Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 83, NWS Flagstaff, AZ

July 22, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 22, 2021, 4:58 PM MDT for Navajo County, Arizona. It was in force for 3 hr. 3 reports 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 22, 2021, 4:58 PM MDT (22:58 UTC)
Expired: Jul 22, 2021, 8:00 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), 105 km from the middle of the area, began a volume at 23:00 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 22, 5:30 PM MDT	FLOOD	4 Ene Show Low, AZ	HIGHWAY 60 EAST OF SHOW LOW FLOODED AT LITTLE MORMON LAKE ROAD.
Jul 22, 5:30 PM MDT	FLOOD	6 Ene Show Low, AZ	HIGHWAY 60 EAST OF SHOW LOW FLOODED AT SECOND KNOLL TARGET RANGE ENTRANCE (N.F. ROAD 206).
Jul 22, 5:45 PM MDT	FLASH FLOOD	3 Sse Show Low, AZ	FLOODING ON SR 260 SOUTH SIDE OF SHOW LOW. CAR STUCK IN HIGH WATER.

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 187 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: 196 J/kg
Mixed-layer CIN: -125 J/kg
Mixed-layer LCL: 1415 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

405 
WGUS55 KFGZ 222258
FFWFGZ
AZC017-230200-
/O.NEW.KFGZ.FF.W.0083.210722T2258Z-210723T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
358 PM MST Thu Jul 22 2021

The National Weather Service in Flagstaff has issued a

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

* Until 700 PM MST.

* At 357 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in the Show Low region. Storms are moving southward 
  through Show Low toward Pinetop-Lakeside. Between 0.75 and 2 
  inches of rain have fallen, with some gauges recording an inch of 
  rain in 15 minutes. Additional rainfall amounts of 0.5 to 1.5 
  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.

  IMPACT...Life-threatening flash flooding of low-water
           crossings, creeks, normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Show Low, Taylor, Linden, Wagon Wheel, Shumway, Pinedale, 
  Pinetop-Lakeside, Fort Apache Reservation, Snowflake, Fool Hollow 
  Lake Campground, White Mountain Lake, Scott Reservoir Campground, 
  Lakeside Campground and Lewis Canyon Group Campground.

This includes the following highways...
	State Route 77 between mile markers 343 and 359.
	State Route 260 between mile markers 327 and 350.
	Highway 60 between mile markers 334 and 351.

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 3424 11030 3436 11024 3442 11012 3449 11008
      3431 10986 3420 10987 3412 11002

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

$$

JJ

2 follow-up statements

125 
WGUS75 KFGZ 222349
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
449 PM MST Thu Jul 22 2021

AZC017-230200-
/O.CON.KFGZ.FF.W.0083.000000T0000Z-210723T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
449 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 PM MST THIS EVENING 
FOR NAVAJO COUNTY...

At 445 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain in the Show Low region were moving to the south.  Between 1.5 
and 3.5 inches of rain have fallen. Additional rainfall amounts of 
0.25 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.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads.

Some locations that will experience flash flooding include...
  Show Low, Taylor, Shumway, Linden, Wagon Wheel, Fool Hollow Lake 
  Campground, White Mountain Lake, Scott Reservoir Campground, 
  Lakeside Campground and Lewis Canyon Group Campground.

This includes the following highways...
	State Route 77 between mile markers 343 and 359.
	State Route 260 between mile markers 327 and 350.
	Highway 60 between mile markers 334 and 351.

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 3424 11030 3436 11024 3442 11012 3449 11008
      3431 10986 3420 10987 3412 11002

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

$$

McCollum

958 
WGUS75 KFGZ 230152
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
652 PM MST Thu Jul 22 2021

AZC017-230202-
/O.EXP.KFGZ.FF.W.0083.000000T0000Z-210723T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Navajo AZ-
652 PM MST Thu Jul 22 2021

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

The heavy rain has ended in the Show Low area. Flooding is no longer 
expected to pose a threat. Please continue to heed remaining road 
closures.

A Flash Flood Watch remains in effect until 1100 PM MST Saturday for 
portions of east central Arizona, north central Arizona, northeast 
Arizona and west central Arizona.

LAT...LON 3424 11030 3436 11024 3442 11012 3449 11008
      3431 10986 3420 10987 3412 11002

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 7:38 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Gila	3 hr
Jul 21, 7:53 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	112 min
Jul 22, 1:28 PM MDT	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 22, 3:10 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 22, 4:01 PM MDT	Severe Thunderstorm Warning	FGZ	Coconino	44 min
Jul 22, 4:31 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	115 min
Jul 22, 5:04 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	116 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.