Alert archive / Arizona / Flash Flood Warnings in 2017

Flash Flood Warning 20, NWS Tucson, AZ

July 20, 2017Santa Cruz County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 20, 2017, 1:54 PM MST for Santa Cruz County, Arizona. It was in force for 2 hr. 1 report 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 20, 2017, 1:54 PM MST (20:54 UTC)
Expired: Jul 20, 2017, 4:00 PM MST
In force: 2 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 63 km from the middle of the area, began a volume at 20:53 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 20, 2:09 PM MST	FLASH FLOOD	1 Sse Nogales, AZ	DOE STREET CLOSED DUE TO FLOODING FROM OVERFLOWING NOGALES WASH

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Tuscon, AZ (KDMA), launched 12:00Z, 8.9 hours before the alert went out and 86 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: 272 J/kg
Mixed-layer CIN: -146 J/kg
Mixed-layer LCL: 1362 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 55 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

521 
WGUS55 KTWC 202054
FFWTWC
AZC023-202300-
/O.NEW.KTWC.FF.W.0020.170720T2054Z-170720T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
154 PM MST THU JUL 20 2017

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  South central Santa Cruz County in southeastern Arizona...

* Until 400 PM MST

* At 153 PM MST, Doppler radar and automated rain gauges indicated
  thunderstorms producing heavy rain across the warned area. Up to 
  one inch of rain has already fallen in the last 30 minutes. Flash 
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Nogales, Rio Rico Southwest, Rio Rico Southeast and Kino Springs. 

LAT...LON 3144 11104 3143 11082 3133 11079 3133 11104

$$

GL

2 follow-up statements

186 
WGUS75 KTWC 202144
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
244 PM MST THU JUL 20 2017

AZC023-202300-
/O.CON.KTWC.FF.W.0020.000000T0000Z-170720T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Cruz-
244 PM MST THU JUL 20 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM MST FOR
SOUTH CENTRAL SANTA CRUZ COUNTY...

At 243 PM MST, local law enforcement reported flash flooding in the 
Nogales area.

Normally dry washes and low water crossings may be inundated in the
following locations...
Nogales, Rio Rico Southwest, Rio Rico Southeast and Kino Springs. 

Flood waters are moving down the Nogales Wash and other area washes 
at this time.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of washes
and streams, urban areas, highways, streets and underpasses as well
as other drainage areas and low lying spots.

&&

LAT...LON 3144 11104 3143 11082 3133 11079 3133 11104

$$

GL

520 
WGUS75 KTWC 202252
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
352 PM MST THU JUL 20 2017

AZC023-202301-
/O.EXP.KTWC.FF.W.0020.000000T0000Z-170720T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Santa Cruz-
352 PM MST THU JUL 20 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL SANTA CRUZ COUNTY WILL
EXPIRE AT 400 PM MST...

The heavy rain has ended. However, urban and small stream flooding 
will continue. Please continue to heed any remaining road closures.

LAT...LON 3144 11104 3143 11082 3133 11079 3133 11104

$$

GL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 5:03 PM MST	Areal Flood Advisory	TWC	Pinal	117 min
Jul 19, 6:15 PM MST	Dust Storm Warning	TWC	Cochise, Graham, Greenlee	105 min
Jul 19, 6:23 PM MST	Special Weather Statement	TWC	Santa Cruz	52 min
Jul 19, 8:21 PM MST	Special Weather Statement	TWC	Graham	39 min
Jul 19, 9:26 PM MST	Flash Flood Warning	TWC	Graham	94 min
Jul 19, 10:54 PM MST	Areal Flood Advisory	TWC	Graham	3 hr
Jul 20, 1:03 PM MST	Special Weather Statement	TWC	Santa Cruz	27 min
Jul 20, 1:20 PM MST	Special Weather Statement	TWC	Santa Cruz	25 min
Jul 20, 1:38 PM MST	Areal Flood Advisory	TWC	Santa Cruz	2 hr
Jul 20, 3:56 PM MST	Areal Flood Advisory	TWC	Santa Cruz	2 hr

Nearby

Flash Flood Warnings in Arizona, 2017 Every flash flood warning in 2017

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.