General Signal Questions/Signal Loss Question

I just had DirecTV installed on Saturday the 17th and I was looking at my signal strength with a clear sky and on two of HD satellites I have about 93-100 signal strength and on the new HD satellite I have about 84-91 signal strength.  This morning there were some storm clouds in the area and it was raining I went to the new HD satellite and saw that my strength was 69 on one of the transponders.  I then used the transponder map from the Hallmark HD post a couple of days ago in this forum to find a channel on the transponder and turned it on, it was Lifetime and it seemed to work fine.  My general questions are can all three HD satellites have 93-100 signal strength with a better alignment or is this the best I can get and also at what general strength do HD channels normally stop working to where I get the searching for signal message?