High Wind in Nevada, February 26, 2024

Area Forecast Discussion
National Weather Service Reno NV
331 AM PST Mon Feb 26 2024

.SYNOPSIS...

Windy conditions will prevail today into tonight, with periods of
lighter snow producing slick travel conditions at times for Sierra
passes. After a cooler day Tuesday, we'll see some warming
Wednesday with generally quiet weather. A major winter storm is
still on track to bring widespread and significant wind and snow
impacts for the region from Thursday into the upcoming weekend.

&&

.DISCUSSION...

Bottom Line Up Front: Although this week will start out windy and
cooler with light precipitation, the main focus will shift to
Thursday into the first weekend of March when a large and intense
winter storm bears down on the Sierra and western NV. For much of
the region, this could be an event we'll be talking about for a
while, with dangerous wind and snow impacts.

Today's weaker storm (see our Wind/Winter Weather Advisory
statements for more details on expected peak gusts and snow
amounts):

* Moisture and upslope flow streaming inland from an upper low
  well off the CA coast will bring periods of mainly light snow to
  areas near the Sierra crest, forming in the mid-late morning and
  peaking in coverage during the afternoon. While the mainly
  daytime snowfall will limit travel impacts for most Sierra
  passes, well-placed bands of heavier showers could produce
  short periods of slushy or snow covered roads for a portion of
  this afternoon's commute.

* Meanwhile, a cold front dropping into the Great Basin from the
  north will bring gusty winds sufficient for travel impacts to
  high profile vehicles, especially for higher elevations and
  areas of western NV from US-50 northward. This front will also
  produce a band of rain and snow showers across the Surprise
  Valley and far northwest NV this afternoon, then shift into
  Pershing County and eastern Churchill County through the
  evening. Its fast movement will limit snowfall amounts, but this
  band could lay down up to 1" of snow and produce patchy slick
  roads on I-80 from Lovelock eastward and US-95 north of Fallon.
  A light dusting of snow may also extend farther west to near
  Reno-Sparks and US-50 west of Fallon late tonight, although
  gusty winds would more likely blow the snow off the main road
  surfaces before it has a chance to stick. Even so, early
  commuters on Tuesday morning should allow some extra travel time
  as temperatures drop below freezing.

Tuesday-Wednesday, Quieter weather but recommended storm
preparation days:

* Behind the cold front passage, highs on Tuesday will drop to the
  40s across most areas, about 4-8 degrees below average. Winds
  will decrease, although some brisk north gusts linger for
  Mineral and southern Lyon/Mono counties. Wednesday will see the
  most benign weather of the week, with about a 10 degree increase
  in temperatures and southwest breezes in the afternoon. For
  those with Sierra travel plans, it is recommended to arrive by
  Wednesday night and have a few days of adequate supplies,
  including non-perishable items in case of potential power
  outages and/or impassable roads buried in snow.

Thursday-Sunday, Major high-impact storm for wind, snow and cold--
especially for the Sierra and far western NV:

* Medium range ensemble guidance continues to show moderate-high
  chances (60+%) for strong, potentially damaging winds (gusts 55+
  mph) across western NV/northeast CA valleys Thursday into Friday
  as a strong cold front crashes through the area, supported by a
  150+ kt Pacific jet stream. For Sierra ridges, peak gusts of
  120+ mph are virtually certain (80+% chance) at times from
  Thursday afternoon through Saturday morning.

