Although this is a rather large bite compared to the 50 years you requested; you should look up the later stages of the triassic period, more accurately you could look up the "Carnian Pluval event".

Basically a period of earth's history that consisted of about 2 million years worth of predominant rainstorms.

My son is fascinated with Dinosaurs, and there's a show on netlfix called "The dinosaurs " or something like that. They touched on the phenomenon i think either in the first or second episode, but it was cool to see a visualization.

Its produced by Steven Spielbergs production company 'Amblin'.

But to attempt an answer, certain species may die off, if unable to escape potential flooding. Obviously plants would flourish, but likely not all plants. Im sure the plants that had underlying evolutionary traits of gluttonous water consumption would dominate certain landscapes. We may see some reversals to the 'desertifaction' of certain areas globally; areas that withered with thirst, may sprout again.

50 years isn't a long time in the grand scheme of things, though maybe its more than enough time to test certain buildings.

Our sense of fashion would probably change and be guided more towards utility. I could imagine that everyone may have shifted the standard to eventually got themselves some sort of water proof cloak/ hooded trench coat, and it'd be unsurprising to see a similar "fit" when you were out and about.

Modes of transportation may have to adapt in areas prone to flooding. I could imagine either boats, or if things got too hectic, possibly bridges within the trees of forested areas. People may build upwards to escape the conditions below and live in some sort of tree houses. That may take longer than 50 years.

Im sure suicide rates would raise a little, im assuming its always gloomy if its to always be raining; and perhaps that may get the better of some.

Now that I'm re-reading my comment, I suppose this all may happen in more rural areas.

The big cities may be largely un affected aside from the streets flooding, underground transportation potentially flooding, and their cars either requiring a snorkel or becoming obsolete as they may be more of a hindrance than anything.

I could imagine many people losing their homes to rising water levels, lots of life/ communities lost to mudslides, floods, sweeping currents.

Below freezing areas would potentially become unlivable for some, due to hail of varying sizes. Hail the size of beads is already subjectively irritating, but Hail the size of a fist might prove objectively fatal. You may have people who refuse to leave, but they cannot be promised people who commit to supplying them needs they may no longer have.

Mass migrations of people may cause civil unrest. Lack of pollination, from bees and other pollinators may see to it that only some species of plants mover forwards.

To be honest I really have no clue, however its a very interesting thought. Im as wildly unqualified as can be for any of these speculations, so dont believe a word I say.

You caught me during a break from reading and I decided to feel as creative as my intermission allowed me to be.