Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 119, NWS Flagstaff, AZ

July 28, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 28, 2021, 8:06 PM MDT for Navajo 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 28, 2021, 8:06 PM MDT (02:06 UTC)
Expired: Jul 28, 2021, 11:15 PM MDT
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 108 km from the middle of the area, began a volume at 02:10 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

Time	Report	Where	Remark
Jul 28, 9:18 PM MDT	FLASH FLOOD	3 Ne Shumway, AZ	HAD FLOODING THROUGH OUR BARN AND THROUGH OUR ANIMAL PENS. PROBABLY GOT ABOUT 2 INCHES OF RAIN IN 45 MINUTES TO AN HOUR.

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 00:00Z, 2.1 hours before the alert went out and 182 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: 132 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 1687 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

684 
WGUS55 KFGZ 290206
FFWFGZ
AZC017-290515-
/O.NEW.KFGZ.FF.W.0119.210729T0206Z-210729T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
706 PM MST Wed Jul 28 2021

The National Weather Service in Flagstaff has issued a

* Flash Flood Warning for...
  Navajo County in north central Arizona...

* Until 1015 PM MST.

* At 705 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in the Snowflake and Taylor area. Between 0.75 and 1.5 
  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...
  Taylor, Shumway and Snowflake.

This includes the following highways...
	State Route 77 between mile markers 352 and 368.
	State Route 277 between mile markers 333 and 336.

This includes the following streams and drainages...
  Cottonwood Wash, Silver Creek, Concho Flat Wash, Sevenmile Draw, 
  Dodson Wash, Hay Hollow Draw and Show Low Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3453 10990 3438 10999 3439 11016 3464 11014

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

$$

TPS

2 follow-up statements

754 
WGUS75 KFGZ 290401
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
901 PM MST Wed Jul 28 2021

AZC017-290515-
/O.CON.KFGZ.FF.W.0119.000000T0000Z-210729T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
901 PM MST Wed Jul 28 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM MST THIS 
EVENING FOR NAVAJO COUNTY...

At 858 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing moderate to heavy rain have moved back into 
the Snowflake area. Between 1 and 1.75 inches of rain have fallen. 
Additional rainfall amounts up to 0.5 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...
  Taylor, Shumway and Snowflake.

This includes the following highways...
	State Route 77 between mile markers 352 and 368.
	State Route 277 between mile markers 333 and 336.

This includes the following streams and drainages...
  Cottonwood Wash, Silver Creek, Concho Flat Wash, Sevenmile Draw, 
  Dodson Wash, Hay Hollow Draw and Show Low Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3453 10990 3438 10999 3439 11016 3464 11014

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

$$

TPS

033 
WGUS75 KFGZ 290507
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1007 PM MST Wed Jul 28 2021

AZC017-290517-
/O.EXP.KFGZ.FF.W.0119.000000T0000Z-210729T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
1007 PM MST Wed Jul 28 2021

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

The heavy rain threat has ended in the Snowflake and Taylor area. 
Water levels will continue to gradually recede over the next few 
hours. Please continue to heed remaining road closures.

LAT...LON 3453 10990 3438 10999 3439 11016 3464 11014

$$

TPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 7:47 PM MDT	Special Weather Statement	FGZ		28 min
Jul 28, 8:18 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Jul 29, 12:48 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 29, 12:57 PM MDT	Severe Thunderstorm Warning	FGZ	Apache, Navajo	33 min
Jul 29, 1:21 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	24 min
Jul 29, 1:36 PM MDT	Severe Thunderstorm Warning	FGZ	Coconino	24 min
Jul 29, 1:44 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	31 min
Jul 29, 1:53 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 29, 1:57 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Jul 29, 2:07 PM MDT	Severe Thunderstorm Warning	FGZ	Apache, Navajo	38 min
Jul 29, 2:10 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	50 min
Jul 29, 2:13 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 29, 2:23 PM MDT	Severe Thunderstorm Warning	FGZ	Yavapai	37 min
Jul 29, 3:05 PM MDT	Flash Flood Watch	FGZ	Apache, Coconino, Navajo, Yavapai	31 hr
Jul 29, 3:09 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 29, 3:16 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Jul 29, 3:41 PM MDT	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Jul 29, 4:03 PM MDT	Severe Thunderstorm Warning	FGZ	Apache, Navajo	27 min
Jul 29, 4:41 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Navajo	3 hr
Jul 29, 5:03 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.