Issued: Oct 08, 2015 7:30 PM HST
The main Hawaiian islands are on the southern side of a col between two surface ridges. The western end of one ridge was about 450 miles east-northeast of Honolulu, while the eastern end of the other one was 370 miles north-northwest. Elsewhere, the leading edge of a surface front was approaching latitude 30°N from the north. These synoptic features were causing light to moderate trade winds across the aloha state early this evening.
An area of broken to overcast stratocumulus clouds was across the main Hawaiian islands from the Kauai channel to Maui. Additional scattered to broken stratocumulus and clouds were in the vicinity of the waters south of the Big Island. The clouds near the central islands were moving slowly toward the north-northwest. Radar showed isolated showers embedded within some of the clouds, mainly south of the Big Island. The highest tops of the clouds were estimated to be about 9 thousand feet.
As of 700 pm HST Thursday, skies appeared to be mostly clear on Kauai. Broken to overcast low clouds were over Oahu, Molokai and Lanai. On Maui, broken to overcast low clouds covered parts of the windward coastline, the lower windward slopes of mount Haleakala, and the western mountains. Broken low clouds were over parts of the lower elevations of the Big Island, particularly the sections north of Hilo on the northeast coast, and parts of the leeward sections.
According to loops of water vapor imagery, upper level high pressure areas were located to the west and east of the main Hawaiian islands. There was a col between these upper level anticyclones, with a broad upper level trough located to the north-northeast of the islands.
In the deep tropics south of the Hawaiian islands, a weak surface low was near 08°N 162°W, or about 975 miles south-southwest of Honolulu. A monsoon trough extended from near 08°N 153°W through the low to 09°N 180°W. There were scattered thunderstorms within 240 miles of the low and the monsoon trough.