Issued: Jul 28, 2014 7:30 PM HST
Water vapor images showed a broad but shallow area of low pressure in the middle atmosphere to the north of the main Hawaiian islands. Isolated towering cumuli developed under this feature within 90 miles of the point 29°N 153°W, and also within 60 miles of the point 26°N 164°W. Middle to high layered debris clouds from this convection partly to mostly obscured lower features within 150 miles of the point 29°N 151°W, and also within 150 miles of the point 26°N 163°W.
To the northwest, deep layered clouds associated with a front obscured lower features mostly to completely northwest of the curve from 30°N 174°W to 28°N 175°W to 28°N 180. Thinner high cloud layers also partly obscured lower features up to about 180 miles further southeast.
To the southwest, a curved band of middle clouds with embedded towering cumuli was located within 60 miles of the curve from 18°N 173°W to 18°N 176°W to 16°N 177°W to 14°N 177°W. This feature moved toward the west northwest at around 20 miles an hour.
To the south, light to moderate thunderstorm activity continued in the ITCZ from 15°N to 03°N. Three weak lows were embedded in the ITCZ near 07°N 174°W, 12°N 162°W, and 13°N 147°W, respectively. Layered middle to high debris clouds from this and earlier convection mostly obscured lower features between the curve from 17°N 140°W to 18°N 146°W to 17°N 156°W to 15°N 163°W to 11°N 166°W to 15°N 175°W to 09°N 180, and the curve from 05°N 140°W to 03°N 145°W to 06°N 150°W to 04°N 157°W to 07°N 161°W to 0°N 161°W. Thinner high cloud layers streaming out of the ITCZ also partly obscured lower features within 120 miles of the curve from 21°N 140°W to 22°N 146°W to 17°N 154°W.
Otherwise, cloud cover across Hawaiian waters consisted mainly of marine stratocumuli and cumuli. These clouds were organized mostly into loose clumps and bands up to about 240 miles across, but they merged into a large area of nearly solid low to middle overcast southeast of the curve from 24°N 140°W to 25°N 142°W to 16°N 151°W. Individual small cumuli also were present throughout. These clouds generally moved toward the west southwest at around 15 miles an hour, and rose to heights of 7000 to 11000 feet, though taller cumuli approached 15000 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 Oahu parallel to the mountain ranges on that islands implied the presence of turbulence within the cloud layer. Areas with the least cloud cover were limited mostly to Niihau, west-central Kauai, southwest Oahu, the west three quarters of Molokai, coastal Lanai, the central isthmus on Maui, the summit and south slopes of Haleakala on Maui, the west coast of north and south Kohala district on the Big Island, the Kau desert on the Big Island, and the summit and middle to upper slopes of Mauna Kea on the Big Island. These clouds generally rose to heights of 5000 to 8000 feet, though a cumulus buildup over the slopes of Mauna Loa on the Big Island approached 15000 feet. Radar data from near the islands showed isolated showers at most.