Alert archive / Nevada / Flash Flood Warnings in 2017

Flash Flood Warning 42, NWS Las Vegas, NV

July 25, 2017Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 25, 2017, 6:55 AM PDT for Clark County, Nevada. It was in force for 5 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 25, 2017, 6:55 AM PDT (13:55 UTC)
Expired: Jul 25, 2017, 12:00 PM PDT
In force: 5 hr
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Flood severity: None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 43 km from the middle of the area, began a volume at 13:57 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 25, 7:56 AM PDT	FLASH FLOOD	3 N Centennial Hills, NV	STREETS IN THE ELK RIDGE SUBDIVISION ARE FLOODED WITH RUNNING WATER 1.5 TO 2 FEET DEEP. STREETS FLOODED INCLUDE EL CAPITAN LOG CABIN OHARE AND SKYE CANYON.
Jul 25, 8:13 AM PDT	FLASH FLOOD	3 Nnw Centennial Hills, NV	US 95 CLOSED DUE TO FLOODING NEAR THE INTERSECTION OF KYLE CANYON ROAD.
Jul 25, 9:30 AM PDT	FLASH FLOOD	3 Nw Aliante, NV	DEBRIS OVER ROADWAY REPORTED ON MAGGIE RD. BY PUBLIC WORKS. TIME IS ESTIMATED.

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

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 1.9 hours before the alert went out and 71 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: 916 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 897 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 167 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

As transmitted.

549 
WGUS55 KVEF 251355
FFWVEF
NVC003-251900-
/O.NEW.KVEF.FF.W.0042.170725T1355Z-170725T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
655 AM PDT TUE JUL 25 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  Central Clark County in southern Nevada...

* Until noon PDT

* At 653 AM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain developing over portions of the Las Vegas Valley. A 
  rain gauge near Tule Springs State Park has received nearly half 
  an inch of rain in 10 minutes. Rainfall is expected to become more 
  widespread early this morning and the threat of flash flooding 
  will increase. 

* Some locations that will experience flooding include...
  Las Vegas, Henderson, North Las Vegas, Boulder City, Lone Mountain,
  Anthem, Summerlin, Mountains Edge, The Strip, Nellis AFB, Blue
  Diamond, Downtown Las Vegas, East Las Vegas, Sam Boyd Stadium, The
  Motor Speedway, Las Vegas Bay, Southern Highlands, Aliante, Lake
  Las Vegas and Spring Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3613 11466 3611 11468 3611 11474 3609 11475
      3606 11473 3604 11474 3603 11472 3601 11474
      3598 11474 3592 11471 3586 11514 3603 11552
      3649 11541 3635 11462

$$

ASG

2 follow-up statements

300 
WGUS75 KVEF 251524
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
824 AM PDT TUE JUL 25 2017

NVC003-251900-
/O.CON.KVEF.FF.W.0042.000000T0000Z-170725T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
824 AM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON PDT FOR
CENTRAL CLARK COUNTY...

At 820 AM PDT, trained weather spotters reported flooding with water 
up to two feet deep in the Elk Ridge subdivision in the northwest 
Las Vegas Valley. Additionally, US 95 has been closed from Kyle 
Canyon Road to Skye Canyon due to flooding.

The most intense rain has fallen across the northwest portion of the 
Las Vegas Valley. Additional storms are still possibly across the 
warning and some locations that may experience flooding in the next 
few hours include... Las Vegas, Henderson, North Las Vegas, Boulder 
City, Lone Mountain, Anthem, Summerlin, Mountains Edge, The Strip, 
Nellis AFB, Blue Diamond, Downtown Las Vegas, East Las Vegas, Sam 
Boyd Stadium, The Motor Speedway, Las Vegas Bay, Southern Highlands, 
Aliante, Lake Las Vegas and Spring Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3613 11466 3611 11468 3611 11474 3609 11475
      3606 11473 3604 11474 3603 11472 3601 11474
      3598 11474 3592 11471 3586 11514 3603 11552
      3649 11541 3635 11462

$$

STEELE

174 
WGUS75 KVEF 251706
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1006 AM PDT TUE JUL 25 2017

NVC003-251710-
/O.CAN.KVEF.FF.W.0042.000000T0000Z-170725T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
1006 AM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING FOR CENTRAL CLARK COUNTY IS CANCELLED...

The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed any 
remaining road closures. Additional thunderstorms remain possible 
through the day.

LAT...LON 3613 11466 3611 11468 3611 11474 3609 11475
      3606 11473 3604 11474 3603 11472 3601 11474
      3598 11474 3592 11471 3586 11514 3603 11552
      3649 11541 3635 11462

$$

STEELE

The office that day

Everything else NWS Las Vegas, NV issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 24, 5:39 PM PDT	Areal Flood Advisory	VEF	Lincoln	3 hr
Jul 24, 7:13 PM PDT	Flash Flood Warning	VEF	Lincoln	3 hr
Jul 24, 9:34 PM PDT	Flash Flood Warning	VEF	Clark	3 hr
Jul 24, 11:59 PM PDT	Flash Flood Watch	VEF	Clark, Nye	20 hr
Jul 25, 12:43 AM PDT	Areal Flood Advisory	VEF	Lincoln	4 hr
Jul 25, 2:15 AM PDT	Flash Flood Warning	VEF	Clark	3 hr
Jul 25, 4:54 AM PDT	Flash Flood Warning	VEF	Clark	6 hr
Jul 25, 5:42 AM PDT	Flash Flood Warning	VEF	Lincoln	10 hr
Jul 25, 8:06 AM PDT	Flash Flood Warning	VEF	Clark	8 hr
Jul 25, 10:28 AM PDT	Areal Flood Advisory	VEF	Clark	3 hr
Jul 25, 10:47 AM PDT	Areal Flood Advisory	VEF	Clark	6 hr
Jul 25, 11:06 AM PDT	Flash Flood Warning	VEF	Clark	6 hr
Jul 25, 1:57 PM PDT	Areal Flood Advisory	VEF	Esmeralda	4 hr
Jul 25, 2:57 PM PDT	Flash Flood Warning	VEF	Lincoln, Nye	3 hr
Jul 25, 4:23 PM PDT	Flash Flood Warning	VEF	Lincoln, Nye	3 hr

Nearby

Flash Flood Warnings in Nevada, 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.