Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 53, NWS Tucson, AZ

July 22, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 22, 2021, 4:35 PM MST for Pima County, Arizona. It was in force for 2 hr. 3 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 22, 2021, 4:35 PM MST (23:35 UTC)
Expired: Jul 22, 2021, 6:36 PM MST
In force: 2 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), 41 km from the middle of the area, began a volume at 23:35 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

Time	Report	Where	Remark
Jul 22, 4:50 PM MST	FLASH FLOOD	4 E Tucson, AZ	CORRECTS PREVIOUS FLASH FLOOD REPORT FROM 4 E TUCSON. SWIFT WATER RESCUE ON A CHILD IN THE AREA EAST OF KOLB RD AND 22ND STREET.
Jul 22, 4:50 PM MST	HEAVY RAIN 1	3 Ene Tucson, AZ	1 INCH OF RAIN IN 43 MINUTES WITH SMALL HAIL.
Jul 22, 5:01 PM MST	FLASH FLOOD	4 E Tucson, AZ	SWIFT WATER RESCUE ON A CHILD IN THE AREA EAST OF KOLB RD AND 22ND STREET.

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, 11.6 hours before the alert went out and 6 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: 970 J/kg
Mixed-layer CIN: -227 J/kg
Mixed-layer LCL: 1720 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: -68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

624 
WGUS55 KTWC 222335
FFWTWC
AZC019-230245-
/O.NEW.KTWC.FF.W.0053.210722T2335Z-210723T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
435 PM MST Thu Jul 22 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  East Central Pima County in southeastern Arizona...

* Until 745 PM MST.

* At 435 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across much of the city of Tucson. Up to 1.5 inches of 
  rain have fallen. Additional rainfall amounts up to 1 inch 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.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Tucson, Davis-Monthan Air Force Base, Casas Adobes, Drexel 
  Heights, Flowing Wells, Tanque Verde, South Tucson, Catalina 
  Foothills, Tucson International Airport, Sabino Canyon Recreation 
  Area, Summit, Saguaro National Park East and Rita Ranch.

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 11076 3232 11088 3229 11105 3217 11103
      3209 11097 3207 11089 3209 11080 3220 11069
      3225 11070

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

$$

GL

2 follow-up statements

581 
WGUS75 KTWC 230006
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
506 PM MST Thu Jul 22 2021

AZC019-230245-
/O.CON.KTWC.FF.W.0053.000000T0000Z-210723T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
506 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MST THIS 
EVENING FOR EAST CENTRAL PIMA COUNTY...

At 506 PM MST, trained weather spotters reported thunderstorms 
producing heavy rain across the warned area. Up to 1.5 inches of 
rain have fallen. Flash flooding is already occurring, especially on 
the east side of Tucson in the vicinity of David Monthan Air Force 
Base.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Trained spotters reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Tucson, Davis-Monthan Air Force Base, Casas Adobes, Drexel 
  Heights, Flowing Wells, Tanque Verde, South Tucson, Catalina 
  Foothills, Tucson International Airport, Sabino Canyon Recreation 
  Area, Summit, Saguaro National Park East and Rita Ranch.

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 11076 3232 11088 3229 11105 3217 11103
      3209 11097 3207 11089 3209 11080 3220 11069
      3225 11070

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

GL

651 
WGUS75 KTWC 230136
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
636 PM MST Thu Jul 22 2021

AZC019-230146-
/O.CAN.KTWC.FF.W.0053.000000T0000Z-210723T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
636 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING IS CANCELLED FOR EAST CENTRAL PIMA COUNTY...

Flood waters are continuing to recede per gauge readings. Flooding 
is no longer expected to pose a threat. Please continue to heed 
remaining road closures.

A Flash Flood Watch remains in effect until 1100 PM MST Saturday for 
a portion of Southeast Arizona.

LAT...LON 3231 11076 3232 11088 3229 11105 3217 11103
      3209 11097 3207 11089 3209 11080 3220 11069
      3225 11070

$$

GL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 6:15 PM MST	Special Weather Statement	TWC	Santa Cruz	45 min
Jul 21, 6:35 PM MST	Special Weather Statement	TWC	Pima	55 min
Jul 21, 7:04 PM MST	Special Weather Statement	TWC	Pima	41 min
Jul 21, 9:02 PM MST	Special Weather Statement	TWC		43 min
Jul 22, 1:04 PM MST	Special Weather Statement	TWC	Santa Cruz	26 min
Jul 22, 1:37 PM MST	Severe Thunderstorm Warning	TWC	Pima	38 min
Jul 22, 2:34 PM MST	Special Weather Statement	TWC	Santa Cruz	26 min
Jul 22, 2:36 PM MST	Areal Flood Advisory	TWC	Graham, Pinal	3 hr
Jul 22, 2:43 PM MST	Severe Thunderstorm Warning	TWC	Pima, Santa Cruz	47 min
Jul 22, 2:51 PM MST	Severe Thunderstorm Warning	TWC	Pima	39 min
Jul 22, 3:17 PM MST	Dust Storm Advisory	TWC	Pima, Pinal	58 min
Jul 22, 3:27 PM MST	Severe Thunderstorm Warning	TWC	Pima	27 min
Jul 22, 3:56 PM MST	Dust Storm Advisory	TWC	Pima, Pinal	34 min
Jul 22, 4:01 PM MST	Severe Thunderstorm Warning	TWC	Pima	59 min
Jul 22, 4:11 PM MST	Areal Flood Advisory	TWC	Pima	2 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.