Lee Vining, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

362
FXUS65 KREV 281038
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
238 AM PST Sat Dec 28 2024

.SYNOPSIS...

* Periods of light showers and breezy conditions continue across NE-
  CA and northern Washoe County today.

* Another storm brings Sierra snow, valley showers, and
  widespread, potentially damaging winds on Sunday.

* Drier and milder weather returns through the New Year, with a
  slight chance of light showers on New Years Eve and Day over
  northeast California and to the Oregon border.

&&

.DISCUSSION

Although high pressure wants to make a brief appearance over the
western US today, an embedded upper short wave trough wants to break
ahead of the advancing ridge axis. What will result will be some
showers moving into northeast CA from the Lake Tahoe Basin
northward, and northern Washoe County through this afternoon.
Winds today for the most part will remain breezy from the
southwest with gusts to 25-35 mph. Any measurable precipitation
will range from a few hundredths to a tenth of an inch around the
Lake Tahoe Basin, and across Lassen County into northern Washoe
County. The brief favorable conditions today will then push east
with the transient upper short wave ridge. Overnight tonight the
upper trough will swing into the West Coast with an attendant cold
front crossing the Sierra into western NV Sunday morning.

Sunday Storm System:

As the upper trough digs south and east into the western US, an
attendant cold front will swing across northern CA early Sunday
morning, then continue across western NV later Sunday morning
through the afternoon. This last in a series of AR supported storm
systems will bring more higher elevation snow, valley rain
showers, and strong southwesterly winds to the region.

* Winds: Look for another round of strong southwest winds with
  gusts up to 40-50 mph in western NV valleys, and 120+ mph across
  Sierra ridges. Wind prone areas along the I-580 corridor through
  the Washoe Valley, Highway 395 corridor through Douglas County
  into Mono County, and Highway 95 through Mineral County will
  once again see a 40-60% chance for peak gusts around 60+ mph
  with this storm system as well. Therefore, a High Wind Warning
  was hoisted for the Sierra Front, Mono, and Mineral Counties
  with Wind Advisories for all other Basin and Range forecast
  zones.

Impacts: Be prepared for hazardous driving conditions, especially
for high profile vehicles, frequent periods of mountain wave
turbulence, rotors, and LLWS for aviation concerns, choppy lake
conditions on larger area lakes, and periods of blowing dust in dry
lake beds/playas for the Basin and Range. Other potential impacts
include downed trees, powerlines, and power outages.

* Precipitation: Light to moderate snow accumulations, with
  blended guidance projecting a 40-60% chance for up to 4-8 inches
  of snowfall possible at higher passes such as Donner Summit,
  Echo and Carson Pass. Snow levels will start near 8000-8500 feet
  this afternoon and evening before dropping to 5500-6000 feet by
  Sunday evening. Look for a slushy, wet snowfall to begin around
  4-7 AM Sunday for Donner Pass before tapering off later Sunday
  night. Blended guidance even projects a 30-50% chance for at
  least a foot of snowfall on higher western peaks around the Lake
  Tahoe Basin. Therefore, a Winter Weather Advisory was hoisted
  for Lassen, eastern Plumas Counties, as well as the Lake Tahoe
  Basin to include eastern Alpine County from 5AM to 8PM. Snow
  amounts at lake level will be limited with an inch at most.

Impacts: Gusty southwest winds and periods of moderate snow may
create additional travel challenges over higher mountain passes
Sunday morning and afternoon, before tapering off Sunday night.

Monday Onward Through the New Year:

* Drier and milder conditions return early next week as high
  pressure ridges into the region. A quick hitting backdoor short
  wave trough may bring an increased chance for a light shower or
  two nearer the Oregon border on Wednesday. Otherwise, look for
  drier conditions and a return of valley inversions under clear
  skies and lighter winds to ring in the New Year. Please stay
  updated on changing conditions and travel safely!

 - Amanda

&&

.AVIATION...

12Z Saturday through 12Z Sunday:

Strong westerly flow aloft will persist through the weekend, with
the main impact being strong winds, periods of moderate to severe
turbulence, rotors, and low-level wind shear.

