High Wind in Nevada, March 13, 2016

Area Forecast Discussion
National Weather Service Reno NV
330 AM PDT SUN MAR 13 2016

.SYNOPSIS...

A strong winter storm will impact the region through early Monday
with strong winds and periods of heavy mountain snow. 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 for the upcoming week.

&&

.SHORT TERM...

A strong winter storm remains on track early today with snow
falling from western Lassen County south into the Tahoe region.
Not much is currently falling along the crest in Mono County...but
that should change through the day. This winter storm is composed
of a series of impulses moving through a very fast mid/upper level
flow that is also tapping into substantial moisture. This will
bring periods of heavy snow to parts of the Sierra and northeast
California but lesser amounts to the east of the Sierra where
shadowing will be much more common along with very strong winds.
All of this activity winds down late Monday with mainly tranquil
weather for Tuesday.

Snow levels could be a little tricky in the Sierra today. A
substantial push of moisture this morning should keep
precipitation intensity high enough to maintain lower snow levels
through about noon...but then the intensity may ease a bit. This
would allow snow levels to rise briefly in the Sierra and
northeast California...possibly above 6000 feet. That would limit
the amount of accumulations in the lower valleys of the Sierra...
central Plumas County and western Lassen County. Snow levels
should fall again tonight as the core of the colder air moves
into the region...but the amount of precipitation will be winding
down after midnight tonight.

East of the Sierra...a substantial stable layer aloft...noted by
the warming in the forecast soundings and cross sections...will
limit any spillover into far western Nevada to later tonight when
the cold air aloft moves in and causes some instability. To the
north in northwest Nevada and far northeast California, the
chances for precipitation look to be increased today as this area
generally benefits from these stronger pushes of moisture.

Winds will again increase through the day. While the low level
gradient will increase due to the pressure/temperature
differential between the Sierra and western Nevada...the
aforementioned stable layer aloft with its attendant warming is a
tell-tale sign of potential downslope enhancement of the wind
today. The strongest winds east of the Sierra should occur between
about 8 am and roughly 2 pm today when gusts could reach up to 70
mph in wind prone areas. These gusty winds will abate
slightly...but still continue strong into the evening hours and
even into the morning hours Monday for areas south of Highway 50
and east of Highway 395.

The storm exits to the east Monday afternoon/evening with cool
northwest flow developing over the region. A few lingering showers
are possible Monday night along with gusty winds to near 35 mph
in the northwest flow. Ridging starts to develop well to the west
by late Tuesday. We will see some warming aloft but limited
warming at the surface as east to northeast flow in the low levels
locks some below average high temperatures into much of the area
for Monday and Tuesday. 20

.LONG TERM...Wednesday through Saturday...

Highlights:
- Dry with daytime temps near average Wed-Fri, generally light NE-E
winds.
- Ridge weakens next weekend with showers possible (mainly Sunday).
Latest guidance favors a weak and fast moving shortwave with
limited precip totals and snow levels rather high (probably above
7000 feet).

Medium range guidance continues to keep all areas dry through at
least Friday with generally light NE-E winds. With shortwave energy
diving south across the eastern Great Basin late Thursday-Thurs
night, it now appears more likely that temperatures on Friday will
not warm up much from Thursday. Winds may increase a bit Thursday
evening mainly in northwest and west central NV.

For Saturday, ridge is projected to move east across CA-NV. This
should allow a few more degrees of warming with some increase in high
clouds. Precipitation chances appear rather slim through Saturday,
before moisture increases later in the weekend. While the latest
guidance trended weaker, there is still some uncertainty in the
strength of this possible weather system, so keep posted on the
latest forecasts if you have travel or outdoor plans next weekend.
MJD

&&

.AVIATION...

Widespread and significant weather impacts to aviation will continue
today and tonight, with conditions improving later Monday.

-Winds-
The strongest winds are expected from late this morning through early
evening with potential for surface gusts above 50 kt and Sierra
ridge gusts above 80 kt. Some of these strongest winds will
continue through tonight south of Highway 50, while elsewhere winds
will drop slightly. Severe and widespread turbulence with periods of
LLWS and possible lee side rotors, which could lead to flight
delays, cancellations or diverted landings. Windy conditions with
gusts 30-40 kt will persist though much of Monday before diminishing
by early evening.

-Precipitation-
Snowfall will be heaviest in the northern Sierra from the Tahoe
terminals northward today through tonight, with long periods of poor
visibility and low ceilings along with significant snow accumulations
on paved surfaces. Snow will arrive later this afternoon and
continue through tonight for the Sierra south of Tahoe including
KMMH, with lesser accumulations. For western NV including KRNO/KCXP,
the best chance for rain is this evening, otherwise most valleys
will likely be shadowed with the strong winds being the main impact.
MJD

&&

.REV Watches/Warnings/Advisories...
NV...High Wind Warning from 8 AM this morning to 3 AM PDT Monday
     NVZ003-005.

     Winter Storm Warning until 11 AM PDT Monday NVZ002.

     Wind Advisory from 11 AM this morning to 11 AM PDT Monday
     NVZ001-004.

CA...High Wind Warning from 8 AM this morning to 3 AM PDT Monday
     CAZ070-071.

     Winter Storm Warning until 11 AM PDT Monday CAZ071.

     High Wind Warning from 3 PM this afternoon to 11 AM PDT Monday
     CAZ073.

     Winter Weather Advisory until 11 AM PDT Monday CAZ073.

     Winter Storm Warning until 11 AM PDT Monday CAZ072.

&&

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