Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 109, NWS Tucson, AZ

August 10, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 10, 2021, 6:49 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: Aug 10, 2021, 6:49 PM MST (01:49 UTC)
Expired: Aug 10, 2021, 10:00 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 Phoenix radar (KIWA), 144 km from the middle of the area, began a volume at 01:52 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

Phoenix, AZ (KPSR), launched 00:00Z, 1.8 hours before the alert went out and 137 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: 934 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 1571 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

402 
WGUS55 KTWC 110149
FFWTWC
AZC019-110500-
/O.NEW.KTWC.FF.W.0109.210811T0149Z-210811T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

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

* Until 1000 PM MST.

* At 649 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...
  Ajo.

This includes the following streams and drainages...
  Rio Cornez Wash, Gibson Arroyo, Tenmile Wash and Sikort Chuapo 
  Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3240 11272 3234 11278 3237 11285 3240 11288
      3251 11289 3251 11285 3248 11284

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

$$

KRG

2 follow-up statements

675 
WGUS75 KTWC 110242
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
742 PM MST Tue Aug 10 2021

AZC019-110500-
/O.CON.KTWC.FF.W.0109.000000T0000Z-210811T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
742 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 10 PM MST THIS 
EVENING FOR NORTHWESTERN PIMA COUNTY...

At 742 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 3 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...
  Ajo and Highway 85 north of Ajo.

This includes the following streams and drainages...
  Rio Cornez Wash, Gibson Arroyo, Tenmile Wash and Sikort Chuapo 
  Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3240 11272 3234 11278 3237 11285 3240 11288
      3251 11289 3251 11285 3248 11284

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

$$

KRG

284 
WGUS75 KTWC 110453
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
953 PM MST Tue Aug 10 2021

AZC019-110503-
/O.EXP.KTWC.FF.W.0109.000000T0000Z-210811T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
953 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 10 PM MST THIS EVENING FOR 
NORTHWESTERN 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 3240 11272 3234 11278 3237 11285 3240 11288
      3251 11289 3251 11285 3248 11284

$$

KRG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 5:03 PM MST	Severe Thunderstorm Warning	TWC	Pima, Santa Cruz	27 min
Aug 10, 6:15 PM MST	Areal Flood Advisory	TWC	Pima	20 min
Aug 10, 6:19 PM MST	Severe Thunderstorm Warning	TWC	Pima	26 min
Aug 10, 6:32 PM MST	Special Weather Statement	TWC		28 min
Aug 10, 6:35 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 10, 6:41 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	4 hr
Aug 10, 7:07 PM MST	Special Weather Statement	TWC	Pima	38 min
Aug 10, 7:43 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 10, 7:50 PM MST	Areal Flood Advisory	TWC	Pima	3 hr
Aug 10, 8:27 PM MST	Special Weather Statement	TWC		33 min
Aug 10, 8:31 PM MST	Special Weather Statement	TWC	Pinal	29 min
Aug 10, 9:41 PM MST	Areal Flood Warning	TWC	Pima	6 hr
Aug 10, 10:06 PM MST	Areal Flood Advisory	TWC	Pima	23 min
Aug 10, 10:29 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	2 hr
Aug 10, 11:35 PM MST	Flash Flood Warning	TWC	Pima	55 min
Aug 11, 12:21 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	4 hr
Aug 11, 12:54 AM MST	Areal Flood Advisory	TWC	Pinal	111 min
Aug 11, 2:04 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 11, 3:24 AM MST	Areal Flood Warning	TWC	Pima	6 hr
Aug 11, 4:13 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	4 hr
Aug 11, 4:55 AM MST	Areal Flood Advisory	TWC	Pima	3 hr
Aug 11, 8:14 AM MST	Areal Flood Warning	TWC	Pima, Pinal	6 hr
Aug 11, 1:41 PM MST	Areal Flood Advisory	TWC	Cochise, Santa Cruz	2 hr
Aug 11, 2:12 PM MST	Areal Flood Advisory	TWC	Santa Cruz	45 min
Aug 11, 2:24 PM MST	Special Weather Statement	TWC	Santa Cruz	21 min
Aug 11, 2:57 PM MST	Flash Flood Warning Considerable damage threat	TWC	Santa Cruz	2 hr
Aug 11, 3:00 PM MST	Severe Thunderstorm Warning	TWC	Cochise	31 min
Aug 11, 3:17 PM MST	Areal Flood Advisory	TWC	Cochise	11 min
Aug 11, 3:28 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise	3 hr
Aug 11, 3:56 PM MST	Special Weather Statement	TWC		34 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.