When that happened to me the first time I called the satellite company and they told me that when it snows hard or sleets, go out with a towel and wipe off the satellite. It works everytime I have to do it, but my satellite is not on the roof....I wonder if Pam spray would really work or somehow put a coating on the satellite that would interfer with reception. In Michigan, I so have to clean off the satellite several times a month due to winter snows and sleet...
No, The PAM will put a nice slippery coating on your dish, and the snow will no easily stick to it as much as before.
If you get a lot of snow, you might consider a dish cover or a dish heater.
I don’t get a lot of snow, so I just tied a lawn and leaf bag over the dish.