A typhoon watch has been issued for the Northern Marianas with winds expected to reach speeds of over 100 kilometres an hour later today.
Tropical Storm Krovanh which is expected to intensify into a typhoon is threatening the Northern Islands of Alamagan, Pagan and Agrihan.
Early today Krovanh was about 150 kilometres north of Agrihan, 240 kilometres north of Pagan and 600 kilometres north of Saipan.
The National Weather Service says residents should prepare for typhoon conditions and to avoid any inter-island travel at this time.