Eric, I have never heard of snow "attenuating" a GPS signal. I have no clue what frequency range the GPS signal is broadcast in but I would think that would one of the places to start. Also, your TV signal is one transmitter and one reciever. The GPS system has many satellites and you only need a few for proper operation. I am just shooting in the dark here. My uneducated guess would be that snow would not be a threat to the GPS signal.
Here is the first link in my google search:
I would suggest going to google and do:*** google+snow****
You may get a tighter search if you put it in quotes.* But I think there is tons of info there...TONS!!!
Whoops.....I just saw my mistake.* I meant,*** GPS+SNOW** !!!!
-- Edited by Baker at 10:02, 2009-01-27