Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 57, NWS Flagstaff, AZ

July 20, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 20, 2021, 1:14 PM MST for Yavapai County, Arizona. It was in force for 3 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: Jul 20, 2021, 1:14 PM MST (20:14 UTC)
Expired: Jul 20, 2021, 4:15 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), 144 km from the middle of the area, began a volume at 20:18 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.2 hours before the alert went out and 127 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: 396 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 1392 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 5 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

761 
WGUS55 KFGZ 202014
FFWFGZ
AZC025-202315-
/O.NEW.KFGZ.FF.W.0057.210720T2014Z-210720T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
114 PM MST Tue Jul 20 2021

The National Weather Service in Flagstaff has issued a

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

* Until 415 PM MST.

* At 113 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in the Kirkland Creek and Sheppard Wash drainages 
  between Peeples Valley and Wilhoit. Between 1 and 2 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...
  Kirkland.

This includes the following highways...
	State Route 89 between mile markers 284 and 296.

This includes the following streams and drainages...
  Copper Basin Wash, Waterman Creek, Hassayampa River, Alkali Wash, 
  Skull Valley Wash, Poplar Wash, North Fork Date Creek, Model 
  Creek, Orofino Wash, Cottonwood Creek, Kirkland Creek, Bland Creek 
  and Sheppard Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

&&

LAT...LON 3443 11285 3448 11282 3443 11273 3443 11257
      3430 11262 3431 11287

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

$$

JJ

2 follow-up statements

881 
WGUS75 KFGZ 202147
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
247 PM MST Tue Jul 20 2021

AZC025-202315-
/O.CON.KFGZ.FF.W.0057.000000T0000Z-210720T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
247 PM MST Tue Jul 20 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM MST THIS 
AFTERNOON FOR YAVAPAI COUNTY...

At 242 PM MST, Heavy rain has ended in the Kirkland Creek and 
Sheppard Wash drainages between Peeples Valley and Wilhoit. Between 
1 and 2 inches of rain fell earlier this afternoon. 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...
  Kirkland.

This includes the following highways...
	State Route 89 between mile markers 284 and 296.

This includes the following streams and drainages...
  Copper Basin Wash, Waterman Creek, Hassayampa River, Alkali Wash, 
  Skull Valley Wash, Poplar Wash, North Fork Date Creek, Model 
  Creek, Orofino Wash, Cottonwood Creek, Kirkland Creek, Bland Creek 
  and Sheppard Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly or mountainous terrain, there are many low water crossings 
which will become dangerous in heavy rain. Do not attempt to cross 
flooded roads. Find an alternate route.

&&

LAT...LON 3443 11285 3448 11282 3443 11273 3443 11257
      3430 11262 3431 11287

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

$$

JJ

882 
WGUS75 KFGZ 202307
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
407 PM MST Tue Jul 20 2021

AZC025-202317-
/O.EXP.KFGZ.FF.W.0057.000000T0000Z-210720T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Yavapai AZ-
407 PM MST Tue Jul 20 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 415 PM MST THIS AFTERNOON FOR 
YAVAPAI COUNTY...

The heavy rain has ended over the warning area from just north of 
Crown King to southwest of Wagoner. High flows could continue into 
this evening in some of the area washes and creeks. Please continue 
to heed remaining road closures and turn around if water is 
encountered over a road.

LAT...LON 3443 11285 3448 11282 3443 11273 3443 11257
      3430 11262 3431 11287

$$

JJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 6:31 PM MST	Severe Thunderstorm Warning	FGZ	Gila	29 min
Jul 20, 11:44 AM MST	Severe Thunderstorm Warning	FGZ	Yavapai	35 min
Jul 20, 11:53 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 20, 1:23 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 20, 1:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 20, 3:45 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 20, 4:57 PM MST	Special Weather Statement	FGZ		48 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.