It's easy to find out whether tomorrow or next week promises rain or sunshine.

But try getting a forecast on vog conditions. Depending on what you're looking for (a one-day glance ahead or a week-long outlook), it's difficult to impossible.

That may not be the case for long.

A team of University of Hawai'i-Manoa researchers is working on a project aimed at providing the state with a regular vog forecast, which will include predictions on sulfur dioxide and fine particulate levels.

People who regularly experience heavy vog — in Big Island communities downwind of the volcanic plume, for example — will know in advance whether they should take precautions.

The project organizers plan to launch a website as early as this summer, that will offer up to a five-day vog forecast, along with historical data and other trends.

"It's pretty unique," said Steven Businger, a meteorology professor at UH-Manoa, who is participating in the federally funded project and has worked since the 1990s to track how volcanic emissions are carried by wind.

The multiyear, $330,000 project was funded through the U.S. Geological Survey as part of about $3.3 million in economic stimulus funds from the agency for volcano monitoring improvement projects in the Islands. Most of the money went to install new vog monitors and other equipment at Kilauea.

Businger said that, though his project will provide reams of new data on how volcanic emissions are carried and how those movements can be predicted, the primary thrust is to get more vog information to residents.

He said the website where people will be able to access vog forecasts and prediction models "can include warnings ... just like we have high surf warnings."

The project started in late 2009. Businger and his team have started installing monitors on the Big Island to measure sulfur dioxide and fine particulate levels and have run some computer prediction models.

"We are just setting up the model at this time," he said. "It's going to be a gradual improvement, the ability to model the vog."

Though hundreds of thousands of people around the world live in places affected by volcanic emissions, no one has yet put in place a vog forecasting or modeling system, Businger said. Right now, the best meteorologists can do is make guesses about whether vog levels will be high, based on prevailing winds. Those forecasts don't consider the amount of emissions or topography.

A key goal of Businger's modeling project is not just to predict whether it will be voggy but to also predict how voggy it will be and how that translates into sulfur dioxide and fine particulate levels in the air.

Debbie Wong Yuen lives in Pahala, which gets some of the thickest vog statewide. She said a better warning system would help people better plan their activities. Yuen suffers from severe asthma that keeps her inside on voggy days. She added that sometimes the state's website giving real-time vog levels isn't working, which leaves people with no information.

"That has been very, very frustrating for people," she said.

Currently, Hawai'i residents are hard-pressed to get good forecasting information on vog. The National Weather Service said it does not track vog, but sometimes adds "haze" to its forecast, based on wind patterns.

The Environmental Protection Agency also offers its "Air Now" website, which rates air quality and gives people nationwide (including Hawai'i) a one-day forecast on whether their air will be "good" to "moderate" to "unhealthy."

Hawai'i residents can also get real-time information on vog conditions from the EPA website.

But, Businger said, a forecast just isn't available. "There's no prediction currently," he said, adding that the vog prediction system his team is working on could be exported to other places with heavy volcanic emissions.