* Snow Levels: Rising to 8000-8500 feet today decreasing to 5500-
  6000 feet by late Sunday. Snow accumulations will be limited to
  an inch or less at KTRK-KTVL by late Sunday before showers
  taper.

* Showers: Light rain possible at KTVL/KTRK 18-00Z today, with
  MVFR conditions and terrain obscuration along the Sierra crest.
  Most widespread MVFR conditions due to heavier showers will
  occur late Sunday morning and afternoon.

* Winds: FL100: 40-50+ knots today, increasing to 55-70 knots
  Sunday between 15-21Z.

* LLWS: expected near all area terminals through 18Z this morning,
  and after 12Z on Sunday.

-Amanda

&&

.AVALANCHE...

A brief break today will still see ridge winds staying elevated
throughout the day with light showers continuing along the Sierra
crest from the Lake Tahoe basin northward. The next storm moves
through Sunday, bringing strong winds and the potential for light
snowfall in the Sierra, mainly above 7000 ft in the Lake Tahoe
Basin, and above 8000 ft in the Eastern Sierra. A High Wind Watch
has been issued for the Greater Lake Tahoe Area, Sierra Front, and
Mono County from 1:00 AM to 8:00 PM PST Sunday.

Today:

* Timing: Light showers through the day.

* Snow Levels: 8000-8500 feet.

* Winds: Sustained ridge winds above 60 mph with gusts up to 80 mph,
  contributing to wind shear at ridgetop level.

* Precipitation: Up to 0.10 inches of liquid equivalent along the
  Sierra crest in the Tahoe Basin with little to no precipitation
  south of US-50.

* Probabilities: 20-40% chance of SWE exceeding 0.2 inches in 24
  hours above 7000 feet along the Sierra crest north of Ebbetts Pass.

* Insolation: Limited solar intensity due to partly to mostly cloudy
  skies.

Sunday`s Storm System:

* Timing: Precipitation begins after 4 AM Sunday and peaks in the
  afternoon. Residual showers will remain Sunday night into Monday
  morning.

* Snow Levels: Falling from 7500 feet late Saturday night to 5500-
  6000 feet by Sunday evening.

* Winds: Sustained ridge winds continue above 90 mph, with gusts
  potentially exceeding 120 mph, contributing to wind shear at
  ridgetop level.

* Precipitation: 1-1.25 inches of SWE along the Sierra crest west
  of Lake Tahoe to Carson Pass and 0.25-0.50 inches in the Eastern
  Sierra decreasing from north to south, with snowfall rates
  exceeding 1 inch per hour at times in the afternoon, especially
  north of Sonora Pass.

* Probabilities: 30-60% chance of SWE exceeding 1 inch in 24 hours
  above 7000 feet north of Sonora Pass and 10-20% chance above 8000
  feet south of Sonora Pass.

* Insolation: Limited solar intensity due to dense cloud cover.

-Amanda

&&

.HYDROLOGY...

Minor river rises are forecast in northeast California, particularly
for the Susan and Pit Rivers, between today and Sunday.

* Probabilities: Susan River at Susanville: <1% chance of reaching
  action stage on Sunday. Pit River at Canby: <5% chance of reaching
  action stage on Sunday.

Flows on both rivers are expected to rise to nearly four times
current levels by Sunday, though flooding is not anticipated.

-Johnston/Amanda

&&

.REV Watches/Warnings/Advisories...
NV...Wind Advisory from 10 PM this evening to 4 PM PST Sunday NVZ005.

     Winter Weather Advisory from 5 AM to 8 PM PST Sunday NVZ002.

     Lake Wind Advisory until noon PST today NVZ002.

     High Wind Warning from 4 AM to 7 PM PST Sunday NVZ001-003.

     Wind Advisory from 7 AM to 7 PM PST Sunday NVZ004.

CA...Wind Advisory from 10 PM this evening to 4 PM PST Sunday CAZ070.

     Winter Weather Advisory from 5 AM to 8 PM PST Sunday CAZ071-072.

     Lake Wind Advisory until noon PST today CAZ072.

     High Wind Warning from 4 AM to 7 PM PST Sunday CAZ073.

&&

$$