The Morning Intel | Tahoe Sector Watch

Location: #HippieHaus | South Lake Tahoe, CA

Date: Friday, December 12, 2025

¡Buenos días, my friends

Cup'O'Joe in hand, #StokeLevelRising up slightly to a 13.1 as we increase confidence in a pattern change next week with light precipitation. However, we are still uncertain about the timing and impacts. Current forecast model guidance now shows Monday afternoon as the onset of precipitation, with chances of high elevation snow (9k👆).

Forecast guidance and models now show Monday afternoon as the onset of precipitation chances over the mountains, which will shift to an unsettled pattern, with the best chances of impactful weather over the mountains and northern Sac Valley.

With the strength of the current ridge, we may see the forecast trend shift later as it attempts to break down, allowing precipitation to impact the area. The Current Climate Prediction Center forecast points to a >60 percent chance of above-normal precipitation over northern CA, peaking in the north half of our CWA from Dec. 19-25.

Changes from Yesterday's Forecast

• Timing Shift (Onset): Yesterday, we looked generally at "early next week." Today's Update: The models have dialed in the onset to Monday afternoon (Dec 15).

• Storm Type: Yesterday, we discussed a generic "shortwave." Today's Update: The NWS explicitly mentions the region being "clipped by the southern tip of an Atmospheric River" moving into the Pacific Northwest.

• Snow Levels (Elevation Rise): Yesterday, we tracked levels at 8,000-9,000 ft. Today's Update: Snow levels have crept higher to 👆 9,000-9,500 ft. This means snow accumulation is likely restricted to the very highest peaks (30% chance).

• Precipitation Amounts: Confidence has increased in liquid amounts. Blended guidance now suggests a 40% chance of exceeding 0.7" of liquid along the Sierra crest (up from 0.25" yesterday), though mostly as rain/snain below 9k.

• Long Range Outlook: Confidence is increasing for the Dec 19-25 window, with CPC outlooks now showing a >60% chance of above-normal precipitation, potentially setting up a white Christmas scenario.

Today's Intel

• 🚠 Bullwheels Turning: KirkwoodMtn, Heavenly, Mt Rose, MammothMtn, Palisades, Boreal, Northstar.

• 🌡️ Temps: Unseasonably Warm. Highs 15-20º degrees above average. South Lake Tahoe and Reno challenging records again today.

• 🌫️ Conditions: Freezing Fog socked in this morning over the lake and Sierra valleys. It should burn off, but low stratus may linger.

• 🚗 Roads: ALL CLEAR in the Sierra. Dense Fog Advisory in the Sacramento/Solano Valleys (Hwy 50 / I-80).

The RS Mindset: The ridge is stubborn, but the signals are there. We are tracking a pattern shift next week that tries to open the storm door. For now, we celebrate the Mtn Teams keeping the cord-carvaliciously fresh despite the inversions. Patience is the practice.

Looking forward to the next 3–7 days:

• Potential Rain and Snow Outlook: Dry Pattern Continues through the Weekend. High pressure remains anchored.

• Forecast Deep Dive:

• Monday PM: The ridge dents. Precip onset begins in the afternoon.

• Tuesday: The Sierra gets clipped by the AR tail. Expect breezy conditions and high-elevation rain/snain.

• Mid-Week: Unsettled zonal flow keeps us on the southern periphery of storms.

• Temperatures: Near Record Warmth. Highs will be 10-15º degrees above average through the weekend.

• Winds / Wind Conditions: Light. Winds remain light and terrain-driven through the weekend.

• Road Conditions: ALL CLEAR. Watch for brake checks on I-80 West.

The Weather Ahead | Temperatures | Winds | Winter

Forecasted Temperatures (Today's High / Tonight's Low):

• #HippieHaus (SLT / 6,380'): 57° / 33°

• Kirkwood (Base / 7,800'): 52° / 30°

• Truckee (North Shore / 5,800'): 57° / 28°

• Mammoth Mtn (Base / 8,900'): 42° / 38°

Timing of wind direction/wind speeds: Light/Variable winds today (ESE 3mph at HippieHaus). No significant wind events expected.

Seven(7) Day forecast (Lake Level Highs/Lows):

• Today (Fri): 57° / 33° (Sunny, Freezing Fog AM)

• Saturday: 57° / 32° (Sunny)

• Sunday: 55° / 30° (Sunny)

• Monday: 53° / 32° (Increasing Clouds, PM Showers?)

• Tuesday: 50° / 34° (Chance of Rain - Snow Level 9k)

• Wednesday: 48° / 32° (Chance of Rain/Snow High Elevation)

• Thursday: 46° / 30° (Unsettled)

Sierra Avalanche Center (Tahoe / Carson Pass):

• Status: #LowTide.

• Hazard: Shallow Obstacles.

• Discussion: Shallow snowpack. Avalanche concerns exist in isolated areas where hard, supportable slabs of wind-drifted snow exist on top of weak sugary snow.

• Link: https://bit.ly/SierraAvyForecast

Eastern Sierra Avalanche Center (Mammoth Zone):

• Status: #LowTide.

• Hazard: Shallow Obstacles.

• Discussion: Thin coverage. Northeast winds may have created isolated slabs.

• Link: https://bit.ly/EasternSierraAvalancheForecast

⚓ Marine Forecast for Lake Tahoe:

• Status: NO HAZARDOUS WEATHER.

• TODAY: Mostly cloudy AM, clearing. Freezing Fog in the morning. Light winds. Highs 52-57. Wave Heights < 1 foot.

• TONIGHT: Clear. Light winds. Lows 33-41. Wave Heights < 1 foot.

• SATURDAY: Sunny. Light winds. Highs around 57.

• Water Temp: 49.0°F.

• Mariner Note: Glassy conditions. Highly recommend a 4/3 or 5/4 wetty if you are paddling/foiling due to cold water shock risk.

✈️ Aviation Forecast (Detailed for Pilots):

• Conditions: VFR prevails, BUT...

• Hazards:

• FZFG (Freezing Fog): Prevalent this morning at KTRK (Truckee) and KTVL (Tahoe). Should burn off just after sunrise.

• Stratus: Low stratus deck socked in over Tahoe/Sierra valleys may linger.

• Haze: Valley inversions producing haze for Western NV terminals.

• Winds: Light surface winds.

Area Forecast Discussions (AFDs) Summaries

For #HippieHaus & Mammoth (NWS Reno):

• Fog Update: "Freezing fog and in some areas a low stratus deck are socked in over Lake Tahoe... Light winds this afternoon may not be enough to fully mix out the low clouds."

• Pattern Shift: "Next Tuesday and Wednesday we'll likely see a little precipitation... clipped by the southern tip of an atmospheric river."

• Snow Levels: "Hover around 9,000-9,500' 👆during this round... just the highest peaks have the greatest chance (30%) to see any snow."

• Long Range: "Encouraging sign for those who want POW for Christmas... Trough setting up off the west coast towards the end of the month."

For Carson Pass / KirkwoodMtn Zone (NWS Sacramento):

• Valley Focus: Dense Fog Advisory continues.

• Mountain Focus: "Increasingly mild temperatures with sunny skies and dry weather."

• Precip Update: "Current forecast now shows Monday afternoon as the onset of precipitation chances over the mountains."

On this #FreedomFriday, we hold fast on the #StokeLevel - NO~#OverStoking, NO~Whiners. The fog is lifting, the sun is shining, the winds are on our shoulders, with the long-range models teasing us with a Christmas miracle. Enjoy the weekend, keep your edges sharp, head on a swivel, and stay tuned for the pattern flip. Patience is the practice.

Stay'nThirsty for POW

Coop | RS#69