First, do not panic-buy bread and milk. You cannot toast a sandwich in a flood. Instead, invest in a good waterproof coat and a sense of humour. You'll need both when you try to walk 10 feet and get hit by a rogue gust that turns your umbrella into a kite.
UK weather maps show 740-mile rain bomb to drench millions of Britons
Second, embrace the chaos. This is a perfect excuse to cancel all your plans with a text that reads: "Sorry, I'm currently being reclassified as amphibian." Also, remember that your car's windscreen wipers were lying when they said they could handle "heavy rain." They can't. They're amateur hobbyists compared to this front.
Finally, here's a pro tip: if you see a canal boat floating down your high street, just wave. You're now living in the UK's newest, wettest theme park. Enjoy the squelch.
So, stay dry, stay indoors, and if you absolutely must go outside, wear waders and a helmet. And if you see a 740-mile rain front coming your way, just remember: it's not the end of the world. It's just a very, very, very wet Tuesday.
Now, if you'll excuse me, I'm off to teach my cat how to swim. Wish me luck.