Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 92, NWS Flagstaff, AZ

July 23, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 23, 2021, 12:51 PM MST for Coconino County, Arizona. It was in force for 114 min. 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 23, 2021, 12:51 PM MST (19:51 UTC)
Expired
Jul 23, 2021, 2:45 PM MST
In force
114 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Coconino County, AZ

The radar

The Cedar City radar (KICX), 169 km from the middle of the area, began a volume at 19:50 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, 7.9 hours before the alert went out and 114 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 2021-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 503 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 2021-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
503 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

161 
WGUS55 KFGZ 231951
FFWFGZ
AZC005-232145-
/O.NEW.KFGZ.FF.W.0092.210723T1951Z-210723T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
1251 PM MST Fri Jul 23 2021

The National Weather Service in Flagstaff has issued a

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

* Until 245 PM MST.

* At 1248 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in the Nankoweap Creek and Bright Angel Creek drainages 
  northeast of Bright Angel Point at the Grand Canyon. 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...
  Bright Angel Point, Grand Canyon National Park and Navajo 
  Reservation.

This includes the following streams and drainages...
  South Canyon, West Fork Carbon Creek, Nankoweap Creek, Bright 
  Angel Creek, Unkar Creek, Sixtymile Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3634 11208 3631 11180 3615 11178 3611 11209

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

$$

JJ
1 follow-up statement
936 
WGUS75 KFGZ 232149
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
249 PM MST Fri Jul 23 2021

AZC005-232159-
/O.EXP.KFGZ.FF.W.0092.000000T0000Z-210723T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
249 PM MST Fri Jul 23 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR COCONINO COUNTY...

The heavy rain has ended over the warning area, including Bright 
Angel Canyon. Flooding is no longer expected to pose a threat. 
Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MST Monday for 
portions of east central Arizona, north central Arizona, northeast 
Arizona and west central Arizona.

LAT...LON 3634 11208 3631 11180 3615 11178 3611 11209

$$

JJ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 7:01 PM MSTAreal Flood WarningFGZNavajo5 min
Jul 22, 7:06 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo3 hr
Jul 22, 8:08 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Navajo3 hr
Jul 22, 10:06 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Gila, Navajo4 hr
Jul 23, 12:57 AM MSTFlash Flood Warning Considerable damage threatFGZGila4 hr
Jul 23, 1:50 AM MSTAreal Flood AdvisoryFGZCoconino, Gila, Yavapai3 hr
Jul 23, 4:07 AM MSTFlash Flood Warning Considerable damage threatFGZYavapai4 hr
Jul 23, 11:21 AM MSTAreal Flood WarningFGZGila6 hr
Jul 23, 11:38 AM MSTSpecial Weather StatementFGZCoconino37 min
Jul 23, 12:07 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai4 hr
Jul 23, 12:14 PM MSTSpecial Weather StatementFGZCoconino46 min
Jul 23, 12:19 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai2 hr
Jul 23, 1:17 PM MSTSpecial Weather StatementFGZ43 min
Jul 23, 1:31 PM MSTSevere Thunderstorm WarningFGZYavapai34 min
Jul 23, 2:12 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai2 hr
Jul 23, 2:24 PM MSTSpecial Weather StatementFGZYavapai36 min
Jul 23, 2:59 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino7 hr
Jul 23, 3:26 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Yavapai3 hr
Jul 23, 3:43 PM MSTSpecial Weather StatementFGZNavajo47 min
Jul 23, 4:01 PM MSTAreal Flood AdvisoryFGZYavapai3 hr
Jul 23, 4:28 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo3 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.