The forecast discussion and vog model predictions displayed on these pages are part of a feasibility study. Please click here for the full disclaimer.

Is it possible or practical to predict vog? The Vog Measurement and Prediction Project (VMAP) is a feasibility study in which scientists will evaluate [are evaluating] whether vog forecasts are achievable and useful. Project collaborators are making the feasibility study available to the public through this Web site, but as an ongoing investigation, VMAP currently provides limited service and reliability. Thus, VMAP users should have no expectation of accuracy or timeliness, and project data should not be used for decision making purposes at this time. Comments and inquiries can be directed to the appropriate contact.

Vog is primarily a mixture of sulfur dioxide (SO2) gas and sulfate (SO4) aerosol. SO2 (invisible) reacts with oxygen and moisture in the air to produce SO4 aerosol (visible). SO2 is expected to be the main problem in areas near the vent (Hawai`i Volcanoes National Park, Pahala, Na`alehu, Hawaiian Ocean View Estates) and SO4 aerosol is expected to be the main problem at locations far from the vent (Kona and farther north and west). For more information on vog visit the FAQ page here.


Vog Forecast Discussion

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Daily discussion explains the expected distribution of vog concentrations over the Hawaiian Islands as a result of the interaction of the volcanic emissions and the current and forecast weather. Photo credit: Mila Zinkova

Current Conditions

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This page provides data on the volcanic emissions, local concentrations of vog (SO2 and Aerosols) along with observations of near surface winds and atmospheric stability (soundings).

Vog Model

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This page provides output in graphical form from the HYSPLIT dispersion model.

Model Performance

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This page provides verification output in graphical form comparing observed and forecast data.

University of Hawai‘i at Mānoa

  • Steven Businger, Director, Dept. of Atmospheric Sciences (ATMO)
  • Lacey Holland, Dept. of Atmospheric Sciences (ATMO)
  • Tiziana Cherubini, Dept. of Atmospheric Sciences (ATMO)
  • Ryan Lyman, Dept. of Atmospheric Sciences (ATMO)