We all know that the GFS sucks with coastal storms and has for years but it hasn't really budged big time. It did budge alittle on 6z. These 12z runs and especially the 0z runs tonight are going to be crucial.
Looking at H5 early in the run will tell you how the rest of the run will go. More energy being held back , more east this will come. The less , the more west. You also have to see where the low forms down south and where or if it closes off.