Chlorine and Horizontal Hail Stones

Not that the weather is confusing or anything, but there I was walking along the road. Suddenly, the already strong and buffeting icy wind decided it would bring with it some sleet, then hail stones, and then more sleet. Maybe there was a bit of rain in there as well. I’m not sure, but I know it was all travelling extremely fast and in a near horizontal plane and I got exceedingly wet.

Fairly immediately I noticed that there was a strong smell of chlorine, like the smell of a swimming pool. It grew stronger, and when the attack of sleet, hail stones, sleet, and possibly rain ceased I sniffed my soaked clothes. Sure enough, quite distinctly they smelt of chlorine.

So, what was that all about? How did water from clouds in the sky smell of chlorine?