If your roof has stripes like this, you’ve got a problem. Either your insulation is failing/missing or you’ve got an air-sealing problem or both.
The good news is that you got a free energy audit. The bad news is that this is one of the things that causes ice dams.
Fixing the problem causing these stripes will make your home warmer in winter AND cooler in summer. A lot of people seem to forget that second part. While these problems are easiest to spot in winter, they save you money and make you more comfortable year-round.