A forecast for a town in the valley won't tell you everything about conditions two thousand metres above it. Before a hike, we check the weather at the altitude we'll be walking, too.
What we check
We check these the evening before each hike and again at the trailhead:
- Freezing level. This helps us judge whether to expect rain or snow and what conditions underfoot might be like.
- Wind at altitude. Thirty kilometres an hour in the valley can be double that on an exposed ridge.
- Storm timing. In summer, we check whether thunderstorms are forecast and when they might arrive.
When we turn back
We keep checking conditions as we walk. These are reasons for us to head down:
- Cumulus clouds building before eleven in the morning. Storms may arrive earlier than forecast.
- Wind that makes conversation difficult on an exposed section.
- Someone in the group stops eating or drinking. We take that seriously, even if we don't yet know why.
These checks help us look after a group of sixteen on a Sunday hike. We go through them with new members during their first few outings.