I apologize, cruzenbye! There are several threads going right now from people who are making trial runs with their gear (good for all of you!) and I grabbed the wrong prior post. It's (obviously!) someone else who has the Hubba Hubba.

I have used the one of the little Coleman tents made for backpacking and it worked fine even in a cloudburst (I encountered several with it when camping in the south of France). My oldest son (owner of the tent) used it on an extremely rainy weekend in the Canadian Rockies with no problems. It has full fly coverage over the entire tent. I don't know if this is the type of tent you have, and from checking the Coleman site I don't think it is made any more. It was about $100 at a discount store in 2001. I'd consider something a little better, though. Most backpacking tents (silnylon ones excepted) come already seam-sealed from the factory. Silnylon tents and tarps need to be seam-sealed by hand as there is no way to make mechanically-applied tape stick to the seam as there is with the heavier tent coatings. Even tents which are factory seam-sealed should be tested, though, because you may have to fill in gaps in the sealing.

The above posters have already thoroughly covered the ways to keep your tent dry.