Take a look at this animated radar (HRRR). Notice the initial wave coming from the west, before the low takes over. There is a "blank" or empty space before it closes in. This is the dry slot that we have been talking about. If that holds on too long and the low develops too late or further east, it will significantly hold down our totals. If that void fills in quicker, we could actually see higher totals than forecasted. So hard to predict....That being said...the mesoscale models (short range)