Weather Forecasters May Look Sky-High For Answers

These days, weather forecasters are lucky if they can accurately predict the weather a week into the future. But a new study, funded in part by NASA, says shifting wind patterns in the stratosphere during the winter may help forecasters predict weather on the surface two months ahead of time, because they have an affect on where storms track in the northern hemisphere.

Changes in the stratosphere, the atmospheric layer from six to 30 miles up, usually take a week or more to work their way down to where they affect weather, giving forecasters some lead-time. Once the changes affect the weather, they tend to last as long as two months.

"The study points weather forecasters towards a new source of information that hasn't been used before in weather prediction," said Mark Baldwin, Senior Research Scientist at the Northwest Research Associates (NWRA), and lead author in the study. The article appears in the October 19th issue of Science.

According to the study, the stratosphere plays an important role in how large-scale waves, which originate near Earth's surface, feed back to affect weather patterns in the Northern hemisphere.

In the winter, when stratospheric winds most often blow from the west, these waves tend to slow the winds in the stratosphere. This process starts with the higher stratospheric winds and over about a week's time, can work its way down to winds of the lower stratosphere, just above the levels of commercial air traffic.

For more details on weather forecasting, go to: http://www.gsfc.nasa.gov/topstory/20011018windsurface.html