Denali Expedition | 40 Days of Provisions and No Weather on Demand

35 Countries, 35 Peaks

In our last article, we introduced you to Tobi’s biggest journey to date: Since April 2026, the Swiss adventurer has been traveling from Alaska to Patagonia. His goal: to visit all 35 countries in North, Central, and South America and climb the highest mountain in each one. He’s covering the distances between them by bike, on foot, on skis, and by sailboat. The diverse landscapes and climate zones place high demands on his gear, planning, and climbing partners.

The first major goal: Denali, at 6,190 meters the highest peak in North America. Joining him are climbing partner Heli Hofmann and, ultimately, polar expert Laetitia Lam, who joined the team on fairly short notice and rounds out the group with her experience from Arctic expeditions. PowderGuide meteorologist Sebastian Müller provides remote support with weather forecasts alongside his colleague.

A successful expedition begins with planning at home

How much food do we need to bring? What gear is essential? And how much leeway do we have if the weather doesn’t cooperate? Injuries and accidents also have to be assessed differently in the wilderness. On an expedition, many decisions are interlinked.

For the team, the challenge begins long before the actual ascent: Instead of flying to base camp as is customary, the three cover the approximately 120 kilometers under their own power. They transport their gear on pulks, which they rent locally. This makes the question of what to bring—and how to get it to the starting point—all the more important.

The Plan Meets Reality

It’s difficult to find resources, information, and good maps for the wilds of North America. Once on the ground, the team discovered that some of their maps didn’t match reality. It really brings home just how spoiled we are in the Alps. Tips from locals and rangers help us adjust the route to suit the conditions. Still, it’s hard to predict how far we’ll get.

Heli sums it up this way: “You can’t plan everything. Some days you hike 20 kilometers; others, just two. You should set out with the mindset that things won’t go exactly as you planned or would like them to—especially when bushwhacking is the order of the day.”

The weather also demands flexibility. Here, the team relies on Sebastian’s assessments, which he provides remotely. Because even though he’s on the other side of the globe, his data is accurate down to the hour. But how does he do it?

Expedition Weather via Satellite

What weather patterns are emerging? When might a suitable window open up for the continued ascent? When should the team be patient and wait it out in the tent? Questions like these accompany an expedition day in and day out. For this, the forecast must reach the right location and be understandable and usable for the team.

It became clear fairly early on during planning that the highest standard of expedition meteorology was required. Because there was already too much luggage and weight to carry, “heavy” equipment like satellite phones and Starlink had to be left behind—but high-quality weather information still needed to be delivered to the Garmin InReach devices using as little data as possible.

To that end, Sebastian from the PowderGuide team systematically refined his PowderGrams. The team worked together to prepare the information for use on the mountain and for transmission via satellite.

Developing Together, Testing Outdoors

The testing and development phase began on a group trip to the Swiss mountains. Afterward, the team continued working on the forecasts daily until the results met their standards. Step by step, the idea that emerged from the meeting in Fribourg grew into the weather support needed for this demanding expedition.

The weather report in their gear

While the team is on the move, Sebastian uses PowderGrams in the background for his weather forecasts. These weather charts from PowderGuide, developed specifically for freeriders and ski tourers, consolidate forecasts for temperature, wind, cloud cover, and precipitation for the mountain, the valley, and the surrounding area.

How are temperature and wind expected to develop? When will clouds roll in, and when can precipitation be expected? The combined visualization helps identify patterns and assess potential time windows for the next stages.

In the weather models, Denali appears significantly lower than it actually is. Therefore, the predicted values cannot simply be applied to the actual conditions on the mountain. This is where Sebastian comes in: He interprets the forecasts and shares his assessments with the team via Garmin Messenger.

The team is pushed to its limits

But what becomes of the plan when the mountain dictates the conditions? When kilometers turn into grueling meters and the weather window doesn’t align with the schedule? On Denali, we see what preparation can achieve—and when the team has to make new decisions.

You can see just how much the mountain pushes the three of them to their limits starting October 30, 2026, in Tobias Renggli’s new episode on his YouTube channel. You won’t want to miss it!

A few impressions can already be seen on Tobi’s Instagram account!