About weather forecasts

Weather forecasts on this page are based on numerical weather prediction (NWP): computer models that solve the equations of fluid dynamics and thermodynamics for the atmosphere. Global and regional models (e.g. GFS from NOAA, ECMWF from the European Centre, or national models) are run by meteorological services; output is post-processed into temperature, precipitation, wind and weather symbols (WMO; national met services).

Forecast skill decreases with lead time; the first few days are generally more reliable than day 10–14. Ensemble forecasts (many runs with slightly different initial conditions) quantify uncertainty and spread; single deterministic runs can be used for a most likely scenario. Different models may disagree, especially beyond a week; meteorologists compare several sources when issuing official forecasts.

Data shown here may come from open or commercial providers that use these models. Symbols and descriptions follow standard conventions (e.g. WMO present weather codes). For authoritative forecasts and warnings, always refer to your national meteorological service.