The VVIX which can be looked at as the "vix of vix" shows implied volatility on the VIX options. This shows an out performance few days before a spike in the VIX. To be precise, this divergence lasts exactly 8-9 days.
This time again, the pattern seems to be playing out as the 9th day was June 11 and the VIX is up ~7.5% today while VVIX is up just 1.5%.