Single observer forecasting
From Glossary of Meteorology
single observer forecasting
Local weather forecasting that is based purely on observation of the weather elements for the same locality.
The application of experience in synoptic meteorology, combined with physical reasoning, is capable of producing reasonably reliable local forecasts for a few hours ahead; in some situations reliability is possible for an appreciable time ahead. The observations chiefly used in such forecasting are those of pressure and pressure tendency, wind velocity at surface and higher levels, cloud, and temperature.