A tropical disturbance began to develop to the southeast of Agrihan, an island of the Northern Mariana Islands, early on November 5, from the tail end of shear line connected to a front that ran to Japan. It strengthened into Tropical Depression 28W early the next day and moved to the northeast along the shear line, reaching its peak with winds. The depression did not develop further, but its motion accelerated and it became an extratropical low 18 hours after forming.
