While it cannot be expected from a global NWP model to forecast individual convective cells, it can be used to determine whether the environment is favourable for development of deep moist convection (DMC). To facilitate forecasting severe convection two new EFI parameters have been added: CAPE and CAPESHEAR (or CAPESHEAR Parameter CSP).

Practical remarks

More information about CAPE and CAPESHEAR parameters can be found in the ECMWF Newsletter No.144 at http://www.ecmwf.int/sites/default/files/NL-144.pdf.

Further details and practical information about the EFI for CAPE and CAPESHEAR are available in the help pages below the EFI web charts in the section EFI for CAPE and CAPESHEAR at http://www.ecmwf.int/en/forecasts/charts/catalogue?f[0]=im_field_chart_type%3A481&f[1]=im_field_product_type%3A1042

Figure 1. EFI forecasts for A) CAPESHEAR; B) CAPE; C) CAPESHEAR where probability of precipitation above 1mm/24h is greater than 5%; D) CAPE where probability of precipitation above 1mm/24h is greater than 5%. The EFI signal disappears over great part of Germany except the northern areas after filtering out the EFI values where probability of precipitation above 1 mm/24h is less than 5%. Severe convection developed just over the northern parts of Germany while it stayed dry and sunny over the rest of the country.