This book has two aims at once. The first: to give free-flight pilots complete independence in weather matters — from the frontal chart to the decision at launch, by way of the emagram, breezes and thermals. The second: to let mountain hikers answer three very concrete questions on their own, in the morning: will it rain, will I be walking in the cloud, and by what time must I have left the ridge?
These two users look at the same sky. The cumulus that delights the pilot at 11:00 is the one that worries the hiker at 15:00; the breeze that inflates the wing at launch is the one that chills the hiker on the pass. So every chapter speaks to both, and most ideas are translated twice: for the air, and for the trail.
How to read this book
Every chapter opens with “The essentials in two minutes”: the simple version, in everyday language, of everything that follows. Read it first; read it on its own if you are short of time. The chapter then adds the precision, the numbers, the pitfalls — and plenty of diagrams: a figure looked at carefully is worth a page of text.
The figures are drawn for a greyscale e-reader, with a consistent code: a solid line for the air temperature and for a bubble of dry air, dashes for the dew point and for descending air, a dotted line for the bubble inside its cloud, a solid arrow for rising air. Areas with diagonal hatching mark an inversion or a danger, hatching in the opposite direction marks cold air, and dotted shading marks warm air or a mixed layer.
The boxes follow a consistent code, recognisable even on a black-and-white e-reader:
Why?
explains a mechanism that is usually accepted without being understood.
Pitfall
defuses a classic mistake.
In flight
translates the idea for the pilot: at launch, in the air, on landing.
Hiker’s reflex
translates the idea for hiking in the mountains.
Your turn
The exercises give their answer straight after the question: cover it up, and work it out yourself first.
Show the answer
it’s here.
Every chapter ends with “What to remember”, its glossary and its key figures. The appendices gather the field quick reference, the sources, the checklists, the general glossary and, in appendix E, where the knowledge in this book comes from, with the reference books to read to go further.
Three possible paths
- The pilot: everything, in order. Chapter 2 (the emagram) and chapters 6 to 8 (terrain, breezes, thermals) are the heart of the craft; chapter 11 is for practice.
- The hiker in a hurry: the prelude (clouds), the “essentials” of chapters 1 and 4, then chapters 7 (breezes), 9 (hazards) and 10 (forecasting), and the checklists in appendix C.
- The day before an outing: chapter 10 for the method, chapter 11 to recognise the day that is coming.
A word of caution
Mountain weather can never be reduced to a book. The figures given here are typical values, to be checked against your own terrain, your flights, your outings, and the advice of instructors and mountain professionals. This book replaces neither training, nor the day’s forecast, nor calling it off when the sky demands it.
How this book was written
This book was written with the help of artificial intelligence, which I have made my profession: the outline, the writing, the figures and the proofreading were produced in dialogue with it, then reviewed and arbitrated by me, a paraglider pilot and hiker. The teaching choices, the key figures retained and any errors that remain are mine; please point them out to me. Happy reading, good flights and fine outings.
Pierre Verley