- Roaring forties, furious fifties, screaming sixties
- What sailors called the westerlies between 40 and 60 degrees south, when square-riggers ran down to Cape Horn. El Chaltén sits at 49° S: in the fifties.
- Westerlies
- The belt of wind that circles the planet around Antarctica. It is the background wind of all Patagonia, all year.
- Foehn
- The wind that comes down dry and warm on the lee side of a range after leaving its moisture on the other side. In the Patagonian Andes it is the normal state of the air that reaches town.
- Katabatic
- Cold, heavy air sliding downslope under its own weight. It pours out of the glaciers and the Ice Field through the valleys. You feel it on the Laguna Torre moraine, coming off the Grande Glacier, above all early in the morning.
- Lenticular cloud, the “hat”
- A plate- or hat-shaped cloud sitting still on a summit while the wind streams through it. It forms on the crest of the waves the air makes passing over the massif. On Fitz Roy it means strong wind up high and, often, a front on its way.
- Flag trees
- Lengas and ñires with every branch pointing east, combed by decades of west wind. You see them on the climb to Laguna Capri and along the edge of the steppe.
- Gust
- The few-second blow much stronger than the mean wind. It is what matters for walking: our limit for climbing the moraine is a 75 km/h gust, not a mean wind.
- Rotor
- The eddy that forms in the lee of a ridge when the wind crosses it hard: the air turns back and upward. On Pliegue Tumbado and on the high passes of the Huemul Circuit it feels like wind changing direction without warning.
And a word we do not use
“Exclusive”. The wind here is shared by everyone who walks these trails. What changes is how you read it: at what height, at what hour, and when you turn back. That is what a local guide does.
The live wind map, the wind on the trail right now and the full guide to the Patagonian wind: Read more →
Questions
What are the roaring forties?
The westerlies between 40 and 50 degrees south, named by the sailors of the square-riggers. Further south come the furious fifties and the screaming sixties. El Chaltén sits in the fifties.
What is a katabatic wind?
Cold air flowing downslope under its own weight, like water. In El Chaltén it pours off the glaciers and the Ice Field into the valleys; you feel it most on the Laguna Torre moraine.
What does the cloud on Fitz Roy mean?
It is a lenticular cloud: strong wind at height, and often a front arriving in the following hours. The guides look at it every morning.