Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 91, NWS Tucson, AZ

August 6, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 6, 2021, 6:00 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 6, 2021, 6:00 PM MST (01:00 UTC)
Expired: Aug 6, 2021, 9:00 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 Tucson radar (KEMX), 14 km from the middle of the area, began a volume at 01:02 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 00:00Z, 1.0 hours before the alert went out and 30 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: 1326 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 2589 m above ground
0-6 km bulk shear: 2 kt
0-1 km storm-relative helicity: -28 m²/s²
0-3 km storm-relative helicity: -6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

699 
WGUS55 KTWC 070100
FFWTWC
AZC019-070400-
/O.NEW.KTWC.FF.W.0091.210807T0100Z-210807T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
600 PM MST Fri Aug 6 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  East Central Pima County in southeastern Arizona...

* Until 900 PM MST.

* At 600 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...
  Vail.

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 3210 11068 3209 11060 3202 11057 3191 11062
      3190 11070

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

$$

GZ

2 follow-up statements

258 
WGUS75 KTWC 070206
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
706 PM MST Fri Aug 6 2021

AZC019-070400-
/O.CON.KTWC.FF.W.0091.000000T0000Z-210807T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
706 PM MST Fri Aug 6 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM MST THIS EVENING 
FOR EAST CENTRAL PIMA COUNTY...

At 706 PM MST, Doppler radar indicated that thunderstorms earlier 
had produced heavy rainfall, with between 1 and 2 inches of rain 
occurring in the warning area.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Vail.

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 3210 11068 3209 11060 3202 11057 3191 11062
      3190 11070

FLASH FLOOD...RADAR INDICATED

$$

GZ

541 
WGUS75 KTWC 070400
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
900 PM MST Fri Aug 6 2021

AZC019-070410-
/O.EXP.KTWC.FF.W.0091.000000T0000Z-210807T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
900 PM MST Fri Aug 6 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR EAST CENTRAL PIMA COUNTY...

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

LAT...LON 3210 11068 3209 11060 3202 11057 3191 11062
      3190 11070

$$

GZ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 5:01 PM MST	Severe Thunderstorm Warning	TWC	Pima	44 min
Aug 6, 5:02 PM MST	Special Weather Statement	TWC	Pima	43 min
Aug 6, 5:14 PM MST	Special Weather Statement	TWC	Greenlee	46 min
Aug 6, 5:18 PM MST	Severe Thunderstorm Warning	TWC	Pima	42 min
Aug 6, 5:27 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Aug 6, 5:28 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Aug 6, 5:29 PM MST	Severe Thunderstorm Warning	TWC	Pima, Pinal	46 min
Aug 6, 5:40 PM MST	Areal Flood Advisory	TWC	Pima	3 hr
Aug 6, 5:50 PM MST	Special Weather Statement	TWC	Graham	25 min
Aug 6, 6:02 PM MST	Severe Thunderstorm Warning	TWC	Pima, Pinal	58 min
Aug 6, 6:19 PM MST	Tornado Warning	TWC	Pima	26 min
Aug 6, 6:23 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima, Pinal	4 hr
Aug 6, 7:02 PM MST	Special Weather Statement	TWC		43 min
Aug 6, 9:25 PM MST	Areal Flood Warning	TWC	Pima	3 hr
Aug 7, 12:54 PM MST	Severe Thunderstorm Warning	TWC	Cochise	51 min
Aug 7, 1:41 PM MST	Severe Thunderstorm Warning	TWC	Cochise	49 min
Aug 7, 2:47 PM MST	Special Weather Statement	TWC	Cochise	28 min
Aug 7, 2:55 PM MST	Severe Thunderstorm Warning	TWC	Cochise	34 min
Aug 7, 3:09 PM MST	Areal Flood Advisory	TWC	Cochise	111 min
Aug 7, 3:17 PM MST	Severe Thunderstorm Warning	TWC	Cochise	43 min
Aug 7, 3:25 PM MST	Special Weather Statement	TWC	Greenlee	50 min
Aug 7, 3:53 PM MST	Special Weather Statement	TWC		52 min
Aug 7, 4:51 PM MST	Special Weather Statement	TWC	Pima	39 min
Aug 7, 4:57 PM MST	Special Weather Statement	TWC	Cochise	48 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.