This week, Wales's favourite weatherman Derek Brockway is out walking at opposite ends of the country. First, he's high in the wilds of Snowdonia with disabled rambler Terry Taylor as they explore an old Roman road leading across the Carneddau Mountains. Later, Derek goes south to Skomer Island off Pembrokeshire. Guided by the warden Bee Buche, Derek gets a close-up view of the puffin population before staying up late to see the reclusive Manx shearwater.