Why European Computers Predicted Sandy First

Ars Technica has a nice article on weather prediction services, and explains why the European weather models predicted Sandy days before the American ones.

Seven days before Sandy made landfall in New Jersey, the atmospheric crystal ball was partly cloudy. The US National Weather Service forecast model showed a chance that Sandy might come ashore, but indicated that it was more likely the storm would spin off into the Atlantic. The European Centre for Medium-Range Weather Forecasts (ECMWF) model, however, definitely pointed the storm ashore. It would be about three days before the US model totally converged on the Europeans' forecast.

Essentially, the Europeans:
- have a bigger, better supercomputer...
- that specializes in medium-range predictions, and
- takes continuous data for half a day for their simulations;

As opposed to Americans who:
- have a less powerful computer
- that does short, medium, and long range predictions, and
- only take "snapshots" of initial conditions and have to run with that.

Ars Technica: Why European forecasters saw Sandy’s path first