661
FXUS65 KVEF 192024
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
124 PM PDT Mon Oct 19 2026

.KEY MESSAGES...

* An incoming trough brings widespread rain and mountain snow
  chances, gusty winds, and below normal temperatures midweek.

* Increasing confidence for a dry conditions and warming
  temperatures this weekend.

&&

.DISCUSSION...Through the Weekend.

An upper level trough, currently centered off the coast of Oregon,
will bring significant chances in the weather pattern this week as
it plunges south and east. Precipitation chances start to appear
over high terrain on Tuesday afternoon due to increasing moisture
and difluence aloft. However, more widespread precipitation is
expected on Wednesday and Thursday as the trough moves into Southern
California. Moisture advection brings PWATS into the 0.5 to 1.0 inch
range, which is 200 to 300 percent of normal for late October.
Elevated moisture combined with instability driven by strong winds
aloft and cold air under the low may prompt particularly efficient
rain rates on Wednesday and Thursday. Forecast soundings show 500-
1000 J/kg MUCAPE and 40+ knots of shear starting Wednesday afternoon
in southern Nevada and northwestern Arizona. Snow levels remain
above 10,000 feet on Wednesday and fall to around 8,500 feet on
Thursday. Although the trough moves east by Friday, lingering
moisture and instability may support additional showers over high
terrain. Forecast confidence in timing for specific locations should
increase with additional high resolution guidance.

Another notable impact will be increased winds starting Tuesday. 850
mb wind speeds increase to 25 to 30 knots. For Tuesday, the
strongest surface winds will be in the Owens Valley and southern
Great Basin. Peak gusts will generally be in the 25 to 35 mph range,
with a low probability (10-20%) of wind gusts reaching 40 mph in the
afternoon. Southerly winds spread to most of the remainder of the
forecast area on Wednesday as the low tracks southeast. Lingering
southwesterly breezes remain across the Mojave Desert on Thursday
before the system moves out.

A ridge should develop this weekend as the trough moves off into the
Four Corners. Moisture will scour out and dry conditions are
expected. Temperatures remain several degrees below normal for this
time of year, but will increase a degree or two compared to
temperatures midweek.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...
Fairly quiet and benign conditions expected for the next 24-30
hours. Light winds favoring an E to NE direction under 8KT develop
late this morning and afternoon. Around 02-04z, light winds shift to
a more WSW direction and remain light and variable throughout the
night. VFR conditions will continue with a few passing clouds around
10-12kft.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Very quiet and benign
conditions to persist through the TAF period. Winds follow typical
daily directional patterns and remain around 8KT or less the next 24
hours. The only exception will be KBIH, where southeasterly up-
valley winds gusting to 15-20KT are expected to develop this
afternoon. Elevated southerly winds may persist a few hours after
sunset at KBIH before becoming light and northerly after 06z. VFR
conditions prevail with no operationally significant cloud cover.

&&

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

&&

$$

DISCUSSION...Meltzer
AVIATION...Moore

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NWS Las Vegas (VEF) Office