Radio Wave Propagation Forecasting
Forecasting involves short-term estimations of how radio waves will travel through the atmosphere, based on recent measurements.
In contrast, predictions are used to determine the best radio communication frequencies and times more generally. They can also optimize radio coverage and plan antenna systems. Predicting propagation conditions relies on models that consider factors such as signal frequency, time of day, season, sunspot cycle, and ionospheric conditions. However, predictions cannot account for erratic solar and geomagnetic storms.
Read more about Radio Propagation Forecast. See also an index for HF Radio Propagarion.
The project "Understanding HF Propagation" provides a detailed overview and tutorials on HF propagation.