Extreme Forecast Index

The Extreme Forecast Index (EFI) ranks the departures between the Ensemble Prediction System forecasts and the model climate to identify unusual meteorological situations (e.g. related to temperature, wind, storms rainfall or snow).

Description & Technical Information

Description

The Extreme Forecast Index (EFI) ranks the departures between the Ensemble Prediction System forecasts and the model climate to identify unusual meteorological situations. EFI is applied on a daily basis to the following variables: temperature, wind speed, wind gust, Convective Available Potential Energy (CAPE), snowfall and total precipitation.
Experience suggests that EFI values of 0.5 – 0.8 (irrespective of sign) can be generally regarded as signifying that “unusual” weather is likely and values above 0.8 as usually signifying that “very unusual” or extreme weather is likely.

Technical information

Hazard
Coverage Global
Horizon 10 days
Time Resolution 1 day
Spatial Resolution 0.2° x 0.2° lat/lon grid (~18 km)
Update Twice a day following either the 00 UTC and 12 UTC ECMWF forecast release
Nature Raster Maps
Availability , , ,

Model or Algorithm