The Morning Intel | Tahoe Sector Watch

Location: #HippieHaus | South Lake Tahoe, CA

Date: Saturday, December 13, 2025

¡Buenos días my friends,

Cup'O'Joe in hand, #StokeLevelRising as the extended guidance models are starting to gel, indicating several waves of precipitation possible as we progress into the latter half of December. The latest Climate Prediction Center 8 to 14 Day Probabilistic Outlook favors above-normal precipitation for December 20-26. After Wednesday next week, confidence is increasing that the storm door will remain open the rest of the week. Deterministic and ensemble models are showing another atmospheric river-type storm moving in on Thursday, followed by another next weekend. LFG!

Today, Bullwheels will turn:

  • KirkwoodMtn

  • Heavenly

  • Mt Rose

  • MammthMtn

  • Palisades

  • Boreal

  • Bear Valley

  • China Peak

  • Northstar

Current Conditions & Sector Data

Regional Temperatures:

  • South Lake Tahoe (KTLV) at 6,308': 28ºF

  • Truckee (KTRK) at 5,899': 18ºF (Chilly start in the TRK icebox!)

  • Mammoth Mtn Race (MTH03) at 11,034': 36ºF

  • Chair 6 Ridge (9,100'): 45ºF (Inversion holds on)

Regional Winds:

  • HippieHaus: 198º (S) 1mph

  • Truckee: 183º (S) 1mph

  • Donner Pass: 69º (ENE) 1mph

  • Carson Pass: 219º (SE) 3mph

Roads (CalTrans @ 0519):

  • SR88 / Hwy 50 / I-80: ALL CLEAR in the Sierra.

  • Valley Warning: Dense Fog Advisory in effect for Solano/Yolo/Sacramento areas. Watch your speed and visibility down the hill.

Lake Tahoe Marine Forecast:

  • Today: Cloudy/Fog early, then clearing. Light winds. Highs around 58. Wave heights < 1 ft.

  • Sunday: Sunny. Light winds.

  • Water Temp: 48.9ºF.

Forecast Update: The Shift & The Nuance

We are comparing three different Area Forecast Discussions (AFDs) this morning, and the picture is getting clearer (and juicier). Here is the breakdown of Changes from Yesterday and the nuance between the reports:

1. The "Storm Door" is Wide Open (Major Change):

  • Yesterday: We were tracking a "clip" or a single shortwave for early next week.

  • Today (Reno & Sac AFDs): The narrative has shifted. Confidence is increasing that after Wednesday, the storm door stays OPEN. Models are showing another AR-type storm on Thursday and another one next weekend. This is a multi-wave pattern, not a "one and done."

2. Wind Velocity Spike:

  • New Data (Reno AFD): We now have specific numbers for the wind event on Tuesday Night. The 700mb jet cranks up to 60kts.

  • Impact: Expect Ridge Gusts up to 100 MPH Tuesday night into Wednesday.

3. Instability & Thunder (Sacramento Nuance):

  • New Data (Sacramento AFD): A key detail missed in other reports—The National Blend of Models indicates a 10-15% chance of Thunderstorms Tuesday afternoon/night. This suggests dynamic energy in the incoming system.

4. Snow Level Reality Check:

  • Consensus: Snow levels remain high for the Tuesday wave (9,000' - 9,500'). This is a rain/snain event for most base areas.

  • The Hope: Ensembles continue to show a trough setting up late-month with cooler temps, keeping the White Christmas dream alive (albeit low probability still).

Aviation Section (Pilots & Travelers)

  • Current Status: LIFR/IFR conditions due to Freezing Fog (FZFG) at KTRK (Truckee) and KTVL (South Lake Tahoe) this morning.

  • Forecast: Fog is locked in but should burn off just after sunrise. Once clear, expect VFR with light surface winds through Sunday.

  • Hazard Watch:

  • Valley Haze: Slantwise visibility restrictions possible for Western NV terminals due to inversions.

  • Turbulence: Smooth sailing this weekend, but prepare for Severe Turbulence/LLWS starting Tuesday night as ridge winds crank to 100mph.

Sierra Avalanche Centers

Central Sierra (Tahoe/Carson):

  • Status: Low Tide / Watch Mode.

  • Hazard: Shallow snowpack and exposed obstacles. Isolated wind slabs may exist where drifts have formed over weak, sugary snow.

  • Update: Daily forecasting resumes next week with the weather shift.

Eastside Region (Mammoth):

  • Status: Low Tide.

  • Hazard: Shallow coverage and variable surfaces. Isolated instabilities in wind-drifted areas.

My friends, the models are gelling, the ridge is breaking, and the Pacific is waking up. We have a beautiful, warm weekend ahead to prep the gear. Use today to check the oil on the blower, cover the wood pile, wax the boards, flog the lolly, and enjoy the sunshine.

To the Mtn Operations teams fighting the inversion and the fog to keep us sliding—Thank You. You guys are the unsung heroes of the early season.

Stay authentic, stay hopeful, and keep your #StokeLevelHigh

Stay'nThirsty for POW,

Coop | RS#69

A weather map showing North America with isobars, precipitation, high and low-pressure systems, and temperature data. It includes weather fronts and pressure values across the continent.
A weather map of North America showing 500mb height and anomaly data. Blue shades indicate colder than average regions, primarily over Canada and the northern US, while orange and yellow shades over the southwestern US indicate warmer than average conditions. Contour lines represent height values, with the highest over the southwestern US and the lowest over the Arctic.

ECMWF AIFS ENS [M] 0.25º 6-hr Precip (in.), MSLP (hPa), 850mb Temp.(ºC)

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Map showing weather forecast anomalies across North America, with heavy precipitation in the Pacific Northwest and parts of the eastern U.S., and dry conditions in the western and central U.S., for December 23, 2025.

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Chair Six(6) Ridge 12/13 - KirkwoodMtn - 9,100’

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NAM 3km | 2m Temperatures - MIN ºf)

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NAM 3km | 24hr Snow (10:1 Ratio) Idaho

NAM 3km | 24hr Snow (10:1 Ratio) Montana

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NAM 3km | 24hr Snow (10:1 Ratio) Wyoming

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Cooper Marketing & Media - Lake Tahoe Weather - Daily Lake Tahoe Snow forecasts - Accurate Lake Tahoe Weather | Lake Tahoe Snow and Resort Forecast
Cooper Marketing & Media - Lake Tahoe Weather - Daily Lake Tahoe Snow forecasts - Accurate Lake Tahoe Weather | Lake Tahoe Snow and Resort Forecast
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