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 areas. The waters around the British Isles are divided into sea areas, also known as weather areas. Within the United States National Weather Service, the Ocean Prediction Center (OPC), established in 1995, is one of the National Centers for Environmental Prediction’s (NCEP’s) original six service centers. Until January 12, 2003, the name of the organization was the Marine Prediction Center. The OPC issues forecasts up to five days in advance for ocean areas north of 31 north latitude and west of 35 west longitude in the Atlantic, and across the northeast Pacific north of 30 north latitude and east of