Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 184, NWS Flagstaff, AZ

August 17, 2021Coconino County, Gila County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 17, 2021, 12:04 PM MST for Coconino County, Gila County, Navajo 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
Aug 17, 2021, 12:04 PM MST (19:04 UTC)
Expired
Aug 17, 2021, 3:15 PM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Coconino County, AZ, Gila County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 54 km from the middle of the area, began a volume at 19:06 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, 7.1 hours before the alert went out and 143 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, Flgstf/Belemont, AZ at 12:00Z on 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 984 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 135 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
984 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
829 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

Open this sounding in Storm Lab

The text

As transmitted.

580 
WGUS55 KFGZ 171904
FFWFGZ
AZC005-007-017-172215-
/O.NEW.KFGZ.FF.W.0184.210817T1904Z-210817T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1204 PM MST Tue Aug 17 2021

The National Weather Service in Flagstaff has issued a

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

* Until 315 PM MST.

* At 1201 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to 1 inch of rain has 
  fallen. Additional rainfall amounts of 1 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...
  Forest Lakes, Christopher Creek, Fort Apache Reservation, Gentry 
  Campground, Black Canyon Rim Campground, Airplane Flat Campground, 
  Canyon Creek Fish Hatchery, Canyon Point Campground, Forest Road 
  237 Camping Area, Forest Road 171 Campground, Sinkhole Campground, 
  Rim Campground, Spillway Campground, Crook Campground, Woods 
  Canyon Lake Campground, Mogollon Campground, Forest Road 195 
  Campground, Forest Road 169 Campground and Forest Road 9350 
  Campground.

This includes the following highways...
	State Route 260 between mile markers 278 and 303.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

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.

Remain alert for flooding even in locations not receiving rain. 
Normally dry washes, slot canyons and creeks can become raging 
killer currents in a matter of minutes, even from distant rainfall.

Get out of washes and creeks if you are camping or hiking! Flooding 
is occurring or imminent and will inundate area drainages.

&&

LAT...LON 3450 11087 3450 11076 3450 11075 3443 11060
      3429 11053 3425 11048 3423 11048 3408 11043
      3403 11079 3418 11077 3432 11101

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

$$

DB
2 follow-up statements
452 
WGUS75 KFGZ 172058
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
158 PM MST Tue Aug 17 2021

AZC005-007-017-172215-
/O.CON.KFGZ.FF.W.0184.000000T0000Z-210817T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Gila AZ-Navajo AZ-
158 PM MST Tue Aug 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 PM MST THIS 
AFTERNOON FOR GILA, COCONINO AND NAVAJO COUNTIES...

At 156 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain have ended in the Forest Lakes area. Trained spotters reported 
between 2.50 to 3.00 inches of rain has fallen. Additional rainfall 
amounts up to 0.25 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...
  Forest Lakes, Christopher Creek, Fort Apache Reservation, Gentry 
  Campground, Black Canyon Rim Campground, Airplane Flat Campground, 
  Canyon Creek Fish Hatchery, Canyon Point Campground, Forest Road 
  237 Camping Area, Forest Road 171 Campground, Sinkhole Campground, 
  Rim Campground, Spillway Campground, Crook Campground, Woods 
  Canyon Lake Campground, Mogollon Campground, Forest Road 195 
  Campground, Forest Road 169 Campground and Forest Road 9350 
  Campground.

This includes the following highways...
	State Route 260 between mile markers 278 and 302.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding of washes and creeks will occur, some dirt roads will 
become muddy and impassable. Paved roads and underpasses could 
become flooded as well.

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 3450 11087 3450 11076 3450 11075 3443 11060
      3429 11053 3425 11048 3423 11048 3408 11043
      3403 11079 3418 11077 3432 11101

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

$$

TPS
686 
WGUS75 KFGZ 172206 RRA
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
306 PM MST Tue Aug 17 2021

AZC005-007-017-172216-
/O.EXP.KFGZ.FF.W.0184.000000T0000Z-210817T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-Gila AZ-Navajo AZ-
306 PM MST Tue Aug 17 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 315 PM MST THIS AFTERNOON FOR 
GILA, COCONINO AND NAVAJO COUNTIES...

The heavy rain threat has ended in the Forest Lakes 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 Tuesday for 
portions of north central Arizona, northeast Arizona and west 
central Arizona.

LAT...LON 3450 11087 3450 11076 3450 11075 3443 11060
      3429 11053 3425 11048 3423 11048 3408 11043
      3403 11079 3418 11077 3432 11101

$$

TPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 5:04 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Navajo3 hr
Aug 16, 6:33 PM MSTSevere Thunderstorm WarningFGZYavapai27 min
Aug 16, 7:08 PM MSTSevere Thunderstorm WarningFGZYavapai37 min
Aug 16, 7:37 PM MSTSevere Thunderstorm WarningFGZCoconino23 min
Aug 16, 7:42 PM MSTSevere Thunderstorm WarningFGZYavapai33 min
Aug 16, 7:57 PM MSTSevere Thunderstorm WarningFGZCoconino33 min
Aug 16, 8:04 PM MSTSevere Thunderstorm WarningFGZYavapai26 min
Aug 16, 8:21 PM MSTSevere Thunderstorm WarningFGZCoconino24 min
Aug 16, 9:18 PM MSTSevere Thunderstorm WarningFGZGila42 min
Aug 16, 10:01 PM MSTSevere Thunderstorm WarningFGZYavapai29 min
Aug 16, 10:33 PM MSTSevere Thunderstorm WarningFGZYavapai25 min
Aug 17, 12:15 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino60 min
Aug 17, 12:22 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 12:29 PM MSTSevere Thunderstorm WarningFGZCoconino, Gila, Navajo46 min
Aug 17, 12:41 PM MSTFlash Flood Warning EmergencyCatastrophic damage threatFGZCoconino3 hr
Aug 17, 12:59 PM MSTSevere Thunderstorm WarningFGZCoconino46 min
Aug 17, 1:06 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 1:16 PM MSTSevere Thunderstorm WarningFGZCoconino44 min
Aug 17, 1:21 PM MSTSevere Thunderstorm WarningFGZCoconino39 min
Aug 17, 1:28 PM MSTSevere Thunderstorm WarningFGZCoconino47 min
Aug 17, 1:37 PM MSTFlash Flood WatchFGZApache, Coconino, Navajo9 hr
Aug 17, 2:03 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 2:09 PM MSTSevere Thunderstorm WarningFGZCoconino51 min
Aug 17, 2:15 PM MSTSevere Thunderstorm WarningFGZCoconino45 min
Aug 17, 2:18 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 17, 3:03 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 17, 3:42 PM MSTSevere Thunderstorm WarningFGZCoconino33 min
Aug 17, 3:44 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 17, 4:06 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Aug 17, 4:19 PM MSTSevere Thunderstorm WarningFGZYavapai26 min
Aug 17, 4:22 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 17, 4:46 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr

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.