what might have happened today? A "severe" low such as this one coming
immediately after a quiet and very warm week is unusual: normally
notable lows come in the middle of a changeable spell. The past few
days have had typical temperatures of 17-18C, about 5-6 degrees above
normal. Move that to the second half of August (probably the earliest
in the year to get autumnal-style lows) and you'd be looking at a week
of 26-27C temperatures followed by this low. I'm guessing that would
have trigged quite severe thunderstorms, and, with the wind, it would
almost feel like a tropical storm (even though obviously it isn't).

Nick