Vog Model

The model output animation and accompanying forecast table is generated using the HYSPLIT numerical dispersion model. This model is an ensemble (a collect of many computer-based forecasts) and uses estimates of volcano emissions along with forecast winds to predict the concentrations of sulfur dioxide gas (SO2) and sulfate aerosol particles (SO4) downwind of the ongoing Kilauea eruption. This is a research effort that is in progress. Disclaimer.

VMAP has a small number of staff. Please read our Frequently Asked Questions (FAQs) section and refresh your web browser for the latest data before contacting us. To go directly to our site-specific forecast tables, click here.


 

Notice: These now show the ensemble average forecast, or the forecast based on averaging many forecasts together to create an improved forecast.

Island of Hawaii SO2

Island of Hawaii Sulfate Aerosols

Hawaiian Islands SO2

Hawaiian Islands Sulfate Aerosols


To view forecast animations, click the images above or select from the options below.

For the 'old' forecast graphics, select the 'Regular (Deterministic) Forecast' from the product options.

      DOMAIN      SPECIES    PRODUCT


For an explanation of the SO2 color scale, click here. The location of the sites in the table below are shown on the map linked here.

Table of model predicted values of Sulfate Aerosols micrograms per meter cubed (µg/m³) (based on 3 hour average)

DAYHSTHilo Mt.
View
Jaggar
Museum
HVNP
Visitor
Center
Pahala Puna Kailua-Kona Honolulu Kihei Ocean
View
Lihue
Tue, Jun 19, 2018 1900 0.03 1.05 0.21 1.22 0.01 0.00 0.07 0.00 0.00 0.03 0.00
Tue, Jun 19, 2018 2200 0.33 0.03 0.13 0.34 0.00 0.00 0.03 0.00 0.00 0.00 0.00
Wed, Jun 20, 2018 0100 0.80 0.00 0.11 0.22 0.00 0.19 0.01 0.00 0.00 0.05 0.00
Wed, Jun 20, 2018 0400 0.00 0.01 0.11 0.22 0.00 3.49 0.01 0.00 0.00 0.02 0.00
Wed, Jun 20, 2018 0700 0.13 0.05 0.04 0.05 0.00 0.60 0.01 0.00 0.00 0.01 0.00
Wed, Jun 20, 2018 1000 0.21 0.47 0.03 0.04 0.00 0.01 0.03 0.00 0.00 0.02 0.00
Wed, Jun 20, 2018 1300 0.01 0.23 0.22 0.36 0.01 0.01 0.01 0.00 0.00 0.01 0.00
Wed, Jun 20, 2018 1600 0.00 0.13 0.34 0.47 0.01 0.23 0.04 0.00 0.00 0.01 0.00
Wed, Jun 20, 2018 1900 0.00 0.03 0.38 0.72 0.02 3.04 0.03 0.00 0.00 0.01 0.00
Wed, Jun 20, 2018 2200 0.00 0.00 0.01 0.04 0.15 13.31 0.05 0.00 0.00 0.03 0.00
Thu, Jun 21, 2018 0100 0.00 0.00 0.00 0.00 0.10 6.43 0.10 0.00 0.00 0.04 0.00
Thu, Jun 21, 2018 0400 0.00 0.00 0.00 0.00 0.08 2.26 0.07 0.00 0.00 0.04 0.00
Thu, Jun 21, 2018 0700 0.00 0.00 0.00 0.00 0.07 0.72 0.02 0.00 0.00 0.01 0.00
Thu, Jun 21, 2018 1000 0.00 0.00 0.00 0.00 0.06 1.37 0.02 0.00 0.00 0.01 0.00
Thu, Jun 21, 2018 1300 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table of model predicted values for Sulfate Aerosols micrograms per meter cubed (µg/m³) (based on 3 hour average); colors correspond to air quality categories for PM2.5.

