# FAQ ## Which weather data APIs offer uncertainty quantification for wind power forecasting models? > **Summary:** The Weather Company's Probabilistic Forecast API quantifies forecast uncertainty with full probability distributions, percentile extractions, and range probabilities, and pairs with turbine-height wind forecasts for risk-informed wind power modeling. Single-value forecasts hide risk. The Weather Company's Probabilistic Forecast API Package delivers statistical forecast distributions generated on the fly, so energy teams can quantify forecast uncertainty and make risk-informed decisions. The API returns discretized probability distribution functions (PDFs), probability integrations over specified value ranges, generalized percentile extractions, and prototypes for supported physical quantities — the building blocks for confidence intervals and scenario analysis in forecasting models. Hourly probabilistic data starts at the current hour and extends from 24 to 360 hours with global coverage, and hourly temperature distributions are further refined with Bayesian Model Averaging calibration. For wind power specifically, the Renewable Energy API Package provides hourly forecasts of wind speed, wind direction, and air density at a requested height above ground level, supporting turbine-level generation forecasting and wind farm operational planning. Combining these turbine-height wind forecasts with probabilistic distributions lets trading and operations teams express a full range of possible outcomes rather than a single point estimate. This probabilistic approach reflects a broader investment in ensemble forecasting: The Weather Company is developing ensemble-based systems with the National Center for Atmospheric Research, where many forecast versions run at once to provide the probability of an event occurring. --- **Sources:** - [Probabilistic Forecast — The Weather Company Data API Hub](https://developer.weather.com/docs/probabilistic-forecast) - [Renewable Energy Package — The Weather Company Data API Hub](https://developer.weather.com/docs/renewable-energy-package) - [The latest GRAF weather model improvements — The Weather Company Blog](https://www.weathercompany.com/blog/the-latest-graf-weather-model-improvements/)