Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 72, NWS Tucson, AZ

July 27, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 27, 2021, 3:49 PM MST for Pima 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 27, 2021, 3:49 PM MST (22:49 UTC)
Expired: Jul 27, 2021, 6:45 PM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 53 km from the middle of the area, began a volume at 22:52 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, 10.8 hours before the alert went out and 22 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: 487 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1850 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -20 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

249 
WGUS55 KTWC 272249
FFWTWC
AZC019-280145-
/O.NEW.KTWC.FF.W.0072.210727T2249Z-210728T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
349 PM MST Tue Jul 27 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Northeastern Pima County in southeastern Arizona...

* Until 645 PM MST.

* At 349 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the Upper Sabino watershed, which will produce 
  elevated flows down Sabino Creek. 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...
  Sabino Canyon Recreation Area and Seven Falls.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3238 11080 3233 11082 3232 11078 3234 11076

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

$$

RH

1 follow-up statement

248 
WGUS75 KTWC 280140
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
640 PM MST Tue Jul 27 2021

AZC019-280150-
/O.EXP.KTWC.FF.W.0072.000000T0000Z-210728T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
640 PM MST Tue Jul 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM MST THIS EVENING FOR 
NORTHEASTERN PIMA COUNTY...

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

LAT...LON 3238 11080 3233 11082 3232 11078 3234 11076

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 1:52 PM MST	Flash Flood Warning Considerable damage threat	TWC	Santa Cruz	2 hr
Jul 27, 1:56 PM MST	Special Weather Statement	TWC	Santa Cruz	49 min
Jul 27, 2:15 PM MST	Special Weather Statement	TWC	Santa Cruz	45 min
Jul 27, 2:33 PM MST	Areal Flood Advisory	TWC	Cochise, Pima, Santa Cruz	3 hr
Jul 27, 3:29 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 27, 3:35 PM MST	Special Weather Statement	TWC	Santa Cruz	40 min
Jul 27, 4:00 PM MST	Special Weather Statement	TWC		45 min
Jul 27, 4:05 PM MST	Areal Flood Advisory	TWC	Pima	115 min
Jul 27, 4:25 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 27, 4:34 PM MST	Blowing Dust Advisory	TWC	Pima, Pinal	87 min
Jul 27, 4:42 PM MST	Flash Flood Warning	TWC	Pima	3 hr
Jul 27, 4:56 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	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.