The direction of wind arrows on weather map is the direction of an arrow "flying" with the wind like the animated particles do (it is NOT the direction shown by a wind vane). Same for the wind symbols which are called wind barbs, they are a simplified design of an arrow flying with the wind. And so, for a northerly wind blowing from North, the arrow is pointing to the South.
Did you compared several models for your location?
You should know that weather forecast models have a resolution of several km (25 km for GFS), so don't expect huge accuracy over areas with mountains, valleys, etc.
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