Use a Little Grease To keep Snow and Ice Off Satellite Dish
I have found that spraying cooking spray like Pam or WD-40 over the entire dish will keep snow and ice from sticking to the satellite dish. A good coating usually lasts all winter for me, unless we get a few heavy rains on the warmer days. Be careful with WD-40 as it may damage or discolor plastic satellite dishes or components and it is really flammable. I usually use cooking spray, but have used WD-40 in a pinch. It works great and will keep your TV snow free during the next snow storm.
Turn up the Heat On Your Satellite Dish
If you happen to live in a very cold climate or your dish is way up on your roof you can also try one of the commercially available satellite dish heaters. Dish heaters don't work very well on plastic dishes and will cost about $100 plus installation. If you receive losts of snow and have a metal dish this may be your best option.
Cover Your Dish
Another technique I have used is a good old trash bag. This works really well if you are expecting a big snow storm and have time to prepare. Just take a large trash bag, one with draw strings works best, and place it over the receiver and around the front edges of the dish. Use the draw strings or some zip ties to secure the bag to the dish. My friends and I have had some succuess with this method, so if it works in your circumstances you may want to look into a commercial satellite dish cover. You can get one for around $40 and can be used year round.
Enjoy your snow free dish TV.