342
FXUS65 KVEF 071505
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
805 AM PDT Mon Oct 7 2024

.SYNOPSIS...Dry and unseasonably warm conditions will persist
through the week as high pressure remains over the southwest.
Temperatures are forecast to cool somewhat by the weekend, and
breezier conditions will develop as a trough of low pressure
approaches the western US. However, temperatures will still remain
several degrees above normal.

&&

.UPDATE...A very subtle cooling trend begins today as a weak system
tries to break down this stubborn ridge. High clouds increase this
afternoon while isolated showers/virga develops over our
northwestern areas. Measurable rain is very unlikely with this
activity as most precipitation will evaporate before reaching the
ground, resulting in localized gusty winds. Temperatures continue to
cool tomorrow and Wednesday with the system moving overhead.
However, it fizzles out mid-week and temperatures hold steady at 10-
12 degrees above normal until the weekend when another system
approaches.

&&

.SHORT TERM...Today and Tuesday.

Another hot day is in store for the region today as a ridge of
high pressure remains over the area. High temperatures are
forecast to top out at 99 at KLAS today, which would tie the daily
record. The NBM probability of 100 degrees is around 10 percent,
so there is still a chance we can reach that today and extend the
record for the latest 100-degree day and the record for the number
of 100-degree-plus days in a calendar year. By Tuesday, a weak upper-
level trough will move across the southern Great Basin, allowing
heights to fall modestly. This will allow temperatures to decrease
slightly, although readings will still be well above seasonal normal
levels. The Excessive Heat Warning remains in place through 8 PM
this evening for the Colorado River Valley, Morongo Basin, and Death
Valley. The heat risk decreases to moderate or lower in most areas
tomorrow, with only a few pockets of major heat risk in the lower
Colorado River Valley and Death Valley. Of course, if future model
runs suggest temperatures will be slightly warmer tomorrow, the
warning may need to be extended until Tuesday evening.

Mid-level moisture streaming in from the Pacific Ocean ahead of
the short wave trough will move across northern Inyo, Esmeralda,
and central Nye counties again today. This will result in a few
weak showers and areas of virga over the Sierra and higher peaks
of the southern Great Basin this afternoon and early evening. The
low-level air mass remains quite dry, and DCAPE in the area is
forecast to be around 1200 J/kg so any showers that do develop
will be capable of producing locally gusty winds. Elsewhere, dry
conditions are expected through Tuesday.

.LONG TERM...Wednesday through Sunday

What`s left of the early week shortwave trough over southern
California early Wednesday will continue to weaken and and move to
our south through the day. With the shortwave out of the picture, a
broad ridge of the high pressure remains in place through Thursday.
Temperatures will stay warm, at least 10-12 degrees above normal
Wednesday and Thursday.

A more significant trough over the northeast Pacific looks to weaken
as it moves into northern California Friday, and into the Great
Basin next weekend. South to southwest winds will likely increase
during that period. Right now, latest NBM temperature guidance
only suggests a minimal dip in temperatures with high still
running some 6-10 degrees above normal.

&&

.AVIATION...For Harry Reid...No aviation impacts are expected today
with continued light winds favoring a typical easterly direction
during the afternoon and west-southwest components at night. FEW-SCT
clouds above 15 kft AGL this afternoon and tonight.

For the rest of southern Nevada, northwest Arizona and southeast
California...No significant aviation impacts are expected across
most of the region with winds less than 10 knots and FEW-SCT clouds
above 15 kft MSL. The exception will be over the area from the
Southern Sierra across south central Nevada where shallow high-based
convection may result in erratic winds near areas of virga this
afternoon and early evening.

&&

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

&&

$$

UPDATE...Woods
SHORT TERM...Planz
LONG TERM...Pierce
AVIATION...Adair

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