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The Met Office Operational Coronal Mass Ejection (CME) Ensemble Forecasting System

Siegfried Gonzi - Met office; David Jackson - Met Office, United Kingdom

Session: Interplanetary CMEs and Solar Particle Events


Since 2015  the Met Office has been using a 24-member ensemble method for forecasting the arrival time of CMEs at Earth. It has been acknowledged that ensemble techniques serve as an important tool for our forecasters. The ensembles are created by perturbing 4 parameters in the so called “cone files.” The forecaster created cone files are the result of coronograph observations of CMEs. The information in the cone files is then used to inform our operational forward model ENLIL to model the transport of the CME from  the Sun to Earth. Met Office forecasters use the ensemble output of the forecast of plasma density and solar wind speed at Earth to derive CME arrival times.

We discuss the pros and cons of the method that we use to create ensembles by perturbing CME speed, cone angle, longitude and latitude.  We will also discuss our plans for our next generation CME forecasting ensemble system.  We still are researching the optimal ensemble size that can realistically be used every 2 hours on our computing systems. Our next generation CME ensemble system will most likely employ a different method of creating ensembles and also the number of ensemble members will change.

Approaching deadlines:

Registration opens:

16 July 2020

Abstract submission opens:

16 July 2020

European Space Weather Medals:

6 September 2020

Registration deadline:

25 September 2020

Registration deadline: [extended]

10 October 2020

Abstract submission deadline:

4 September 2020