Flash Flood Warning 77, NWS Las Vegas, NV

581 
WGUS75 KVEF 210224
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
724 PM PDT Sun Aug 20 2023

CAC071-210600-
/O.CON.KVEF.FF.W.0077.000000T0000Z-230821T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
724 PM PDT Sun Aug 20 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS 
EVENING FOR SAN BERNARDINO COUNTY...

At 724 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Flash flooding is ongoing or expected 
to begin shortly.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads. Flood report of
         water reaching the hoods of cars in Baker at State Route
         127 and Baker Boulevard.

Some locations that will experience flash flooding include...
  Cima, Kelso, Mitchell Caverns, Baker, Needles, Mid Hills 
  Campground, Mountain Pass, Hole In The Wall Campground, Black 
  Canyon Equestrian Campground, Nipton And Ivanpah Roads, Nipton, 
  Essex, Dumont Dunes, Sr 127 Near Dumont Dunes, Tecopa, Highway 95 
  And I-40 and Mohave Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3482 11458 3442 11531 3580 11713 3581 11565
      3500 11463 3487 11463

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JV

498 
WGUS55 KVEF 210553
FFWVEF
CAC071-210900-
/O.EXT.KVEF.FF.W.0077.000000T0000Z-230821T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
1053 PM PDT Sun Aug 20 2023

The National Weather Service in Las Vegas has extended the

* Flash Flood Warning for...
  San Bernardino County in southern California...

* Until 200 AM PDT.

* At 1053 PM PDT, Doppler radar and automated rain gauges indicated 
  moderate to heavy rain continuing across northeast San Bernardino 
  County. Between 0.75 and 1 inch of rain has fallen. Additional 
  rainfall amounts of 0.25 to 0.5 inches are possible in the warned 
  area. Flash flooding is ongoing.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of washings, low-water crossings, poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  The York Fire burn scar, Cima, Kelso, Mitchell Caverns, Baker, 
  Needles, Mid Hills Campground, Mountain Pass, Hole In The Wall 
  Campground, Black Canyon Equestrian Campground, Nipton And Ivanpah 
  Roads, Nipton, Essex, Dumont Dunes, Sr 127 Near Dumont Dunes, 
  Tecopa, Highway 95 And I-40 and Mohave 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.

&&

LAT...LON 3482 11458 3442 11531 3580 11713 3581 11565
      3500 11463 3487 11463

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

JA

943 
WGUS55 KVEF 210816
FFWVEF
CAC071-211200-
/O.EXT.KVEF.FF.W.0077.000000T0000Z-230821T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
116 AM PDT Mon Aug 21 2023

The National Weather Service in Las Vegas has extended the

* Flash Flood Warning for...
  San Bernardino County in southern California...

* Until 500 AM PDT.

* At 116 AM PDT, Doppler radar and automated rain gauges indicated 
  persistent moderate rain over northeast San Bernardino County. 
  Between 0.75 and 1.25 inch of rain has fallen. Additional rainfall 
  amounts of 0.25 to 0.5 inches are possible in the warned area. 
  Flash flooding is ongoing.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of washings, low-water crossings, poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  The York Fire burn scar, Cima, Kelso, Mitchell Caverns, Baker, 
  Needles, Mid Hills Campground, Mountain Pass, Hole In The Wall 
  Campground, Black Canyon Equestrian Campground, Nipton And Ivanpah 
  Roads, Nipton, Essex, Dumont Dunes, Sr 127 Near Dumont Dunes, 
  Tecopa, Highway 95 And I-40 and Mohave 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.

&&

LAT...LON 3482 11458 3442 11531 3580 11713 3581 11565
      3500 11463 3487 11463

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

JA

225 
WGUS75 KVEF 211148
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
448 AM PDT Mon Aug 21 2023

CAC071-211200-
/O.CON.KVEF.FF.W.0077.000000T0000Z-230821T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
448 AM PDT Mon Aug 21 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 AM PDT EARLY THIS 
MORNING FOR SAN BERNARDINO COUNTY...

At 448 AM PDT, Lingering rain persists over the Mojave Preserve and 
flooding remains possible.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Cima, Mitchell Caverns, Black Canyon Equestrian Campground, Hole 
  In The Wall Campground and Mid Hills Campground.

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.

