Heavy Snow and High Wind in California, March 12 to 14, 2016

Area Forecast Discussion
National Weather Service Reno NV
303 AM PST SAT MAR 12 2016

.SYNOPSIS...

A series of winter weather systems will impact the region this
weekend bringing gusty winds along with periods of mountain snow and
valley rain. Snow amounts will be significant across the northern
Sierra and higher terrain of northeast California with significant
impacts to travel. Drier and warmer conditions will return next
week.

&&

.SHORT TERM...

A multi-part winter storm will begin to impact the region today and
persist through Monday with several rounds of heavy Sierra snowfall
and intense winds expected. A few of the highlights and specifics
can be found below:

Winds:

Two rounds of strong and gusty winds are expected this weekend with
winds strengthening today followed by the stronger and more
severe event for Sunday. For today, winds across Lake Tahoe have
already increased this morning and have hoisted a Lake Wind
Advisory. Winds will increase through the afternoon with south to
southwest wind gusts of 45-55 mph expected from Reno north along
Hwy 395 to Susanville and across northwest Nevada.

Sunday's stronger winds will stem from the arrival of a powerful
upper level jet, increased surface gradient, and mechanical
mixing of a whopping 70 kts at 700 mb. This may translate to
widespread gusts between 55-65 mph with wind prone areas having
the potential to reach the 70-80 mph range. A High Wind Watch
remains in place for Sunday along the Hwy 395 corridor north of
Mono County. Have also included the western Nevada Basin and Range
to the High Wind Watch for Sunday (includes Pershing and Churchill
counties). Significant wind impacts are expected which include:
dangerous boating conditions on area lakes, hazardous cross winds
for high profile vehicles, low visibility in blowing dust, and the
potential snapping of weak/drought stressed trees.

Rain and Snow:

The first swath of moisture will push across western Lassen County
by this afternoon and Sunday, but will feature a fairly sharp
mountain precipitation shadow until the main shortwave trough
produces the heaviest push of precipitation and spillover Sunday
evening into Monday morning. Substantial travel impacts across the
Tahoe basin can be expected by late this afternoon and early
evening. Snow levels will remain below 6000 feet today and tonight
with the possibility of 4-8 inches of snowfall along pass level
through the Tahoe basin by early Sunday morning. Much of Mono
county will remain dry until the moisture plumes dips south during
the day Sunday.

Snow levels will rise a bit during the day Sunday which may produce
a period of a rain/snow mix at lake level. This should return to
all snowfall as snow levels drop with the main period of heaviest
snow which is expected by Sunday afternoon and evening. A Winter
Storm Warning is in place later this afternoon through Monday
morning for the Sierra mainly north of Mono County into Lassen
County. All told 2 feet of snowfall is possible above 7000 feet
with up to 3 feet right along the crest. Roughly 10-18 inches are
possible at lake level with 15-20 inches possible along highway
89. Mono County will miss the bulk of the moisture but still
possible to receive 1-1.5 feet of snow right along the crest
mainly across northern Mono County. Have issued a Winter Weather
Advisory as a result. Snow impacts through Sunday for western NV
down into eastern Mono County east of Hwy 395 are going to be
little or none as these areas remain mostly shadowed with higher
snow levels. The system will quickly depart by Monday afternoon
with only lingering light snow showers expected. Fuentes

.LONG TERM...Tuesday through Friday...

Ridge building near the west coast will keep dry conditions and
light winds through the remainder of next week with temperatures
near or slightly above average. There is a little more discrepancy
with the evolution of this ridge, as some of the medium range
guidance sources keep the axis west of the Sierra through late in
the week as shortwave energy moves south across the Rockies or
eastern Great Basin. Therefore we will only indicate slow warming
through Thursday, with a more notable jump in temps by Friday with
some of the warmer valleys approaching 70 degrees.

There may be some precipitation returning by next weekend, although
latest guidance was trending notably weaker with weather systems
reaching the west coast. This is a substantial departure from
previous guidance data which hinted at a potentially deep low
pressure approaching the west coast with widespread moisture
spreading inland across the Sierra. MJD

&&

.AVIATION...

Periods of strong winds will keep widespread turbulent conditions
with substantial impacts to aviation travel throughout the weekend.
The strongest winds are expected Sunday with potential for surface
gusts above 50 kt and Sierra ridge gusts above 80 kt which could
lead to flight delays, cancellations or diverted landings. LLWS is
most likely later this evening through Sunday morning when surface
winds subside, but stronger winds persist at ridge level and
foothill locations. Lee side rotors are also possible at KRNO, KCXP,
and KMMH this weekend and are near impossible to forecast ahead of
time. Be on the lookout for lighter surface winds from an odd
direction compared to surrounding locations.

In addition to the winds, unsettled weather will add to the aviation-
related hazards with periods of mountain snow. Snowfall will be
heaviest in the northern Sierra from the Tahoe terminals northward
later this afternoon through Sunday night, with potentially long
periods of poor visibility and low ceilings and significant snow
accumulations on paved surfaces. Snow will arrive later for the
Sierra south of Tahoe including KMMH, mainly Sunday thru Sunday
night with lesser accumulations. For western NV including KRNO/KCXP,
rain is possible Nevada Sunday night into Monday, but otherwise most
valleys will likely to be shadowed with the gusty winds being the
main impact. MJD

&&

.REV Watches/Warnings/Advisories...
NV...Wind Advisory from 7 AM this morning to 7 PM PST this evening
     NVZ003-005.

     High Wind Watch from Sunday morning through Sunday evening
     NVZ003-005.

     Lake Wind Advisory until noon PST today for Lake Tahoe in NVZ002.

     Winter Storm Warning from noon PST today to 11 AM PDT Monday
     NVZ002.

     Lake Wind Advisory from 7 AM this morning to 7 PM PST this
     evening for Pyramid Lake in NVZ004.

     High Wind Watch from Sunday morning through late Sunday night
     NVZ004.

CA...Wind Advisory from 7 AM this morning to 7 PM PST this evening
     CAZ070-071.

     High Wind Watch from Sunday morning through Sunday evening
     CAZ070-071.

     Winter Storm Warning from noon PST today to 11 AM PDT Monday
     above 5000 feet in CAZ071.

     Winter Weather Advisory from 5 AM Sunday to 8 AM PDT Monday for
     Pyramid Lake in CAZ073.

     Lake Wind Advisory until noon PST today for Lake Tahoe in CAZ072.

     Winter Storm Warning from noon PST today to 11 AM PDT Monday
     CAZ072.

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For more information from the National Weather Service visit...
http://weather.gov/reno