Winter Storm Warning 7, NWS Reno, NV

Area Forecast Discussion
National Weather Service Reno NV
226 AM PST Thu Mar 2 2023

.SYNOPSIS…

A short break in winter weather activity through Friday will be
followed by another potent winter storm for this weekend. Below
average temperatures continue through the middle of next week as
an ongoing active pattern brings additional snow chances later
next week.

&&

.DISCUSSION…

Now that the March lion briefly sleeps today and Friday, the lambs
have a chance to frolic under clearer skies and lighter winds as
a quick moving upper ridge passes across the region this morning.
But a follow-up weak short wave passing over the the Pacific
northwest will drag across northeastern California and
northwestern Nevada this afternoon and bring enhanced breezes and
a quick overhead pass-by of some mid and high level cloudiness.
Otherwise, quieter conditions will prevail with mostly below
average temperatures continuing into next week...a result of
widespread snow from the recent series of winter storms passing
through the region.

So expect chilly morning lows through the weekend with single
digits to teens for most Sierra locations and Mono County, and 20s
for most lower valley areas. Daytime highs will rise into the
high 20s and 30s across those same Sierra locations with lower
valleys seeing mostly 40s. A few Basin and Range valley locations
may even briefly touch 50 this Saturday.

By the weekend the March lion will be once again be on the prowl.
This will herald the return to a more active weather pattern as
this winter storm system tracks along that well traveled route
this winter season from the Gulf of Alaska into the western US.
The low center presses south along the western Canada coastline
before settling briefly offshore the Pacific Northwest. Once
established offshore the WA/OR coastline, it will loiter around
the base of a long wave trough that extends into western Canada.
From his lofty vantage point, the March lion will swing out his
giant paw and rotate shortwave energy and decent low-mid level
moisture into CA and NV this weekend into early next week.

Spillover into western Nevada will be limited for much of the
initial stages of this storm system’s movement into the Sierra.
Later Saturday evening, however, light to moderate snow and
winter conditions will begin to push into western Nevada as
favorable mid level winds encourage spillover into the region.
Once again, expect the travel delays and road closures not only
across the Sierra, but also into western Nevada through Sunday
morning. Another, weaker upper short wave will surge more energy
with limited moisture across the region Monday into Tuesday.

* WINDS: His growl will be heard first across higher Sierra ridge-
  tops as gusty winds reach 100 plus mph with winds gusting to
  40-50 mph mixing down to western Nevada valleys later Saturday
  morning and afternoon. This will bring impacts that include
  choppy conditions for area lakes as well as LLWS and turbulence
  to aviation interests.

* SNOW: By early Saturday morning, the leading edge of snow
  steadily increases in intensity first across northeast
  California and then spreads moderate to heavy snow across the
  Sierra Saturday afternoon and evening. Blended guidance still
  projects a higher chance (70-80%) for 2-3 feet of accumulated
  snow above 7000 feet as well as 1-2 feet around the Lake Tahoe
  Basin. Guidance also favors a better chance (30-40%) for 1-3
  inches of accumulated snow for western Nevada valleys.
  Surrounding foothill areas above 5000 feet could see another 3-5
  inches of new snow.

Will the March lion continue to roar into late next week?
Ensemble guidance does seem to favor his regal roar the later half
of next week. But timing, strength, and extent remain a challenge
through the remainder of the long-term period. -Amanda

&&

.AVIATION...

* Strong, north winds (40 to 50 kts) will continue along the Sierra
  crest through 15z this morning with mountain wave turbulence
  possible along and west of the crest.

* Dry and cold with VFR conditions on tap for today into Friday
  night. Winds will remain light for all western NV and Sierra
  terminals.

* Quiet weather period will come to an end Sat as the next winter
  storm arrives in the Sierra. Plan on periods of IFR or worse
  conditions, a return of the winds, as well as more accumulating
  snow for the Sierra. Western NV will contend with the strong,
  gusty winds first on Sat afternoon with surface wind gusts
  nearing 40-45 kts. Spillover and snow will arrive Sat night into
  Sun morning.

* The active, unsettled weather will continue through much of next
  week, with periods of winds and snow lending to deteriorating
  flying conditions.

-Edan

&&

.AVALANCHE WEATHER...

Strong easterly ridge winds will subside through this morning and
switch more westerly 20-30 mph today. Temperatures will warm to
above freezing today, potentially as high as 9000 feet.

After a short break, another strong winter storm is expected to
impact the Sierra Saturday through next Monday/Tuesday. Projected
estimates for the Saturday through Monday portion of the storm cycle
are for 2-3" QPF (1-2" in Mono) with the heaviest snowfall expected
Saturday evening through Sunday evening. Another weaker wave on
Monday-Tuesday could bring an additional 0.3-0.7" QPF. Snow levels
will again be quite low with 700 mb temperatures dropping to -12 to -
15C and snow to liquid ratios of ~18 to 1.

Winds will start picking up along the crest Friday evening with
typically strong storm winds gusting 100+ mph along the ridges early
Saturday through Sunday morning. -Zach/Amanda

&&

.REV Watches/Warnings/Advisories...
NV...Winter Storm Watch from Saturday morning through Monday morning
     NVZ002.

CA...Winter Storm Watch from Saturday morning through Monday morning
     CAZ071.

     Winter Storm Watch from Saturday morning through Monday morning
     CAZ072.

     Winter Storm Watch from Saturday afternoon through Monday
     morning CAZ073.

&&