I learned this term while reading the novel The Cardturner by Louis Sachar over the past two days. I'm very glad to have come across it.
This type of event happens to me frequently. I'll contact a friend and they'll say they were just thinking about catching up, and vise-versa. I've experienced intense grief and later found out a friend was grieving at the exact same time. Another friend suddenly came to mind one day after a long-being absent from my mind, and a few hours later, I found out they'd been admitted into the ER that day.
Unlike Carl Jung who first described the concept, I know how it happens. The Holy Spirit impresses things upon our own spirits, and I've known this for as long as I've experienced synchronicity. It's just really nice to have a word that describes the event itself. Before I had to describe it in terms of what the Spirit was doing. Now, I have a definition, and definition is a greatly freeing thing.