* The main factor for snowfall totals will be the duration of the
  heaviest snow, especially when occurring during the night hours.
  The most likely onset of snow for the Sierra/northeast CA is
  during the day Thursday, with the most intense snowfall
  (2+"/hour rates) projected from Thursday night through Saturday
  morning. Additional snow could develop during the remainder of
  Saturday and Saturday night as the main low moves across the
  Sierra, although guidance shows less certainty with this
  feature's location. Solid confidence (75% chance) exists for 2+
  feet of snow in the Tahoe basin, central Mono County along
  US-395 and higher elevations (5500+ feet) of northeast CA. Lower
  elevations aren't out of the mix either, with a similar 75%
  chance for 12+" in northeast CA west of US-395 and foothills of
  far western NV (~5000+ feet). For lower valleys (below
  4500-5000'), precip likely begins as rain Thursday night,
  changing to snow by either Friday or Friday night. Any precip
  from Saturday morning onward will be snow at all elevations as
  cold air spreads across all of western NV. Because of the wider
  time window of a changeover to snow for the urban valleys (Reno-
  Sparks, Carson City, Minden), confidence in the snow totals is
  lower, but 6" or more currently appears to be at a 50/50 chance.
  Farther east across west central NV, snow amounts look far
  less impressive, but the arrival of the cold air (15-20 degrees
  below average) would lead to slick roads even with lighter
  snowfall.

As with any storm projection this far in advance, there's a slim
potential of the track wobbling off its current course and
producing amounts below these initial expectations. However, this
particular storm has shown more consistency than any other system
we've tracked so far this winter season. MJD

&&

.AVIATION...

* Widespread mountain wave turbulence near/east of the Sierra
  through tonight with steady WSW 40-60+ kt winds and gusts 80-100
  kt across Sierra ridges. Enhanced LLWS concerns will be present
  though early this afternoon, then stronger winds mix down to
  lower elevations with gusts 30-40 kt most likely from 18z-03Z at
  the western NV terminals.

* This storm is mainly a wind producer, but will also bring a
  period of rain and snow showers to the region, with MVFR/brief
  IFR at Sierra terminals mainly from 18Z-03Z. For western NV,
  mainly VFR conditions prevail although mountain top obscurations
  are likely this afternoon and tonight. Snow accumulation up to
  2" accumulation at KMMH with less than 1" at KTVL/KTRK, and
  spotty light rain showers into western NV. About a 20% chance
  for brief -SHSN between 04-08Z tonight at KRNO/KCXP but no
  accumulation is expected on paved surfaces.

* Breezy northerly flow continues into Tuesday, but speeds will be
  significantly lighter than today. The next period to keep an eye
  on will be Thursday through Sunday as a potent winter storm
  makes its way into the region with widespread strong winds and
  heavy snow. Dawn/MJD

&&

.AVALANCHE...

* WINDS: Sustained WSW winds 50-75 mph on exposed ridges with
  peak gusts 100-120 mph continue until around 2 AM Tuesday.

* SNOWFALL RATES/AMOUNTS: Peak snowfall rates generally up to
  0.5"/hour with shorter bursts near 1"/hour between 12 noon and 8
  PM. Total amounts 6-10" along the immediate crest, dropping to
  around 2-4" between 6500-7000 feet.

* SNOW-LIQUID RATIOS/SWE: Moderate moisture content of about
  10-12:1. Liquid SWE totals of 0.4-0.8" along the Sierra crest,
  rapidly dropping eastward with 0.15-0.30" down to near 6500
  feet west of CA-89 near Tahoe, and down to near 7000 feet west
  of US-395 in Mono Co.

* Major winter storm is shaping up for late Thursday and through
  much of the upcoming weekend. High confidence for very strong
  winds combined with prolonged heavy snowfall rates.

&&

.REV Watches/Warnings/Advisories...
NV...Wind Advisory from 4 AM Monday to 4 AM PST Tuesday NVZ003>005.

     Lake Wind Advisory from 4 AM Monday to 4 AM PST Tuesday NVZ002.

     Winter Weather Advisory from 6 AM Monday to 4 AM PST Tuesday
     NVZ002.

CA...Wind Advisory from 4 AM Monday to 4 AM PST Tuesday CAZ070-071.

     Lake Wind Advisory from 4 AM Monday to 4 AM PST Tuesday CAZ072.

     Winter Weather Advisory from 6 AM Monday to 4 AM PST Tuesday
     CAZ072-073.

&&