How to remove past due forecast from ASCP DENORM table

As a organization practise we generate weekly forecasts and publish it at the first week of the month.

For the rest of the weeks in the month no now forecast is published. As we get into the sencond and third week of the month we accumulate unconsumed past due forecast.

Is there a standard process that we could use to remove the past due forecast from the DENORM table? During the 2nd and 3rd weeks the Demand planners are working on the next forecast so we cannot export any new forecast till the end of the month.

Please advise.

Thanks