There are certain features that help drive a storm track including:
- Position of the ridge axis out west
- Timing of disturbances interacting
- Upstream blocking near Greenland
In this case, I want to focus on the difference in the ridge axis in the different model ensembles. Where the center of the ridge pumps up will determine how close to the coast this storm comes. Ideally we want the ridge axis over MT. Looking below you can see the European ensemble on the left and GFS ensemble on the right...
Notice the euro ensemble has a low slightly more off the coast compared to the GFS (top images). This is due to that ridge axis being more to the east on the Euro. You can see this below by the black line I drew in. It might be hard to see but that slight difference has a big impact on track.
Also notice the euro has a stronger area of high pressure to the north of the low. This means colder air would be allowed to funnel into the storm creating more of a snow threat closer to the coast. Regardless, we do not have ideal conditions near Greenland with blocking high pressure. This means the track is all the more important to who gets snow.
Here is the bottom line at this time:
- Chances are increasing for a storm to develop next week
- The overall setup does not really support snow for the big cities due to ridge positioning and lack of blocking upstream
- This can change considering we are 7 days away.
- Further inland, the best chance at snow at this time would be NW of I-95
- There is potential for this to shift even more west causing rain for those areas too
- The sweet spot looks to be interior New England if I had to speculate
Again, this is still pure speculation. I am gaining confidence in storm development but I can not really give any predictions on regional impacts for at least another couple of days.
Thanks for reading.