Extended range temperature forecasts are important to certain elements of the Energy sector. Shorter range load forecasts that are utilized for planning energy demands and power generation are often updated on an hourly basis to take into effect evolving weather observations and forecasts. These forecasts are most often concerned with the next several days. Beyond this time frame forecasts of temperature become more important for capturing the deviation from normal conditions and the extent to how long abnormal departures are likely to persist. Updates to forecasts in the Day 4-10 timeframe are often made on a frequency of twice per day as new global model guidance becomes available. Forecasts for more extended periods from two weeks to several seasons out are updated less often by most long range forecast processes as new datasets are updated infrequently.

An operational sub-seasonal and seasonal global forecast system will be described that has been in use for several years. Output from this system includes hourly weather data that covers a forecast period ranging from two weeks to two years into the future. A methodology for deriving temperature forecasts encompassing this timeframe will be outlined. The derived forecasts are entered via a graphical editor into a climate database. The combined datasets are used to construct hourly temperature forecasts for specific locations across the globe with forecasts extending out to 2 years. Station output can be utilized for long range energy demand planning. The ease of the process allows forecasts to be updated as often as changing forecast conditions warrant.