Issued: Dec 11, 2013 8:30 AM HST
There has been little change in cloud cover around the main Hawaiian islands since late last night.
Clouds are isolated over Niihau and Lanai. On Kauai, Oahu.molokai and Maui there are broken low clouds over the windward slopes with isolated low clouds over lower lee areas and clear skies over Haleakala above about 5500 feet of elevation. On the Big Island of Hawaii there are broken to overcast low clouds along the windward coast from Upolu Point to Waipio valley and over the coast and lower slopes from Laupahoehoe to Cape Kumukahi to Volcano with a patch of broken low clouds over the slopes between Pahala and Naalehu. Clouds are isolated over the rest of the Big Island.
Low cloud motions east of the Big Island are from slightly north of east at 15 to 20 mph veering to east southeast at 15 to 20 mph near Kauai. There are broken low clouds upstream of all the islands. The clouds near the main Hawaiian islands are mostly stable stratocumulus clouds, cu, with some moderate cumulus clouds, cu, mixed in. Radars show scattered light showers falling from the cumulus over windward areas of Maui county and over water northeast of the islands from the Big Island to Oahu. Broken cu and sc extend upstream for about 850 miles with stable overcast sc beyond that.
A 120 mile wide frontal cloud band is north of a line from 27°N 150°W to 235 miles north of Kauai to 30°N 162°W. The band is 120 miles wide and contains overcast low clouds. Over the past several hours the part of the band east of 158°W has been nearly stationary while the part farther northwest has been moving north ahead of another front.
A 100 mile wide frontal cloud band containing showery overcast low clouds is northwest of a line from 30°N 158°W to 27°N 170°W to 20°N 180°W. The band has been moving toward the east southeast at around 15 mph. A prefrontal convergence band centered from 30°N 167°W to 24°N 170°W to 16°N 180°W is much more active than the frontal band itself. The part of the band north of 22°N is 150 miles wide and contains overcast layered clouds and numerous cumulonimbus clouds with tops to 47000 feet. The part of the band south of 22°N contains broken low clouds and scattered towering cumulus clouds. The northeast half of the convergence band has been moving toward the east southeast a bit more slowly than the front itself. The part of the band west of 172°W is nearly stationary.
Water vapor imagery, which show features mainly above 24000 ft, shows a ridge aloft centered from 30°N 160°W to Kauai to 15°N 170°W with troughs aloft from 30°N 132°W to 26°N 144°W amd from 30°N 173°W to 26°N 175°W.