Understand the forecast output from Engine Log

We have sales and promotion history and ran Engine for base forecast and uplift. During the recent run, the engine wrote the forecast output in Fore_3 in sales_data table based on forecast_history table and engine 2k log. I picked one item 310180 with Sell To
Customer Site 100232 in the week of 09/25/2016 to verify the data. In sales_data table, fore_3 for this combination is 2118.65388 (please find details in the attachment). Per my understanding, the data in fore_3 should be base forecast (e.g. Base Fcst or Volume Base Ttl) but the worksheet shows 3511 as base forecast for this item/location combination at the week. May I know how the forecast output generated by engine be calculated or utilized in this scenario?