Observability of planetary waves and their predictability in the ECMWF H500 forecasts

The problem of a hard contradiction between limited possibilities of meteorological observations and uncontrolled complication of the present-day weather forecasting models, and its consequences for the planetary wave predictability are considered with examples from the ECMWF short- and medium-range H500 forecasts for the Northern Hemisphere. A supposition is voiced that this problem adds difficulties to the weekly predictability limit overcoming.