Comparing Sandy and Nilam Forecast Performance, European Models Trump IMD

The forecast for Hurricane Sandy was fantastic, and could be considered as one of the finest moments in meteorology.

The European Centre for Medium-Range Weather Forecasts, also known as ECMWF or the European model, nailed down the track of Sandy a week before the storm pushed into southern New Jersey. The Europeans have more money invested into their weather model, and it uses 4D data assimilation unlike US model, the Global Forecast System (GFS).

Seven days before the event, the GFS model insisted that Sandy would push out to sea and possibly affect Bermuda. However, run after run of consistent forecasts, the European model kept its solution of a New England storm affecting millions of people.

The IMD in forecasting Cyclone Nilam perhaps did a shade better than GFS but definitely nowhere near the ECMWF performance. Here are extracts from IMD’s own assessment of their model performance of Cyclone Nilam: