Hi Kyle,
SAM requires the time series wave data files to have data for an entire year starting January 1 and ending December 31. Your data starts on September 6, 2022 and ends on September 6, 2023.
You could modify your file so that it starts on January 1, 2023 and ends on December 31, 2022.
For 3-hour data, the file should have 2923 rows (including the 3 header rows). Yours has 2931 rows because it includes both September 6 2022 and September 6 2023.
Best regards,
Paul.