Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 4, NWS Tucson, AZ

July 2, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 2, 2021, 3:24 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
Jul 2, 2021, 3:24 PM MST (22:24 UTC)
Expired
Jul 2, 2021, 6:30 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), 54 km from the middle of the area, began a volume at 22:27 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 2, 3:50 PM MSTHEAVY RAIN 1.028 Wnw Tucson, AZESTIMATED 1.02 INCH IN 30 MINUTES.
Jul 2, 4:31 PM MSTFLASH FLOOD10 Ne Three Points, AZTWEETER POST OF TUCSON WASH FLOWING WITH 15 INCHES DEEP OVER THE ROAD.

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 12:00Z, 10.4 hours before the alert went out and 14 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 12:00Z on 2021-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 385 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 12:00Z on 2021-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
385 J/kg
Mixed-layer CIN
-127 J/kg
Mixed-layer LCL
1652 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

484 
WGUS55 KTWC 022224
FFWTWC
AZC019-030130-
/O.NEW.KTWC.FF.W.0004.210702T2224Z-210703T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
324 PM MST Fri Jul 2 2021

The National Weather Service in Tucson has issued a

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

* Until 630 PM MST.

* At 324 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 inches of rain have fallen. Additional rainfall amounts of 
  1 to 2 inches are possible in the warned area. Flash flooding is 
  ongoing or expected to begin shortly.

  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, Oro Valley, Marana, Casas Adobes, Drexel Heights, Flowing 
  Wells, South Tucson, Pascua Pueblo Yaqui Reservation, Tucson 
  Estates, Saguaro National Park West, Valencia West, Catalina 
  Foothills and Ryan AirField.

This includes the following Flash Flood Prone Locations...
1st Ave north of Fort Lowell Rd, Stone Ave at Mabel St, Camino De La 
Tierra at the Rillito River, Camino de Oeste Sweetwater Dr Gates 
Pass Rd, Ironwood Hills Dr Shannon Rd Camino de Oeste and Sunset Rd 
west of Camino de Oeste.

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 3236 11089 3236 11098 3232 11108 3229 11113
      3226 11117 3220 11121 3211 11116 3213 11106
      3218 11102 3220 11098 3222 11089 3226 11088
      3228 11094 3232 11093

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

$$

JM
2 follow-up statements
397 
WGUS75 KTWC 022333
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
433 PM MST Fri Jul 2 2021

AZC019-030130-
/O.CON.KTWC.FF.W.0004.000000T0000Z-210703T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
433 PM MST Fri Jul 2 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM MST THIS 
EVENING FOR NORTHEASTERN PIMA COUNTY...

At 433 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 1 
and 3 inches of rain have fallen. Additional rainfall amounts of 0.3 
to 0.6 inches are possible in the warned area. Flash flooding is 
ongoing in portions of the warned 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, Oro Valley, Marana, Casas Adobes, Drexel Heights, Flowing 
  Wells, South Tucson, Pascua Pueblo Yaqui Reservation, Tucson 
  Estates, Saguaro National Park West, Valencia West, Catalina 
  Foothills and Ryan AirField.

This includes the following Flash Flood Prone Locations...
1st Ave north of Fort Lowell Rd, Stone Ave at Mabel St, Camino De La 
Tierra at the Rillito River, Camino de Oeste Sweetwater Dr Gates 
Pass Rd, Ironwood Hills Dr Shannon Rd Camino de Oeste and Sunset Rd 
west of Camino de Oeste.

This includes the following streams and drainages...
  West Branch Santa Cruz River, Arroyo Chico, Canada del Oro, Santa 
  Cruz River, Pantano Wash, Brawley Wash and Rillito River.

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 3236 11089 3236 11098 3232 11108 3229 11113
      3226 11117 3220 11121 3211 11116 3213 11106
      3218 11102 3220 11098 3222 11089 3226 11088
      3228 11094 3232 11093

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

$$

JM
245 
WGUS75 KTWC 030133
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
633 PM MST Fri Jul 2 2021

AZC019-030143-
/O.EXP.KTWC.FF.W.0004.000000T0000Z-210703T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
633 PM MST Fri Jul 2 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTHEASTERN PIMA COUNTY...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3236 11089 3236 11098 3232 11108 3229 11113
      3226 11117 3220 11121 3211 11116 3213 11106
      3218 11102 3220 11098 3222 11089 3226 11088
      3228 11094 3232 11093

$$

JG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 5:15 PM MSTSpecial Weather StatementTWCCochise45 min
Jul 2, 11:58 AM MSTAreal Flood AdvisoryTWCCochise, Graham3 hr
Jul 2, 12:46 PM MSTFlash Flood Warning Considerable damage threatTWCCochise3 hr
Jul 2, 1:34 PM MSTSpecial Weather StatementTWCGraham26 min
Jul 2, 2:05 PM MSTSevere Thunderstorm WarningTWCPinal40 min
Jul 2, 2:27 PM MSTSpecial Weather StatementTWC33 min
Jul 2, 2:36 PM MSTSevere Thunderstorm WarningTWCPinal39 min
Jul 2, 2:48 PM MSTSevere Thunderstorm WarningTWCPima42 min
Jul 2, 2:53 PM MSTFlash Flood Warning Considerable damage threatTWCPima3 hr
Jul 2, 3:01 PM MSTSevere Thunderstorm WarningTWCPima, Pinal44 min
Jul 2, 3:10 PM MSTSevere Thunderstorm WarningTWCGraham, Greenlee50 min
Jul 2, 3:14 PM MSTAreal Flood AdvisoryTWCPinal3 hr
Jul 2, 3:25 PM MSTDust Storm WarningTWCPima, Pinal95 min
Jul 2, 3:33 PM MSTSevere Thunderstorm WarningTWCCochise42 min
Jul 2, 3:35 PM MSTSevere Thunderstorm WarningTWCPima, Pinal40 min
Jul 2, 3:54 PM MSTSpecial Weather StatementTWCSanta Cruz51 min
Jul 2, 3:55 PM MSTSpecial Weather StatementTWCGraham65 min
Jul 2, 4:06 PM MSTSevere Thunderstorm WarningTWCCochise39 min
Jul 2, 4:09 PM MSTSpecial Weather StatementTWCGraham51 min
Jul 2, 4:24 PM MSTSpecial Weather StatementTWCSanta Cruz36 min
Jul 2, 4:34 PM MSTSpecial Weather StatementTWCSanta Cruz26 min
Jul 2, 4:35 PM MSTSpecial Weather StatementTWCCochise40 min
Jul 2, 4:46 PM MSTSpecial Weather StatementTWCSanta Cruz29 min
Jul 2, 4:51 PM MSTSpecial Weather StatementTWCPinal24 min
Jul 2, 4:56 PM MSTAreal Flood AdvisoryTWCSanta Cruz3 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.