677
FXUS65 KREV 222057
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
157 PM PDT Thu May 22 2025

.KEY MESSAGES...

* Gusty winds will produce recreation and fire weather concerns
  into this evening, with dry and breezy conditions also expected
  Friday.

* Near average temperatures will continue through Friday as weak
  weather systems brush by to the north.

* The holiday weekend continues to favor warm and dry conditions,
  however, be aware of fast and cold rivers and streams due to
  continued high Sierra snowmelt.

&&

.DISCUSSION...

Today`s trough passage across Oregon-Idaho has produced its
anticipated winds across eastern CA and western NV, with gusts
30-40 mph in many locations and around 45 mph for a few wind-
prone sites near US-395. Sierra crest ridge gusts peaked near 85
mph earlier today. These winds and associated impacts for lake
recreation and travel for high profile vehicles will continue
through the remainder of the afternoon, then decrease this
evening.

Another weak trough passage is on tap for Friday, but it will
produce less wind with gusts mainly 30 mph or less. Although this
system will have limited moisture, a small area of upper level
forcing and instability with this trough could produce a few
showers and possibly a stray thunderstorm for areas near the OR
border Friday afternoon (10-15% chance). Little or no rainfall is
anticipated with any showers that form, which will move at a
relatively fast pace.

The holiday weekend looks to be warm and dry overall, as a high
pressure ridge moves across CA-NV. Afternoon cumulus buildups are
likely for both Saturday and Sunday with the warmer air mass in
place, but potential for showers/thunder is quite low, only about
5% chance. By Memorial Day, a weak trough passage could produce a
few late day showers in areas near the OR border, although this
potential is also rather low (about 10-20% chance). Sunday is
still expected to be the warmest day of the weekend, with highs
pushing the upper 80s to near 90 for western NV valleys and 70s
for Sierra communities. The other weekend days won`t be quite as
warm but still above late May averages. Winds will be lightest on
Saturday, followed by zephyr-type breezes Sunday-Monday. Rivers
and streams will look appetizing to cool off in, but they will be
running fast and cold due to high Sierra snowmelt. Even limited
water exposure can pose the risk of hypothermia. Stay safe this
weekend!

The warm pattern continues next week with highs in the mid
80s-near 90 for western NV valleys by midweek. Dry conditions are
again the prevailing scenario, although a few simulations keep a
remnant of Monday`s trough around the northern Great Basin for a
couple more days, with low 10-20% shower chances persisting for
sites near the OR border. MJD

&&

.AVIATION...

Widespread VFR conditions prevail through this weekend. Peak wind
gusts of 30-35 kts at the main terminals with FL100 gusts to 60
kts continue through early this evening, resulting in mountain
wave turbulence and periods of LLWS. Winds Friday will be lighter
with gusts near 20 kts followed by even less wind for Saturday,
then typical zephyr-type breezes return for the rest of the
holiday weekend. MJD

&&

.FIRE WEATHER...

Very dry air mass has settled across the region from I-80
southward with minimum RH values in the single digits to lower
teens--even as low as 4% at Hawthorne. Wind gusts have generally
been in the 30-40 mph range, and these dry and windy conditions
will continue until early this evening, resulting in elevated to
locally critical fire weather conditions.

These elevated conditions retreat Friday and into the weekend as
gusty winds subside. However, dry conditions will remain in place
with minimum RH between 8-16% for much of western NV southward to
eastern Mono County, and 15-25% for the eastern Sierra, Tahoe
basin and northeast CA/far northwest NV. Therefore, anyone
celebrating the holiday outdoors this weekend should use extra
caution with activities that may cause fires. This includes camp
fires, sparklers, dragging trailer chains, and target shooting.
MJD

&&

.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory until 8 PM PDT this evening NVZ002-004.

CA...Lake Wind Advisory until 8 PM PDT this evening CAZ072.

&&

$$