SnowGoose69

GFS with the bogus best of both worlds solution. Ice storm in ATL up through the Piedmont and somehow storm climbs the coast too

I agree for ATL metro there may be a better shot of snow next week if the system ejects in time. That said, the 12Z ECMWF solution might be a snowier event for ATL than the model depicts if it unfolded as shown as far as track

The 3k NAM/HRRR now are similar, 12K not as far north with a 3-5 hour period where snow can reach metro NYC. This tells me again it may be jet induced in some manner because there is no notable fgen showing up that far north. Still a question if there may be too much virga, the surface temp/dp spread is not too huge on models at least but have to saturate areas above that

I still think this is an AL/MS/GA snow event and thats basically it and I've felt that for a few days if it ejected, even there though the cold air largely escapes in time so might only be parts of TN/SC that really see notable snow from it.

In other news GEFS again trying to revert to a La Nina pattern, again the EPS/GEPS do not want to fully do it. If again in 5-6 days we start seeing the ensembles keeping the PNA positive again it'll be getting near time to declare this an inverse 18-19 or 23-24 where signs of whatever the background ENSO are keep showing in the long range and never happen

I'm not sure ATL sees snow out of this even if the low takes a 06Z Euro track, there just is not enough cold air in place really. The higher risk here is something slower and stronger forms allowing the high to slide over into NC more and they see a sleet/freezing rain event.

It really depends on the setup, if its a huge closed low south of Dallas there is a decent chance something like that is going to cut up into the OH Valley. It needs to be more of an overrunning type event for that rule to work. Most Atlanta snow storms either are a weak Gulf low which maybe starts near Houston or developing Miller As that form further east and weaker than normal like 1/87 or 12/2010

The HRRR concerns me a bit because despite the fact it sucked the last 2-3 months with seemingly everything, it HAS often seen these further north extensions of snow before, usually due to jet dynamics. I am not sure if thats the reason the HRRR is showing that signal or not but we do have the 150kt plus jet up here north of the system.

The UKMET pretty much shows that now, most of the snow is in VA

Everyone has to just hope there is a timing or strength error on that little vort lobe. Its a wildy chaotic piece of energy spinning around that massive low. I am actually surprised to see all models within reasonable agreement at the moment given how sensitive a piece it is and how it evolves quite a bit in the next 3 days. Given how strong this s/w is as it comes across the Oh Valley there would be a nasty late track bust on this if either that vort is weaker/late and it was not resolved til the final 24-36 hours.

KC will likely mix alot with pellets, WAA tends to be underdone, the 3k NAM sort of shows that happening there

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