Weather forecasts are made by collecting as much data as possible about the current state of the atmosphere (particularly the temperature, humidity and wind) and using understanding of atmospheric processes (through meteorology) to determine how the atmosphere evolves in the future.

How is weather forecasting done?

Meteorologists use a process called numerical weather prediction to create forecasts by inputting current conditions — which they call the “nowcast” — into computer models. ... Ground radar, weather balloons, aircraft, satellites, ocean buoys and more can provide three-dimensional observations that a model can use.

Will it snow in Dorset 2021?

Precipitation and snowfall will be much above normal, with the snowiest periods in mid-December, early to mid-January, and early to mid-March. ... September and October will be cooler than normal, with near-normal precipitation.