Not so gute Reise?

So my Aunt Fran and Uncle Jim are in Switzerland for a couple of weeks of sightseeing, and they're supposed to arrive in Basel this evening for a few days. The only problem is that after griping about how hot it had been recently, the past couple of days have taken a serious turn in the other direction. Both yesterday and today started relatively sunny, and by noon the sky was black with lots of thunder and lightning. At the moment it's hailing. In July. If I look out one window it looks like night is falling, but if I look in the other direction I can still see patches of blue sky. Suffice it to say that weather like this isn't conducive to seeing the Alps, the lakes, the city streets, etc. (We were thinking about it this weekend when we saw trainloads of tourists going up to the Jungfraujoch, which is very expensive but on Saturday was completely covered in clouds so presumably everyone had to buy postcards to see what it actually looks like.)