Issued: Oct 09, 2015 8:30 AM HST
Water vapor imagery showed a weak upper level ridge just north of the state. The east northeast to west southwest aligned ridge axis extended from 27°N 155°W to 21°N 180°E. The ridge was nearly stationary.
Just north of the ridge, a strong and wide jet stream was traversing the region. This roughly 350 to 400 miles wide jet stream was centered along a line through 40°N 168°W to 34°N 154°W then curved northeast through 40°N 140°W and continued to southwest Canada. The jet was flowing along the base of an upper level trough that dipped south to 29°N between 150°W and 160°W.
A weak front extended southwest through 30°N 151°W to 28°N 165°W this morning. That part of the front along 30°N was moving east at 15 to 20 miles an hour while the part further west was moving southeast near 10 miles an hour. The associated cloud band was only comprised of scattered to broken low clouds.
South of the area, a surface trough extended from 10°N 144°W to 04°N 148°W. It was moving west near 15 miles an hour. Mostly broken low clouds along with isolated thunderstorms were within 225 miles east and west of the trough. Storm tops in this area were between 40000 and 45000 feet.
A large cluster of stronger thunderstorms Sat between 11°N 164°W and 03°N 156°W. These storms had tops to over 50000 feet and were associated with a surface trough in the area.
Meanwhile, light trade winds had settled over the state. Low clouds in the area were moving west at 10 to 15 miles an hour. At 8 am, skies were mostly clear over Maui county and the Big Island. Oahu was cloudy along the windward sections but sunny over the southwest half of the island. Nearly all of Kauai was cloudy due to a large cluster of overcast low clouds surrounding that island and extending about 200 miles to the southwest. Few clouds surrounded the other islands.