A melt blowing apparatus and method includes a melt blowing die and at least one louver. The melt blowing die has a nosepiece comprising at least one aperture and at least one air slot adjacent the aperture. The at least one louver is movably positioned adjacent a face of the melt blowing die forming a zone through which can pass air and molten filaments from the air slots and nosepiece of the melt blowing die.