Extreme weather forecast for Eastern US

Posted by Kate Taylor

The US East Coast is set for a big rise in heat waves and storms, a study using the world's fastest supercomputer has shown.

Researchers at the University of Tennessee, Knoxville, say that heat waves will become more severe in most of the eastern US, and that both the Northeast and Southeast will see a drastic increase in precipitation.

Using the Jaguar supercomputer - now Titan, the fastest in the world - the researchers combined high-resolution topography, land use information and climate modeling. They then used dynamical downscaling to develop their climate model results for areas as small as four square kilometers.

"Instead of studying regions, which is not useful when examining extreme weather, dynamical downscaling allows us to study small areas such as cities with a fine resolution," says civil and environmental engineering professor Joshua Fu.

The researchers evaluated extreme events along with daily maximum and minimum temperatures and daily precipitation. For the 23 states east of the Mississippi River, they analyzed the present-day climate from 2001 to 2004 and predicted the future climate to 2059.

Nashville, they claim, will see a temperature rise of 3.21 degrees Celsius, while temperatures in Memphis will rise by 2.18 degrees. Heat waves will become more severe throughout the eastern part of the nation - indeed, they'll increase so much in the Northeast and eastern Midwest that these areas will become as hot as the south is now.

"Currently, the mean heat wave duration is about four days in the Northeast and eastern Midwest and five days in the Southeast," says Fu. "By the end of the 2050s, the Northeast and eastern Midwest will be gaining on the Southeast by increasing two days."

In addition, the Northeast and eastern Midwest are likely to see heat waves become much more severe.

"While the Southeast has the highest intensity in heat waves, the northeast is likely to experience the highest increase," said Fu. "We are looking at temperature increases of 3 to 5 degrees Celsius, with New York experiencing the highest hike."

Precipitation in both the Northeast and Southeast will go up by 35 percent or more, with coastal states seeing the greatest increase, says the team.

"It is important that the nation take actions to mitigate the impact of climate change in the next several decades," says Fu. "These changes not only cost money - about a billion a year in the US - but they also cost lives."