Forecasters may soon be able to better predict rainy Seattle days, thanks to a new smartphone and tablet app developed by UW atmospheric scientists.
The PressureNet app uses pressure sensors included in some of the newest smart phones, to measure atmospheric pressure and provide the data to UW researchers. Precise tracking of pressure readings and pressure changes could help weather forecasters to pinpoint exactly where and when a major storm will strike.
"With this approach we could potentially have tens or hundreds of thousands of additional surface pressure observations, which could significantly improve short-term weather forecasts," said Cliff Mass, a UW professor of atmospheric sciences.
Android devices equipped with pressure sensors include Samsung's Galaxy S3, Galaxy Nexus, Galaxy Note and Nexus 4 smartphones, and the Nexus 10 and Motorola Xoom tablet computers.
Mass first saw opportunity to enhance weather prediction, when he noticed some smartphone manufacturers added pressure sensors to the newest smart phones to estimate the phone's elevation and help pinpoint its location. Last fall, he approached Cumulonimbus, a Canadian app company that developed a barometer application for smartphones that collects all the data and shares it back with users.
The PressureNet app this week collected about 4,000 observations per hour, with users clustered in the northeastern United States and around some major cities.
"We need more density," Mass said. "Right now it's a matter of getting more people to contribute."
Mass is particularly interested in the center of the country, which is prone to severe storms but includes fewer weather observation stations.
"Thunderstorms are one of the areas of weakest skill for forecasting," Mass said. "I think thunderstorms in the middle part of the country could potentially be the biggest positive for this approach. They are relatively small-scale, they develop over a few hours, they can be severe and can affect people significantly.”
Tracking storms a few hours out could help people better protect themselves and their property. In the Seattle area, the tool could improve short-term forecasts for wind and rain.
"I think this could be one of the next major revolutions in weather forecasting, really enhancing our ability to forecast at zero to four hours," Mass said.
Cumulonimbus updated the app's privacy settings last week so users could allow access to the data by scientific researchers. Since then, the UW group has been uploading the pressure data each hour and preparing it for use in weather forecasting models. The data will soon be available to all researchers who want to incorporate it in weather-prediction tools.
If the app’s technique is successful, researchers hope to supply it to the National Weather Service and the weather bureaus of other countries.
The technique could be particularly useful, Mass noted, in countries that have little weather-forecasting infrastructure but where smartphones are becoming more common.
The research has been funded by Microsoft Corp. and the National Weather Service.