SATELLITE DISCUSSIONBased on data through 0500 UTC February 14 2016.
The eastern half of the tropical central north Pacific, from 10°N to 30°N between 140°W and 160°W, is dominated by scattered stable and shallow low clouds that are tracking generally westward within a sturdy trade wind flow. However, near and north of the main Hawaiian islands, north of 20°N between 153°W and 160°W, the low clouds are turning toward the north. Between 160°W and the international date line along 180, a broken to overcast, northeast to southwest oriented, band of layered clouds dominates the area, marking a frontal boundary that is moving east and southeast at varying speeds depending on the latitude at which the speed is measured.
Over and near the main Hawaiian islands, the low-level flow is moving from east to west near and south of the Big Island, but becomes a southeast to northwest flow near Kauai, is response to the front mentioned above slowly drawing closer to the islands. As was the case this afternoon, low cloud motion east of the Big Island is from slightly south of east at 20 to 25 mph, veering to east southeast at 20 mph near Oahu and Kauai.
The infrared satellite images centered over the islands show that low clouds near the islands are predominantly scattered in coverage and are very shallow and stable, not likely able to drop any rainfall over the islands. Water vapor imagery shows why the eastern portion of the tropical central north Pacific lacks anything beside shallow stable low clouds, as a strong and relatively sharp northeast to southwest oriented ridge aloft prevails over the area, providing strong large-scale sinking motion over the region.