I am talking specifically about severe rainstorms. Thunder doesn't seem to matter but heavy rainstorms do if dense clouds get somehow in the path of the beam. I have had rather heavy rain without dropouts which I explain by the main clouds hanging out of the path of the beam. In fact I don't regularly trade via satellite but I often monitor the condition of a satellite link. If need be, I could go on satellite. I have some plans to do this in the future. Interruptions due to weather are so infrequent that I really haven't given it much thought about how to handle this. Orderly shutdown should not be too big a problem as the dropout never seems to occur all of a sudden. I kind of consider the risk of interruption rather on par with cable. In fact cable interruptions, albeit equally rare, will occur without warning and last longer.
I've been using DirecWay satellite for trading with IB for years. It works, but the reliability is not great. At least compared to almost any other ISP. A lot of it is DirecWay. Another choice coming on line is Wild Blue. It might be more reliable, but it's fairly new and not everywhere yet. Like nonon sez, latency is not a problem at all, at least not for me. And here in the desert weather problems are not too bad. What's bad is the overall unreliability and over-subscribing problem DirecWay has. The modems are terrible and the DNS and acceleration servers are worse. The Indian CS sux big time too. All in all, the whole experience can be described as "Better than 21K dial-up, but if I had ANY other choice for broadband..." http://www.dslreports.com/forum/sat