Real-time forecast data, or 'valid' data, is all meteorological information in the form of pictures, charts, text or data files for which the verification time is in the future or less than 24 hours ago. This means that it can be used to predict the weather conditions.
Real-timedata are also referred to asvalid data.
Expired real-time data are any data with a verification time ‘more than 24 hours in the past’ (i.e. data which cannotbe used to forecast).
Once real-time forecast data has expired, it becomes archive data. ECMWF also offers other types of archive data.