Been discussing this threat quietly in the 3/7 storm thread and finally decided to pull the trigger on starting a new thread, even though the Monday into Tuesday storm is looking more likely to go out to sea than hit us. However, there is still some chance of getting hit by this one and the storm is almost certainly going to be a powerful one, so if we do get hit, it'll be quite impactful. Also, keep in mind that if it does hit, we'll likely have some of the same surface temp issues and precip type issues we've had the past two storms, i.e., could be some white rain or even a mix, but if intensity is great enough, it could be an impactful snowfall. Anyway, the rest of this post is essentially from my last post in that thread.
Consensus from 00Z model runs is generally out to sea, but only 100-200 miles from being a significant storm, and the UK (2nd best model) does show a modest hit for our area, and we've seen several storms this winter at this timeframe (~72 hours out - looking like a Monday into Tuesday storm) shift NW in track over the last 72 hours and end up being hits for us.
So same bottom line - not worth sending out the Bat-Signal yet, but this one still has some potential to hit us (as model errors are at least +/-150 miles at 72 hours) and it it does, it'll be very impactful, as it looks to be quite a powerful storm, and therefore bears watching. Plus, the northern jet stream energy is still in the Pacific, off the coast of BC, meaning it's not being well-sampled data-wise, which only increases model inaccuracy at this point.
Also, the 6Z models are in and the GFS is a near miss (100-150 miles from the benchmark), the NAM is way out to sea, and the RDPS (Canadian mesoscale version of the 12 km NAM) is a modest hit for 95/coast, i.e., there's still potential there, but obviously not an imminent threat.
Edit: just saw the NWS discussion, below. They're a bit more optimistic for this storm than I am, so I think it's thread time, even if it ends up being a miss, which is more likely than a hit, plus this way I don't incur the wrath of he who shall not be named, lol.
https://www.weather.gov/phi/
https://www.33andrain.com/topic/831-winter-2017-2018-the-grand-finale-part-2/?page=12
National Weather Service Mount Holly NJ
412 AM EST Sat Mar 10 2018
LONG TERM /SUNDAY THROUGH FRIDAY/...
500 mb: The interactions of two digging short waves in central North
America Monday will ultimate determine our snowfall potential. The
lead short wave in Missouri midday Sunday, is modeled by the GEFS to
sharpen as it crosses the Carolinas on Monday. Meanwhile a meager
looking short wave over central Canada on Sunday amplifies
southeastward and negative tilted, heading into the Great
Lakes region Monday evening, then either ejecting the Carolinas
short wave east northeast out to sea, or absorbing it into what
should be a large closed low over NYS-New England on Tuesday.
That closed low then weakens eastward off the east coast by
Friday night with ridging to follow next weekend.
I dont think the models are cohesive here. The NAM is late to
the table on this one but am expecting much more NAM development
by this time tomorrow. For now its trying to set up an inverted
trough for Tuesday as our primary snow event. The UKMET was my
favored model since its been consistent for two cycles, and
closer to the coast, which is what I expect again this winter
with this upcoming system (SST`s offshore still above normal).
The GFS UK ECMWF all seem to be onto the rapid intensification.
That said, forecast uncertainty continues and haven`t said too
much yet about what may happen.
Monday...Cloudy. Snow or rain/snow mix changing to snow as the
boundary layer temp cools, all this to the southeast of PHL.
Amts and northwest extent yet tbd.