A high-surf advisory is in effect for the east shores of the major Hawaiian Islands through this afternoon.

The National Weather Service said a strong high-pressure system to the north-northeast will produce high surf along east-facing shores for the next several days. The waves are forecast to be in the 6- to 10-foot range.

The shore break and currents could make swimming difficult and dangerous, the weather service said.

Meanwhile a flash flood watch was in effect Sunday for Kauai and Niihau, with the potential for locally heavy showers and isolated thunderstorms, the agency said.

Iridium-18 satellite will ‘explode’ if night skies are clear

Honolulu skies will host a pair of spectacular celestial displays tonight and Thursday if the clouds cooperate.

At 8:07 p.m. the Iridium-18 satellite will briefly reflect the rays of the sun, looking much like an exploding star. This will occur in the south-southeast, near the tail of the Big Dog, Canis Major.

Canis Major contains the brightest star in the sky, Sirius, which shines at magnitude minus 1.46. The Iridium flare will be many times brighter at minus 7.

Just before 7:54 p.m. Thursday, the same satellite will flash again — but even more brightly, at minus 8 — in roughly the same spot.