&&

LAT...LON 3492 11497 3486 11553 3535 11567 3541 11532
      3506 11491 3497 11488

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

CO

262 
WGUS55 KVEF 211149
FFWVEF
CAC071-211600-
/O.EXT.KVEF.FF.W.0077.000000T0000Z-230821T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
449 AM PDT Mon Aug 21 2023

The National Weather Service in Las Vegas has extended the

* Flash Flood Warning for...
  San Bernardino County in southern California...

* Until 900 AM PDT.

* At 449 AM PDT, Light to moderate rain persists across the Mojave 
  Preserve and local roadways remain impassable. So the flash flood 
  warning has been extended through 9 am.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Cima, Mitchell Caverns, Black Canyon Equestrian Campground, Hole 
  In The Wall Campground and Mid Hills Campground.

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.

&&

LAT...LON 3492 11497 3486 11553 3535 11567 3541 11532
      3506 11491 3497 11488

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

CO

524 
WGUS75 KVEF 211557
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
857 AM PDT Mon Aug 21 2023

CAC071-211607-
/O.EXP.KVEF.FF.W.0077.000000T0000Z-230821T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
857 AM PDT Mon Aug 21 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 9 AM PDT THIS MORNING FOR SAN 
BERNARDINO COUNTY...

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



LAT...LON 3492 11497 3486 11553 3535 11567 3541 11532
      3506 11491 3497 11488

$$

BKP

Area Forecast Discussion
National Weather Service Las Vegas NV
1246 PM PDT Sun Aug 20 2023

.SYNOPSIS...The remnants of Hilary will lift through the region
today with widespread rain and instances of significant flash
flooding. Strong winds will also accompany this storm system with
gusts of 50-60 mph spreading across the region during the
afternoon and evening hours. Decreasing shower coverage is
expected Monday but daily chances for showers and thunderstorms
will persist through the week with temperatures remaining below
normal.
&&

.SHORT TERM...The Rest of Today through Monday.

Continuing to watch as the historic event unfolds.

This afternoon will feature two areas of differing concerns and
impacts.

Area 1: In Inyo County, Nye County, Esmeralda, and far western San
Bernardino County (including areas such as the Western Mojave
Preserve, the Morongo Basin, Daggett Barstow), the main threat
through this evening will be heavy rain and flash flooding. An 300mb
jet will provide continued upper level support while PWATs will
continue to increase...therefore expecting an widespread and
continuous rain area to develop and sit over this region. Moderate
rain with embedded thunderstorms and heavier rain are expected. HREF
3hr PMMs bullseyes Inyo County with high probabilities for 3hr
rainfall totals over 1.00 inch through 5PM tonight. Embedded
thunderstorms will be possible, especially with any upsloping in the
terrain, however the continued highest risk with storms in this
region today will be heavy rain.

Area 2: Further east in Clark, Lincoln, much San Bernardino, and
Mohave counties, precipitation this afternoon and evening should be
more scattered and convective in nature. Instability will increase
to 500-1500 J/Kg through the afternoon with the highest instability
over southern areas such as Twentynine Palms, the southern Colorado
River Valley, and southern Clark. Deep layer shear will be a lot to
overcome as 50-70KT of 0-6km shear being shown on mesoanalysis.
However, storm initiating of the edge of the moisture push acting
much like a warm front should have enough instability to tap into
to result in strong to severe thunderstorms today. The main
threat will be heavy downpours as the atmosphere is super moist.
Along with that, strong winds will be possible as sounding show
strong winds just above the surface that could easily transfer
down with rapid storm motion or heavy rain. Continuing to watch
the threat for a few tornadoes. While a low chance, the atmosphere
is primed for it as LCLs are very low and 0-3km shear is high.

For the rest of the day, ensure you have multiple ways to receive
weather warnings and updates. Take all forecasts and warnings
seriously. The small scale details of this forecast continue to
change and are hard to pinpoint. Even if its not raining now or
flooding isn't occurring at this moment- the weather will rapidly
change and impacts will develop quickly if intense weather hits your
location. Not every location will see high impact weather today, but
all locations have some risk of high impact and dangerous
conditions. As meteorologists, our main goal is ensure everyone
remains safe.

For tonight...Tropical system Hilary will continue it's
northward track tonight and Monday, bringing heavy rain and strong
winds to the region. Flash flooding remains a concern overnight,
especially in San Bernardino, Inyo, and southern Nye counties.
High winds with gusts over 60MPH are possible tonight with
widespread moderate to high wind impacts possible.

