Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 169, NWS Tucson, AZ

September 5, 2021Pinal County, Arizona

NWS Tucson, AZ issued this flash flood warning at Sep 5, 2021, 5:41 PM MST for Pinal County, Arizona. It was in force for 2 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: Sep 5, 2021, 5:41 PM MST (00:41 UTC)
Expired: Sep 5, 2021, 7:45 PM MST
In force: 2 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Pinal County, AZ

The radar

The Phoenix radar (KIWA), 89 km from the middle of the area, began a volume at 00:43 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, 0.7 hours before the alert went out and 121 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: 48 J/kg
Mixed-layer CIN: -147 J/kg
Mixed-layer LCL: 3562 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 36 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

582 
WGUS55 KTWC 060041
FFWTWC
AZC021-060245-
/O.NEW.KTWC.FF.W.0169.210906T0041Z-210906T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
541 PM MST Sun Sep 5 2021

The National Weather Service in Tucson has issued a

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

* Until 745 PM MST.

* At 541 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.7 and 1.2 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  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...
  Kearny and Dudleyville.

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.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

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 3309 11067 3289 11066 3285 11077 3306 11103
      3311 11095 3310 11086 3298 11078 3299 11077
      3300 11076 3302 11073 3304 11073 3304 11072
      3307 11073 3308 11072 3308 11070 3308 11069
      3309 11069

FLASH FLOOD...RADAR INDICATED

$$

GZ

2 follow-up statements

170 
WGUS75 KTWC 060119
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
619 PM MST Sun Sep 5 2021

AZC021-060245-
/O.CON.KTWC.FF.W.0169.000000T0000Z-210906T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pinal AZ-
619 PM MST Sun Sep 5 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MST THIS 
EVENING FOR NORTHEASTERN PINAL COUNTY...

At 619 PM MST, Doppler radar indicated that thunderstorms earlier 
had produced heavy rainfall, with between 0.7 and 1.5 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...
  Kearny and Dudleyville.

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.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

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 3309 11067 3289 11066 3285 11077 3306 11103
      3311 11095 3310 11086 3298 11078 3299 11077
      3300 11076 3302 11073 3304 11073 3304 11072
      3307 11073 3308 11072 3308 11070 3308 11069
      3309 11069

FLASH FLOOD...RADAR INDICATED

$$

GZ

390 
WGUS75 KTWC 060245
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
745 PM MST Sun Sep 5 2021

AZC021-060255-
/O.EXP.KTWC.FF.W.0169.000000T0000Z-210906T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pinal AZ-
745 PM MST Sun Sep 5 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHEASTERN PINAL 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 3309 11067 3289 11066 3285 11077 3306 11103
      3311 11095 3310 11086 3298 11078 3299 11077
      3300 11076 3302 11073 3304 11073 3304 11072
      3307 11073 3308 11072 3308 11070 3308 11069
      3309 11069

$$

GZ

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 5, 5:01 PM MST	Severe Thunderstorm Warning	TWC	Graham, Pinal	59 min
Sep 5, 5:09 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	111 min
Sep 5, 5:18 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Graham, Pima	42 min
Sep 5, 5:37 PM MST	Dust Storm Advisory	TWC	Pima, Pinal	95 min
Sep 5, 5:58 PM MST	Severe Thunderstorm Warning	TWC	Pima, Pinal	47 min
Sep 5, 6:02 PM MST	Special Weather Statement	TWC		43 min
Sep 5, 6:39 PM MST	Areal Flood Advisory	TWC	Pima, Pinal	2 hr
Sep 5, 7:05 PM MST	Special Weather Statement	TWC	Pima	40 min
Sep 5, 10:09 PM MST	Areal Flood Advisory	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.