Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 84, NWS Tucson, AZ

August 1, 2021Graham County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 1, 2021, 6:03 PM MST for Graham 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, 6:03 PM MST (01:03 UTC)
Expired: Aug 1, 2021, 9:15 PM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Graham County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 1.1 hours before the alert went out and 145 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: 972 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 2391 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -27 m²/s²
0-3 km storm-relative helicity: 19 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

479 
WGUS55 KTWC 020103
FFWTWC
AZC009-020415-
/O.NEW.KTWC.FF.W.0084.210802T0103Z-210802T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  The Valley burn scar in...
  Western Graham County in southeastern Arizona...

* Until 915 PM MST.

* At 603 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Valley Burn Scar. Flash flooding is ongoing or 
  expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through Hackberry Creek. The debris flow can consist of rock, 
mud, vegetation and other loose materials.

  HAZARD...Flash flooding caused by thunderstorms in and around
           the Valley Burn Scar.

  SOURCE...Radar.

  IMPACT...Flooding of areas in and around the Valley Burn Scar.

* Some locations that will experience flash flooding include...
  mainly rural areas of Western Graham County

This includes the following streams and drainages...
  Salt Creek, Triplet Wash and Hackberry Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of 
creeks, roads and normally dry washes is likely. The heavy rains 
will likely trigger rockslides, mudslides and debris flows in steep 
terrain, especially in and around these areas.

&&

LAT...LON 3341 11020 3332 11043 3337 11045 3337 11044
      3338 11044 3339 11043 3339 11042 3340 11041
      3340 11039 3341 11038 3340 11038 3340 11037
      3340 11036 3341 11035 3342 11035 3342 11034
      3343 11034

FLASH FLOOD...RADAR INDICATED

$$

WJM

1 follow-up statement

564 
WGUS75 KTWC 020410
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
910 PM MST Sun Aug 1 2021

AZC009-020420-
/O.EXP.KTWC.FF.W.0084.000000T0000Z-210802T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham AZ-
910 PM MST Sun Aug 1 2021

...FLASH FLOOD WARNING FOR THE VALLEY BURN SCAR WILL EXPIRE AT 915 
PM MST THIS EVENING FOR WESTERN GRAHAM COUNTY...

No additional rainfall has been noted over the burn scar area in the 
past 90 minutes. However heavy flow will continue in some streams 
and washes into the early morning hours. Please continue to heed 
remaining road closures.

LAT...LON 3341 11020 3332 11043 3337 11045 3337 11044
      3338 11044 3339 11043 3339 11042 3340 11041
      3340 11039 3341 11038 3340 11038 3340 11037
      3340 11036 3341 11035 3342 11035 3342 11034
      3343 11034

$$

WJM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 5:23 PM MST	Special Weather Statement	TWC		52 min
Aug 1, 6:35 PM MST	Areal Flood Advisory	TWC	Graham	3 hr
Aug 1, 6:44 PM MST	Special Weather Statement	TWC		31 min
Aug 1, 8:28 PM MST	Special Weather Statement	TWC	Cochise	47 min
Aug 1, 8:40 PM MST	Areal Flood Advisory	TWC	Cochise	2 hr
Aug 2, 12:43 PM MST	Special Weather Statement	TWC	Greenlee	47 min
Aug 2, 1:27 PM MST	Special Weather Statement	TWC	Greenlee	48 min
Aug 2, 2:26 PM MST	Excessive Heat Warning	TWC	Graham, Greenlee, Pima, Pinal	54 hr
Aug 2, 2:43 PM MST	Special Weather Statement	TWC	Cochise	47 min
Aug 2, 2:50 PM MST	Severe Thunderstorm Warning	TWC	Cochise	40 min
Aug 2, 2:51 PM MST	Areal Flood Advisory	TWC	Cochise	114 min
Aug 2, 3:20 PM MST	Areal Flood Advisory	TWC	Santa Cruz	115 min
Aug 2, 4:04 PM MST	Special Weather Statement	TWC	Graham	56 min
Aug 2, 4:22 PM MST	Areal Flood Advisory	TWC	Cochise	113 min
Aug 2, 4:47 PM MST	Special Weather Statement	TWC		43 min

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.