HYPE: Snow in New England, PA Tonight?

The GFS Forecast Model [JessePedia] printed out something interesting in last night's run... snow again in the Northeast tonight.

But it's mid-May right? Is this even possible? Let's delve deeper into the possibilities with tools from our AccuWeather.com Professional website:

Those of you who know the GFS well know that it tends to overestimate light snow, even with a 10:1 Snow Ratio [JessePedia], so the 6 inches it is claiming for northern Maine is probably not going to happen, but certainly some light snow is possible in favored locations there.

Checking the "official" forecasts, AccuWeather.com says that Clayton Lake, Maine (see map below) has a 33% chance of snow tonight, per AccuPOP, but the official forecast has only rain: "A touch of evening rain; otherwise, rather cloudy and chilly; Low 29." The NWS disagrees, saying "RAIN AND SNOW LIKELY IN THE EVENING...THEN SNOW LIKELY. SNOW ACCUMULATION AROUND AN INCH ESPECIALLY OVER THE HIGHER TERRAIN. LOWS AROUND 30."

Here's two frames from the "NDFD" model from The NWS [JessePedia] which shows 6-hour snowfall forecasts for Maine tonight. If you add them all up, you get 0.66" of snow somewhere in the forest in the middle of Maine overnight. The AccuModel map for accumulated snow in Maine tonight shows even less.

The biggest roadblock that the snow forecasts from the GFS have is simply the temperatures tonight (GFS | NAM), which will be above freezing in most locations, and has been for a long time, so the ground is warm. This is something the model probably can't sense or wouldn't take into account with snowfall. So, we may have some wet snow across Maine but it likely won't stick in any populous places. The NAM Model forecast is much more reasonable and pretty much confirms this idea:

What about Canada? Not much besides a chilly rain there, per Canadian expert Brett Anderson (PREMIUM | PRO), who wrote in his blog yesterday: "The real nasty conditions will be from southern Quebec, through Maine and into New Brunswick and northwestern Nova Scotia with a chilly, soaking rain. Midday and afternoon temperatures will be falling through the single digits Celsius (40's F). If it was late April we would be talking about a heavy, wet snow from southeastern Quebec to central New Brunswick."