Last Updated on Thursday, 24 July 2014 11:50
Issued: Jul 24, 2014 7:30 PM HST
Water vapor images showed an area of low pressure in the middle atmosphere located mostly north of 30°N near the dateline. Towering cumuli and their thin high layered debris clouds formed under this feature within 60 miles of the line from 30°N 167°W to 28°N 170°W and further northeast.
To the south, light to moderate thunderstorm activity continued in the ITCZ from 13°N to 03°N. Layered middle to high debris clouds from this and earlier convection mostly to partly obscured lower features from 16°N to the equator. Thinner high cloud layers separating from the main part of the ITCZ also partly obscured lower features within 60 miles of the curve from 23°N 166°W to 17°N 172°W to 15°N 171°W, and also south of the curve from 17°N 140°W to 17°N 150°W to 08°N 162°W.
A trough of low pressure located in the ITCZ about 900 miles southeast of the Big Island of Hawaii produced pulsing thunderstorms showing a limited, asymmetrical organization. This system may develop during the next few days as it moves further westward across the central Pacific.
Otherwise, cloud cover across Hawaiian waters consisted mainly of marine stratocumuli and cumuli. These clouds were greatest in areal coverage east of 168°W. Individual small cumuli also occurred throughout. These clouds generally moved toward the west southwest at around 15 miles an hour, and rose to heights of 8000 to 10000 feet.
Across the main Hawaiian islands, cloud cover consisted about equally of marine stratocumuli and cumuli moving ashore along slopes facing north through east on the one hand, and afternoon cumulus buildups with their layered debris clouds over higher terrain inland on the other. Banding of the clouds over Kauai and Oahu parallel to the mountain ranges on those islands suggested the presence of turbulence in those cloud layers. Areas with the least cloud cover were limited mostly to Niihau, west Kauai, the south coast of Oahu, central Molokai, coastal Lanai, west slopes of the west Maui mountains, the central isthmus on Maui, the summit and southeast slopes of Haleakala on Maui, the west coast of north and south Kohala districts on the Big Island, the Kau desert on the Big Island, and interior uplands of the Big Island above elevations of about 6000 feet. These clouds generally rose to heights of 6000 to 9000 feet. Radar data from near the islands showed scattered showers over the Koolau range on Oahu and offshore in the lee plume well to the west of the Big Island, but isolated showers at most elsewhere.