I wish I had time to get more in depth here, but unfortunately I just haven’t had the time given work and everything else in between, so this will have to be quick.
The storm is currently streaking over Kentucky and by tomorrow will be redeveloping off the Virginia Capes and then RAPIDLY deepen as it heads just east of due north.
Once it reaches our latitude, the 500mb or upper level low will close off somewhere around the Delmarva peninsula, which subsequently will capture the surface low and cause it to slow down and meander around near the 40/70 benchmark, just southeast of eastern Long Island. Where and how rapidly this upper level low forms will determine how far west the heavier snow gets with respect to eastern Pennsylvania. The European and its ensembles have been rock solid consistent in this scenario, which is typical for nor’easters, and I’m leaning heavily on their outcomes. I just don’t buy the further east solution of the other models given the insistence of the Euro and the very warm ocean temperature just off the east coast, which storms like this feed off of.
Assuming the European and its ensembles are correct, and I think they will be, expect lighter snows to begin in the early morning hours and then continue through most of the day Monday. There may be a lull in the action Monday afternoon, and then Monday evening things will dramatically pick up in intensity from southeast to northwest as the coastal storm ramps up. Heavy snow, where it does fall, will occur from Monday evening through at least Tuesday afternoon. The worst weather will be near the coast, where 2-3 feet is likely from central NJ up into southern Maine. Farther west, at our latitude, snowfall will drop off, and there will likely be a rather sharp cutoff along the western fringe of the precip shield. The hardest area to forecast for our area will be on a line from about Scranton to Hamburg to West Chester PA. Within just 10-15 miles of this line, one could got from 6-7 inches of snow to well over a foot. There is the possibility that this storm gets its act together more quickly, and the 500mb low develops faster and farther southwest, resulting in a slightly further west surface low track, but I’m not ready to go there yet. I will be watching tomorrow though as the storm develops for this possibility however.
That being said, I like NOAA’s forecast below for this storm. Extreme eastern PA should see double digits, in the realm of 10-18 inches, greatest along the Delaware river, least further west. Farther east, amounts of 2-3 feet will be common, but given the gale and storm force winds associated with this storm at the coast, after you get beyond 18 or 20, let’s be honest, it’s rather hard to measure. Farther west there should be 6-12″ along the Scranton-Hamburg-West Chester line I described above. Accumulations will likely drop off from there as one heads toward and beyond the Susquehanna river.
After the storm winds down, colder air will follow with some moderation towards the end of the week, and another chance of snow come later Thursday into Friday. This will be followed by the coldest air of the season, likely quite brutal, next weekend into the first week of February. Winter has truly returned.
More tomorrow as warranted…