Under cover


POSTED: Sunday, January 24, 2010

The National Weather Service says the volcanic haze, or vog, might clear today over Honolulu, but will likely return tomorrow.

A cold front was expected to move through Kauai and Oahu last night, bringing shifting winds that could briefly clear the voggy weather today.

However, forecasters said southerly and southwesterly winds will return tomorrow and Tuesday and will blow the volcanic haze from the Big Island back over Oahu and other islands.

For today through Tuesday, forecasters expect partly cloudy and hazy conditions with scattered windward and mauka showers. Expect variable winds from 5 to 15 miles per hour.

Vog, or volcanic smog, is the haze caused by a combination of weather, wind conditions and volcanic activity. Vog becomes thicker or lighter depending upon the amount of emissions from Kilauea volcano on the Big Island, the direction and amount of wind, and other weather conditions.

People with pre-existing respiratory conditions are more prone to adverse effects of vog, which may include headaches, breathing difficulties, increased susceptibility to respiratory ailments, watery eyes and sore throat.

State civil defense officials recommend that people with asthma, heart or lung disease, and older adults who are particularly vulnerable should remain indoors during heavy vog episodes.

The public can obtain information on vog and volcanic emissions from the state Department of Health's Hawaii Volcano Helpline, toll-free (866) 767-5044.

The help line staff will answer questions from Monday through Friday from 5 a.m. to 5 p.m., and on weekends from 9 a.m. to 5:30 p.m. Recorded messages (updated daily at 7 a.m.) are accessible seven days a week, 24 hours a day, including holidays.