Tree in the way?

I have a tree that I think may be affecting my signal, but I'm not sure.  Today my signal strength is all over the place, ranging from the low 60s to the high 90s, and I have clear, blue skies, as does my gateway.  

I thought that a tree might be in the way a couple of months ago, but then my signal strength seemed to improve quite a bit.  I did notice, however, that when the last four of the IPGW string are in the 1200s, the signal tends to be in low-mid 90s, and when in the 1300s in the mid-upper 90s, and when in the 1400s the upper 90s to mid 100s.  Right now it's 1201 and my signal strength is 57.  It's bouncing all over the place.  Now it's 94.  There's a slight breeze, but nothing major.  I don't believe my dish is moving, as that's been pretty rock solid whenever I check it.  

Could someone check my system to see what might be going on?  

Thanks.