Calpine, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

780
FXUS65 KREV 190927
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
127 AM PST Fri Dec 19 2025

.KEY MESSAGES...

* Widespread strong winds today and possibly again on Sunday.
  Likely impacts for both road and air travel. Localized fire
  weather concerns in the Eastern Sierra.

* Showers including mountain snow showers this afternoon and
  evening. Heavier rains likely Saturday night through Sunday that
  could lead to localized flooding concerns.

* Another storm or two could bring significant rain and snow
  Tuesday into Christmas Day, but confidence remains mixed.

&&

.DISCUSSION...

* Welp, it`s still looking rather busy weather-wise over the
  coming 7 days with a series of Pacific storms including
  atmospheric rivers. Anyone with holiday travel plans by road and
  by air should keep an eye on the forecast and adjust
  accordingly.

* Wind: Today & Sunday are the windiest days in what will be a
  breezy period through most of next week. Rather impressive zonal
  jet moving though the Pac NW & N Calif coupled with increasing
  pre-frontal gradient will yield widespread strong winds today.
  Given W/SW flow orientation and 700mb speeds 50-60 knots, wave
  breaking and downslope enhancement is possible today along Hwy
  395 from Susanville-Reno-Mammoth where we have wind advisories
  posted. Low humidity could create fire weather concerns, and it
  won`t be a pretty day for flying either. For Sunday another
  plume of high speed air aloft comes in with an moderate
  atmospheric river. RRFS showing 700mb winds over 70 knots. Wow.
  So if we end up being more shadowed on Sunday (more T than V
  from the AR IVT) we could have another round of rather strong,
  impactful winds regionwide.

* Rain: While today will generally be dry, high-res models show
  showers moving in post-front this afternoon into the evening.
  Should be mostly rain except the Sierra peaks, however NBM and
  HREF are showing potential for snow p-type at passes if we see
  heavier precip rates. Rapid p-type changes can catch travelers
  off- guard. Saturday night through Sunday is still the main show
  for heavy rain with pronounced atmospheric river signal and
  high rain- snow lines (8000`+). QPF in the mountains is similar
  to guidance 24 hours ago but a little less in lee-side areas of
  W Nevada (more periods of shadowing/wind perhaps?). Highest risk
  of heavy rains and potential flooding remains the Tahoe Basin
  into NE Calif where models stall/pivot the main AR band for the
  longest time. If there were an area to underperform it would be
  the Eastern Sierra/Mono Co based on further north trajectories
  of the AR plume.

* Snow: Precip never totally shuts off in the mountains but does
  lessen in intensity Monday into early Tuesday. Starting Monday
  night the snow lines drop enough were we could start seeing more
  regular impacts to travel over the passes. Simulations showing
  one or two additional notable and cooler storms moving in
  Tuesday evening through Christmas Day. Lots of variables here
  with models digging troughs off the coast which sometimes can
  result in a southward shift of the heaviest precip, wide
  boom/bust scenarios, and an increased airing of grievances next
  week. That all being said, QPF and snowfall in the NBM 50th
  percentiles has gone up quite a bit vs 24 hours ago for
  Wednesday-Thursday. Potentially good news for the snowpack and
  local "white Christmas" stats, but not so good news for those
  trying to get someplace at the last minute before Christmas.

-Chris

&&

.AVIATION...

* Buckle up, it`s not exactly going to be a smooth day for flying
  with strong winds, mountain waves, rotors, and low level wind
  shear all on the table today into this evening.

* Strong W/SW flow with RRFS 700mb winds to 60 knots forecast
  today and tonight, associated with an upper jet and approaching
  cold front. 80% chance of seeing peak gusts at least 35 knots at
  most airfields including RNO/CXP/MEV, TRK/TVL, MMH with 40-60%
  at NFL/SVE/HTH. High-end gusts over 50 knots cannot be ruled out
  in more wind prone areas along Hwy 395. NBM has 40-60% chances
  of 50 knot peak gusts at RNO and MMH for example. Another round
  of strong winds is looking likely on Sunday as well.

* With that front today, we will have showers develop this
  afternoon and evening. Mainly in the mountains from SVE to
  TRK/TVL with potential for MVFR-IFR conditions in rain. Can`t
  rule out a rain/snow mix but low confidence. For RNO/CXP/MEV,
  light showers are possible (40% chance) but visibility/ceilings
  look to remain VFR. MMH misses out on this one, just wind for
  them.

* Additional showers possible Saturday but mainly light
  intensity. Winds should be less robust as well.

-Chris

&&

.FIRE WEATHER...

* There is concern over areas of critical wind and low humidity
  in the Eastern Sierra today, specifically fire weather zones
  CA274 and NV421.

* Latest NBM and HREF guidance suggest 1-3 hours of critical
  conditions especially along Hwys 395 & 6 where W/SW winds could
  gust over 50 MPH this afternoon (see Wind Advisory). Humidity
  values already in the teens as of this writing and it`s been
  rather dry lately with well above normal ERC levels.

* No Red Flag Warning at this time due to limited spatial extent
  and duration of critical conditions however we will highlight
  the risk in the FWF and our morning briefing email.

-Chris

&&

.HYDROLOGY...

Repost of yesterdays hydro section. This will be updated with the
daytime discussion.

* Moderate to heavy rains will lead to significant rises on
  rivers and streams Sunday into Monday most notably from the
  Tahoe Basin north through Lassen County, but no mainstem river
  flooding is currently expected.

* Minor flooding of urban and poor drainage areas and rockfall
  are possible during any prolonged periods of high intensity
  rainfall. Watch for additional rises near Christmas Eve and
  possible flooding concerns especially in drainages with large
  mountain drainages below about 6,000 feet, like the Susan River
  for example.

* You can find river forecasts updated twice daily at:
  www.cnrfc.noaa.gov

-Tim

&&

.REV Watches/Warnings/Advisories...
NV...Wind Advisory until 4 AM PST Saturday NVZ002-003-005.

     Lake Wind Advisory until 4 AM PST early this morning NVZ002.

     Lake Wind Advisory until 4 AM PST Saturday NVZ004.

CA...Wind Advisory until 4 AM PST Saturday CAZ070>072.

     Lake Wind Advisory until 4 AM PST early this morning CAZ072.

&&

$$