Sadeennuste

Sadeennuste is the forecast of precipitation for a specific location and time. It typically specifies whether precipitation is expected, the type (rain, snow, sleet, hail), the expected start and end times, the anticipated amount or accumulation, and the probability of precipitation. In meteorology, forecasts are often presented as a combination of a qualitative expectation (precipitation likely or unlikely) and quantitative values (millimeters of precipitation).

Forecast products commonly include the probability of precipitation (PoP) and, when possible, a quantitative precipitation forecast (QPF) expressed in millimeters. Types and intensities may be given for different time windows, ranging from nowcasting (the next few hours) to short- and medium-term outlooks covering a day or several days. Additional details may describe regions or elevation ranges where precipitation is most likely, which is important for mountainous terrain and urban drainage planning.

Methods and data sources used to produce sadeennuste combine numerical weather prediction models, ensemble forecasting, radar and satellite observations, weather stations, and weather balloons. Nowcasting relies heavily on radar to estimate ongoing precipitation, while longer-range predictions depend on dynamical model output and statistical post-processing. Forecast uncertainty is a persistent feature, influenced by atmospheric dynamics, terrain, and the inherent probabilistic nature of precipitation.

Applications span agriculture, aviation, transportation, flood risk management, and daily life, where people use the forecast to plan activities and mitigate weather-related impacts. In Finland, institutions such as the Finnish Meteorological Institute provide sadeennuste to the public and various sectors.