I doubt that any of sail flows stuff is "theirs". What it looks to me like is they get the gribs and repost them. Don't know what engine for the gribs their using.

I've found gribs to be about 50-80% accurate. 24 hours out their 50% and for the current conditions they're 80%. And closer to the coast and land masses the less accurate the seem to be. Obviously all the bldgs and parking lots and hills / mtns effect the ground level wx more then they know. Also usually they're on 1 degree grids which is covering a 60 nm area. So within that area you can get lots of little effects.

Fair Winds