Source : Webster's Revised Unabridged Dictionary (1913)

Northeastward \North`east"ward\, Northeastwardly
\North`east"ward*ly\, adv.
   Toward the northeast.

Source : WordNet®

northeastwardly
     adv : in a northeastward direction; "the river flows northeastward
           to the gulf" [syn: {northeastward}]