This is the ERA5 System for Classification of Low-Pressure Systems (SyCLoPS) dataset version 8. SyCLoPS is an LPS classifier built upon the TempesteExtremes (TE) software. Details of SyCLoPS algorithms are described in the paper titled The System for Classification of Low-Pressure Systems (SyCLoPS): An All-in-One Objective Framework for Large-scale Data sets published on J. Geophys. Res. Atm.: [https://doi.org/10.1029/2024JD041287]. Please cite this paper if you use this dataset. Important: The most up-to-date SyCLoPS codes are now kept on GitHub: [https://github.com/yepkids/SyCLoPS] SyCLoPS user manual: [https://climate.ucdavis.edu/syclops.php]See Chapter 3 of the manual for instructions on how to load and use the output classified catalog In the list of datasets below, "classified" refers to the output LPS catalogs with classification. "Input" refers to the input LPS catalogs that contains the parameters used for classification. "3hr" and "6hr" describes the detection time interval (temporal frequency). Updates in this version: Fixed the issues reported in the version 7, 6-hourly tracked data. The 6-hourly classified catalog now has significantly better weak LPS node stitching and jumpy false connections are largely removed in both 3-hourly and 6-hourly catalogs, thanks to a recent update in the SyCLoPS program. Introduced a new label "Hybrid TC," which groups a type of LPS that mainly resides in the North Atlantic basin. Details on this will be described later in an upcoming paper manuscirpt and the next version user manual. Stay tuned. Next major update expected within about one month. This will include simplified classification for the first two branches and extension to 2025. The following files can be obtained from version 4: The labeled size blobs of each year: "size_blobs_1979_2022.tar.gz" The labeled precipitation blobs of each year: "preci_blobs_1979_2022.tar.gz" Other SyCLoPS-related data products: SyCLoPS HighresMIP LPS catalogs: Link SyCLoPS HighresMIP TC-only catalogs: Link Please contact Yushan Han (yshhan@ucdavis.edu) if you have questions about the SyCLoPS framework. Please contact Paul Ullrich (paullrich@ucdavis.edu) if you have any questions about the TE software. See below for a table of atmospheric variables required for SyCLoPS and a flowchart of the classification process. See the SyCLoPS manual for more details.