Of all the computer model data I look at – model derived snowfall totals is either dead last or not looked at at all. They’re about as useful as a piece of garbage.
Take today’s 12z GFS run valid Monday morning. I’m sure this map will make the rounds soon from bad TV weather readers, weather hobbyists, and knowledgeable meteorologists who have sold out their credibility for page views, twitter followers, and/or Facebook likes.
Are you excited for the 7″ of snow in Willimantic??? Don’t get too excited yet! A look at the GFS model for Willimantic shows that during the height of the storm the freezing level is over 2,000 feet above ground and temperatures are as warm as 2.5C just above the surface. That would be some wet snow for the hills but it certainly wouldn’t be 7″ of snow for Willimantic or Norwich. More like 0″ for Norwich and Willimantic.
Don’t be fooled by computer generated maps with funky snow algorithms. I haven’t found one that is even remotely useful. Going back to basics with model soundings is the only way to accurately forecast events like this.