The windward side of Hawaii Island has been hit with heavy vog as a result of an unseasonable lack of trade winds.
John Bravender, a meteorologist with the National Weather Service in Honolulu, said Tuesday that a slowly dissipating low-pressure system has been creating light wind patterns around the Big Island. That means that the steady stream of sulfur dioxide and other volcanic gases escaping into the air above Hawaii Island’s eruptions is lingering, rather than being whisked away by the trades.
“It’s really allowed the vog to build up near the island, and there’s even been a little bit of a background flow, carrying it in a southerly direction, helping to spread it to Hilo and other parts of East Hawaii, where it normally doesn’t go,” Bravender said.
The current conditions are more in keeping with weather patterns seen in January and February, he added.
“Normally, this time of year we would be well into the tradewinds. Having a front like this come in is more usual for a wintertime pattern,” he said.
The low-pressure front was expected to continue weakening Tuesday, but that doesn’t mean an end of East Hawaii’s vog problems, he said.
“We’ll have another weak boundary move in from the northwest, and that’s not expected to do much but keep winds very light and delay the trades from building back in,” Bravender said. “It doesn’t look like until Friday we’ll start to see a regular tradewind flow out of the northeast.”
The air was hazy in Hilo on Tuesday, with the view of Mauna Kea completely obscured. Meanwhile, sulfur dioxide levels around Hawaii Volcanoes National Park went into the red for several hours during the morning, meaning that air quality had reached unhealthy levels in some areas.
Rangers shut down the Kilauea Visitors Center and Volcano Arts Center in the park for about an hour and a half on Monday, said Emily Catey, the center’s curator.
She was monitoring the state Department of Health’s sulfur dioxide advisory website when the Tribune-Herald called around 11 a.m.
“We usually have it up, especially on days like this when we are closely monitoring the situation,” she said. “We want to keep ourselves safe, as well as the visitors to the park. Usually, if it’s in the red for more than an hour, we’ll close the center and wait.”
Catey said Monday was the first time in the past year that the center was forced to close due to vog.
“Yesterday, it was a bit worse than today. It was really thick with particles in the air. It kind of looked like you were in a bad haze condition. It kind of moves in fingers, moving out through the community when there’s no wind. I can be in my car and see it on one street, and then drive three streets down and it’s clear,” she said.
She said that she had seen worse vog conditions over the years, but the current situation is definitely out of the ordinary.
“I feel heaviness in my chest, and there’s that thickness in the air. People that are more sensitive, with allergies and so forth, they really notice it a lot more. I’m not as badly affected,” she said.
Cynthia Orlando, superintendent at the national park, said she wasn’t too concerned with the voggy conditions.
“I’m looking out my window and looking at blue skies,” she said. “We are expecting to have hazy conditions, but that is normal in specific locations. … We have intermittent spikes in vog, that’s not unusual.”
Orlando said rangers closely monitor sulfur dioxide levels and shut down areas where pockets of the gases have built up until the levels go back down.
“We have this down. We’ve gotten pretty good at moving people. We’ll bring visitors inside and make sure everyone is safe,” she said.
She added that the area around the Jaggar Museum is especially susceptible to build up of vog.
“But yesterday, we had the bad air at KVC (Kilauea Visitors Center) and the clear air at Jaggar, so we sent everyone out there,” she said. “Usually after March, that doesn’t happen as much.”