Aiming to reduce errors like the one it made in 2012, when it wrongly forecast the track of Hurricane Sandy into the New York area, the National Oceanic and Atmospheric Administration on Wednesday introduced a major upgrade to the software at the heart of its weather prediction capability.
Using huge amounts of computing power, the software, known as the Global Forecast System, or G.F.S., models the physics of global weather, taking data from satellites and sensors to produce predictions of conditions in coming hours and days. Meteorologists around the world rely on it for making forecasts.
NOAA said the upgrade to the core of the system — the first in four decades — should help improve predictions of severe weather, including winter storms and hurricanes and other tropical storms.
The G.F.S. model had come under criticism in recent years, with researchers and meteorologists saying it was less accurate than similar models from other governments and institutions — most notably one produced by the European Center for Medium-Range Forecasts, which, along with G.F.S., is the most widely used worldwide.
To critics, the deficiencies in the G.F.S. model were especially apparent during Sandy, which inundated the New York area in 2012, causing 44 deaths and $19 billion in damage in New York City alone. Early on as the storm, which was then a hurricane, moved northward, the European model accurately forecast how it would intensify, shift westward and strike the coast. For days, the G.F.S. model forecast that Sandy would head harmlessly out to sea.
Brian Gross, director of NOAA’s Environmental Modeling Center, said in a teleconference that the G.F.S. upgrade had been tested for a year, running models based on data from past warm and cold seasons and comparing the results with what occurred in the real world.
“We are confident the upgrade will provide an overall improvement,” Dr. Gross said. Specifically, he added, it should help produce more accurate forecasts of temperature and the amount of rain and snow.
Among other improvements, he said, the new model should more accurately reflect changes that occur between daytime and nighttime. As for hurricanes, he said, the upgrade should help improve forecasts both of a storm’s track and its intensity.
The upgrade is part of a series of improvements that were undertaken after Sandy. In addition to improving the software, more computing power was added. The European model also had the advantage of vastly greater number-crunching capacity.