There might be a small enhanced snow from upslope, but I think your extra snow is from your 300 feet of higher elevation. Its amazing what a couple hundred feet of elevation can do. During the APril 15th storm, Lebanon had about an inch on slush down in the valley at 600 feet. At 1000 feet, there was 7 inches of heavy wet snow and the power lines were threatening to come down. Thankfully it changed to rain. Further north across Lyme, Canaan, Enfield area, 12-24 inches of sloppy, wet, elevation snow fell above 1500 feet, causing major power outages, and tree damage. You should see the damage. Its still remarkable to look at the areas that had to be cut down. So I'd be willing to bet its more the elevation that plays a factor in your heavier snows than upslope.
grouseking