Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 92, NWS Tucson, AZ

August 6, 2021Pima County, Pinal County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 6, 2021, 6:23 PM MST for Pima County, Pinal County, Arizona. It was in force for 4 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, 6:23 PM MST (01:23 UTC)
Expired
Aug 6, 2021, 10:20 PM MST
In force
4 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 Phoenix radar (KIWA), 105 km from the middle of the area, began a volume at 01:22 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, 1.4 hours before the alert went out and 113 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 00:00Z on 2021-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1326 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 00:00Z on 2021-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 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
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.

129 
WGUS55 KTWC 070123
FFWTWC
AZC019-021-070430-
/O.NEW.KTWC.FF.W.0092.210807T0123Z-210807T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  North Central Pima County in southeastern Arizona...
  Southwestern Pinal County in southeastern Arizona...

* Until 930 PM MST.

* At 623 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2.5 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...
  Santa Rosa, Covered Wells, Anegam, North Komelik, Palo Verde 
  Stand, Ventana, Ak Chin, San Luis and Santa Rosa School.

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 3256 11200 3255 11183 3212 11201 3217 11236
      3249 11224

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

$$

GZ
3 follow-up statements
001 
WGUS75 KTWC 070239
FFSTWC

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

AZC019-021-070430-
/O.CON.KTWC.FF.W.0092.000000T0000Z-210807T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-Pinal AZ-
739 PM MST Fri Aug 6 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM MST THIS 
EVENING FOR NORTH CENTRAL PIMA AND SOUTHWESTERN PINAL COUNTIES...

At 739 PM MST, Doppler radar indicated that thunderstorms had 
produced very heavy rainfall, with a large area of Doppler 
precipitation estimates between 3 and 4 inches occurring within the 
warning area.

HAZARD...Flash flooding caused by thunderstorms and heavy rain.

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...
  Santa Rosa, Covered Wells, Anegam, North Komelik, Palo Verde 
  Stand, Ventana, Ak Chin, San Luis and Santa Rosa School.

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 3256 11200 3255 11183 3212 11201 3217 11236
      3249 11224

FLASH FLOOD...RADAR INDICATED

$$

GZ
234 
WGUS55 KTWC 070405
FFWTWC
AZC019-021-070530-
/O.EXT.KTWC.FF.W.0092.000000T0000Z-210807T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has extended the

* Flash Flood Warning for...
  North Central Pima County in southeastern Arizona...
  Southwestern Pinal County in southeastern Arizona...

* Until 1030 PM MST.

* At 905 PM MST, Doppler radar indicated that thunderstorms had 
  produced very heavy rainfall earlier, with a large area of Doppler 
  precipitation estimates between 3 and 4 inches occurring within 
  the warning area. Therefore, the Flash Flood Warning has been 
  extended another hour.

  HAZARD...Flash flooding caused by thunderstorms and heavy
           rainfall.

  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...
  Santa Rosa, Covered Wells, Anegam, North Komelik, Palo Verde 
  Stand, Ventana, Ak Chin, San Luis and Santa Rosa School.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 3256 11200 3255 11183 3212 11201 3217 11236
      3249 11224

FLASH FLOOD...RADAR INDICATED

$$

GZ
280 
WGUS75 KTWC 070520
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1020 PM MST Fri Aug 6 2021

AZC019-021-070530-
/O.CAN.KTWC.FF.W.0092.000000T0000Z-210807T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-Pinal AZ-
1020 PM MST Fri Aug 6 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH CENTRAL PIMA AND 
SOUTHWESTERN PINAL COUNTIES...

The heavy rain has ended and the flow from the initial runoff is 
diminishing across northern portions of the Tohono O'Odham Nation. 
Elevated flow will continue in some area washes, so please continue 
to heed remaining road closures.

LAT...LON 3256 11200 3255 11183 3212 11201 3217 11236
      3249 11224

$$

WJM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 5:01 PM MSTSevere Thunderstorm WarningTWCPima44 min
Aug 6, 5:02 PM MSTSpecial Weather StatementTWCPima43 min
Aug 6, 5:14 PM MSTSpecial Weather StatementTWCGreenlee46 min
Aug 6, 5:18 PM MSTSevere Thunderstorm WarningTWCPima42 min
Aug 6, 5:27 PM MSTAreal Flood AdvisoryTWCPima2 hr
Aug 6, 5:28 PM MSTAreal Flood AdvisoryTWCPima2 hr
Aug 6, 5:29 PM MSTSevere Thunderstorm WarningTWCPima, Pinal46 min
Aug 6, 5:40 PM MSTAreal Flood AdvisoryTWCPima3 hr
Aug 6, 5:50 PM MSTSpecial Weather StatementTWCGraham25 min
Aug 6, 6:00 PM MSTFlash Flood Warning Considerable damage threatTWCPima3 hr
Aug 6, 6:02 PM MSTSevere Thunderstorm WarningTWCPima, Pinal58 min
Aug 6, 6:19 PM MSTTornado WarningTWCPima26 min
Aug 6, 7:02 PM MSTSpecial Weather StatementTWC43 min
Aug 6, 9:25 PM MSTAreal Flood WarningTWCPima3 hr
Aug 7, 12:54 PM MSTSevere Thunderstorm WarningTWCCochise51 min
Aug 7, 1:41 PM MSTSevere Thunderstorm WarningTWCCochise49 min
Aug 7, 2:47 PM MSTSpecial Weather StatementTWCCochise28 min
Aug 7, 2:55 PM MSTSevere Thunderstorm WarningTWCCochise34 min
Aug 7, 3:09 PM MSTAreal Flood AdvisoryTWCCochise111 min
Aug 7, 3:17 PM MSTSevere Thunderstorm WarningTWCCochise43 min
Aug 7, 3:25 PM MSTSpecial Weather StatementTWCGreenlee50 min
Aug 7, 3:53 PM MSTSpecial Weather StatementTWC52 min
Aug 7, 4:51 PM MSTSpecial Weather StatementTWCPima39 min
Aug 7, 4:57 PM MSTSpecial Weather StatementTWCCochise48 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.