603
FXUS65 KREV 200738
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
1238 AM PDT Sun Sep 20 2026

.KEY MESSAGES...

* Dry and mild conditions persist through today with periods of
  breezy east to northeast winds along the Sierra crest.

* Precipitation potential returns Monday and Tuesday for the Sierra,
  especially from Lake Tahoe southward.

* Plan on increased winds for Thursday onward and a return of
  precipitation chances for next weekend.

&&

.DISCUSSION...

Dry and mild weather remains today with transient ridging over the
Sierra and western Nevada. Valleys will be in the low to mid 80s by
this afternoon with mid 70s for the Sierra. Winds will remain light
this afternoon, although stronger breezes will impact the
ridgelines. The gusty east to northeast ridge winds will remain a
fixture, especially for the Eastern Sierra, through much of the week
as a couple of low pressure systems sweep through the West.
Smoke/haze from the Dome wildfire near Yosemite will mostly remain
on the west side of the Sierra. Southwest wind influence later today
may allow some smoke to cross into the Mono Lake area late tonight
into Monday morning. Be sure to check airnow.gov for the latest air
quality readings.

Simulations have trended up for precipitation potential Monday into
Tuesday as a quick-moving closed low pushes across the Sierra and
western Nevada. The progression of the low into the region will
allow showers and storms to kick off along the Sierra and migrate
northward from Mineral county all the way into Lassen county.
Precipitation chances range from around 10-15% for southern Lassen
and the Tahoe Basin to 25-60% for the Eastern Sierra and foothills.
Plan on a few rumbles of thunder with the showers that develop, but
chances remain on the low side (<10%). Areas above 10,000 feet may
see a few snowflakes as well, but it will be too warm to accumulate.
Showers may linger overnight across southern Mono and Mineral
counties as the low quickly ejects eastward into central and eastern
Nevada Tuesday.

Ensemble clusters have aligned for Thursday into the weekend with
higher confidence for the Pacific Northwest trough to slide into the
Sierra and western Nevada. Blended guidance has been consistent with
highlighting increased wind potential from Thursday onward, and the
timing of the trough progression will contribute to stronger winds
during the Thursday - Saturday timeframe. Confidence in
precipitation potential isn`t as high, but the northern tier of the
region could see some 5-15% chances for rain. If the large trough
drops southward, then there would be some better potential for
precipitation as well as a drop in temperatures, but we will have to
wait and see.

-Edan

 &&

.AVIATION...

Plan on VFR conditions at all area TAF sites today and tonight.
There is around a 20% chance for patchy fog near KTRK between 11-16Z
Monday.

Light winds with afternoon gusts up to 15 kts. However, forecast
models show E-NE winds gusting up to around 25 kts between 06-12Z
Sunday and Monday which may result in minor mountain wave
turbulence concerns along and west of the Sierra. Afternoon
precipitation chances return to Mineral County and the eastern
Sierra on Monday.

-078/Edan

&&

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

$$