Everything trended south in the last 24 hours…
So what happened? The main northern stream energy that was supposed to interact/guide the southern energy creating the snow storm has actually moved out ahead of the storm. This changes a few things…
1. The boundary layer will be able to get cooler and drier ahead of the system.
2. The storm itself (the southern stream energy) has slowed a bit and is allowed to stay further south.
3. Less phasing/interaction with the northern stream leads to a weaker, less amplified system.
There will still be some boundary layer issues along the southern line of the snowfall area, but the boundary layer impact on accumulation is significantly less than what we were looking at a day ago.
Many risks still plague this forecast, and they are
1. The storm could be even more suppressed, which would shift the snow further south.
2. Some models still show a more amplified solution, expanding the precipitation northward.
3. Convection in Alabama and Georgia cutting off some of the moisture feed from the Gulf, which would result in lower QPF and lower snow totals.
I will probably make my final snowfall forecast late tomorrow after the 18z models come out. There are still some big differences between the models, but the trends have been hard not to notice. The most likely change would be shifting the whole thing south.