Areal Flood Advisory 3, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
1245 PM PDT Thu Jun 24 2021

.SYNOPSIS...Scattered showers and thunderstorms over the Mojave
Desert and southern Great Basin will dissipate after sunset this
evening. The main threats will be lightning and gusty winds, which
may contribute to new wildfire starts, along with locally heavy
rain. A few leftover storms will be possible in northern Lincoln and
far northern Mohave counties Friday, with dry weather expected
elsewhere. A warming trend will send temperatures to near normal on
Friday and above normal over the weekend, followed by another push
of moisture which could bring more showers and thunderstorms next
week.
&&

.SHORT TERM...Today and tonight. As of noon, thunderstorms were
popping in an area from near Rachel to near Searchlight, as well as
on the Hualapai Mountains near Kingman. Drier air was moving in from
the west, but as has been the case for three days now, the trend
continues to get slower. Thus, storms were initiating a bit farther
west than anticipated, and made manual adjustments to account for
this. The drier air will slowly erode away the storms from the west
as the afternoon progresses, with a rapid weakening trend expected
after sunset. Temperatures will top out slightly below normal in the
western zones where clouds are at a minimum, and farther below
normal in the central and eastern zones where clouds and rain are
more prevalent.

.LONG TERM...Friday through Tuesday.

A few lingering showers and/or thunderstorms in parts of Lincoln
and northern Mohave counties on Friday but otherwise expect dry
conditions elsewhere. An area of high pressure that has been
bringing record-breaking heat to the Pacific Northwest this week
will extend southward, returning above-average temperatures
through the weekend. Though temperatures will not be as
significant nor as long-duration as the last heat event, it's
important that people do not get caught off guard. HeatRisk values
will climb into the "Moderate" category for much of the region,
with valleys inching into "High" and "Very High" going into next
week. Excessive Heat Watches and/or Warnings will likely be needed.

Models continue to hint at a moisture surge up through the Colorado
River Valley next week, but too early, and too low of confidence to
anticipate impacts at this time.
&&

.AVIATION...For McCarran...Light winds favoring an east to southeast
direction are expected through the late morning. Main concern today
will be the vicinity thunderstorms that develop in and around the
Las Vegas Valley. With any thunderstorms that develop, expect
erratic and gusty outflow winds. The potential for a strong outflow
from the south and southeast is probable this afternoon with gusts
to around 25-35 knots. The gusty outflow winds may reach KLAS
between 20-23Z this afternoon, but are possible through 02Z this
evening. Thereafter, winds are expected to resume to more of the
typical south to southwest direction, generally less than 10 knots.
Light and diurnal winds expected tomorrow. SCT to BKN aoa 10 Kft
potentially dropping to 8-9 Kft with storms overhead. Mostly clear
skies overnight with FEW-SCT developing along the higher terrain
tomorrow afternoon. Not anticipating storms Friday.

For the rest of southern Nevada, northwest Arizona and southeast
California...Scattered showers and thunderstorms are expected to
continue across much of Lincoln, Clark, Nye, Mohave and be more
isolated across central to eastern San Bernardino Counties this
afternoon. The main terminals with possible thunderstorm impacts
will be the Las Vegas Valley terminals and the Colorado River Valley
terminals today. With any thunderstorms that do develop, expect
erratic and gusty outflow winds. Storms are expected to diminish
between 02-04Z this evening, and winds are expected to return to
typical diurnal directions overnight. SCT to BKN aoa 10 Kft
potentially dropping to 8-9 Kft with storms overhead. Mostly clear
skies overnight with FEW-SCT developing along the higher terrain
tomorrow afternoon. Mostly dry conditions and light winds are
expected Friday.
&&

.FIRE WEATHER...A Red Flag Warning remains in effect through this
evening for parts of southern Nevada and NW Arizona due to the
potential for dry thunderstorms. Storms that form further south in
eastern San Bernardino County and southern Mohave County should be
able to produce more accumulating rain, lessening the threat of fire
starts from lightning.
&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to
report any significant weather or impacts according to standard
operating procedures.
&&

SHORT TERM...Morgan
LONG TERM...Varian
AVIATION...Peters
FIRE WEATHER...Salmen

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