Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 18, NWS Tucson, AZ

July 12, 2021Pima County, Pinal County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 12, 2021, 10:16 PM MST for Pima County, Pinal County, Arizona. It was in force for 3 hr. 6 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
Jul 12, 2021, 10:16 PM MST (05:16 UTC)
Expired
Jul 13, 2021, 1:15 AM MST
In force
3 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 Tucson radar (KEMX), 72 km from the middle of the area, began a volume at 05:17 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
Jul 12, 10:30 PM MSTFLASH FLOOD9 Sw Oro Valley, AZPUBLIC REPORT RECEIVED VIA SOCIAL MEDIA OF ROAD CLOSURE ON ORANGE GROVE ROAD AT INTERSTATE 10 UNDERPASS DUE TO FLOODING. VEHICLE STRANDED IN FLOOD WATERS. DELAYED REPORT. TIME ESTIMATED BY RADAR.
Jul 12, 10:35 PM MSTFLASH FLOOD9 Ssw Oro Valley, AZPUBLIC REPORT RECEIVED VIA SOCIAL MEDIA OF CAMINO DE LA TIERRA SOUTH OF ORANGE GROVE CLOSED DUE TO FLOODING UNDER RIVER RD. DELAYED REPORT. TIME ESTIMATED BY RADAR.
Jul 12, 10:40 PM MSTFLASH FLOOD4 W Tucson, AZPUBLIC REPORT RECEIVED VIA SOCIAL MEDIA OF A SWIFT WATER RESCUE AT THE INTERSECTION OF SILVERLAKE ROAD AND EUCLID AVE. DELAYED REPORT. TIME ESTIMATED BY RADAR.
Jul 12, 10:40 PM MSTFLASH FLOOD5 Wnw Tucson, AZTUCSON DEPARTMENT OF TRANSPORTATION REPORTED ROAD CLOSURE AT THE 6TH AVENUE UNDERPASS JUST NORTH OF TOOLE AVE. DELAYED REPORT. TIME ESTIMATED BY RADAR.
Jul 12, 10:42 PM MSTFLASH FLOOD5 Wnw Tucson, AZPUBLIC REPORT OF VEHICLE STRANDED IN FLOOD WATERS AT MABEL ST AND 7TH AVE. DELAYED REPORT. TIME ESTIMATED BY RADAR.
Jul 12, 10:45 PM MSTFLASH FLOOD5 Nw Tucson, AZBROADCAST MEDIA REPORT RECEIVED OF A SWIFT WATER RESCUE AT THE INTERSECTION OF GRANT RD AND TUCSON BLVD. DELAYED REPORT. TIME ESTIMATED BY RADAR.

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, 5.3 hours before the alert went out and 32 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 2021-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1102 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 2021-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
1102 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
2775 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

749 
WGUS55 KTWC 130516
FFWTWC
AZC019-021-130815-
/O.NEW.KTWC.FF.W.0018.210713T0516Z-210713T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
1016 PM MST Mon Jul 12 2021

The National Weather Service in Tucson has issued a

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

* Until 115 AM MST.

* At 1016 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...
  Tucson, Oro Valley, Marana, Davis-Monthan Air Force Base, Casas 
  Adobes, Drexel Heights, Flowing Wells, Tanque Verde, South Tucson, 
  Avra Valley, Tortolita, Saguaro National Park West, Catalina 
  Foothills, Tucson International Airport, Picture Rocks and Dove 
  Mountain.

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.

&&

LAT...LON 3261 11120 3240 11099 3226 11075 3211 11093
      3247 11146

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

$$

RH
2 follow-up statements
896 
WGUS75 KTWC 130650
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1150 PM MST Mon Jul 12 2021

AZC019-021-130815-
/O.CON.KTWC.FF.W.0018.000000T0000Z-210713T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-Pinal AZ-
1150 PM MST Mon Jul 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 AM MST TUESDAY 
FOR NORTHEASTERN PIMA AND SOUTH CENTRAL PINAL COUNTIES...

At 1150 PM MST, Doppler radar indicated that the thunderstorms that 
produced the heavy rainfall had moved southwest out of the warning 
area. Between 1 and 2 inches of rain had occurred in the warning 
area. Additional rainfall amounts of 0.1 to 0.2 inches are possible. 
Flash flooding is ongoing with flooded washes and some roads are 
impassible.

