Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 68, NWS Flagstaff, AZ

July 21, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 21, 2021, 1:06 PM MST for Coconino County, Arizona. It was in force for 92 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 21, 2021, 1:06 PM MST (20:06 UTC)
Expired
Jul 21, 2021, 2:38 PM MST
In force
92 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 83 km from the middle of the area, began a volume at 20:09 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, 8.1 hours before the alert went out and 8 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 2021-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 77 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 2021-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
77 J/kg
Mixed-layer CIN
-129 J/kg
Mixed-layer LCL
1785 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

835 
WGUS55 KFGZ 212006
FFWFGZ
AZC005-212315-
/O.NEW.KFGZ.FF.W.0068.210721T2006Z-210721T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
106 PM MST Wed Jul 21 2021

The National Weather Service in Flagstaff has issued a

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

* Until 415 PM MST.

* At 106 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  0.75 and 1.5 inches of rain have fallen. The expected rainfall 
  rate is 1 to 2 inches in 1 hour. Additional rainfall amounts of 
  0.75 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 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...
  Flagstaff and Downtown Flagstaff.

This includes the following highways...
	State Route 89A between mile markers 397 and 398.
	Interstate 17 between mile markers 336 and 339.
	Interstate 40 between mile markers 187 and 197.
	Route 66 between mile markers 192 and 197.

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.

&&

LAT...LON 3523 11179 3523 11167 3513 11157 3511 11182

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

EL
3 follow-up statements
636 
WGUS75 KFGZ 212020
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
120 PM MST Wed Jul 21 2021

AZC005-212315-
/O.CON.KFGZ.FF.W.0068.000000T0000Z-210721T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
120 PM MST Wed Jul 21 2021

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

At 120 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
0.75 and 1.75 inches of rain have fallen. The expected rainfall rate 
is 1 to 2 inches in 1 hour. Additional rainfall amounts of 0.75 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 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...
  Flagstaff and Downtown Flagstaff.

This includes the following highways...
	State Route 89A between mile markers 397 and 398.
	Interstate 17 between mile markers 337 and 339.
	Interstate 40 between mile markers 188 and 197.
	Route 66 between mile markers 192 and 197.

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.

&&

LAT...LON 3523 11179 3523 11167 3513 11157 3511 11182

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

EL
261 
WGUS75 KFGZ 212047
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
147 PM MST Wed Jul 21 2021

AZC005-212315-
/O.CON.KFGZ.FF.W.0068.000000T0000Z-210721T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
147 PM MST Wed Jul 21 2021

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

At 145 PM MST, Doppler radar and automated rain gauges indicated 
decreasing rainfall rates across the warned area. Between 0.75 and 
1.75 inches of rain have fallen with flash flooding still likely as 
water drains.

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...
  Flagstaff and Downtown Flagstaff.

This includes the following highways...
	State Route 89A between mile markers 397 and 398.
	Interstate 17 between mile markers 337 and 339.
	Interstate 40 between mile markers 188 and 197.
	Route 66 between mile markers 192 and 197.

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.

&&

LAT...LON 3523 11179 3523 11167 3513 11157 3511 11182

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

$$

EL
597 
WGUS75 KFGZ 212138
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
238 PM MST Wed Jul 21 2021

AZC005-212148-
/O.CAN.KFGZ.FF.W.0068.000000T0000Z-210721T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino AZ-
238 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING IS CANCELLED FOR COCONINO COUNTY...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3523 11179 3523 11167 3513 11157 3511 11182

$$

EL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 6:16 PM MSTSpecial Weather StatementFGZ29 min
Jul 20, 7:32 PM MSTSevere Thunderstorm WarningFGZNavajo28 min
Jul 20, 7:55 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo2 hr
Jul 20, 8:33 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo117 min
Jul 21, 12:17 AM MSTFlash Flood Warning Considerable damage threatFGZGila118 min
Jul 21, 2:38 AM MSTFlash Flood WatchFGZApache, Coconino, Gila, Navajo, Yavapai5 days
Jul 21, 10:19 AM MSTSpecial Weather StatementFGZYavapai26 min
Jul 21, 10:48 AM MSTFlash Flood Warning Considerable damage threatFGZYavapai2 hr
Jul 21, 12:03 PM MSTSpecial Weather StatementFGZYavapai42 min
Jul 21, 12:13 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai56 min
Jul 21, 12:20 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai114 min
Jul 21, 12:35 PM MSTSpecial Weather StatementFGZ40 min
Jul 21, 12:47 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino118 min
Jul 21, 12:54 PM MSTSpecial Weather StatementFGZ36 min
Jul 21, 1:24 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino110 min
Jul 21, 1:27 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai74 min
Jul 21, 1:57 PM MSTSpecial Weather StatementFGZYavapai48 min
Jul 21, 2:01 PM MSTAreal Flood AdvisoryFGZYavapai119 min
Jul 21, 2:05 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Jul 21, 2:22 PM MSTAreal Flood AdvisoryFGZCoconino3 hr
Jul 21, 2:30 PM MSTSpecial Weather StatementFGZ45 min
Jul 21, 2:36 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai54 min
Jul 21, 2:53 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino82 min
Jul 21, 2:57 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai60 min
Jul 21, 2:59 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai60 min
Jul 21, 3:21 PM MSTSevere Thunderstorm WarningFGZCoconino26 min
Jul 21, 3:34 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino98 min
Jul 21, 3:49 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 21, 4:35 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino115 min

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.