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GFS keeps the northern crew happy

WB 0Z GFS also a little drier.

Here's my quick breakdown as a bit of practice for my upcoming atmosphere and weather test. I am going to start with the negatives before ending with the path to victory I can imagine. I think the more notable issue is that the high appears to go from helping to hurting before the event even starts. By Friday midday the main surface high pressure is off the coast which promotes flow in from the Atlantic (which as a reminder it is still early December). Additionally, we have no real mechanism for keeping any cold air in place for the layers below 700mb as the surface high is unhelpful. The upper level low and surface low are both in a position to eat away at the remaining cold wedge before precipitation even comes close to our area. Just take a look at this 925mb map. The flow is completely out of the south 12 hours before the event even begins. It should be noted our saving grace here is that the storm is weak so the winds are minimal. The better news is that the 850+ level is less affected by the surface high and general weak low that is "attacking" from the south. This means that the flow is firstly, not that strong; secondly, out of the southwest/westsouthwest. Once you get above 850mb the flow largely veers to be out of the west as there just isn't enough cyclogenesis to really distort the westerly flow. All of this said, I think that ultimately with currently modeling the event this Friday is not in a good spot. I believe this as in order to get a real plowable snowstorm we need two things to go right. 1. A stronger low pressure center in order to actually get lift into the area 2. A correspondingly stronger/more stubborn high. If we get 1. and not 2. all of the thermal issues I highlighted goes from bad to worse as the southern flow just becomes stronger. Meanwhile, if we get 2. but not 1. then we probably end up suppressing this storm. In the end it seems like another thread the needle event that just seems unlikely to get more than 1-3 inches. Disclaimer is that ofc I would be happy with 1-3 inches but this analysis is from a "how could we get a plowable storm" perspective. That said, I think there is room for hope as it is not impossible we get 1. and 2. to align. The 5h pattern isn't horrible after all. There is clearly a path here. Though as it stands everything is slightly off. We have a some semblance of a 50/50, though we need it to be further southwest if we want to trap the surface high pressure in. Additionally, the shortwave out west isn't in a horrible spot. However, as it stands it seemingly gets both weakened and pulled north by the larger low pressure center over central Canada. I think the path to victory here is quite simply that the low out west doesn't get stuck. Currently, the energy enters the southwest around hour 60 then languishes there through 110 before a secondary shot of energy pulls it along. I think if we're able to have the first ball of energy keep its form and progress eastwards and the second shot of energy enters faster its honestly quite possible we manage to get a stronger, more consolidated, and further south system without as much northern stream interference. Additionally, the 50/50 would naturally be in a better spot which would help offset the WAA from a stronger storm. Thank you for listening to my Ted-Talk and if any met read this through let me know if I am gonna fail my test. TDLR: As it stands I don't think Friday looks good for anything more than 1-3 inches, however, I think the path to victory for a bigger storm is still there if the energy out west is more progressive

meh, even here in rockland county I’m not overly excited. I’m expecting maybe an inch or so(If that).

It's amazing how the two E to W highways (Pike and RT2) are often viable dividing lines wrt frozen precip in winter storms with marginal temp profiles.

Ahhhhh from Totally Screwing RI to…. Totally Screwing RI? Ya. Same Picture to me.

if taken verbatim, RDPS zr in the metros might be an issue with these temperatures

My Average was a couple degrees colder than KTRI. The high on the 10th here was 33. Some area's remained below freezing that Day. The Month was near Normal. I wonder how John's Location faired.?.

WB 0Z RDPS (less precip.)

Elevation at that same latitude would certainly be favored. What a legendary snow spot Winter Hill is… decades of wins in winter events (proven on the forums) compared to surrounding areas. Hopefully it can go isothermal paste for your current spot. How many times is “the Pike” the boundary zone over the years? Could be another one.

I mean this sounding from the Catoctins really says it all. Though, it appears if you're able to keep the column cool it will be dumping with a saturated atmosphere up to 500mb and good lift in the DGZ

Sane and realistic.

I’d sign for that to get on the official board for the season.

I’m hedging on the lower end here at the moment. I’m not convinced of some of these rates but we’ll see. If we can get a temporary bombing low scenario which isn’t impossible for a few hours, then we might be able to rip if we stay on the cold side. Id feel a lot better on winter hill, lol

Ego batteries charged up. Going with 2.5” for MDT.

below freezing and above freezing, almost like 31.8f vs 32.3f

There are some things to like about Dec 5-6 and there are some things not to like about Dec 5-6. The -NAO certainly helps that cold high-pressure in that location, which will promote CAD. However, as modeled, the high is weak, isn't in a great spot, and will retreat east. Therefore, we lose the CAD, hence the flip from snow/ice to ice/rain. Perhaps this will trend colder as models start to take MJO 8 into consideration. It's probably a better overall setup and we've got more things going for this than Dec 2, and there's a decent signal on the EPS. We shall wait and see.

Still looking good locally for 2-4”. Hopefully someone cashes in on some fgen magic. These smaller events are fun in their own way.

These early runs have a been a little flaccid on dynamics. But some of these mesos were also pretty bonkers to begin with. The massive 1-1.5 QPf getting well inland never looked that realistic.

Canadian update continues to insist on El Nino conditions developing in February at the surface. Likely by January below the surface. Fairly cold winter nationally. Has the cold look for the North-Central US I've been getting from analogs since Aug/Sept. My blend from Oct - (2013 x4, 2024 x4, 2018, 2022). Hasn't broken yet. I am expecting a pretty widespread warm up after a cold first 10 days or so - we'll see if that pans out.

What’s the difference between a purple zero and a white zero?

Looks like qpf is getting reduced on the NAM (no suprise) and ICON. At least in Maine. Alas.

Ahhh the classic snow to rain event in Allentown while the Poconos get hammered. I’m just glad we’re getting something this early in the season.

This is bothering me a lot, as the NAMs are usually the colder solutions. I think we're still in the range where the NAM could be having synoptic issues, but if it continues on Monday to keep the accumulations further northwest of the I-95 corridor, I'm going to guess it's right. The faster onset, shown by the GFS and its hi-res HiResW FV3, would help a ton here, although even where it shows snow, the thermal profile has pretty much zero margin for error.

High of 52 after a morning low of 34. Was quite raw this afternoon, picked up .24” of rain and temps dropped to mid 40s