Alert archive / Arizona / Flash Flood Warnings in 2017

Flash Flood Warning 60, NWS Las Vegas, NV

August 1, 2017Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 1, 2017, 5:45 PM MST for Mohave County, Arizona. It was in force for 3 hr. 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 1, 2017, 5:45 PM MST (00:45 UTC)
Expired
Aug 1, 2017, 8:45 PM MST
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Mohave County, AZ

The radar

The Las Vegas radar (KESX), 83 km from the middle of the area, began a volume at 00:45 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

Las Vegas, NV (KVEF), launched 00:00Z, 0.8 hours before the alert went out and 178 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-pSkew-T log-p diagram, Las Vegas, NV at 00:00Z on 2017-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 277 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 00:00Z on 2017-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
277 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
3687 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

267 
WGUS55 KVEF 020045
FFWVEF
AZC015-020345-
/O.NEW.KVEF.FF.W.0060.170802T0045Z-170802T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
545 PM MST TUE AUG 1 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  West central Mohave County in northwestern Arizona...

* Until 845 PM MST

* At 545 PM MST, Doppler radar and automated rain gauges indicated
  thunderstorms producing heavy rain across the warned area. Flash
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Oatman and Golden Valley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 3521 11413 3499 11414 3497 11440 3528 11439
      3537 11425

$$

STEELE
2 follow-up statements
446 
WGUS75 KVEF 020254
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
754 PM MST TUE AUG 1 2017

AZC015-020345-
/O.CON.KVEF.FF.W.0060.000000T0000Z-170802T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
754 PM MST TUE AUG 1 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM MST FOR
WEST CENTRAL MOHAVE COUNTY...

At 752 PM MST, Doppler radar and automated rain gauges indicated 
only light rain remaining over the area. However, runoff will 
continue and flooding is likely ongoing.

Some locations that will experience flooding include...
Oatman and Golden Valley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3521 11413 3499 11414 3497 11440 3528 11439
      3537 11425

$$

STEELE
425 
WGUS75 KVEF 020342
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
842 PM MST TUE AUG 1 2017

AZC015-020352-
/O.EXP.KVEF.FF.W.0060.000000T0000Z-170802T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
842 PM MST TUE AUG 1 2017

...THE FLASH FLOOD WARNING FOR WEST CENTRAL MOHAVE COUNTY WILL EXPIRE
AT 845 PM MST...

The heavy rain has ended. Flooding is no longer expected to pose a
new threat. Please continue to heed any remaining road closures.

LAT...LON 3521 11413 3499 11414 3497 11440 3528 11439
      3537 11425

$$

STEELE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 5:30 PM MSTSevere Thunderstorm WarningVEFMohave75 min
Aug 1, 5:37 PM MSTAreal Flood AdvisoryVEFMohave3 hr
Aug 1, 6:09 PM MSTSevere Thunderstorm WarningVEFMohave51 min
Aug 2, 4:18 PM MSTFlash Flood WarningVEFMohave3 hr
Aug 2, 4:38 PM MSTSevere Thunderstorm WarningVEFMohave37 min

Nearby

Flash Flood Warnings in Arizona, 2017Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.