I just saw the forecasters was all over twitter, facebook, press, itv news, sky news and bbc news of a possible severe thunderstorms in all over UK start from this Sunday onwards lasted until next Thursday because of very high heat, humidity and cape index leads to severe storms.
I know during thunderstorms that all FTTC modem / router should be turned off and pulled out dsl cable from the telephone socket. I saw press newspaper a long while back where a lightning bolt damaged bt socket.
I expecting ISP's will be huge pressure to deal with FTTC customers will complaints of DLM during bad storms next week.
Probably advised best to leave modem off overnight when go to bed and pulled out cable of dsl socket during overnight storms as possible.