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...
  Tucson, Oro Valley, Marana, Davis-Monthan Air Force Base, Casas 
  Adobes, Drexel Heights, Flowing Wells, Tanque Verde, South Tucson, 
  Avra Valley, Tortolita, Saguaro National Park West, Catalina 
  Foothills, Tucson International Airport, Picture Rocks and Dove 
  Mountain.

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.

&&

LAT...LON 3261 11120 3240 11099 3226 11075 3211 11093
      3247 11146

FLASH FLOOD...RADAR INDICATED

$$

GZ
469 
WGUS75 KTWC 130813
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
113 AM MST Tue Jul 13 2021

AZC019-021-130823-
/O.EXP.KTWC.FF.W.0018.000000T0000Z-210713T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-Pinal AZ-
113 AM MST Tue Jul 13 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 115 AM MST EARLY THIS MORNING 
FOR NORTHEASTERN PIMA AND SOUTH CENTRAL PINAL COUNTIES...

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

LAT...LON 3261 11120 3240 11099 3226 11075 3211 11093
      3247 11146

$$

GZ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 6:29 PM MSTSpecial Weather StatementTWCGraham31 min
Jul 12, 6:39 PM MSTSpecial Weather StatementTWCGraham36 min
Jul 12, 7:09 PM MSTSevere Thunderstorm WarningTWCCochise, Pima36 min
Jul 12, 7:28 PM MSTSevere Thunderstorm WarningTWCGraham, Pinal47 min
Jul 12, 7:45 PM MSTSevere Thunderstorm WarningTWCCochise, Pima, Santa Cruz45 min
Jul 12, 7:49 PM MSTSevere Thunderstorm WarningTWCCochise, Pima41 min
Jul 12, 7:50 PM MSTSpecial Weather StatementTWC40 min
Jul 12, 8:05 PM MSTAreal Flood AdvisoryTWCGraham3 hr
Jul 12, 8:22 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz38 min
Jul 12, 8:37 PM MSTSevere Thunderstorm WarningTWCPinal38 min
Jul 12, 8:37 PM MSTTornado WarningTWCSanta Cruz23 min
Jul 12, 8:51 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz39 min
Jul 12, 9:11 PM MSTSpecial Weather StatementTWC34 min
Jul 12, 9:14 PM MSTSpecial Weather StatementTWCPinal31 min
Jul 12, 9:22 PM MSTSevere Thunderstorm WarningTWCCochise, Pima38 min
Jul 12, 9:30 PM MSTDust Storm WarningTWCPima, Pinal60 min
Jul 12, 9:32 PM MSTSpecial Weather StatementTWCSanta Cruz43 min
Jul 12, 9:54 PM MSTAreal Flood AdvisoryTWCCochise, Pima3 hr
Jul 12, 9:58 PM MSTSpecial Weather StatementTWC47 min
Jul 12, 10:24 PM MSTFlash Flood Warning Considerable damage threatTWCPima3 hr
Jul 12, 10:33 PM MSTFlash Flood Warning Considerable damage threatTWCPima3 hr
Jul 12, 10:34 PM MSTSpecial Weather StatementTWCSanta Cruz56 min
Jul 12, 11:17 PM MSTSpecial Weather StatementTWCPima28 min
Jul 13, 2:02 PM MSTSpecial Weather StatementTWCCochise43 min
Jul 13, 2:57 PM MSTSpecial Weather StatementTWCSanta Cruz33 min
Jul 13, 3:02 PM MSTSevere Thunderstorm WarningTWCCochise, Pima, Santa Cruz43 min
Jul 13, 3:21 PM MSTAreal Flood AdvisoryTWCPima, Santa Cruz2 hr
Jul 13, 3:45 PM MSTSpecial Weather StatementTWCSanta Cruz45 min
Jul 13, 4:15 PM MSTSpecial Weather StatementTWCSanta Cruz45 min
Jul 13, 4:20 PM MSTSpecial Weather StatementTWC25 min
Jul 13, 4:38 PM MSTAreal Flood AdvisoryTWCPima, Pinal3 hr
Jul 13, 4:44 PM MSTSpecial Weather StatementTWCCochise46 min
Jul 13, 4:45 PM MSTSpecial Weather StatementTWC30 min
Jul 13, 4:58 PM MSTSevere Thunderstorm WarningTWCPinal32 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.