ECMWF Model Description

European Center for Medium Range Weather Forecasting Integrated Forecast System

The European Medium Range Forecast Model is considered one of the premiere global forecasting model for the mid-latitudes. The European Centre for Medium-Range Weather Forecasts (ECMWF, the Centre) is an intergovernmental organization supported by 34 countries and based near London. The model is run twice a day at 0z and 12z out to 10 days in the future. The ECWMF model runs both in a "deterministic forecast" mode and as an ensemble. Deterministic refers to cause and effect. An ensemble forecast takes the output from many deterministic models and creates an average or consensus. The graphic above shows the ECWMF deterministic global dynamical model.

The ECMWF does not alter its initial fields for Tropical Cyclones. Despite this, it has shown skill in forecasting Tropical Cyclones. Beyond the good medium-range track prediction skill of the ECMWF model, its high resolution has shown potential for useful intensity forecasting.

Global models (such as the ECWMF, the GFS and the NAVGEM) are dynamical models with a domain of the entire planet. Dynamical models are the most complex and most computationally expensive numerical models run. These models make forecasts by solving the physical equations that govern the atmosphere, using a variety of numerical methods and initial conditions based on available observations.

The graphics above show the barometric pressure field. Lower pressures are indicated in blue to purple shades. Higher pressures are indicated in orange to red shades. Hurricanes and tropical storms, as well as non-tropical low-pressure areas are associated with low pressure (Blue). The black lines are isobars (lines of equal pressure). The closer the lines are to each other, the stronger the winds.

Remember that these are mathematical models with varying initial assumptions. Thus, different models produce different final results. They do not necessarily reflect the "official" hurricane track issued by the National Hurricane Center. Forecasters review all of the model data but use their own experience and scientific expertise to arrive at a final forecast.