810
FXUS65 KVEF 210001
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
401 PM PST Thu Nov 20 2025

.KEY MESSAGES...

* Rain showers and high elevation snow will move in from west to
  east this evening through tomorrow morning, bringing light to
  moderate precipitation accumulations across the region.

* Snow accumulation trended down with the latest forecast package,
  with winter weather advisories still issued for the Sierra
  Nevada/White Mountains and the Spring Mountains/Sheep Range.

* Cooler than normal temperatures will persist through tomorrow,
  with a warming and drying trend beginning as high pressure builds
  in this weekend.

&&

.DISCUSSION...through Thursday.

The brief break in precipitation for much of the region will end
tonight as a broad low pressure system moves into south central
California and western Arizona this evening. Widespread showers will
bring up to an inch of precipitation in southern portions of San
Bernardino and Inyo counties by Friday afternoon, with the heaviest
precipitation falling from 2am PST to 7am PST. Lighter
precipitation amounts are anticipated for southern Nevada and
northwestern Arizona, with totals ranging from a few hundredths in
valleys up to a half of an inch over northwestern Arizona.
Heavier showers could bring localized areas of higher
accumulations overnight. The Las Vegas Valley will see up to a
quarter of an inch in any heavier showers that form, with a sharp
accumulation gradient from the spotty nature of the precipitation.
Limited instability paired with the timing of the coolest air
passing overnight keeps lightning potential over the region low,
less than 10% for the region. Scattered showers will continue into
the afternoon on Friday, gradually tapering off as the low center
moves into northern Mexico.

Snow accumulations anywhere from 5-10 inches will favor the Sierra
Nevada and White Mountains with trends indicating lower amounts (3-8
inches) for high terrain in southern Nevada. Therefore, winter
weather advisories will be continued for elevations above 6000
feet. The highest accumulations look to be above 8500 feet with
summits seeing up to 12 inches of snow by tomorrow morning.

Temperatures will continue to be slightly below normal today and
tomorrow, with a warming and drying trend returning as high pressure
builds northwest flow into the region over the weekend. Current
forecast models favor normal temperatures with dry conditions over
the region but this regime typically favors embedded shortwaves.
This could bring a slight chance of precipitation next week, but
current forecast confidence in that outcome is low.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast
Package...Clouds increase this evening, with SCT-BKN ceilings
around 8-10kft gradually decreasing to 4-5kft by late evening.
Another round of rain is expected, with rain/snow developing over
the higher terrain surrounding the Valley this evening, with rain
showers moving into the Valley overnight. The window for heaviest
rain looks to be from roughly 08Z-14Z, when there is a 50% chance
for ceilings 3kft or less and a 10-15% chance for ceilings under
1kft and visibility under 6SM. Showers will linger most of the
day, with with ceilings slow to improve/scatter out through Friday
evening. East winds early in the period will become light and
variable by mid evening, with speeds remaining under 8KT
thereafter, settling out of the northeast Friday morning.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Deteriorating flight
conditions are expected through tonight, with increasing clouds
and ceilings falling from 7-10kft early in the period to 3-5kft
this evening and tonight. One notable exception is BIH in the
Owens Valley, where ceilings between 1-2kft are expected through
the period, with persistent rain showers expected to slowly
diminish through the on Friday. Elsewhere, showers will overspread
the area from northwest to southeast through tonight, with
visibility reductions to 3-6SM in heavier rain showers expected,
as well as ceilings under 3kft at times late tonight through
Friday morning. Improvement will be slow, with showers lingering
through Friday evening. Winds will be somewhat variable, with
speeds around 5-10KT, increasing to 10-12KT through portions of
the Colorado River Valley and western Mojave Desert late tonight
and Friday.

&&

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

&&

$$

DISCUSSION...Adams
AVIATION...Phillipson

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