ILMRoss

I looked under the hood and I want to couch that for a zone between Raleigh to Norfolk a decent amount of this accumulation is from Thursday night action.

Going to go forth and say I don't like the Christian McCaffery model either, funny enough that northern shortwave was solidly south of the GFS but the precipitation response was much more muted in comparison. Probably some other stuff going on but you'd expect to see more expansive precip with the Canadian.

One thing I'd like to add- I think sometimes everyone (mets, hobbyists, whoever) can fall into the pitfall of humanizing models too much- I see some "I trust the Euro over everything" like the Euro is a close friend you've been gossiping with, or "the GFS has been hot this month" as if the GFS is Klay Thompson. This isn't a message saying not to rely on models for known strengths and accounting for known biases- but at the end of the day every model is just a supercomputer taking in data, running it through different recipes of the same planetary laws and equations, and spitting stuff out and I think it's good not to get too caught up with the narrative behind each model.

The GFS wants to bring some of the southern stream system to Cabo San Lucas and I just don't see this occurring. While most models do have this energy diving a little bit the GFS is on an island with both the strength and southerly extend of this lobe of vorticity.

Shout out GFS this is a jolt SW with our northern shortwave just what the doctor ordered and this should be tangibly improved precipitation wise (we'll see how ptypes look)

NAM looks better. I'm used to our set-ups going through a slow degradation as we go through the week. But I gotta say the speed at which we went front praying for a more amplified pattern to looking like a zr event for a lot of us really took me aback. I think that the main culprit is the northern shortwave.. see below for 12 run GFS trend. 3 days ago, that shortwave was diving into the Dakotas with a little oil and vinegar... there's been noise but you'll notice it's gotten weaker and is diving further east. Our current version doesn't dig as far, which is a lose-lose. Not only does it struggle to pop the coastal, but because it is weaker and more retreated into the polar trough, the cold press is weaker, and I think has really allowed for warmer mid levels to sneak back into the picture. I don't think over amplification is the key culprit. Sure, looks like it on the Euro, but that's the risk in playing with southern energy as the Euro currently depicts. A stronger northern shortwave in that case would bring a stronger cold press and would likely be able to throw cold water on the southern shortwave's idea of going up the coast. The NAM had an encouraging jolt westward with our energy. It may be a little late, I think "go time" is sooner than most people realize, but I think there's still some wiggle room to trend to some more positive solutions.

I think that that particular site incorporates sleet/zr into the totals

*sherlock holmes voice* that's meteorology my dear brick

Funny thing about the CMC is that even after all that pessimism we still get a decent event. The CMC splits the two shortwave so much that the northern shortwave, less encumbered by the southern wave interaction, is able to maintain some integrity and have a better tilt. The things that stings is that this set up does not need southern stream interaction. The northern stream can get this done on its own; we need to trend with the shortwave being stronger and digging more. We're currently seeing the opposite trend.

I'll pump the breaks and say @84 never mind. Too much separation. Another event coming but it won't be a kingmaker.

@54 the Canadian looks very similar to that 12z run yesterday. Our Arizona energy looks a little weaker and I think it would be easy to get it to phase with our northern shortwave. Let's find out...

I'm not super duper enthused about the "second wave" because the cold appears way more marginal. Give me improvements on the first wave all day.

That northern stream short wave on this run is worst its looked (weaker and ticking NE) so far.

As of now yeah it's more or less overrunning. I'm sort of struggling with that "why does RDU have mixing issues in some runs" question. I'm settling on this: The "strung out, positively tilted" look is just generally no bueno for straight snow. I think there's likely some sort of destructive interference going on between the two waves that just kill them both and cause the general trough complex to slow and stall. If they stall, lower heights can never really press into the Carolinas and we're just simply left with warmer mid-level air. No crazy dynamics overamping stuff going on, we just would't be able to cool those mid levels sufficiently in that spot. I do think that the surface cold press is here to stay. Crazy cold air masses can and do undercut warmer mid level air, i mean, how do you think places like Missouri get ice storms?

To me, I think that the battle lines are set today. Going to use the Canadian from last night because it's a good example of our "dudes out on the field". The northern energy drops in from the plains. We want this energy to be stronger and nudging further to the SW; our dud runs are when this trough stays too positively tilted and just can't get anything to pop. The southern energy comes from Cali/Arizona and we want it to be quicker; our dud runs come when it's held back. It's a shame that we have to deal with this because Baja/Mexi lows have the predictability/reliability of orange cats (you know the type). So far it seems a host of solutions are on the table. The runs where the Zona shortwave is held back make this plains shortwave dominant and we just have to hope it is digging enough/strong enough to pop something. The runs where the Zona energy kinda mingles with our northern stuff (saw this with Canadian) will be murky. The end product would depend on how cute the models get with fluid dynamics but generally it looks like the trough would be large/south enough to bring some good moisture transport but positively tilted/sheared enough to cause ptype issues. 1.28.2014 is the obvious analog here. The runs where the Zona energy comes together in melodious harmony with our northern energy (yesterday's 12z Canadian) would be iconic southeast winter events. Famous last words here but the surface temps shouldn't be an issue with this cold press.

Canadian shortwaves ended up getting modeled out of sync, these need to be together. Shows the potential we have that even with this we still pulled off a moderate event.

Canadian looks like it's going to be a treat, similar look to 12z at hour 96

There are minor difference so far on the Canadian through hour 78 but so far it looks like it could be similar to the 12z.

@120 Boom!!!! Snowing across the entire Carolinas with heaviest at the coast... what a run!!! Edit- let me couch this by saying the snowmap won't look incredible yet but the GFS took a huge step forward

@114 Snow breaking out across central GA, SC and coastal NC... much healthier run

At hour 90 500 mb setup looks way different... that southern energy is much more consolidated... could be a big run...

ICON with a healthy NW jolt. itshappening.gif

ICON trickling in and 60 hours in think this run is going to look pretty good (or at least improved)

Gonna be honest I didn’t see any sign of that at all, our chief problem will be getting enough qpf if you take modeling verbatim right now. Temps are beyond fine and any event would produce pixie dust snow.

If you are hemming and hawing about losing the storm, I would not. I saved a trend GIF that storm that buried Nashville a few weeks ago. It's the clearest NW trend/amped example I've ever seen. It happens a lot. "Hey shortwave, be more amped! Be stronger! Dig a little more!" Not the hardest things to root for on modeling going forward