Select the name of the institution responsible of the forecasting system of your interest
![seasonal-original-single-levels_01_OriginatingCentre.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
Select the version of the forecasting system. This is a numeric label and the available values are different for the different "originating centres". Note that for a given start date you could find more than one system available for a single "originating centre".
Please bear in mind that you must pair up your forecasts with the relevant hindcasts by using the same "system" for both of them.
![seasonal-original-single-levels_02_System.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
Select the parameter(s) you are interested in.
![seasonal-original-single-levels_03_Variable.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
Select the year of the initialization date of the model run(s) you are interested in.
Note that there could be differences in the data available depending on your selection of forecast or hindcast years.
Please bear in mind that you must use the hindcast data in order to make a meaningful use of the forecast data. And remember you must pair forecasts and hindcasts up by using the same "system" for both of them.
![seasonal-original-single-levels_04_Year.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
Select the month of the initialization date of the model run(s) you are interested in.
![seasonal-original-single-levels_05_Month.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
Select the day of the initialization date of the model run(s) you are interested in.
Note that due to different production schedules, the available dates may differ between hindcasts and forecasts and among "originating centres".
You can find more details about the production schedules in the CDS documentation for the seasonal forecast datasets.
![seasonal-original-single-levels_06_Day.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
Select the lead-time(s) you are interested in. This is the offset in hours since the initialization date.
Bear in mind that some variables are available every 6 hours, and some others every 24 hours. You will find the full list in the "Overview" tab of this CDS form and in the link to the "Detailed list of parameters" available in the "Documentation" tab
Note that the length of the outputs is at least 6 calendar months, but it may differ between "originating centres".
![seasonal-original-single-levels_07a_LeadtimeHour.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
...
![seasonal-original-single-levels_07b_LeadtimeHour.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
You can select the data format for your data retrieval.
Currently, just GRIB format is available for C3S seasonal forecast datasets requests in the CDS.
An experimental netCDF conversion can be accessed by using the CDS API. You can find some related information in the "Recommendations and efficiency tips" link available in the "Documentation" tab
![seasonal-original-single-levels_08_Format.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)
You must accept the terms and conditions of the Copernicus User Licence in order to access the C3S seasonal forecast data
![seasonal-original-single-levels_09_TermsOfUse.png](/plugins/servlet/confluence/placeholder/unknown-attachment?locale=en_GB&version=2)