GPS - losing signal

Hi,

I know GPS works in bad weather, but...

When would a GPS lose a signal due to weather? i.e. do certain clouds (or
huge ones) make a GPS signal go bad? Does rain? If so, how much? What
about snow? If I was in a hurricane, would I lose the signal? Lightning?

What other things can make GPS signals go bad? Any good research papers out
there? I'm sure there must be now that we're going to GPS approaches.

Speaking of hurricanes, would it be possible to take off in the eye in a 172
and fly along with it for hours in the eye?

Hilton