Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 99, NWS Tucson, AZ

August 10, 2021Pima County, Pinal County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 10, 2021, 6:26 AM MST for Pima County, Pinal County, Arizona. It was in force for 5 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 10, 2021, 6:26 AM MST (13:26 UTC)
Expired
Aug 10, 2021, 11:00 AM MST
In force
5 hr
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Pima County, AZ, Pinal County, AZ

The radar

The Tucson radar (KEMX), 68 km from the middle of the area, began a volume at 13:29 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, 1.4 hours before the alert went out and 35 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, Tuscon, AZ at 12:00Z on 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1176 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, Tuscon, AZ at 12:00Z on 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
1176 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
1330 m above ground
0-6 km bulk shear
1 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

021 
WGUS55 KTWC 101326
FFWTWC
AZC019-021-101630-
/O.NEW.KTWC.FF.W.0099.210810T1326Z-210810T1630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
626 AM MST Tue Aug 10 2021

The National Weather Service in Tucson has issued a

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

* Until 930 AM MST.

* At 626 AM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain near the Catalina Mountains as 
  well as Catalina and Oro Valley. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

Excessive rainfall over the Bighorn burn scar will result in debris 
flow moving through the Sutherland Wash and into the CDO. The debris 
flow can consist of rock, mud, vegetation and other loose materials.

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

  SOURCE...Radar and automated gauges.

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

* Some locations that will experience flash flooding include...
  Catalina, Oro Valley, Saddlebrooke, Mount Lemmon/Summerhaven and 
  Catalina State Park.

This includes the following Flash Flood Prone Locations...
	E Wilds Rd at the Canada del Oro.

This includes the following highways...
	Route 77 between mile markers 80 and 88.

This includes the following streams and drainages...
  Bird Canyon, Big Wash, Sabino Creek, Sutherland Wash, Rillito 
  River, Canada del Oro, Stratton Wash, Chalk Creek, Alder Wash, 
  Chirreon Wash, Gibb Wash and Esperero Wash.

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.

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

&&

LAT...LON 3257 11077 3246 11067 3234 11083 3242 11097
      3251 11094

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

$$

WJM
1 follow-up statement
991 
WGUS55 KTWC 101408
FFWTWC
AZC019-021-101800-
/O.EXT.KTWC.FF.W.0099.000000T0000Z-210810T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
708 AM MST Tue Aug 10 2021

The National Weather Service in Tucson has extended the

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

* Until 1100 AM MST.

* At 708 AM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms still producing very heavy rain in and around the 
  Catalinas. Between 1.5 and 3 inches of rain have fallen. Flash 
  flooding is ongoing.

Excessive rainfall over the Bighorn burn scar will result in debris 
flow moving through the Sutherland Wash and into the CDO. The debris 
flow can consist of rock, mud, vegetation and other loose materials.

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

  SOURCE...Radar and automated gauges.

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

* Some locations that will experience flash flooding include...
  Catalina, Oro Valley, Saddlebrooke, Mount Lemmon/Summerhaven and 
  Catalina State Park.

This includes the following Flash Flood Prone Locations...
	E Wilds Rd at the Canada del Oro.

This includes the following highways...
	Route 77 between mile markers 81 and 88.

This includes the following streams and drainages...
  Bird Canyon, Big Wash, Sabino Creek, Sutherland Wash, Rillito 
  River, Canada del Oro, Stratton Wash, Chalk Creek, Alder Wash, 
  Chirreon Wash, Gibb Wash and Esperero Wash.

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.

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

&&

LAT...LON 3257 11077 3246 11067 3234 11083 3242 11097
      3251 11094

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

$$

WJM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 4:04 AM MSTAreal Flood AdvisoryTWCPima, Pinal3 hr
Aug 10, 4:44 AM MSTSpecial Weather StatementTWC46 min
Aug 10, 5:12 AM MSTFlash Flood WarningTWCPima, Pinal3 hr
Aug 10, 5:39 AM MSTAreal Flood AdvisoryTWCPima, Pinal111 min
Aug 10, 6:49 AM MSTAreal Flood AdvisoryTWCCochise, Graham116 min
Aug 10, 6:55 AM MSTAreal Flood AdvisoryTWCCochise, Pima, Pinal4 hr
Aug 10, 8:27 AM MSTAreal Flood AdvisoryTWCGraham, Greenlee3 hr
Aug 10, 8:32 AM MSTFlash Flood Warning Considerable damage threatTWCGreenlee3 hr
Aug 10, 9:11 AM MSTAreal Flood AdvisoryTWCPima, Santa Cruz3 hr
Aug 10, 10:51 AM MSTAreal Flood WarningTWCPima, Pinal18 hr
Aug 10, 11:00 AM MSTAreal Flood AdvisoryTWCCochise, Pima, Pinal2 hr
Aug 10, 11:09 AM MSTAreal Flood AdvisoryTWCCochise, Graham111 min
Aug 10, 11:41 AM MSTFlash Flood Warning Considerable damage threatTWCCochise3 hr
Aug 10, 12:52 PM MSTSpecial Weather StatementTWCCochise38 min
Aug 10, 12:55 PM MSTSevere Thunderstorm WarningTWCCochise50 min
Aug 10, 1:38 PM MSTSpecial Weather StatementTWCCochise52 min
Aug 10, 1:43 PM MSTAreal Flood AdvisoryTWCCochise3 hr
Aug 10, 1:46 PM MSTAreal Flood AdvisoryTWCCochise119 min
Aug 10, 1:58 PM MSTFlash Flood Warning Considerable damage threatTWCCochise3 hr
Aug 10, 2:00 PM MSTSpecial Weather StatementTWC45 min
Aug 10, 2:08 PM MSTFlash Flood Warning Considerable damage threatTWCCochise2 hr
Aug 10, 2:39 PM MSTFlash Flood Warning Considerable damage threatTWCCochise3 hr
Aug 10, 3:41 PM MSTSpecial Weather StatementTWCSanta Cruz34 min
Aug 10, 4:38 PM MSTSpecial Weather StatementTWCSanta Cruz52 min
Aug 10, 4:39 PM MSTSpecial Weather StatementTWCPima36 min

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.