Either with every thunderstorm or rarely during a wet, heavy snow. It doesn't have to be raining to lose the signal -- in fact it's a good indication it's about to pour.
Yes, that's true, as it indicates there is very heavy precip to your south, between your dish and the satellite. Rarely, if ever, is rain heavy enough directly in front of the dish to cause an outage. If you look at your local radar image at the time of a loss (assuming it's current), you can pick out the cells that are causing the problem, quite easily.
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