Flash Flood Warning 13, NWS Las Vegas, NV

574 
WGUS75 KVEF 100635
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1135 PM PDT Thu May 9 2019

CAC071-100815-
/O.CON.KVEF.FF.W.0013.000000T0000Z-190510T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
1135 PM PDT Thu May 9 2019

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 AM PDT FOR
NORTH CENTRAL SAN BERNARDINO COUNTY...

At 1134 PM PDT, Doppler radar indicated thunderstorms producing 
heavy rain across the Mojave National Preserve. The heaviest rain 
was falling just east of Kelso Cima Road.

Some locations that will experience flooding include...
Mitchell Caverns, Cima, Kelso, Nipton And Ivanpah Roads, Hole In The
Wall Campground, Mid Hills Campground, Nipton and Black Canyon
Equestrian 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 3505 11581 3533 11553 3559 11537 3537 11510
      3487 11552

$$

Morgan

534 
WGUS75 KVEF 100807
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
107 AM PDT Fri May 10 2019

CAC071-100815-
/O.EXP.KVEF.FF.W.0013.000000T0000Z-190510T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
107 AM PDT Fri May 10 2019

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 115 AM PDT...

The heavy rain that caused the Flash Flood Warning has ended. 
Additional flooding impacts are no longer expected. Please continue 
to heed any remaining road closures and be careful of water on 
roadways, especially at night. 

LAT...LON 3505 11581 3533 11553 3559 11537 3537 11510
      3487 11552

$$

TB3

Area Forecast Discussion
National Weather Service Las Vegas NV
724 PM PDT Thu May 9 2019

.SYNOPSIS...An unusual May weather pattern will bring periods of
shower and thunderstorm activity along with cooler temperatures to
the region through the weekend. A concentrated band of rainfall is
likely to develop across southern Nevada and eastern California
tonight which may result in localized flash flooding. Conditions
will dry out and temperatures will climb by early next week.
&&

.UPDATE...Storms over Inyo and San Bernardino counties were
intensifying this evening as 300 mb difluence, low level
convergence, and low level shear all overlapped. Farther north and
east, storms over Lincoln County had been struggling as too many
updrafts competed for too little instability. Updated grids to raise
PoPs in San Bern county and increase QPF for Inyo and San Bern as a
tongue of precipitable water greater than 0.75 inch was poking north
into the storm environment. No changes beyond the immediate term.
Will continue to monitor.
&&

.PREV DISCUSSION...
315 PM PDT Thu May 9 2019

.SHORT TERM...through the weekend.

Shower and thunderstorm activity has increased this afternoon as low
pressure from the intermountain west retrogrades west and forms a
closed low over Nevada and California by Friday morning. A
persistent band of showers extending from southern Inyo through
Mohave County has continued to move east today, but this area has
generally been rather stable and only light to moderate rainfall has
been reported. Further north, closer to the developing low,
thunderstorms have been developing with some heavier rain embedded in
some of these storms. This trend is expected to continue into this
evening with majority of the hires models showing showers and
thunderstorms developing across Inyo, Nye, Lincoln, and Clark
Counties. Increasing instability, plenty of deep moisture and
additional energy from the low should help generate these storms
which are likely to continue through much of the overnight period.
Rainfall totals across Inyo could range from a quarter to half an
inch with half an inch to over an inch across southern Nye, Lincoln,
and parts of Clark County. It is noted that PW values forecast for
this evening are approaching record territory for this time of year.
At this time, changes to the current flash flood watch are not
needed.

The area may see a slight break in coverage Friday morning, but with
afternoon heating and increased instability in the afternoon showers
and thunderstorms are once again expected to develop. At this time
storms look to be a bit more scattered across the region, but with
plenty of moisture still available any storm will be capable of
producing flash flooding.

In addition to heavy rainfall, some winter weather will also be
possible in the high Sierra, mainly above 8,000 feet. While snow
amounts will be fairly minimal by Sierra standards, 3-6 inches of
wet slushy snow may catch outdoor enthusiasts by surprise and can
prove dangerous for those unprepared for the conditions. As such,
issued a Winter Weather Advisory through Friday afternoon for the
higher Sierra elevations.

Rainfall will become more scattered over the weekend with the best
forcing pulling west and south with the low. However,
precipitable water values will remain quite high through the
weekend and the region will remain in a broad cyclonic flow
pattern with daily chances of scattered shower and thunderstorm
activity. At least isolated flash flooding will remain possible.
Temperatures through the weekend will remain several degrees below
normal thanks to the abundance of moisture and cloud cover.

.LONG TERM...Monday through Wednesday.

Closed low which plagued the forecast during the short term period
will begin to lift eastward Monday with ridging attempting to
rebuild over the Southwest. There will still be an abundance of
low level moisture across the region Monday which will be slow to
mix out for the early part of next week, so at least a few terrain
driven showers will remain possible Monday and Tuesday
afternoons. Thereafter, an increasing southwesterly flow aloft
will begin to scour out any remaining moisture thats left across
our region. Meanwhile, temperatures will climb a few degrees each
day, returning to above normal territory Tuesday onward.
&&

.HYDROLOGY...Widespread moderate to heavy rainfall is expected to
produce higher than normal flows in area creeks, washes, and
drainage basins across southern Nevada and Eastern California.
The Amargosa River, Fortymile Wash, Meadow Valley Wash, and Muddy
River may experience elevated flows and increased flash flood
risk. Washes and drainages around the Las Vegas metro area will
also be prone to rapid rises in water levels. Heavy precipitation
in the Sierra along with mid-slope snowmelt may cause elevated
water levels in the eastern Sierra drainages as well. Flash Flood
Watch is in effect Thursday afternoon through Friday afternoon
with these concerns in mind, though at least isolated flood
potential will linger through the weekend.
&&

.AVIATION...For McCarran...Scattered light showers still moving east
across the Las Vegas Valley this afternoon with CIGS around 10-12k
feet. Some scattered clouds around 6-7k feet, but cigs are expected
to lower this evening as showers and thunderstorms become more
widespread. The greatest threat of rain looks to be between 03z and
10z overnight and then again after 18z on Friday with cigs certainly
possible to 5k feet or less. East winds around 6-8 kts into this
evening, but may turn more northerly after 05z with speeds around 10-
15 kts which may continue through the night. Additional scattered
showers and thunderstorms are possible Friday with cigs down to
around 5k feet at times.

For the rest of southern Nevada, northwest Arizona and southeast
California...East to northeast winds over most areas into this
evening before shifting more to the north and northeast after 04z.
Wind speeds should generally remain at 10 kts or less. Weather
conditions will start to deteriorate after sunset with precipitation
increasing over most areas. Lowering cigs down to 5k feet at times
and increasing precipitation chances are expected through Friday.
&&

.SPOTTER INFORMATION STATEMENT...Spotter activation is requested
today and Friday as widespread shower and thunderstorm activity is
expected. Reports of flooding or excessive rain rates are
encouraged.
&&

UPDATE...Morgan
SHORT TERM/AVIATION...Gorelow
LONG TERM/HYDRO...Outler

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