Issued: May 25, 2013 2:00 PM HST
A band of broken to overcast high clouds streaking from the west continues to sweep over the aloha state, and adjacent waters, from Oahu to the Big Island this early afternoon. Most of the cirrus cloudiness has cleared Kauai.
At the lower levels, ceilings, some with embedded showers, are favoring windward and mauka sections on each isle. Broken low clouds are also affecting the Kau and Kona slopes on the Big Island, the west-facing slopes of Haleakala in east Maui, and, occasionally, leeward areas of the smaller isles and west Maui. Low cloud movement is from the east-northeast between 25 and 30 mph just east of the Big Island and veers slightly to the east and slows to near 20 mph moving up the chain to Kauai.
Immediately upwind from the islands are scattered to occasionally broken showery low clouds. Skies are otherwise clear to partly cloudy over the adjacent coastal waters, ignoring any high cloudiness.
Water vapor imagery shows an elongated, east-northeast to west- southwest oriented, upper trough over the central north Pacific. This feature is a tutt, tropical upper tropospheric trough. The system has been drifting south over the past 12 to 24 hours. Its axis is currently along a line from 25°N 140°W to 22°N 150°W to just north of the Big Island to 21°N 170°W to 17°N 180°. The high clouds over the Hawaiian islands are along and just south of the trough axis.
Showers and thunderstorms are sparse along the intertropical convergence zone far south of Hawaii. Most of the convection is south of 07°N west of 152°W, with another area located from 08.5°N to 11°N between 140°W and 147°W.