Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 76, NWS Tucson, AZ

July 27, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 27, 2021, 5:10 PM MST for Pima County, Arizona. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 27, 2021, 5:10 PM MST (00:10 UTC)
Expired: Jul 27, 2021, 8:15 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), 47 km from the middle of the area, began a volume at 00:14 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.

What was reported inside it

Time	Report	Where	Remark
Jul 27, 5:10 PM MST	FLASH FLOOD	9 Ssw Summerhaven, AZ	PIMA COUNTY SEARCH AND RESCUE CONDUCTED A RESCUE OF SEVERAL GROUPS OF HIKERS FROM SABINO RECREATION AREA OF THE CORONADO NATIONAL FOREST AFTER BEING STRANDED FROM RISING FLOOD WATERS (SABINO CREEK). 2 GROUPS (6 PEOPLE TOTAL) WERE RESCUED IN THE AREA OF SEVEN F

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 0.2 hours before the alert went out and 16 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: 232 J/kg
Mixed-layer CIN: -212 J/kg
Mixed-layer LCL: 1647 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -100 m²/s²
0-3 km storm-relative helicity: -66 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

283 
WGUS55 KTWC 280010
FFWTWC
AZC019-280315-
/O.NEW.KTWC.FF.W.0076.210728T0010Z-210728T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

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

* Until 815 PM MST.

* At 510 PM MST, streamflow gage reports indicated water from 
  earlier thunderstorms atop Mt. Lemmon is currently moving down 
  Sabino Creek. Flash flooding is ongoing or expected to begin 
  shortly. Avoid low water crossings.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Gages reported.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Tucson, Tanque Verde, Sabino Canyon Recreation Area and Catalina 
  Foothills.

Sabino Creek

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 3233 11082 3229 11081 3227 11081 3226 11083
      3225 11082 3227 11080 3229 11080 3232 11078

FLASH FLOOD...GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

RH

1 follow-up statement

599 
WGUS75 KTWC 280312
FFSTWC

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

AZC019-280322-
/O.EXP.KTWC.FF.W.0076.000000T0000Z-210728T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
812 PM MST Tue Jul 27 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 815 PM MST THIS EVENING FOR 
EASTERN PIMA COUNTY...

Waters levels continue to recede moving down Sabino Creek. Flooding 
is no longer expected to pose a threat. Please continue to heed 
remaining road closures.

LAT...LON 3233 11082 3229 11081 3227 11081 3226 11083
      3225 11082 3227 11080 3229 11080 3232 11078

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
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
Jul 28, 4:22 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise, Santa Cruz	2 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.