Three inches of rain on empty soil will cause stones to float, it will cause weed seeds to germinate and very much worse, it will compact the soil, because soil that's been shoveled around for a month or so, is pretty much rootless, so it just sort of sits there asking its own set of questions, the most trying of which is "What Now?"
So while it is very nice to have had three inches of rain, it does mean a
gardener can no longer stare lovingly at his tilth and instead has to reappraise
the meaning of his own life. And very likely during this reappraisal he will
reconsider his attitude toward 'cover crops.' And one of the things about
'cover crops' is the long term planning they require.