381
FXUS65 KREV 201924
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
1224 PM PDT Mon May 20 2024


.SYNOPSIS...

Several upper level waves push through the Sierra and western Nevada
this week with intermittent afternoon breezes, cooler temperatures,
and some late day showers and storms across the Sierra. A warming
trend will settle in for late this week and over the Memorial Day
weekend.

&&

.DISCUSSION...

Key Points:

* Today will be the coolest of the week with near freezing
  temperatures possible tonight into early Tuesday. Keep an eye on
  those sensitive plants tonight! Warming trend will kick off this
  weekend following a couple of cool bumps this week.

* Plan on typical afternoon breezes (gusts 20-30 mph) through the
  week. Wednesday and Saturday are projected to be a bit more windy
  (localized gusts 40-50 mph).

* There is 10-15% chance for some Sierra showers and thunder this
  afternoon. Another round will be possible Thursday into the
  holiday weekend (10-15% chances).

Details:

Freezes: Clear skies, dry conditions, and a colder air mass left
in the wake of the frontal passage yesterday will provide
efficient radiational cooling significantly lower overnight
temperatures tonight into early Tuesday morning. While the chances
for freezing temperatures are relatively low for the Reno/Carson
urban areas (up to 5%), we can`t rule out freezes for some of the
colder valleys. Highest chances (70-100%) for freezes will be in
the Sierra areas and northern Lassen and Washoe counties, but in
the Basin and Range there is a 10-20% chance as well. Once we get
past early Tuesday morning the risk of freezes tapers off, but
until then maybe consider protecting some of the more sensitive
foliage.

Happy Little Troughs: We`re going to see several troughs either brush-
by our pass through the region this week. The first on Wednesday
will result in an uptick in the winds where we could have the
strongest wind gusts this week (~35-50 mph). The standard concerns
are at play with wind gusts of this nature: bumpy aviation
conditions and choppy lakes. As we head into late spring/early
summer, we want to keep fire concerns in mind too. Fuels and
vegetation aren`t quite ready for significant fire spread, but we
want to avoid any activities that could start an early season fire.
The trough will also slow our warming trend this week. This trough
appears to be dry with the best potential for showers across
southeast OR and northeast NV for now. A secondary trough passes
through on Thursday, which may bring enough instability to pop few
thunderstorms and showers along the Sierra crest.

Memorial Day Weekend: Looking at a general warming trend over the
weekend, but there will be lingering shower and thunderstorm
potential. We all know how Memorial Day weekend can be, so have a
plan to escape a lightning threat if you plan on being in the great
outdoors. Blended model guidance holds onto at least a 10-15% chance
for a shower or storm through Memorial Day.

&&

.AVIATION...

* VFR conditions will persist outside of a 10-20% chance of showers
  and thunderstorms over the Sierra this afternoon. A typical
  afternoon breeze of 20-25 kts and light turbulence are expected
  this afternoon and evening, with light and variable winds surface
  winds Tuesday morning. Increased northeasterly flow above FL100
  may produce periods of light to moderate turbulence over and west
  of the Sierra crest tonight into Tuesday morning.

* Several upper-level troughs will migrate over the region this
  week, bringing increased afternoon breezes, especially Wednesday,
  cooler temperatures, and some late-day showers and thunderstorms
  mainly over the Sierra. VFR conditions will prevail during this
  period outside of any showers/thunderstorms. A warming trend will
  take place Memorial Day weekend with chances for showers and
  thunderstorms lingering.

-Johnston

&&

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

$$