Alpine mornings clear, afternoons don't

In the Alps this week the pattern is fixed: bright mornings, wet afternoons. Zermatt sat under an open sky at 15°C at 1,600 metres this morning, yet its daily rain total climbs from under 2mm today to over 3mm tomorrow, almost all of it after midday. Chamonix reads the same, clear until noon and clouding over by three. Start at dawn. A summit reached by eleven beats a thunderstorm at three, and the walk down stays drier for it.