Area Forecast Discussion
Issued by NWS Reno, NV

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000
FXUS65 KREV 282220
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
320 PM PDT Thu Mar 28 2024

.SYNOPSIS...

We are in a brief break between storms through Friday morning. The
next storm arrives midday Friday bringing waves of valley rain and
mountain snow through the holiday weekend. Brief mild and dry
conditions return early to mid next week with more active weather
possible by late next week.

&&

.DISCUSSION...

Key Points:

* Lingering Showers with Breezes Today: Isolated snow showers will
  be possible through the afternoon from Tahoe northward with
  little accumulations (up to 1" possible). Plan on breezy
  southwest winds persisting through the evening today.

* Easter Weekend Storm: Increasing confidence exists for a longer
  duration storm to bring multiple rounds of mountain snow and
  valley rain/rain-snow mix Friday through Easter. Heaviest
  precipitation rates are aimed at late Friday - Saturday. Holiday
  weekend travel difficulties are likely in the Sierra, especially
  during the nighttime hours.

* Quieter Weather Early April: We are still expecting a break in
  precipitation for the first few days of April. Gusty northeast
  ridge winds are possible across Sierra ridges as high pressure
  builds.

For the incoming holiday weekend storm, the snow accumulation
potential has been trending up from day-to-day. The key player in
the eventual snow totals will be the cut off low`s trajectory as
it slides into the West. Recent simulations drop the low center
just off the CA coast with wrap-around bands of moisture into the
Sierra and western Nevada. There is potential for a deformation
zone to set up Saturday night into Sunday as the low passes over
the region, which would boost precipitation potential across the
I-80 corridor, but we will have to see if this shows up in higher
resolution simulations as we get closer to the event. Snow
probabilities are hanging on with about a 50-60% chance of 12" of
snow or more along the Sierra crest, with probs nearing 85% for
Mono county. For Sierra communities (including Truckee, South
Lake, and Mammoth Lakes), there is a 50-70% chance for greater
than 6" of snow through Sunday. Plan on travel slowdowns across
the Sierra, especially since we`re in the vicinity of spring
break vacation time! Daytime snow accumulations may be more
difficult to come by in the Sierra, but with extra travelers on
the road along with precipitation, you can plan on taking it slow
in the Sierra.

As the upper level low digs south and east into the four corners
region, we see a ridge building in on heels. Northeast to east
ridge winds will develop behind the exiting trough and building
high pressure that may result in some aviation turbulence along
and west of the rest and backcountry recreation concerns.
Ensemble clusters are in decent agreement with this brief pattern
shift, but then midweek into late next week we see the arrival of
more trough potential. Along with the ridge, blended guidance
highlights a warming trend from Monday into Wednesday for next
week, but the temperatures spread by Thursday which aligns with
the potential for more disruptive weather to arrive by mid to late
next week.

-Edan


&&

.AVIATION...

WINDS: FL100 winds decreased across the Sierra and western Nevada
and will continue their downward trend overnight. Surface winds
through the afternoon and evening will remain westerly with gusts 20-
30kts for most regional terminals with winds tapering off after 3z
Friday.

PRECIPITATION: VFR conditions for much of the afternoon and evening
before the next storm arrives on Friday. KTRK/KTVL may experience a
few isolated snow showers between 21z-6z.

NEXT STORM: A long-duration storm arrives Friday with multiple
rounds of Sierra snow and a mix of rain/snow to valley areas. Snow
showers will result in periods of MVFR/IFR conditions in the Sierra
for KTRK/KTVL/KMMH Friday overnight into Sunday before the trough
slowly moves out of the region Monday. Can`t rule out some periods
of light snow for KRNO/KCXP/KMEV as well, especially on late
Saturday into early Sunday, but blended guidance shows a less than
15% chance of accumulation for now.

-Edan

&&

.AVALANCHE...

The next storm pushes into the Sierra on Friday and brings multiple
waves of precipitation through Sunday afternoon.

* Liquid totals (SWE): For Mono county above 7000 feet, 0.5" - 2.5"
  from Friday through Sunday afternoon. For the Tahoe Basin along
  the crest 1.5"-2.5", and around 1" in the Basin.

* Peak Snowfall Rates: For the Tahoe Basin, 1-2" per hour rates will
  be possible Friday afternoon with another round possible after
  8pm. For Mono County, the best time frame for 1-2" per hour rates
  in the high Sierra appears to be 8pm until 4am on Saturday for
  now.

* Snow-Liquid Ratios: Drier snow ratios around 10-13:1 for much of
  the storm.

* Peak Ridge Level Wind Gusts: Winds won`t be as strong with this
  storm with peak wind gusts 40 to 50 mph possible along the Eastern
  Sierra crest.

-Edan


&&

.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory from 11 AM Friday to 5 PM PDT Sunday
     NVZ001-003.

     Lake Wind Advisory until 8 PM PDT this evening NVZ002-004.

     Winter Storm Warning from 11 AM Friday to 5 PM PDT Sunday NVZ002.

CA...Winter Weather Advisory from 11 AM Friday to 5 PM PDT Sunday
     CAZ071.

     Lake Wind Advisory until 8 PM PDT this evening CAZ072.

     Winter Storm Warning from 11 AM Friday to 5 PM PDT Sunday
     CAZ072-073.

&&

$$


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