I have found that spraying your dish with Rain X window treatment will help. Used to have the same problem when I first got dish and then someone told me about using RainX and it helped. Still have an outage in really bad weather but no where's near as bad as it used to be.I know that satellite TV doesn't work great in Rain, but Direct TV is much better, at least in NY.
Down here in Florida Dish Sucks in the Rain
Time to rethink Cable for Florida, if I'm going to be watching games