoon.

Please continue to heed remaining road closures.

LAT...LON 3421 11276 3422 11276 3423 11274 3423 11272
      3421 11274 3421 11275

$$

Peterson

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 6:15 PM MSTSevere Thunderstorm WarningFGZYavapai45 min
Aug 28, 6:39 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai111 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.