Does forecast rain count as received water?

No. Forecast rain helps planning. Only accepted observed or estimated-past rainfall can enter the historical water balance.

A little more detail

Forecast and received rain are displayed separately. When reliable rainfall evidence changes, Baraka may reconcile the water history or ask for Re-Sync. Rainy periods can require runoff information because not all rain stays available to roots.

Scientific and source detail

Rainfall provenance and measurement method remain visible in scientific detail. Unknown runoff is not assumed to be zero.