Issued: Nov 23, 2009 8:30 AM HST
Based on data through 8:00 am Nov 23 2009 HST
Water vapor imagery highlights a very dry and stable air mass over the islands, especially in the mid and upper-levels, as subsident northwest flow prevails aloft. Despite this, infrared and visible imagery shows scattered small trade wind showers moving over the main Hawaiian islands from the east, embedded in scattered to broken cumulus ' cu' and stratocumulus ' sc' .
Large scale picture shows the islands in the middle of the trade wind belt, with little in the way of significant clouds and showers anywhere near the islands. However, the state scale view reveals a few patches of broken sc and cu moving over the islands from the east, with radar detecting a few embedded showers. These clouds and showers are moving toward the west at speeds between 20 and 24 mph.
Skies over Kauai, and adjacent waters, are mostly cloudy, with broken showery cu over windward and interior slopes, and broken to overcast sc and cu over leeward areas and leeward waters. In contrast, skies over the leeward sides of the other main Hawaiian islands are mostly sunny this morning, with few to no cu overhead. Broken cu are over the slopes of the Koolau range on Oahu, the northeast side of Molokai, the windward sides of both the west Maui mountains and Haleakala, and over portions of the Hilo and Hamakua districts on the Big Island. Aside from a small area of overcast sc on the lower slopes of the big island' s Kau district near Naalehu and Pahala, skies over the remainder of the islands are mostly sunny.
Scattered to broken low clouds lie within 15O miles east of the islands, but further east, out to at least 145°W, the low cloud cover decreases to scattered, with little in the way of showers embedded. An area of broken to overcast mid and high clouds well east of the islands, from 12°N to 22°N between 140°W and 149°W, is moving east while decreasing in coverage, and is associated with a broad trough aloft that extends along a line from 30°N 140°W to about 400 miles east of the Big Island near 19°N 148°W to 10°N 160°W. A large anticyclone aloft is centered west of the islands near 16°N 180, and between this high and the trough to the east, a dry subsident northwest flow aloft is over the islands.
