Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 112, NWS Tucson, AZ

August 10, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 10, 2021, 11:35 PM MST for Pima County, Arizona. It was in force for 55 min. 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 10, 2021, 11:35 PM MST (06:35 UTC)
Expired: Aug 11, 2021, 12:30 AM MST
In force: 55 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 50 km from the middle of the area, began a volume at 06:37 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, 6.6 hours before the alert went out and 11 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: 684 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1753 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 13 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.

946 
WGUS55 KTWC 110635
FFWTWC
AZC019-110730-
/O.NEW.KTWC.FF.W.0112.210811T0635Z-210811T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
1135 PM MST Tue Aug 10 2021

The National Weather Service in Tucson has issued a

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

* Until 1230 AM MST.

* At 1135 PM MST, Doppler radar indicated a line of thunderstorms 
  producing heavy rain moving across the western and northern 
  portions of the Tucson Metro Area.  Between 0.75 and 1.25 inches 
  of rain have fallen in less than an hour. Flash flooding is 
  ongoing or expected to begin shortly.

  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, South Tucson, Tortolita, 
  Catalina Foothills, Tucson International Airport, Saguaro National 
  Park West, Tucson Estates and San Xavier Mission.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3208 11103 3230 11114 3245 11095 3233 11087
      3217 11088

FLASH FLOOD...RADAR INDICATED

$$

CWR

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 5:03 PM MST	Severe Thunderstorm Warning	TWC	Pima, Santa Cruz	27 min
Aug 10, 6:15 PM MST	Areal Flood Advisory	TWC	Pima	20 min
Aug 10, 6:19 PM MST	Severe Thunderstorm Warning	TWC	Pima	26 min
Aug 10, 6:32 PM MST	Special Weather Statement	TWC		28 min
Aug 10, 6:35 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 10, 6:41 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	4 hr
Aug 10, 6:49 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 10, 7:07 PM MST	Special Weather Statement	TWC	Pima	38 min
Aug 10, 7:43 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 10, 7:50 PM MST	Areal Flood Advisory	TWC	Pima	3 hr
Aug 10, 8:27 PM MST	Special Weather Statement	TWC		33 min
Aug 10, 8:31 PM MST	Special Weather Statement	TWC	Pinal	29 min
Aug 10, 9:41 PM MST	Areal Flood Warning	TWC	Pima	6 hr
Aug 10, 10:06 PM MST	Areal Flood Advisory	TWC	Pima	23 min
Aug 10, 10:29 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	2 hr
Aug 11, 12:21 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	4 hr
Aug 11, 12:54 AM MST	Areal Flood Advisory	TWC	Pinal	111 min
Aug 11, 2:04 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Aug 11, 3:24 AM MST	Areal Flood Warning	TWC	Pima	6 hr
Aug 11, 4:13 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	4 hr
Aug 11, 4:55 AM MST	Areal Flood Advisory	TWC	Pima	3 hr
Aug 11, 8:14 AM MST	Areal Flood Warning	TWC	Pima, Pinal	6 hr
Aug 11, 1:41 PM MST	Areal Flood Advisory	TWC	Cochise, Santa Cruz	2 hr
Aug 11, 2:12 PM MST	Areal Flood Advisory	TWC	Santa Cruz	45 min
Aug 11, 2:24 PM MST	Special Weather Statement	TWC	Santa Cruz	21 min
Aug 11, 2:57 PM MST	Flash Flood Warning Considerable damage threat	TWC	Santa Cruz	2 hr
Aug 11, 3:00 PM MST	Severe Thunderstorm Warning	TWC	Cochise	31 min
Aug 11, 3:17 PM MST	Areal Flood Advisory	TWC	Cochise	11 min
Aug 11, 3:28 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise	3 hr
Aug 11, 3:56 PM MST	Special Weather Statement	TWC		34 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.