Issued: Apr 16, 2014 7:00 PM HST
Based on data through 7:00 pm Apr 16 2014 HST
Skies are clear to partly cloudy over much of the aloha state this early evening, including the adjacent coastal waters. Low ceilings, on the other hand, have been favoring mauka and windward upslope sections on the individual isles, at least from time to time. On the Big Island, broken to overcast low cloudiness has also been affecting upslope and coastal areas of Kona and leeward Kohala. Low cloud motion is from the east-northeast at 20 to 25 mph across the island chain.
In the upper air above 25 thousand feet, water vapor imagery shows dry conditions over the islands. Also, the axis of a northeast-to- southwest oriented trough is roughly along a line from 23°N 154°W to just over Maui county to 15°N 165°W. The northern part of the system has been nearly stationary, while the southern portion has been heading slowly west. The upper winds on the east side of the trough are from the south and southwest, and are carrying a large swath of high clouds to the north and northeast. The cirrus clouds, with some elements sweeping just east of the Big Island, are debris from the convection that has been occurring far to the south and southwest of Hawaii.
Broken high clouds have been streaming over Midway atoll from the west in advance of a front that is approaching the date line. Winds at the site have recently been from the south and southwest between 15 and 20 mph as the feature gets closer to the isle.
As alluded to above, convection has been firing along the intertropical convergence zone far south of Hawaii. Much of the activity has been igniting from 02.5°N to 06.5°N east of 153°W. More intense cells, though, have been evident south of 04°N west of 162°W.