DAYHSTHilo Mt.
View
Jaggar
Museum
HVNP
Visitor
Center
Pahala Puna Kailua-Kona Honolulu Kihei Ocean
View
Lihue
Tue, Jun 19, 2018 1900 4 78 13 44 4 0 71 0 0 5 0
Tue, Jun 19, 2018 2200 38 3 10 23 0 0 26 0 0 0 0
Wed, Jun 20, 2018 0100 99 0 11 18 0 6 11 0 0 14 0
Wed, Jun 20, 2018 0400 0 1 19 27 0 152 13 0 0 8 0
Wed, Jun 20, 2018 0700 20 7 4 4 0 33 2 0 0 4 0
Wed, Jun 20, 2018 1000 39 52 5 6 0 0 10 0 0 4 0
Wed, Jun 20, 2018 1300 1 19 29 43 2 0 3 0 0 0 0
Wed, Jun 20, 2018 1600 0 9 27 38 2 1 13 0 0 0 0
Wed, Jun 20, 2018 1900 0 2 33 72 3 22 17 0 0 0 0
Wed, Jun 20, 2018 2200 0 0 2 5 22 181 50 0 0 4 0
Thu, Jun 21, 2018 0100 0 0 0 0 16 66 111 0 0 16 0
Thu, Jun 21, 2018 0400 0 0 0 0 12 16 107 0 0 32 0
Thu, Jun 21, 2018 0700 0 0 0 0 10 4 29 0 0 7 0
Thu, Jun 21, 2018 1000 0 0 0 0 6 8 23 0 0 1 0
Thu, Jun 21, 2018 1300 0 0 0 0 0 0 0 0 0 0 0

Frequently Asked Questions


What are the lines on the forecast graphics?  

The new graphics now include contours of the topography (lines that connect areas of equal elevation) to display important features of the terrain. These are spaced at 500 m (~1640 ft)

What is the vog forecast ensemble?  

An ensemble is a group of items viewed together instead of individually. In this case, the ensemble is a group of vog forecasts. We are now running the vog model 27 times! When you view the entire ensemble of forecasts together, it can create a better forecast and provide information about how 'certain' the model is. For example, imagine a lot of forecasters in a room together. When individual people produce forecasts each forecaster may have considered something a little different than the other people in the group. By combining forecasts together and averaging them, often a better forecast is created than any one forecaster working alone. Not only that, but how much the forecasts differ from each other provides information about how certain the group is of their forecast. The ensemble average (or mean) represents the average concentration predicted by all 27 members together. The ensemble spread (or variance) provides information about where the forecasts agree or differ from each other and by how much.

Are the emissions from the lava fissures at Leilani included?

Yes.

How often are the emission rates updated?

The emission rates are updated daily for the Kilauea summit caldera (Halema'uma'u) and the east rift (Pu'u 'O'o' vent). The emission rates for the new lava fissures in the Leilani Estates/Puna/Pahoa area are updated whenever reliable and quality-controlled estimates are made available to us from the U.S. Geological Survey.

Should I alter my plans based on air quality?

Please use the concentration forecasts responsibly and with the knowledge that there are limits to computational skill. The ensemble variance and probability plots show information about the likelihood of different types of air quality. Also use our forecasts with the knowledge of the health effects of volcanic ash and gases available from the International Volcanic Health Hazard Network (IVHHN) and the alerts from the County of Hawai'i Civil Defense to make responsible decisions about your visit. This is a personal decision. We provide information we hope you find useful to make this decision, but ultimately any decisions are yours. Find advice for visitors here.

What is the Probability of Exceeding (#), and how is it calculated?  

The probability of exceeding the different thresholds indicate how likely the air quality will be as bad as or worse than the threshold indicated. These are calculated by applying a threshold to each of the 27 members of the vog model forecast ensemble. The probability graphics do not indicate the severity of vog in the color scales but instead the probability of encountering vog-influenced air with concentrations that exceed each threshold. For example, in the SO2 graphics below (threshold of 0.01 ppm SO2), if red colors (>50%) are shown over the south Kona area, there is a 75-50% chance the air over the area will exceed a concentration of 0.01 ppm of SO2.

Why were these thresholds selected for the probability of exceedance plots?

The lowest thresholds (0.01 ppm SO2, 1 ug/m3 SO4) shown in the graphics below were selected to indicate the presence of air that has been exposed to vog. The other thresholds (0.1 ppm SO2/15 ug/m3 SO4; 1 ppm SO2/65 ug/m3 SO4;) respectively indicate air quality that falls into the 'Moderate or Worse' and 'Unhealthy or Worse' categories.

What is 'vog'?

'Vog' is volcanic 'smog', and 'smog' is atmospheric fog/haze combined with other atmospheric pollutants. Yuck! In the case of vog, it all comes from a volcano.

Is 'vog' the same as volcanic ash?

No. Some volcanoes produce ash and some gas. Other volcanoes produce gas but almost no ash at all. Some produce both. Read this brochure from the IVHHN for more information to learn more about the differences between vog, laze, and volcanic ash.

Where can I get more information about vog, air quality, and emissions at Kilauea?

The IVHHN has a wealth of information about everything from the composition of vog to its health effects and other helpful resources.