Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 77, NWS Tucson, AZ

July 28, 2021Cochise County, Santa Cruz County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 28, 2021, 4:22 PM MST for Cochise County, Santa Cruz County, Arizona. It was in force for 2 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 28, 2021, 4:22 PM MST (23:22 UTC)
Expired: Jul 28, 2021, 6:22 PM MST
In force: 2 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Cochise County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 39 km from the middle of the area, began a volume at 23:24 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

Tuscon, AZ (KTUS), launched 12:00Z, 11.4 hours before the alert went out and 79 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: 135 J/kg
Mixed-layer CIN: -424 J/kg
Mixed-layer LCL: 1855 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -23 m²/s²
0-3 km storm-relative helicity: 41 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

697 
WGUS55 KTWC 282322
FFWTWC
AZC003-023-290230-
/O.NEW.KTWC.FF.W.0077.210728T2322Z-210729T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
422 PM MST Wed Jul 28 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Southwestern Cochise County in southeastern Arizona...
  Eastern Santa Cruz County in southeastern Arizona...

* Until 730 PM MST.

* At 422 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. 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 creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Sierra Vista, Whetstone, Huachuca City and Fort Huachuca.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Remain alert for flooding even in locations not receiving rain. 
Washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

&&

LAT...LON 3162 11045 3161 11048 3170 11049 3175 11033
      3167 11024 3152 11017 3150 11029 3164 11036

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

$$

RH

1 follow-up statement

907 
WGUS75 KTWC 290122
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
622 PM MST Wed Jul 28 2021

AZC003-023-290132-
/O.CAN.KTWC.FF.W.0077.000000T0000Z-210729T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-Santa Cruz AZ-
622 PM MST Wed Jul 28 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN COCHISE AND 
EASTERN SANTA CRUZ COUNTIES...

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

LAT...LON 3162 11045 3161 11048 3170 11049 3175 11033
      3167 11024 3152 11017 3150 11029 3164 11036

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 5:10 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 27, 5:47 PM MST	Areal Flood Advisory	TWC	Pima	3 hr
Jul 28, 3:29 PM MST	Special Weather Statement	TWC	Santa Cruz	31 min
Jul 28, 4:05 PM MST	Special Weather Statement	TWC	Santa Cruz	25 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; radar from the NEXRAD Level II archive.