Issued: Jan 08, 2009 7:30 PM HST
Based on data through 7:00 pm Jan 08 2009 HST
A band of clouds associated with a front extended across the northwest Hawaiian islands and surrounding waters. The clouds composing this feature were quite dense northeast of the curve from 30°N 173°W to 27°N 177°W to 27°N 168°W to 30°N 162°W and further northeast, while low to middle clouds formed the spurs extending within 60 miles of the line from 25°N 180 to 28°N 174°W, and within 60 miles of the line from 20°N 180 to 28°N 170°W. The feature as a whole moved toward the east at 10 to 15 miles an hour. Sparse cold-air cumuli prevailed northwest of the cloud band.
Water vapor images showed a weak center of low pressure in the middle atmosphere centered near 12°N 150°W. Thin high clouds associated with this feature appeared to be dissipating.
To the south, very light thunderstorm activity continued in the ITCZ between 08°N and 06°N, mostly east of 150°W. Layered high to middle debris clouds from this and earlier convection partly to mostly obscured lower cloud features between 09°N and 04°N.
Otherwise, cloud cover across Hawaiian waters consisted mainly of marine cumuli and stratocumuli organized into loose bands or streams arcing from east to west to northwest to north. Individual elements within these streams varied from small cumuli to large clumps of stratocumuli up to 300 miles long and 120 miles wide. These clouds generally rose to heights of 6000 to 8000 feet, though taller cumuli approached 12000 feet. These clouds followed their parent arcs in direction at 15 to 20 miles an hour.
Across the main Hawaiian islands, cloud cover consisted mostly of layered debris clouds from daytime buildups inland, though marine clouds also moved ashore along east to southeast slopes. Areas with the least cloud cover were limited mainly to Niihau, the south shore of Kauai, central Oahu, most of Lanai, the central isthmus of Maui, the summit of Haleakala on Maui, and the interior uplands of the Big Island above elevations of about 6000 feet. These clouds generally rose to heights of 6000 to 8000 feet. Radar data from near the islands showed scattered showers over the Koolau range on Oahu, east Molokai, east Maui, and far offshore to the southwest of Oahu, but isolated showers at most elsewhere.
