A couple of images might clarify my post, and yes checking the insulation is on the list of things to do as a long term solution. You can see there is a diverter at the 90 degree corner where the gutters meet, but it is not as larger as the one in the imager above. The ground is pretty flat at the entrance. And, the snow melts from the top and sides of the valley and comes over the edge at the diverter as well as along the edge of the gutters. I'm thinking for this winter that heat mats in the area where the water drips is my best solution. Longer term, I still need to investigate the options, including getting a larger diverter. Up until the past two days thee was about 8" of snow on the roof, but temperatures in the 40s and 50s melted most of the snow and high winds too care of the rest. It is snowing again today.