Issued: Apr 24, 2014 2:30 PM HST
Based on data through 2:00 pm Apr 24 2014 HST
Surface high pressure centered north of 30°N is driving a trade wind flow across most of the region. An associated surface ridge stretches over Midway atoll, where the low level flow turns southerly. The area north of 23°N is dominated by scattered stable stratocumulus while shower-bearing cumulus clouds prevail between 23°N and 10°N.
Near the main Hawaiian islands, a 150 mile-wide, nearly east to west oriented band of scattered to broken cumulus clouds is drifting southward just north of the state. The band is centered along 21°N 140°W, 21°N 150°W, 22°N 160°W near Kauai, and 22°N 170°W. Individual low clouds within the band near the islands are travelling from the east-northeast 25 to 30 mph, and cloud tops are in the 8000 to 10000 ft range.
The cloud band continues to produce broken to overcast low clouds over windward slopes of Kauai and to a lesser degree on Oahu. These clouds are spilling over to central Oahu is the form of lee wave clouds, narrow bands downwind of and parallel to the Koolau rage which hint at stable conditions. Across the rest of the state, the cloud band is just offshore, leaving patches of broken low clouds along typical windward slopes. In addition, afternoon sea breezes have produce broken low clouds over leeward Big Island slopes south of waikoloa.
A shallow upper level trough bisects the region from 29°N 140°W, 25°N 160°W, and 19°N 180°. This feature is travelling to east around 25 mph east of 160°W and is nearly stationary to the west. The upper trough is drawing up broken high clouds over waters south of 19°N. The source of the upper level moisture is thunderstorm activity within the ITCZ. These thunderstorms are confined between 09°N and 03°N.