Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 138, NWS Flagstaff, AZ

August 1, 2021Gila County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 1, 2021, 3:58 PM MST for 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 1, 2021, 3:58 PM MST (22:58 UTC)
Expired
Aug 1, 2021, 7:00 PM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Flood severity
None

Counties Gila County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 132 km from the middle of the area, began a volume at 22:58 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

Phoenix, AZ (KPSR), launched 12:00Z, 11.0 hours before the alert went out and 181 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, Phoenix, AZ at 12:00Z on 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 445 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
445 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
2155 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

893 
WGUS55 KFGZ 012258
FFWFGZ
AZC007-017-020200-
/O.NEW.KFGZ.FF.W.0138.210801T2258Z-210802T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Flagstaff AZ
358 PM MST Sun Aug 1 2021

The National Weather Service in Flagstaff has issued a

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

* Until 700 PM MST.

* At 357 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts of 0.25 to 0.75 
  inches are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Whiteriver, Rainbow City, Fort Apache, Turkey Creek, Fort Apache 
  Reservation and East Fork.

This includes the following highways...
	State Route 73 between mile markers 325 and 334...and
	between mile markers 336 and 345.

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.

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 3377 11018 3384 11016 3385 11014 3393 10991
      3380 10990

FLASH FLOOD...RADAR INDICATED

$$

DB
1 follow-up statement
833 
WGUS75 KFGZ 020153
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
653 PM MST Sun Aug 1 2021

AZC007-017-020203-
/O.EXP.KFGZ.FF.W.0138.000000T0000Z-210802T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Navajo AZ-
653 PM MST Sun Aug 1 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 7 PM MST THIS EVENING FOR GILA 
AND NAVAJO COUNTIES...

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

LAT...LON 3377 11018 3384 11016 3385 11014 3393 10991
      3380 10990

$$

DB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 5:22 PM MSTAreal Flood AdvisoryFGZYavapai113 min
Jul 31, 6:08 PM MSTAreal Flood AdvisoryFGZApache, Navajo3 hr
Aug 1, 12:03 PM MSTSpecial Weather StatementFGZ27 min
Aug 1, 12:15 PM MSTSpecial Weather StatementFGZ30 min
Aug 1, 12:53 PM MSTSpecial Weather StatementFGZCoconino22 min
Aug 1, 1:08 PM MSTSpecial Weather StatementFGZ22 min
Aug 1, 1:14 PM MSTSpecial Weather StatementFGZ31 min
Aug 1, 1:30 PM MSTSpecial Weather StatementFGZNavajo30 min
Aug 1, 1:38 PM MSTSpecial Weather StatementFGZCoconino22 min
Aug 1, 1:53 PM MSTSpecial Weather StatementFGZ37 min
Aug 1, 2:03 PM MSTSpecial Weather StatementFGZNavajo27 min
Aug 1, 2:26 PM MSTSpecial Weather StatementFGZNavajo34 min
Aug 1, 2:55 PM MSTSpecial Weather StatementFGZ35 min
Aug 1, 3:12 PM MSTSpecial Weather StatementFGZ33 min
Aug 1, 3:15 PM MSTSpecial Weather StatementFGZ30 min
Aug 1, 3:21 PM MSTSpecial Weather StatementFGZ24 min
Aug 1, 4:18 PM MSTAreal Flood AdvisoryFGZCoconino3 hr
Aug 1, 4:24 PM MSTSpecial Weather StatementFGZ51 min
Aug 1, 4:38 PM MSTSevere Thunderstorm WarningFGZApache, Navajo37 min
Aug 1, 4:51 PM MSTFlash Flood WarningFGZGila, Navajo3 hr
Aug 1, 4:52 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Coconino, Navajo3 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.