Planning with uncertainty

Cross-check, don’t forecast-shop.

More than one forecast can help you understand the range of conditions to prepare for. The useful question is not “which one lets me do my route?” but “what changes if the less favourable forecast is right?”

By Simon Grogan, mountain leader and founder of Mountain Weather.

Compare the same thing.

Read the explanation, not just the score.

A favourable daily score can sit alongside a short spell of strong gusts or cloud arriving during your summit hours. Read the timing, confidence and hazard detail. A forecast is one input alongside terrain, the group’s experience, equipment and the conditions you encounter.

When forecasts disagree.

Differences can come from the underlying models, update times, regional interpretation or how terrain is represented. Several apps may also use related inputs, so counting matching icons is not a vote from independent witnesses.

First check whether the disagreement is really about the same place and time. If it remains, keep more room in the plan: a lower route, a shorter day, a later decision or postponement. Do not average away a credible warning about conditions beyond your group’s capability.

The most optimistic forecast is not automatically wrong. It simply should not win because it is the one you would prefer. Likewise, agreement is useful context, not a guarantee.

Use these alongside our forecast.

Our peak and region forecasts include links to relevant regional reports where we have a mapping. Boundaries differ between services, and the links open their latest report, not necessarily your selected day. No affiliation or endorsement is implied.

A winter forecast needs a separate avalanche check.

Good visibility or lighter wind does not establish stable snow. Our hill-weather score is not an avalanche danger rating. A location or date without an avalanche bulletin is not a statement that there is no avalanche hazard.

What our confidence means.

Mountain Weather’s confidence information describes uncertainty within our forecast. It does not say that we have compared the live reports from the services linked above. We link to those services so you can read the original information yourself.

Further guidance.

Mountaineering Scotland’s weather and avalanche forecast guidance explains the services available and how they fit into mountain planning. For what we have tested ourselves, read the evidence behind Mountain Weather.