That’ll be the average wind speed. Gusts will reach higher speeds. The threshold for damage to buildings is 47mph and up. Depending on which part of London you live in you should be spared the worst of it as London is both inland, and the mass of buildings will attenuate the force of the wind.
Will this storm be as severe as forecast? We won’t know until it hits. Living on the central south coast I’m sure I’ll find out.,. I’m prepped and waiting with both anticipation and trepidation.