According to one embodiment, a forming body of a glass forming apparatus may include an upper portion with a first forming surface and a second forming surface extending from the upper portion. The first forming surface and the second forming surface may converge at a bottom edge of the forming body. A trough for receiving molten glass may be positioned in the upper portion of the forming body. The trough may include a first weir, a second weir opposite from and spaced apart from the first weir, and a base extending between the first weir and the second weir. At least a portion of a vertical surface of the first weir may curve inward towards a centerline of the trough. Similarly, at least a portion of a vertical surface of the second weir may curve inward towards the centerline of the trough.