FLASH FLOOD THREAT: Overall, the forecast for rainfall remains on
track from previous forecast.  Increasing forcing as Hilary lift
north through the night along with extreme moisture advecting into
the region will result in heavy rain at times for many areas.
Moderate rain with embedded thunderstorms and heavier rain is
expected through tonight. The main change from the previous forecasts
is an increase in rainfall amount in northern areas of Inyo. The
latest WPC day 1 excessive rainfall forecast has been extended the
high risk for flash flooding further north to include this area
while continuing to highlight San Bernardino and southern Nye
counties. Through this area, HREF shows high probabilities for 3hr
rainfall totals over 1.00 inch . Also of note, HREF probabilities
has low chances (10%-20%) for 3 hour rainfall amounts over 3.00
inches a between 5pm and 8pm PT in San Bernardino, and between 8pm
and 11pm in Inyo County. Areas further east may see waves of
rainfall with varying intensity and impacts tonight as opposed to a
large, widespread swath of continuous rain like areas further west.
Main unknown for eastern areas tonight will be how long
thunderstorms will continue into tonight before transition to just
rain. Currently expecting thunderstorm activity through at least
10pm in most areas of Clark, Mohave, Lincoln, and eastern San
Bernardino counties. No changes were made the the flash flood
watches as we continue to see a risk for heavy rain and flooding
through tonight.

STRONG WINDS: As Hilary moves north, models continue to show
increasing south to southeast winds this evening and overnight.
There is still uncertainty on how strong the winds will get as
ensembles showing varying probabilities for winds over 60MPH. There
is at least a high risk for impactful wind gusts after 40MPH so will
not make changes to the High Wind Warning that is in place. Expect a
sharp increase in winds as Hilary moves through, with the strongest
winds located closest to the center of the low,, lasting 3 to 6
hours before then before slowly tapering off the rest of the night
and Monday morning. The highest probability for wind gusts over 60MPH
will be southern Nevada, eastern San Bernardino, and the Colorado
River Valley where ensembles paint at least 40%-50% probabilities.

By Monday, Hilary will be a thing of the past but widespread low
level moisture will remain well entrenched across the area. This
will keep the forecast rather moist and unstable with numerous
showers and thunderstorms, especially in the higher terrain. While
coverage will decrease from past days, storms will remain very
efficient rain producers and flash flooding will remain a
possibility. There is low confidence in the precipitation
probability forecast as models show varying solutions on where
precipitation may develop, if they will be convective or not, and how
widespread the scattered precipitation may cover.

.LONG TERM...Tuesday through Saturday.

Broad ridge will remain over the central US steering at least low
to moderate grade monsoonal moisture northward around its perifery
through next weekend. This will keep shower and thunderstorm
activity in the forecast, especially across southern Nevada and
Northwest Arizona. Meanwhile, temperatures will remain on the cool
side of normal thanks to wet soils, persistent moisture feed, and
scattered storm activity in the area, though temperatures will
slowly be trending upward each day.
&&

.AVIATION...For Harry Reid...Adverse conditions are forecast through
most of the TAF period as the remnants of Hilary track across the
area.  Light scattered showers early this afternoon will ll transition
to thunderstorms this afternoon through early tonight. Rain this
afternoon and evening may not be continuous, instead expecting waves
of rain with rapidly deteriorating conditions as the precipitation
moves through. High confidence for lightning, heavy rain, reduction
in visibility to 4SM, and CIGs to 5000ft with the rounds of
precipitation this afternoon. Low probability for sudden gusty winds,
CIGS below 3000ft, and visibility less than 3SM with afternoon
convection. Thunderstorm risk and convective driven impacts will
decrease after 06Z tonight, but continued showery activity is likely
through at least Monday morning. Low confidence in precipitation
forecast Monday afternoon as showers and thunderstorms will be
possible in and around LAS, however not expecting as widespread of
activity and unsure if precipitation will directly impact the
terminals.

Northeast winds around 10KT will become southeast and rapidly
increase late this afternoon and tonight. Increasing confidence for
wind gusts over 40KT, especially between 03Z to 09Z. Low
probability (20%) for wind gusts over 50KT, mainly centered around
06Z. Southeast wind gusts will slowly decrease after 09Z, with wind
gusts dropping below 35KT by 12Z, then dropping below 25KT
sometime after 15Z. Elevated south to southeast winds are expected
through MOnday afternoon with speeds 10-15KT but little to no gusts.

