Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 74, NWS Tucson, AZ

July 27, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 27, 2021, 4:42 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 27, 2021, 4:42 PM MST (23:42 UTC)
Expired: Jul 27, 2021, 7:45 PM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 27 km from the middle of the area, began a volume at 23:43 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 27, 5:45 PM MST	FLASH FLOOD	13 Ese Tucson, AZ	CAMINO LOMA ALTA FLOODED FROM THE RINCON CREEK. VIDEO OF FLOW IS FROM TWITTER POST.
Jul 27, 7:14 PM MST	FLASH FLOOD	10 Ese Tucson, AZ	12-18 INCHES OF WATER FLOWING OVER OLD SPANISH TRAIL FROM THE RINCON CREEK. VIDEO OF FLOW OF WATER FROM TWITTER POST.

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, 11.7 hours before the alert went out and 24 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: 487 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1850 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -20 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

800 
WGUS55 KTWC 272342
FFWTWC
AZC019-280245-
/O.NEW.KTWC.FF.W.0074.210727T2342Z-210728T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
442 PM MST Tue Jul 27 2021

The National Weather Service in Tucson has issued a

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

* Until 745 PM MST.

* At 442 PM MST, An automated gauge on the Rincon Creek reported 
  high flows from earlier thunderstorms in the area. Flash flooding 
  is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Gauges reported.

  IMPACT...Flash flooding of Rincon Creek and other small creeks
           in the area.

* Some locations that will experience flash flooding include...
  Tucson and Saguaro National Park East.

This includes the following Flash Flood Prone Locations...
Old Spanish Trail at Rincon Creek and Camino Loma Alta at Rincon 
Creek.

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 3214 11063 3213 11065 3213 11067 3213 11071
      3215 11074 3214 11074 3213 11073 3211 11071
      3211 11068 3211 11062 3213 11060 3213 11059
      3213 11057 3214 11057 3214 11058 3215 11061

FLASH FLOOD...GAUGE INDICATED

$$

JD

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 1:52 PM MST	Flash Flood Warning Considerable damage threat	TWC	Santa Cruz	2 hr
Jul 27, 1:56 PM MST	Special Weather Statement	TWC	Santa Cruz	49 min
Jul 27, 2:15 PM MST	Special Weather Statement	TWC	Santa Cruz	45 min
Jul 27, 2:33 PM MST	Areal Flood Advisory	TWC	Cochise, Pima, Santa Cruz	3 hr
Jul 27, 3:29 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 27, 3:35 PM MST	Special Weather Statement	TWC	Santa Cruz	40 min
Jul 27, 3:49 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 27, 4:00 PM MST	Special Weather Statement	TWC		45 min
Jul 27, 4:05 PM MST	Areal Flood Advisory	TWC	Pima	115 min
Jul 27, 4:25 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 27, 4:34 PM MST	Blowing Dust Advisory	TWC	Pima, Pinal	87 min
Jul 27, 4:56 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 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.