SnowGoose69

We need the gradual ticking back north the final 48-60 hours if maybe that vort relaxes or timing change and then need help from frontogenesis up on the far north end of the snow shield. That probably will happen somewhere but we'd need the system to be more north than even say the 12Z RGEM was with the snow

I don’t think pattern goes to full hell til early February when the impact of the MJO raging into phase 3 is felt. And remember there is always a lag and it may also slow down somewhat. If we continue to have poleward ridging by AK and a -AO the pattern could even be workable in a phase 3-4 MJO run, especially if it’s weaker

The problem is this is all reliant on that one little piece of energy at 500 that swings down over NNE at the wrong time around 90 hours. With so many little piece of energy pinwheeling around there is no way to know at this range if that timing is correct, 6-12 hours off and this could go 50-75 miles more north or south.

I found it funny that the ICON slowed down but was somehow more south vs 18z, albeit it was not a huge difference. The tendency in the last 15-20 years is when in doubt on what a S/W will do over the rockies/Midwest always go stronger and 7 out of 10 you'll be right. Everything seems to amp up now

The UKMET is wildly progressive and weaker with the S/W so that coupled with it probably moving the system in before the confluence can exit east all leads to it being way south

I don't know what will happen now since the Euro got upgraded but the last 5 years or so whatever the UKIE does the Euro has more or less always done the opposite. Its been a growing joke that they now go the opposite way when they used to seemingly always move in tandem with each other

GFS is usually just bad in -NAO/+PNA patterns. The fast Pac has probably prevented it from verifying even worse as it might be playing into its bias somewhat but usually the blockier the pattern is the more likely the CMC/Euro are going to be better than the GFS and its been that way for awhile

I like the CMC idea better though. I just think due to the pattern flow we've had the system is going to eject out faster and be a classic weak Gulf wave that gives snow to MS/AL/GA

The CMC nailing some of those confluence setups would worry me somewhat if over the next 3-4 cycles it starts being the most squashed. It was the only model to see the March 2013 storms were all going to be south and its hit a few others. I might have said it 2 days ago too, watch to see if the CMC is the most north or south. When there's been confluence issues in SE Canada its sometimes sniffed these out before the other models do.

The redeveloping of the low is not the best thing in the world as it might cause a screw zone. Not to the extreme we see in clippers but this is a case where some dynamics could be lost if we have a hard weakening and transfer to a coastal.

I've seen the Canadian sometimes nail these nasty confluence events before. We've seen a few storms where its causing cirrus sniffing everywhere and the GFS/NAM/Euro were still hits and the Canadian was right. I wonder if it might be due to it having better data in Canada near the Maritimes in those types of setups. Its certainly one reason I'd be a bit worried it was the most south so far at 00Z.

This is a SWFE. Most people don’t realize that because it’s so far south relative to normal. They usually do not show any northward movement that is notable til the final 72-84 hours most of the time and sometimes not til the final 48. I had said by the time this was 96 or so out we wanted the jackpot to be DC preferably or northern to central VA. If it was there we’d be in good position to get snow, albeit not the jackpot. I still feel the jackpot zone in the end though might end up southern PA to southern NJ. So maybe a 50 mile shift from what we currently see

I sort of think the whole system is gonna eject out way faster anyway. If that happens its likely just a deep south winter event.

As forky pointed out the other day too, there is going to be convection for sure with this in TN Valley which might have a downstream impact on track too. It likely also will totally shaft someone on QPF across IL/IN/OH somewhere. Thankfully we never have that problem here

There's been a joke for a few years that the ICON is better at 120 or 144 than it is inside Day 4 and I've honestly felt thats overall true. I've seen many instances where a storm is inside that range and the Euro/GFS/UKIE/NAM all agree and the ICON is nowhere close yet 2 days before it had that idea the others all now agree on

I tend to ignore the ICON once inside 96. It actually seems to perform better on the end result often times beyond that, once inside it can do wild stuff. The NAM had a classic NAM run at 18Z for sure, not in a good way unless you're in a small niche of MD.

It sucks in -NAO/+PNA regimes...the one thing maybe going in its favor here is the Pac is still screaming so the S/W traverses the country insanely fast. The Euro has been owning the GFS for the last month or so on the grading numbers.

They would not get 6-10 in that scenario probably because the convection would rob moisture

I'd rather be in Philly or Richmond right now. DC you just know its moving one way or another given we are still 120 hours or more out.

With a strong -NAO not nearly as often. Some of the least track insanity inside 72-96 occurs in patterns like 09-10 or now when things are slowed down by the NAO. You won't often see massive changes.

There has been a wild snow drought in places like GSP/ATL. Those are not exactly snowy places but they also do not go 5 plus years without a 1-2 inch snow event that often, they both have gone I think 7-8 now

Always seems to me when models see raging confluence at D5-8 in a solid -NAO pattern they always overdo it and it inevitably ends up less suppressive as we get closer. The patterns where the blocking is not as raging and they pick it up late inside D5 its like a never ending congrats southern hemisphere as we get closer like March 2013

Funny thing is that would never happen. Having forecast for that area for years lows needs to usually be 1000mb or weaker or they'll track over cntrl or northern AL/GA. Its very rare you can get a low to deepen into the 990s and remain all snow in ATL, the track will usually end up over or near them

18Z GFS congrats Valdosta GA lol

the NavGEM is north of the GFS which is nice