Alert archive / Arizona / Flash Flood Warnings in 2017

Flash Flood Warning 35, NWS Tucson, AZ

July 27, 2017Graham County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 27, 2017, 4:45 PM MST for Graham 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 27, 2017, 4:45 PM MST (23:45 UTC)
Expired: Jul 27, 2017, 6:45 PM MST
In force: 2 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Flood severity: None

County Graham County, AZ

The radar

The Tucson radar (KEMX), 113 km from the middle of the area, began a volume at 23:48 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, 5:30 PM MST	FLASH FLOOD	6 Se Mount Graham, AZ	WET CANYON CHANNEL OVERTOPPED ROUTE 366

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, 11.8 hours before the alert went out and 114 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: 351 J/kg
Mixed-layer CIN: -249 J/kg
Mixed-layer LCL: 1946 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: -31 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

570 
WGUS55 KTWC 272345
FFWTWC
AZC009-280145-
/O.NEW.KTWC.FF.W.0035.170727T2345Z-170728T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
445 PM MST THU JUL 27 2017

The National Weather Service in Tucson has issued a

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

* Until 645 PM MST

* At 441 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over Mt Graham over Highway 366 in the vicinity of the 
  Shannon campground area. Flash flooding is expected to begin 
  shortly.

* Some locations that will experience flooding include...
  Fort Grant, Highway 366 from Treasure Park to Twilit and the 
  gulches and canyons draining from this area. 

Additional rainfall amounts of over an inch area are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This warning includes areas in or below a wildfire burn scar.
Rainfall on burned areas can cause increased flash flooding, debris
flows, mud slides, and rock slides. Take action now to protect
yourself from the effects of flash flooding and remember, Turn
Around, Don't Drown!

&&

LAT...LON 3273 10977 3264 10973 3255 10975 3257 10992
      3263 10995 3269 10993

$$

Cerniglia

2 follow-up statements

951 
WGUS75 KTWC 280030
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
530 PM MST THU JUL 27 2017

AZC009-280145-
/O.CON.KTWC.FF.W.0035.000000T0000Z-170728T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham-
530 PM MST THU JUL 27 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MST FOR
SOUTH CENTRAL GRAHAM COUNTY...

At 522 PM MST, Doppler radar continued to show rain occurring across 
the the southern portion of Mt Graham in the warned area. Estimated 
rainfall from radar over this area is between one and two inches and 
this amount of rain will lead to flash flooding.

Excessive rainfall over the warned area will cause mud slides over 
and near the steep terrain. Mud slides can consist of rock, mud, 
vegetation and other loose materials.

Normally dry washes and low water crossings may be inundated in the 
following locations...Fort Grant, Highway 366 (Swift Trail) from 
Treasure Park to Twilight and the gulches and canyons draining from 
this area. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This warning includes areas in or below a wildfire burn scar.
Rainfall on burned areas can cause increased flash flooding, debris
flows, mud slides, and rock slides. Take action now to protect
yourself from the effects of flash flooding and remember, Turn
Around, Don't Drown!

&&

LAT...LON 3273 10977 3264 10973 3255 10975 3257 10992
      3263 10995 3269 10993

$$

Cerniglia

205 
WGUS75 KTWC 280147
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
647 PM MST THU JUL 27 2017

AZC009-280156-
/O.EXP.KTWC.FF.W.0035.000000T0000Z-170728T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham-
647 PM MST THU JUL 27 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL GRAHAM COUNTY HAS
EXPIRED...

Only light to moderate showers remain in the Mt Graham area. Flash 
flooding is no longer expected to pose a threat, however heavy flow 
will continue in streams and washes. Please continue to heed any 
remaining road closures.

LAT...LON 3273 10977 3264 10973 3255 10975 3257 10992
      3263 10995 3269 10993

$$

Zell

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 1:30 PM MST	Areal Flood Advisory	TWC	Cochise	3 hr
Jul 27, 1:38 PM MST	Special Weather Statement	TWC	Greenlee	52 min
Jul 27, 2:01 PM MST	Areal Flood Advisory	TWC	Cochise	3 hr
Jul 27, 2:13 PM MST	Special Weather Statement	TWC	Cochise	32 min
Jul 27, 2:17 PM MST	Special Weather Statement	TWC	Cochise	28 min
Jul 27, 2:24 PM MST	Areal Flood Advisory	TWC	Graham	111 min
Jul 27, 2:27 PM MST	Special Weather Statement	TWC		33 min
Jul 27, 2:47 PM MST	Special Weather Statement	TWC	Graham	43 min
Jul 27, 4:09 PM MST	Special Weather Statement	TWC	Graham	36 min
Jul 27, 4:56 PM MST	Flash Flood Warning	TWC	Cochise	3 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.