The undersea volcano near Tonga erupted for the 2nd time on Tu B'Shevat. I find it very odd that the news keeps reporting that communications are down and the full extent of any damage cannot be assessed as yet. I am writing this on Monday January 17th (Tu B'Shevat) so we will have received more news by Sunday January 23rd when John publishes.
But - for now - this is obviously a date to keep in mind. It most definitely represents a warning.