Subtropical jet stream over Maui creates sun halo

Sailors know sun halos can mean bad weather, like a hurricane, is on its way. But today’s ring around the sun that was seen on Maui is a fair-weather halo created by the subtropical jet stream that brought high-altitude cirrus clouds, according to meteorologist Robert Ballard, Science and Operations Officer for the National Weather Service in Honolulu.

Sun halos are beautiful, but Ballard reminds people not to look directly into the sun.

They are created from the refraction, reflection and dispersion of light through ice particles that are suspended within thin, wispy and high-altitude cirrus or cirrostratus clouds.

The halo is a prism effect of the light passing through six-sided ice crystals that separate the light into various color frequencies. This is why the halo will look like a very pale rainbow, with red on the inside and blue on the outside, according to the Farmers’ Almanac.

Ballard said the sun halo probably could be seen from Moloka’i to the Big Island in the Hawaiian islands after looking at satellite images today that showed high cloudiness over that area. There is not much high cloudiness over O’ahu or Kaua’i.

“We don’t get a lot of high cloud days compared to some areas,” said Ballard, a meteorologist. “That’s why we don’t see them as often here.”

Usually, the high clouds are further southeast of Hawai’i. That jet stream is usually not blowing right over the island. And when it does, it usually is during the wet season.

“But whenever you do have high clouds, you can see the halo,” Ballard said.

He said they are more common than people think.

“Something that’s up there that I think doesn’t catch a lot of people’s attention because they are busy with their daily lives,” Ballard said. “But if you’re weather wise and look at the sky a lot, you’ll notice them more.”