How does mid-season adversity cover work under PMFBY before harvest?

PMFBY has a mid-season adversity provision for exactly this situation. If during the season the standing crop in a notified area faces a severe adverse condition such as a long dry spell, flood or unseasonal weather and the expected yield is likely to fall well below normal, the scheme can release an on-account or advance payment, often up to about 25 percent of the likely claim, before the final harvest figures are in. This is decided at the notified area level, not field by field. The state or district authorities assess the situation during the season and trigger the advance, which is later adjusted against the final claim worked out from the crop-cutting experiments. So you do not have to wait for harvest if a mid-season adversity is officially declared for your area. Whether it is triggered in a given season depends on the state notification and the assessment, so ask your agriculture office or check the PMFBY portal for your district.