18 Inches of Snow in Southwest PA?

I just passed an AccuWeather forecaster in the hall who said "You know we think there could be 12-18 inches of snow in the Laurel Highlands by the weekend!" I was admittedly surprised by this prediction, but our maps usually low-ball lake-effect and clipper snow events, especially in the high elevations. Here's our official map through Friday, which includes both lake-effect snow and snow from the Clipper system moving through the area:

(See (PREMIUM | PRO for the Canadian version).

So, based on the map and his comments, maybe we're starting to be more receptive to predicting higher amounts, starting with the local area that we have knowledge of, here in Pennsylvania. We're admitting the 12 on the map above, and (internally) guessing up to 18 inches in the Laurel Highlands area (the highest elevations of southwest PA, see this official map). Here's the Hi-Res WRF Forecast Model [JessePedia] from our Pro site, which is not that much different than our map. All this aligning makes me think that the forecast confidence is high for heavy snow at high elevations in PA by Friday night.

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