Battle Of The Forecasting Models
By Kate Bilo
PHILADELPHIA (CBS) -- When meteorologists are trying to determine the path of a storm like Hurricane Joaquin we rely on dozens of sophisticated computer forecast models. The 2 models most referred to are the U-S government's G.F.S. or Global Forecast System and the Euro or European model.
They were among the models of spaghetti track lines projecting Joaquin's course. The American model showed it heading for the east coast and possibly the Jersey shore. The Euro model sharply disagreed and showed Joaquin heading out to sea. That turned out to be correct.
Eric Horst is Director of Meteorology at Millersville University.
"Every time there's a big ticket item, a major storm, it seems the Euro model outperforms the other models," he explains.
That was the case 3 years ago with the projected path of Hurricane Sandy. It was the Euro model that was the first to accurately predict Sandy's hard left turn that dealt a devastating blow to New Jersey and other areas in the Northeast. Like all models, the Euro takes weather data and puts it into a computer program in a process known as initialization.
"The Europeans they spend a longer period of time gathering data and maybe adjusting it slightly to make it a cleaner initialization and therefore the computer model takes longer to run," says Horst. "The American initialization is very very good but they do it more quickly, they initialize in a matter of an hour or two."
The G.F.S. runs four times a day and the Euro runs only twice. Of course the Euro isn't perfect. Who could forget last January when predictions of a blizzard shut down the region.
The Euro model was forecasting 2 feet of snow in our area while the G.F.S. showed much less of an accumulation.
In turned out the region got little more than a dusting.
"The European model is kind of the Tom Brady of models," says Horst. "It occasionally has a bad day and throws an interception but more often than not it wins and in the big games it nails the forecast."
While the European computers are said to be more powerful the G.F.S. model is scheduled for a major upgrade early next year. But the Europeans are also working on an upgrade that according to Horst is set to be significant.
