I have had Uverse for over a year and never had any interference from the weather.

For the first couple of months, my system would get a little flakey during storms.  I never completely lost signal, but I started noticing more macroblocking and pixilization when it rained.  Thanks to the folks here and on Utalk, I learned how to get some meaningful stats on my connection and noticed that even during good weather, I was getting millions of corrected errors per 15 minutes and hundreds of uncorrectable errors each day.

I called tech support, they ran some sort of line quality check from the office, and said that I had a problem.  They dispatched a tech who looked at a few things in my house, but spent most of his time out at the NID.  He didn't say exactly what he did, but whatever it was cleaned up my signal significantly.  He also identified a possible bridge tap on my line and put in a ticket for I/R to remove it.  Initially (before the bridge tap was removed) my corrected blocks dropped to a few thousand an hour.  After the bridge tap repair, I now only get a few thousand corrected blocks a day, and only a few uncorrectable blocks.  We haven't really had any significant weather (other than heat and humidity) since he fixed it, but I'm anticipating that my system will be much more stable the next time it storms.

Bottom line is, if your signal is marginal when the weather is good you're likely more susceptible to having problems when the weather gets bad.

Mine was having trouble too, the tech came out yesterday, and found a ground problem, he could not mess with so he had another tech come out, who was working it out for like 4 hours, he found a "Floating ground" somewhere between my house and the cross box along 1800 feet of wire, he located and repaired a rubbed through section of wire insulation, immediatly error counts in the status screen of my gateway were stopped. It did take the uverse tech and a line tech to get it worked out, and they said if it had not still been fairly damp out they would have had a hard time locating it.

Yesterday was my first day on Uverse in Fishers and I experienced the same characteristics as others have described here.  My service is 2600 +/- feet away and they found a bridge-tap yesterday and removed it.  Kind of funny to experience what seemed like weather interference that you would expect on Dish or DirecTV.  I was viewing an HD channel during the interference... funny thing is... it had not even quite raining completely and the issued subsided.  Makes me wonder if it's lightening related verses moisture in the copper.

I agree it's a great lesson to learn, but even though I've called them out several times I still have a blip after a lot of moisture (heavy dew) or rain.  I'm to monitor the next rain event and report back to them.  Sure is a tedious process to make things right.  Good thing for them  I like U-verse and don't like Comcast