Update: Lightning, ‘blinding downpours’ face mariners; special warning extends into Friday

10:45 p.m. April 11 update: The special marine warning for waters surrounding Kaua‘i and Ni‘ihau has been extended until 12:15 a.m.

At 10:16 p.m. a large area of heavy rain and embedded strong thunderstorms was located over the waters south and southwest of Kaua‘i, and south of Ni‘ihau, moving northeast at 15 knots. Other more isolated strong thunderstorms were located 10 to 20 nautical miles north of Kaua‘i.

8:22 p.m. April 11 update: The special marine warning for waters surrounding Kaua‘i and Ni‘ihau has been extended until 10:15 p.m.

At 8:16 p.m. several strong thunderstorms located 4 nautical miles southeast of Poʻipū and additionally within 10 miles surrounding Ni‘ihau.

“These cells are moving northeast at 25 knots,” the National Weather Service said.

Wind gusts to nearly 50 knots and small hail are reported hazards. Small craft could be damaged in briefly higher winds and suddenly higher waves.

“Prepare for gusty winds, steep and fast-building seas, and blinding downpours. Stay low or go below, and make sure all on board are wearing life jackets,” the National Weather Service said.

“Frequent lightning is occurring with this storm,” the National Weather Service continued. “If caught on the open water, stay below deck if possible.”

Original post: The National Weather Service in Honolulu has issued a special marine warning for waters surrounding Kaua‘i and Ni‘ihau.

At 6:27 p.m. several thunderstorms – extending from the south and west shores of Kaua‘i to more than 40 nautical miles offshore – were moving northeast at 30 knots.

Wind gusts 34 knots or greater and small hail are possible. Small craft could be damaged in briefly higher winds and suddenly higher waves.

“Prepare for gusty winds, steep and fast-building seas and blinding downpours. Stay low or go below, and make sure all on board are wearing life jackets,” the National Weather Service said.

“Boaters should seek safe harbor immediately until this storm passes,” the service continued. “Wind gusts 34 knots or greater, small hail, high waves, dangerous lightning and heavy rain are possible with this storm.”

The special marine warning is slated to conclude at 8:30 p.m.