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Massive Snowstorm Approaching the Chilean Andes: What to Expect in Valle Nevado and Portillo

As we head into the latter part of August 2025, the Southern Hemisphere’s winter is delivering one of its most anticipated events: a powerful snowstorm barreling toward the central Andes Mountains in Chile, offering a thrilling experience for those interested in skiing South America. This system, fueled by moisture-rich Pacific fronts, is set to bring heavy snowfall, frigid temperatures, and potentially transformative conditions for the region’s world-renowned ski resorts. With forecasts predicting over 4 feet of snow in some areas this week alone, skiers and snowboarders are buzzing with excitement, while travelers should brace for disruptions. Multiple storms are tracking through the Andes over the next week, with the latter ones merging into what could feel like a single massive dump for central Chile. In this post, we’ll dive into the details, focusing on two iconic spots: Valle Nevado and Portillo.

South America snowstorm

Overview of the Incoming Storm

This week’s weather pattern is no ordinary flurry. Originating from the Pacific, the storm cycle kicks off midweek, targeting the central Chilean Andes with cold, high-ratio powder. The peak intensity is expected Wednesday night into Friday (August 20-22, 2025), delivering heavy snow and below-freezing temps. Forecasters are tracking several systems, but for resorts like those in the Andes, they may blend into one prolonged event, bringing light to moderate snow midweek followed by heavier accumulations. Recent social media chatter from the region highlights significant snow already falling earlier in August, with 27 cm reported at Valle Nevado on August 3, and more in the forecast. This storm could add substantial base depth to the slopes, extending the ski season into late September, but it also raises concerns for road access and safety in the rugged terrain.

Spotlight on Valle Nevado: Heavy Snow and Freezing Conditions Ahead

Valle Nevado, one of Chile’s premier ski destinations, perched at over 9,000 feet in the Andes, is directly in the storm’s path. The forecast calls for a heavy fall of snow, with the heaviest accumulations from Wednesday night through Friday morning. Temperatures will remain below freezing, peaking at 30°F on Wednesday morning and plummeting to 7°F on Thursday night. Winds are expected to pick up, reaching up to 22 mph from the WNW by Thursday afternoon.

Here’s a breakdown of the short-term forecast based on detailed models (temperatures converted to °F for consistency):

  • Tuesday, August 19: Clear AM (max 23°F, min 19°F), light snow PM (max 23°F, min 23°F), snow showers night (max 21°F, min 21°F). Winds 6-9 mph. Snow: 0 inches AM, 0.3 inches PM, 0 inches night. Humidity 71-94%.
  • Wednesday, August 20: Clear AM (max 30°F, min 25°F), cloudy PM (max 30°F, min 27°F), heavy snow night (max 23°F, min 21°F). Winds 6-9 mph increasing to 9 mph. Snow: 0 inches AM/PM, 10.2 inches night. Humidity 40-97%.
  • Thursday, August 21: Heavy snow AM (max 19°F, min 19°F), heavy snow PM (max 19°F, min 18°F), heavy snow night (max 12°F, min 7°F). Winds 16-22 mph. Snow: 0 inches AM, 10.6 inches PM, 7.9 inches night. Humidity 92-96%.
  • Friday, August 22: Heavy snow AM (max 7°F, min 3°F), light snow PM (max 5°F, min 7°F), heavy snow night (max 3°F, min 3°F). Winds 9-12 mph. Snow: 20.9 inches AM, 0.4 inches PM, 5.1 inches night. Humidity 50-93%.
  • Saturday, August 23: Snow showers AM (max 16°F, min 9°F), clear PM (max 19°F, min 18°F), clear night (max 23°F, min 16°F). Winds light, 0-3 mph. Snow: 1.6 inches AM, 0 inches PM/night. Humidity 8-33%.
  • Sunday, August 24: Clear AM (max 32°F, min 27°F), clear PM (max 34°F, min 34°F), clear night (max 34°F, min 32°F). Winds light, 3 mph. Snow: 0 inches. Humidity 27-37%.

