Pacific Ocean To determine the phase of ENSO, the most recent three-month sea surface temperature average for the area approximately to the southeast of Hawaii is computed, and if the region is more than above or below normal for that period, then an El Niño or La Niña is considered in progress. In the tropical western Pacific, the monsoon and the related wet season during the summer months contrast with dry winds in the winter which blow over the ocean from the Asian landmass. Worldwide, tropical cyclone activity peaks in late summer, when the difference between temperatures aloft and sea surface temperatures
Marine weather forecasting began being produced by the Ocean Prediction Center in 2006, a first step toward digital marine service for high seas and offshore areas. Additional gridded products such as surface pressure and winds are under development. Recently, National Weather Service operational extratropical storm surge model output to provide experimental extratropical storm surge guidance for coastal weather forecast offices to assist them in coastal flood warning and forecast operations. Within the Japan Meteorological Agency, marine observatories are seated in Hakodate, Maizuru, Kobe and Nagasaki. These stations observe ocean waves, tide levels, sea surface temperature and ocean current etc. in the Northwestern Pacific