Why Were Irene's Intensity Predictions So Off?

From Technology Review

A timely piece on weather prediction - a heavily data-intensive modeling discipline.

"Hurricane path prediction has enormously improved. Forecasters knew days before it made landfall that Irene would hit the Carolinas and move up the East Coast, reaching New York and New England."

"While path prediction has steadily improved over the decades, forecasting the intensity of storms still proves tricky. Irene's expected monster intensity—much to the nation's relief—was far less as she weakened a day or so after reaching land. "What made Irene especially difficult for the forecasting models was that she had three landfalls and followed the coastline," says Heymsfield. "We need a lot more research to understand how to better model this land interaction."