Looking further out (through August 30, based on extended models):

  • Days 7-9 (August 25-27): Mostly clear with some clouds, freeze-thaw conditions (max 39°F on Monday morning, min 32°F on Tuesday night). Light winds.
  • Days 10-12 (August 28-30): Clear to partly cloudy with a chance of snow showers, freeze-thaw (max 41°F on Friday morning, min 23°F on Saturday night). Light winds.

This dump could make for prime powder days, but with humidity spiking to over 97% during heavy snow periods and freezing levels dropping as low as 1,640 feet, visibility and avalanche risks may increase. No detailed hindcast for the past week was available, but recent events include light snow and clear spells setting the stage for this major event.

Portillo: Similar Intensity with Even Deeper Powder Potential

Just a short drive from Santiago, Portillo Ski Resort—famous for its steep terrain and Hotel Portillo—is bracing for a comparable onslaught. Forecasts indicate a heavy fall of snow, heaviest during Thursday night into Friday morning, with freeze-thaw conditions (max 34°F on Wednesday morning, min 12°F on Thursday night). Winds will remain generally light. As of the latest reports, the resort has seen 129 inches of snowfall this season, with current depths at 21 inches at the hotel and 63 inches on the plateau as of August 2025. On August 15, the base was 21 inches with 12 of 14 lifts open.

Detailed forecast highlights (temperatures in °F):

  • Tuesday, August 19: Clear AM (max 27°F, min 19°F), snow showers PM (max 28°F, min 25°F), light snow night (max 25°F, min 23°F). Winds light, 3 mph. Snow: 0 inches AM/PM, 0.6 inches night. Humidity 71-88%.
  • Wednesday, August 20: Clear AM (max 34°F, min 25°F), light snow PM (max 34°F, min 30°F), heavy snow night (max 25°F, min 25°F). Winds light, 3-6 mph. Snow: 0 inches AM/PM, 7.9 inches night. Humidity 51-96%.
  • Thursday, August 21: Clear AM (max 27°F, min 25°F), heavy snow PM (max 25°F, min 23°F), moderate snow night (max 19°F, min 12°F). Winds 6-9 mph. Snow: 0 inches AM, 3.9 inches PM, 5.1 inches night. Humidity 94-98%.
  • Friday, August 22: Heavy snow AM (max 19°F, min 16°F), heavy snow PM (max 19°F, min 19°F), light snow night (max 16°F, min 3°F). Winds light, 3-6 mph. Snow: 12.2 inches AM, 0.8 inches PM, 2.4 inches night. Humidity 31-96%.
  • Saturday, August 23: Moderate snow AM (max 21°F, min 10°F), snow showers PM (max 21°F, min 19°F), clear night (max 23°F, min 14°F). Winds light, 3 mph. Snow: 0.8 inches AM, 0 inches PM/night. Humidity 5-40%.

Extended summaries indicate moderate additional snow through early next week, followed by clearer skies:

  • Days 4-6 (August 23-25): Moderate snow tapering to clear, freeze-thaw (max 37°F on Sunday afternoon, min 3°F on Friday night). Light winds.
  • Days 7-9 (August 26-28): Mostly dry and clear with some clouds, freeze-thaw (max 43°F on Monday morning, min 30°F on Tuesday night). Light winds.
  • Days 10-12 (August 29-31): Mostly dry with occasional clouds, freeze-thaw (max 45°F on Friday morning, min 25°F on Saturday night). Light winds.

Tips for Travelers and Skiers

If you’re heading to the Andes:

  • Monitor updates from sources like Snow-Forecast or OnTheSnow.
  • Pack for extremes: Layers, chains for vehicles, and emergency kits.
  • Resorts may close lifts during peak storm hours, so flexibility is key.
  • For the powder hounds, post-storm days (weekend onward) promise bluebird skies and fresh tracks.

Tim Konrad is the founder and publisher of Unofficial Networks, a leading platform for skiing, snowboarding, and outdoor adventure. With over 20 years in the ski industry, Tim’s global ski explorations...