Reading a mountain forecast, Thunderstorms and lightning on the trail, Wind, Heat, Shoulder seasons, Reading the sky without a forecast.
Sooner or later every walker ends up somewhere the forecast does not reach: a third day out with no signal, a hut whose bulletin is two days old, a valley where the printed forecast is for a town on the other side of the range. The sky still tells us most of what we need, … Read more
The months either side of summer are the best and the worst of the hiking year. Trails are empty, the light is long, the huts are closed and the ground has not decided whether it is winter or summer. Three hazards define the shoulder season and they are all, at root, about snow: the old … Read more
A mountain forecast is not a valley forecast with a bigger number for the wind. It is a different product, written for a different atmosphere, and most of the disappointment we hear about “wrong” forecasts comes from reading the wrong one, or reading the right one badly. Here we go through the four numbers that … Read more
Lightning kills a few hundred people a year worldwide, and a disproportionate number of them are outdoors, on high ground, in the afternoon. That last detail is the important one, because it means the danger is mostly a scheduling problem. Thunderstorms in the mountains follow a daily rhythm that is remarkably reliable, and a walker … Read more
Of all the numbers in a mountain forecast, wind is the one walkers most consistently underestimate, partly because we experience it in the valley where it is tame, and partly because the forecast quotes a speed while the body experiences a force. A 60 km/h gust on a narrow crest is not “quite windy”; it … Read more
Heat is a quieter danger than cold. There is no dramatic forecast line, no gust number, just a warm day that turns into a dangerous one by the third hour of climbing. Understanding why comes down to one idea: the body’s only serious cooling system is evaporation, and evaporation depends on humidity as much as … Read more
