An explanation of the required processes before a weather forecast becomes available in the Spire Weather API.
All global forecast models require some amount of time before new forecasts are made available. The process works as follows:
Data collection — Forecasts are based on observational data collected during a window of time, on the order of hours.
Waiting period — A shorter period allows those observations to arrive at the location where they will be combined with Spire’s global model.
Data assimilation — When data collection concludes, the computation phase begins. The data assimilation system performs quality assurance and analysis. This process also takes time.
Forecast calculation — Once these steps complete, the actual forecast calculations begin.
API availability — After this full window has elapsed, the forecast becomes available in the API.
Unlike most other weather data providers, Spire owns and operates each component of the value chain—from satellites in orbit to end-user forecast products. Spire is actively exploring methods to optimize and improve these processes, but some degree of latency is expected and is in line with other top providers such as NOAA and ECMWF.
Summary: Some time is needed for data movement and the full forecast calculation.