There's been a lot of talk of the models trending north/west with the mid-week snow potential. I wanted to show exactly what we are watching. I just used the 6z/18z gfs as an example of what the trend is....the timing of the kicker coming out of canada is slightly slower....not by much, but enough to slow the breakdown of the ridge out west..which causes the trough to clearly dig much deeper; therefore we get a storm that impacts more parts of our area than just south-east Virginia.
At 500 mb (roughly 18,000 feet up in the atmosphere shown above) these changes are slight, but these minor changes translate to significant ones down at the surface (shown below).
Each of the models today have trended towards a more north-western reaching storm to some degree. Now the questions are...
1) Will this trend continue farther north and west?
2) Will it stop where it is?
3) Will it trend back south and east? (yes there is still time for that 48+ hours out)
These are questions that we do not have the answers to right now. It will be important to watch as the pieces of the puzzle to our storm become better sampled as they come into North America.