this time on weather world, i'm in scotland, the country that hosted the 2021 cop climate summit. and even though i've come to one of the coldest and snowiest parts of the country, the cairngorms ski area, it faces its own challenges as our world warms. i'll be talking to the people whose livelihoods depend on winter snow here, even if sometimes they have to make it themselves. the factory produces four tonnes an hour, so injust under a month that's about 3,000 tonnes. and i'm in london, where, like many major cities around the world, mass transport systems are facing up to the threat of flash flooding. and i'll be asking what can be done to keep travellers safe in extreme rainfall. also on weather world, sudden and savage — disaster in the usa, hit by one of its largest tornado outbreaks in history. how one canadian province found itself at the epicentre of 2021's climate change—fuelled extremes.