Looking at an update of the 19Z HRRR run and the 17Z PHS run, the more recent HRRR run is catching up to a sooner initiation solution. The 19Z HRRR is initiating cells as early as 21Z with a series of cells displayed above by 22Z, similar to the 17Z PHS. Another note is that the newer HRRR run has a higher SBCAPE value than the PHS at 1700-2700 J/kg compared to 1000-2000 J/kg from the PHS. Recent visible satellite trends look to favor an earlier initiation as well.

-Joaq