ST. PETERSBURG, FLA. — When forecasters from the National Weather Service track a hurricane, they use models from several supercomputers located around the world to create their predictions.
Some of those models are more accurate than others. During Hurricane Sandy last October, for instance, the model from the European Center for Medium-range Weather Forecasting in the United Kingdom predicted eight days before landfall that the large storm would hit the East Coast, while the American supercomputer model showed Sandy drifting out to sea.
The American model eventually predicted Sandy’s landfall four days before the storm hit — plenty of time for preparation — but revealed a potential weakness in the American computer compared to the European system. It left some meteorologists fuming.
“Let me be blunt: The state of operational U.S. numerical weather prediction is an embarrassment to the nation, and it does not have to be this way,” wrote Cliff Maas, a professor of atmospheric sciences at the University of Washington on his weather blog.
Meteorologists agree that the two American supercomputers that provide storm models are underpowered, which is why the National Weather Service plans to upgrade those computers in the next two years. The two main forecasting computers, one in Orlando and the other in Reston, Va., will receive $25 million in upgrades as part of the Hurricane Sandy supplemental bill that was recently approved by Congress.
“This will improve weather forecasting across the board,” said Christopher Vaccaro, a spokesman for the National Oceanic and Atmospheric Administration. “Certainly one area of concern that has received some attention were these larger, high-impact, extreme weather events. The European model is able to pick up on those storms earlier than our model.”
Jeff Masters, meteorology director at the online forecasting service Weather Underground, said that other than Hurricane Sandy, the American model outperformed the European model during the 2012 hurricane season, but if you look at a three-year period, the European model still comes out on top.
“If the U.S. did invest more money and people into making the model better, then the forecast would be better,” Masters said. “The money we spend on weather forecasts and improving them pays for itself.”
With the hurricane season starting Saturday, forecasters at the National Hurricane Center in Miami will use American and European models, and other models, then average them together for a storm’s projected path.
The computers take data from weather satellites, observations and weather balloons, then plug the data into complex algorithms.