Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 85, NWS Tucson, AZ

August 2, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 2, 2021, 5:58 PM MST for Pima County, Arizona. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 2, 2021, 5:58 PM MST (00:58 UTC)
Expired
Aug 2, 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), 35 km from the middle of the area, began a volume at 01:01 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.

What was reported inside it

TimeReportWhereRemark
Aug 2, 6:27 PM MSTFLASH FLOOD9 Ene Tucson, AZFLOODING AT TANQUE VERDE RD AND N CONESTOGA AVE CAUSED A CAR TO STALL AND BECOME STUCK.
Aug 2, 8:35 PM MSTFLASH FLOOD7 Ene Tucson, AZSWIFT WATER RESCUE OF 3 PEOPLE NEAR TANQUE VERDE WASH AND BONANZA.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 1.0 hours before the alert went out and 19 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 2021-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1093 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 2021-08-03The 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
1093 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
2632 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

932 
WGUS55 KTWC 030058
FFWTWC
AZC019-030400-
/O.NEW.KTWC.FF.W.0085.210803T0058Z-210803T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
558 PM MST Mon Aug 2 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 558 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  0.5 and 1 inch of rain has fallen. The Aqua Caliente rain gauge 
  reported 0.74 inches of rainfall in 15 minutes. Flash flooding is 
  ongoing or expected to begin shortly. This warning replaces the 
  Urban and Small Stream Advisory for the same area.

  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...
  Tucson, Tanque Verde and Saguaro National Park East.

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.

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.

&&

LAT...LON 3231 11075 3226 11065 3217 11064 3211 11061
      3208 11069 3211 11070 3219 11077 3227 11080

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

$$

GZ
1 follow-up statement
291 
WGUS75 KTWC 030205
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
705 PM MST Mon Aug 2 2021

AZC019-030400-
/O.CON.KTWC.FF.W.0085.000000T0000Z-210803T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
705 PM MST Mon Aug 2 2021

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

At 705 PM MST, Doppler radar and automated rain gauges indicated 
that thunderstorms had produced heavy rain, with between 1 and 2 
inches of rainfall occurring in the warning area. The rain gauge at 
Aqua Caliente Wash at Tanque Verde reported 1.14 inches of rainfall, 
with a report of flooding at Tanque Verde Rd and North Conestoga Ave.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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...
  Tucson, Tanque Verde and Saguaro National Park East.

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.



&&

LAT...LON 3231 11075 3226 11065 3217 11064 3211 11061
      3208 11069 3211 11070 3219 11077 3227 11080

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

GZ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 5:15 PM MSTSpecial Weather StatementTWCSanta Cruz30 min
Aug 2, 5:19 PM MSTDust Storm AdvisoryTWCCochise41 min
Aug 2, 5:33 PM MSTSpecial Weather StatementTWC42 min
Aug 2, 5:48 PM MSTSpecial Weather StatementTWC42 min
Aug 2, 5:51 PM MSTAreal Flood AdvisoryTWCPima114 min
Aug 2, 6:24 PM MSTAreal Flood AdvisoryTWCPima2 hr
Aug 2, 6:26 PM MSTAreal Flood AdvisoryTWCCochise, Santa Cruz2 hr
Aug 2, 6:31 PM MSTSpecial Weather StatementTWC59 min
Aug 2, 6:37 PM MSTSevere Thunderstorm WarningTWCPima38 min
Aug 2, 6:55 PM MSTFlash Flood Warning Considerable damage threatTWCPima3 hr
Aug 2, 7:06 PM MSTAreal Flood AdvisoryTWCPinal114 min
Aug 2, 7:06 PM MSTSpecial Weather StatementTWCCochise39 min
Aug 2, 7:15 PM MSTSpecial Weather StatementTWCSanta Cruz45 min
Aug 2, 7:25 PM MSTSpecial Weather StatementTWC50 min
Aug 2, 7:31 PM MSTSevere Thunderstorm WarningTWCPima44 min
Aug 2, 8:13 PM MSTSevere Thunderstorm WarningTWCPima33 min
Aug 2, 8:14 PM MSTFlash Flood Warning Considerable damage threatTWCPima3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.