Model forecasts depicted the solar storm striking from around 6:00 AM CDT - 9:00 AM CDT, but there does appear to be a 7 hour window of 'wiggle room' for the storm to arrive. This latest bump in the K index may suggest that the storm could be upon us.
Each update on the K index is 3 hours apart, so the next update will be in the next 3 hours. If we are going by UTC time, and the first bar after the beginning of a day is the 0z reading, and each reading appears to be shown 2 hours after the measurement is taken, the next update could arrive just before 4:00 PM CDT. I have yet to confirm that, but based on how the image does use the update periods in UTC, the graph is most likely in UTC as well.