Hilo’s Shroud of Vog Could Stay Until Friday

A low-pressure system over the state is keeping winds light, resulting in heavy volcanic haze over much of the Big Island, particularly in Hilo and surrounding areas.

“Vog plume headed right into Hilo,” the National Weather Service tweeted late this afternoon. “Air quality not very good tonight.”

The weak pressure gradient is expected to continue for the next several days, the weather service said.

Vog-clearing trade winds are not expected until Friday at the earliest.

The forecast calls for only scattered showers and variable winds through Thursday.

Vog is created when sulfur dioxide and other volcanic gases combine and interact chemically in the atmosphere with oxygen, moisture, dust and sunlight.

During heavy vog events, health officials advise staying indoors with windows closed and the use of an air conditioner if available.

According to scientists at the University of Hawaii at Hilo, the resulting aerosols can be partially neutralized by draping a hand towel saturated with a thin paste of baking soda and water over a fan.

They note that the cloth needs to be kept damp and care needs to be taken not to get moisture near the fan motor.