The Collaborative International Dictionary of English v.0.48:
Northwestward \North`west"ward\, Northwestwardly \North`west"ward*ly\, adv. Toward the northwest. [1913 Webster]WordNet (r) 3.0 (2006):
northwestward adv 1: in a northwestward direction [syn: northwestward, northwestwardly] adj 1: toward the northwest n 1: the compass point midway between north and west; at 315 degrees [syn: northwest, nor'-west, northwestward, NW]