Alert archive / Arizona / Flash Flood Warnings in 2017

Flash Flood Warning 97, NWS Las Vegas, NV

August 24, 2017Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 24, 2017, 9:51 AM MST for Mohave County, Arizona. It was in force for 2 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 24, 2017, 9:51 AM MST (16:51 UTC)
Expired
Aug 24, 2017, 12:15 PM MST
In force
2 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), 45 km from the middle of the area, began a volume at 16:52 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 12:00Z, 4.9 hours before the alert went out and 99 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 12:00Z on 2017-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 119 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2017-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 square meters per square second.193958Sfc1 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
119 J/kg
Mixed-layer CIN
-213 J/kg
Mixed-layer LCL
2787 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
-13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

090 
WGUS55 KVEF 241651
FFWVEF
AZC015-241915-
/O.NEW.KVEF.FF.W.0097.170824T1651Z-170824T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
951 AM MST THU AUG 24 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  Northwestern Mohave County in northwestern Arizona...

* Until 1215 PM MST

* At 948 AM MST, Doppler radar indicated thunderstorms producing 
  heavy rain just east of Hoover Dam and over Temple Bar Road. Flash 
  flooding has already been reported in the area, and additional 
  rain will only worsen the situation.

* Some locations that will experience flooding include...
  Temple Bar Campground and Willow Beach. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3563 11427 3563 11462 3585 11470 3587 11466
      3591 11471 3599 11474 3602 11472 3608 11475
      3611 11474 3615 11459 3614 11450 3613 11451
      3614 11446 3612 11445 3614 11442 3614 11437
      3610 11433

$$

Morgan
2 follow-up statements
077 
WGUS75 KVEF 241749
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1049 AM MST THU AUG 24 2017

AZC015-241915-
/O.CON.KVEF.FF.W.0097.000000T0000Z-170824T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
1049 AM MST THU AUG 24 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 PM MST FOR
NORTHWESTERN MOHAVE COUNTY...

At 1047 AM MST, Doppler radar indicated that rain was tapering off 
over northwest Mohave County. However, very heavy rain fell earlier, 
especially in the area of Temple Bar Road, and flooding had already 
been reported. Runoff is likely still flowing, so the warning will 
remain in effect.

Some locations that will experience flooding include...
Temple Bar Campground and Lake Mead National Recreation Area. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3563 11427 3563 11462 3585 11470 3587 11466
      3591 11471 3599 11474 3602 11472 3608 11475
      3611 11474 3615 11459 3614 11450 3613 11451
      3614 11446 3612 11445 3614 11442 3614 11437
      3610 11433

$$

Morgan
674 
WGUS75 KVEF 241907
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1207 PM MST THU AUG 24 2017

AZC015-241916-
/O.EXP.KVEF.FF.W.0097.000000T0000Z-170824T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
1207 PM MST THU AUG 24 2017

...THE FLASH FLOOD WARNING FOR NORTHWESTERN MOHAVE COUNTY WILL EXPIRE
AT 1215 PM MST...

Heavy rain had ended over northwest Mohave County, and flooding is 
no longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 3563 11427 3563 11462 3585 11470 3587 11466
      3591 11471 3599 11474 3602 11472 3608 11475
      3611 11474 3615 11459 3614 11450 3613 11451
      3614 11446 3612 11445 3614 11442 3614 11437
      3610 11433

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 5:24 PM MSTAreal Flood AdvisoryVEFMohave3 hr
Aug 24, 6:33 AM MSTAreal Flood AdvisoryVEFMohave3 hr
Aug 24, 6:58 AM MSTFlash Flood WarningVEFMohave3 hr

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.