GFS

Hurricane Florence stumped most computer predictions in September as it made landfall near the South Carolina-North Carolina border.

In reality, the storm was weaker than forecast and didn't come in where the model runs said it would.

One model, though, read the storm more accurately than the rest — and that one just became the official National Weather Service model.

A new and improved GFS, or Global Forecast System, has been put into use for the current hurricane season after running on an experimental basis for the past three years.

It has been 14 percent more accurate than the old GFS at forecasting the tracks of tropical storm systems through the Atlantic Basin, and 10 percent more accurate forecasting the intensity of the storms, said Brian Gross, the director of the the Environmental Modeling Center at the National Oceanic and Atmospheric Administration.

"Of course, it depends on the storm," he said.

The new GFS should improve weather forecasting generally, he said.

"Virtually any aspect of the weather forecast, whether it's temperature or precipitation, will see overall improvement," Gross said.

The Finite-Volume Cubed-Sphere, or FV3 model of the GFS isn't technically a new computer program. It's a stronger calculator, better able to read and incorporate data from measuring devices aboard satellite and NOAA hurricane hunter aircraft. 

One prime example was Hurricane Florence.

Hurricane Wire is a pop-up newsletter during hurricane season that delivers anyone who lives on the East Coast all the information they need to know as storms brew in the Atlantic and beyond.


The GFS model without the FV3 called for Florence to make landfall near the Outer Banks in North Carolina as an extremely powerful hurricane. The improved GFS called for it to make landfall more than 100 miles south, about where it did land, as the minimal hurricane the storm became.

Hurricanes in recent years have gotten tougher for the computer models to figure out. The most powerful computers around the world are trying to keep up, working in petaflops — equations designed to simulate a real number for calculations — was a way to express continually changing conditions.

The FV3 works with new computers that have what NOAA officials call augmented supercomputing systems considered to be 50 percent more powerful and capable of 60 percent more data storage than previous NOAA computers.

Neil Jacobs, the acting NOAA administrator, said the new GFS and computer systems should help the United States reclaim an international leadership role in computer modeling.

Reach Bo Petersen at @bopete on Twitter or 843-937-5744.

Science and environment reporter. Author of Washing Our Hands in the Clouds.

We're improving out commenting experience.

We’ve temporarily removed comments from articles while we work on a new and better commenting experience. In the meantime, subscribers are encouraged to join the conversation at our Post and Courier Subscribers group on Facebook.