Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 109, NWS Flagstaff, AZ

July 25, 2021Apache County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 25, 2021, 7:05 PM MST for Apache 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: Jul 25, 2021, 7:05 PM MST (02:05 UTC)
Expired: Jul 25, 2021, 10:15 PM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Apache County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 183 km from the middle of the area, began a volume at 02:05 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 00:00Z, 2.1 hours before the alert went out and 201 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: 44 J/kg
Mixed-layer CIN: -47 J/kg
Mixed-layer LCL: 976 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

403 
WGUS55 KFGZ 260205
FFWFGZ
AZC001-017-260515-
/O.NEW.KFGZ.FF.W.0109.210726T0205Z-210726T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
705 PM MST Sun Jul 25 2021

The National Weather Service in Flagstaff has issued a

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

* Until 1015 PM MST.

* At 702 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of the Navajo Nation. Between 1 and 2 
  inches of rain have fallen. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Thunderstorms producing flash flooding.

  SOURCE...Radar.

  IMPACT...Flash flooding of low-water crossings, creeks,
           normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Klagetoh, Wide Ruins, Hubbell Trading Post National Historic Site, 
  Cornfields Chapter House, Kinlichee Chapter House, Sunrise 
  Springs, Burnside, Pine Springs, Greasewood Springs, Ganado and 
  Greasewood.

This includes the following highways...
	Highway 191 between mile markers 380 and 420.
	State Route 264 between mile markers 439 and 463.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3566 10985 3594 10938 3591 10930 3538 10921
      3517 10966 3561 10992 3562 10993

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

$$

McCollum

1 follow-up statement

315 
WGUS75 KFGZ 260507
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
1007 PM MST Sun Jul 25 2021

AZC001-017-260517-
/O.EXP.KFGZ.FF.W.0109.000000T0000Z-210726T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Apache AZ-Navajo AZ-
1007 PM MST Sun Jul 25 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 PM MST THIS EVENING FOR 
NAVAJO AND APACHE COUNTIES...

The heavy rain has ended in the area from Ganado to Greasewood. 
Flooding is no longer expected to pose a threat. Please heed road 
closures and avoid driving through water covered roads.

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

LAT...LON 3566 10985 3594 10938 3591 10930 3538 10921
      3517 10966 3561 10992 3562 10993

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 12:38 PM MST	Special Weather Statement	FGZ		37 min
Jul 26, 3:21 PM MST	Special Weather Statement	FGZ		39 min
Jul 26, 4:29 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.