South Lake Tahoe, California Weather Forecast Discussion

320
FXUS65 KREV 160800
AFDREV
Area Forecast Discussion
National Weather Service Reno NV
100 AM PDT Tue Sep 16 2025
.KEY MESSAGES...
* Warm, sunny, and dry weather is expected through Wednesday.
* Smoke and haze from the Garnet Fire will continue to impact
  parts of Mono and Alpine County today.
* Shower and thunderstorm activity increases Thursday into the
  weekend with greatest chances on Friday.
&&
.DISCUSSION...
Taking a look this early morning at satellite and air quality obs,
the Garnet Fire remains active and continues to degrade the air
quality on our side of the Sierra. The latest smoke forecast has
smoke pushing over the Sierra crest this afternoon and moving into
Alpine and Mono counties. I would expect only slight reductions
to air quality this afternoon/evening as the smoke looks to stay
mostly aloft, although if you fall into the sensitive group I
would continue to monitor nearby observations at fire.airnow.gov.
Lower chances to see smoke and haze on Wednesday due to a slight
change in wind direction near the fire.
Looking at the temperature outlook this week, we`ll see one more
push of summer-like temps peaking on Wednesday in the upper 80`s and
low 90`s for lower NV valleys and low 80`s in the Sierra. Today and
Wednesday will be filled with warmth, sunshine, and light winds.
Once Thursday comes around we`re going to have a low pressure system
move in from the south along the coast. Temps won`t see the effects
of this low until Friday when they take a 10 degree hit, so Thursday
will still be warm. After Friday, temps will slowly rebound back
into the mid 80`s in lower valleys as the low moves out.
Going back to that low on Thursday - We`re going to receive the
remnants of Tropical Storm Mario, currently located off of Baja
California. By the time it reaches our area it`ll just be rain
showers with embedded isolated thunderstorms. Precip chances will
increase as early as Thursday morning and as late as Thursday
evening. Timing and location is still uncertain within the hi-res
models and ensembles, but right now sometime Thursday remains a
good bet. Showers will continue overnight into Friday morning and
possibly linger through Saturday. Again, there`s quite a bit of
uncertainty that far out with this system, so stay tuned for more
detailed information later this week!
-Justin
&&
.AVIATION...
VFR conditions are expected for the main terminals today, with the
exception being KMMH where haze remains an issue. Light winds
today generally out of the N/NE, however smoke and haze could
still work its way into the Mammoth Lakes area this afternoon,
resulting in periods of HZ and reduced VIS. Conditions Wednesday
are likely to be the same as today with sunny skies, light winds,
with possibly less smoke/haze near KMMH.
-Justin
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$

NWS REV Office Area Forecast Discussion