684
FXUS65 KREV 211959
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
1259 PM PDT Tue May 21 2024

.SYNOPSIS...
Progressive weather pattern across the West tosses a few upper level
waves into the Sierra and western Nevada this week and into the
holiday weekend. Plan on enhanced afternoon and evening breezes
Wednesday and Saturday, as well as some low chances (10-15%) for
showers and thunderstorms in the afternoons starting on Friday.
Forecast temperatures will hover around seasonal values.

&&

.DISCUSSION...

Key Points:

* Enhanced breezes will develop on Wednesday and Saturday afternoons
  this week bringing periods of choppy lakes and bumpy aviation
  conditions. Otherwise, plan on typically breezy afternoons through
  the holiday weekend.

* We`re still looking at a 10-20% chance for some Sierra showers
  and isolated thunder starting Friday afternoon with the
  potential persisting through the holiday weekend.

* Takeaway: Outdoor plans this weekend? Be prepared for periods of
  gusty afternoon winds for much of the region Wed and Sat. Watch
  the skies for building clouds and listen for thunder. When thunder
  roars, go indoors (sturdy building or vehicle, not a tent).


Details:

A rather progressive weather pattern in place across the West will
allow for multiple shortwaves and troughs to migrate through the
Sierra and western Nevada. Overall, these troughs will be dry and
result in wind increases and direction shifts. The better
potential for wetting rains through the long weekend will be
across Oregon and Idaho. That doesn`t mean we will be completely
out of the precipitation game, but our chances will be around
10-20% at the most from Friday through Memorial Day and primarily
along the Sierra. This is subject to change day-to-day since it
will rely heavily on the trajectory of the passing troughs through
the region. Don`t check the forecast once and assume you`re "good
to go" for the weekend. Weather forecasts are updated 2/day as
improved, higher resolution data becomes available.

WINDS: The primary concern over the next several days will be the
potential for enhanced wind gusts on Wednesday and Saturday
afternoons. Peak wind gusts will be around 30-40 mph late Wednesday
as the dry front passes through the region. While there may be a
period of choppy lake conditions late in the day, the rapidly
shifting wind direction may prevent alignment with the fetch of
Lake Tahoe or Pyramid Lake long enough to warrant lake wind
advisories.

SHOWERS: There is a less than a 5% chance for showers today
through Thursday. The potential for showers and storms is
slightly higher on Friday, but still topping out at 20% for the
Sierra. The storm potential over the Holiday weekend isn`t zero,
but it is on a downward trend with chances less than 10% for the
Sierra. Just keep in mind this may change with how the shortwaves
drift through the region.

Early Look at Next Week: Ensemble clusters show a ridge signal for
the Great Basin that will be in contention with a trough over the
Eastern Pacific. For now the ridge signal appears to be "winning"
the synoptic battle with a trend for drier conditions and a
general warming trend. Any west or eastward shift in the ridge
axis will dictate the extent of warming or drying we will
experience following Memorial Day. Just for example, the blended
model guidance for max temperatures on May 31st for Reno ranges
from 84 to 94 degrees.
-Edan

&&

.AVIATION...

* Plan on light winds and VFR conditions for all terminals today. A
  few cumulus buildups along the Eastern Sierra may produce SCT sky
  conditions near KMMH, but shower and thunderstorm probabilities
  are less than 5% this afternoon and evening.

* WSW FL100 winds will increase around 9-12z Wednesday in advance of
  an upper level wave. FL100 winds will peak around 30kts between
  18z WED and 3z THU with surface wind gusts around 25-30kts as
  well. Late Wednesday evening winds will gradually taper off and
  turn N-NW by Thursday morning. Keep an eye out for periods of
  light to moderate mountain wave turbulence Wednesday and possibly
  again on Saturday.

* Additional upper level waves will swing through the Sierra and
  western through Memorial Day resulting in periodic enhanced
  breezes (particularly Saturday) and some afternoon/evening
  shower and thunderstorm potential each afternoon starting on
  Friday (roughly 10-20% for the Sierra).

-Edan

&&


.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$