Last Updated on Saturday, 19 April 2014 03:50
Issued: Apr 19, 2014 8:30 AM HST
A stable trade wind flow dominates across most of the region, while a weak upper level low is spinning about 600 miles to the southwest of the main Hawaiian islands.
The trade winds are being driven by a surface high centered north of 30°N and are only partially interrupted by a dissipating front located 500 miles north of Kauai. The nearly stationary feature is marked by a 100 mile-wide band of overcast low clouds centered along 30°N 161°W, 27°N 170°W, and 28°N 175°W.
Over the main Hawaiian islands, the first visible images of the day show a mix of scattered to locally broken stratocumulus clouds moving in the trade wind flow from the east at 20 to 25 mph. These clouds are piling up on windward slopes of all islands, while leeward areas are mostly free of low clouds. Cloud cover increases substantially to the east of the state. A field of broken stratocumulus with a few embedded cumulus clouds runs between 27°N and 17°N east of 155°W.
A weak nearly stationary upper level low is centered southwest of the islands near 16°N 165°W. This feature is driving a narrow band of overcast layered clouds on its southeast flank along 17°N 160°W, 14°N 161°W, and 11°N 163°W. Lightning detection picked up a thunderstorm overnight, and tops continue to rise as high as 45000 ft. The upper low is also generating a shield of broken high clouds from 17°N to 21°N between 166°W and 153°W. These clouds have thinned over the state since last night.