For the rest of southern Nevada, northwest Arizona and southeast
California...Poor aviation conditions expected through much of the
TAF period across the region. Widespread areas of moderate to
locally heavy rainfall can be expected as the remnants of Hilary
pass across the region with the heaviest precipitation is expected
across far western Nevada and the Mojave Desert in California. Winds
this afternoon should generally be 10KT or less from an east-to-
south direction before rapidly increasing south to southeast winds
arrive late this afternoon and tonight. Gusts to 50KT are possible,
especially in the lower Colorado River Valley. The gusts should then
diminish south to north overnight into Monday morning. During
periods of heavier precipitation today, CIGs may fall below 2kft,
and visibilities may be reduced to 3mi or less. Outside of the
heavier rain, prevailing CIGs around 5kft can be expected.&&

.SPOTTER INFORMATION STATEMENT...Heavy rain, high winds or wind
damage, and flash flooding reports are requested through the
weekend as the remains of Hurricane Hilary lift through the
area.
&&

SHORT TERM/AVIATION...Nickerson
LONG TERM...Outler

For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter

Preliminary Local Storm Report
National Weather Service Las Vegas NV
424 PM PDT Sun Aug 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0401 PM     Flash Flood      2 W Joshua Tree         34.13N 116.35W
08/20/2023                   San Bernardino     CA   Dept of Highways

            State Route 62 eastbound just east of
            Olympic has mud and debris on the roadway.

&&

SM

Preliminary Local Storm Report
National Weather Service Las Vegas NV
514 PM PDT Sun Aug 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     Flash Flood      3 NE Twentynine Palms   34.17N 116.02W
08/20/2023                   San Bernardino     CA   Emergency Mngr

            Baghdad between Amboy and Valle Vista is
            closed due to flooding.

0500 PM     Flash Flood      1 NE Twentynine Palms   34.15N 116.03W
08/20/2023                   San Bernardino     CA   Emergency Mngr

            Joe Davis between Utah and Sherman Hoyt is
            closed due to flooding.

0500 PM     Flash Flood      Twentynine Palms        34.14N 116.05W
08/20/2023                   San Bernardino     CA   Emergency Mngr

            Ocotillo between Gorgonio and Veterans Way
            is closed due to flooding.

0500 PM     Flash Flood      Twentynine Palms        34.14N 116.06W
08/20/2023                   San Bernardino     CA   Emergency Mngr

            Tamarisk between Buena Vista and Bagley is
            closed due to flooding.

0500 PM     Flash Flood      Twentynine Palms        34.14N 116.06W
08/20/2023                   San Bernardino     CA   Emergency Mngr

            Split Rock between Buena Vista and Bagely is
            closed due to flooding.

&&

Preliminary Local Storm Report
National Weather Service Las Vegas NV
603 PM PDT Sun Aug 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0410 PM     Non-Tstm Wnd Gst 10 SSE Essex            34.59N 115.21W
08/20/2023  M83 MPH          San Bernardino     CA   Public

            At 1530 PDT, the sensor at Old Woman
            Mountain began measuring sustained winds of
            40 mph or greater. These winds continued
            through 1650 PDT. The peak gust was 83 mph
            and the peak sustained wind speed was 52
            mph. Both occurred at 1610 PDT.

&&

SM

Preliminary Local Storm Report
National Weather Service Las Vegas NV
639 PM PDT Sun Aug 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0613 PM     Flash Flood      Morongo Valley          34.04N 116.58W
08/20/2023                   San Bernardino     CA   Law Enforcement

            Rock slid off mountain and into roadway at
            SR62 and Hess Rd.

&&

SM

Preliminary Local Storm Report
National Weather Service Las Vegas NV
650 PM PDT Sun Aug 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0622 PM     Flash Flood      5 SSE Keeler            36.41N 117.84W
08/20/2023                   Inyo               CA   Dept of Highways

            State Route 190 remains closed due to
            flooding. There is water flowing over the
            roadway.

&&

SM

Preliminary Local Storm Report
National Weather Service Las Vegas NV
655 PM PDT Sun Aug 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0637 PM     Flash Flood      Baker                   35.27N 116.08W
08/20/2023                   San Bernardino     CA   Law Enforcement

            Water is reaching vehicle hoods.

&&

SM