psuhoffman

@stormtracker its really hard imo to get an early read here because the SW that shows up first around 72 hours isn't the one we want to be the storm...its the next one which until later is still a part of the TPV rotating mess up top that splits off around hour 100 and dives in. Until we get a look at how its oriented its hard to tell much.

We need the guidance to resolve the cutter. Not sure exactly when they will do that, but until the details with how that affects the ultimate orientation of the TPV which will affect all these moving parts involved in this "threat" we wont have any clarity.

I agree with this. Initially there was no trailing wave of note, and that was why a few days ago I was pretty blah about this threat...I just didn't see much potential from that lead wave. It's positioned right under the TPV, the only way to get it to be much would be to phase and amplify but that would cut it too far NW of us given the location of the boundary and the lack of any confluence in front. Now if this keys on that second wave...its a whole different situation. The front clears the area, we have some confluence created by the lead wave, and that second one has more room to amplify.

FWIW we got back the gefs extended and now all 3 extended systems show us going into a perfect pattern by Jan 30 and rolling through Feb with it. Op gfs shows how we cold even snow during the “relax” because there is a lot of cold left around.

It’s a good sign that no one has even mentioned the 6z gfs had a PD2 type storm out in unicorn land.

Bob just alluded to this also. I’m not a huge fan of the big pna ridge when there is blocking. It’s critical in a hostile Atlantic. No way we snow with a +nao and -pna. But a lot of our best Nino snow periods came with a nao block and -pna. It prevents the NS from squashing or running interference. It can work. Dec 2009 was a pna ridge. But remember that wasn’t a long lead tracking storm. From 5+ days there were doubts it would come together. Because of the pna ridge we needed NS energy to dive in and phase. A huge PNA ridge guarantees the NS will be diving in over us and means we need it to play nice. Opens up phasing issues and all that jazz. I tend to prefer the simple route of a system crashing into the southwest sliding east under a quiet split flow with the NS out of the Fng way and the the stj system having room to amplify and attack the blocked in cold in the east. That’s the least complicated path to snow in a Nino. You’re right. The control is run off the same unperturbed data as the op but at a lower resolution. It’s the unperturbed base for the ensemble members. It tends to be pretty identical to the op out to about day 7 then they often start to diverge some due to the resolution differences. Bob ninjad me. I don’t know. If we get the huge epo pna ridge some guidance shows maybe. That has a lot of upside but some risk of suppression and miller b type outcomes also. I doubt we would be skunked but 1969 is an example of how that can be less epic here. We got some snowstorms but New England got smoked by late developing miller b storms that gave our area 3-6” and them 2-3 feet. It’s the huge pinwheel on top of us dominating the whole flow. You can’t miss it. Right now it’s up on NW Canada which is bad and why all the cutters. But the storm this weekend phases all the prices of energy together and consolidates into one monster vortex right on top of us. Look at an h5 map you won’t miss it.

People should stop worrying about each run in general given this setup. We have a monster amplified wave in front of it. The kind that can impact the hemispheric long wave pattern. Then we have a tpv sitting over us with 700 pieces of NS energy rotating around it while an STJ wave comes along just for fun. We’re going to keep getting different looks every op run until we get closer and the cutter is 100% resolved. Even then this is the type of scenario with short range bust potential either way.

They are better in a Nino because often in Nino split flow regimes the northern stream is quiet and if no TPV gets displaced into our area a non factor. 2010 and 2016 were like that. Models have a much easier time resolving stj systems. They are less stochastic. But this still a NS dominant pattern. The tpv getting displaced above us created that. A couple weeks ago I said I might prefer not having a tpv there. Yes it makes this a colder pattern but it opens the door to complications like suppression from NS waves running interference, miller b scenarios or phased bombs that cut despite a -nao. This isn’t the typical stj dominant Nino pattern.

Pretty sure everyone has him on ignore.

I actually agree with this. This isnt good. Chuck is honking about -NAO and a favorable PNA and I'm agreeing with JB. End times man, end times.

I feel a lot better than I did coming into today. The flavor of this threat changed in a way I wasn't expecting...and it was a favorable change for a change.

it just misses something big, the STJ wave slides off and misses the phase with the NS energy diving in behind...but this was closer to something big than the GFS has ever been with this threat.

man if that stronger wave diving in behind can round the bend and catch the STJ...with the front having cleared and the TPV out ahead of it locking in the cold...might not do it this run but this is moving towards a setup with way more upside.

The lead wave is problematic because its directly under the TPV which is tricky and most likely either squashed or would take a phase which would cut it west. The trailing wave is behind the TPV initially which is where we want a wave to be on approach.

This is evolving towards a frontrunner wave escaping and the trailing energy swinging around behind type deal which is a much better setup than what most guidance was suggesting yesterday.

OMFG

Explain to me again how you know there is potential?

I thought Jan/Feb 2021 was pretty good and it was so close to a big period just not quite cold enough. The last time I was this excited for a pattern was March 2018, which kind of underperformed here. There were 4 legit threats and only 1 worked out. We were also fighting the end of our realistic snow climo towards the end of that period too.

You're thinking about it wrong imo. We don't have the skill to be able to make a "this many inches" forecast from 6 days out! That's why we call them "clown maps". But if you look at the mean SLP, H5, surface and 850 temps you get the picture that the guidance is indicating there is a pretty decent chance of a wave sliding along the boundary just to our south next Tuesday. A responsible and reasonable forecast right now would be "there is a chance of a storm along the east coast affecting us early next week, and there could be enough cold air for it to be snow. It could also still slide out to sea. We will keep an eye on it and know a lot more in a few days" You can try to give a more specific forecast but the truth is we don't have the ability to with any accuracy, you would just be guessing which of the possible solutions within the typical margin of error from this range is going to happen. But the guidance isn't showing EVERY solution. There is absolutely no chance of a snowstorm tomorrow, or Saturday. Not much of one Next Wednesday. 95% of the time there is NO chance of snow on a given day! So narrowing the scope to one where there is a reasonable chance of a storm that COULD be snow in our area next Tuesday is good enough for this range and the guidance does that. If you know what is important, what is just noise, and what are reasonable assumptions to make from them.

Ok who kidnapped Chuck and replaced him with his less evil twin?

The key is this.... As soon as that canonical pacific configuration sets up any ridge and warmth in the east is living on extremely borrowed time. By the time it warms up the cold is coming again. And this time the continent isn't a blow torch so we don't have to waste weeks trying to slowly develop a cold enough profile. The next pattern reboot should come quick imo. The MJO is flying in and out of the MC. This isn't going to be a big problem imo.

Any pattern breakdown continues to look brief if at all. By the time it hits we might already be tracking a threat on the other side. Day 15 5 days later Next 30 days That's how I drew it up in my mind. I couldn't have created a better pattern if you handed me the magic crayons. If this pattern doesn't work, during prime climo, during a nino... well it just better. We aren't going to get a better chance than this to break out of our snow funk.

Well be careful with that... because a NS dominant solution would likely not end well here. Almost all of our big snowstorms need to be STJ dominant. That is why there is such a huge difference in snow climo in la nina years between DC and NYC. We are simply too far southwest for NS systems to work. They develop to late for us 90% of the time. I agree this time period has a LOT of potential, but if you want the mid atlanticn south of 40 to get in on it there will have to be a trend towards a stronger STJ component to the threat.

There is one there, it's just too weak as of yet and gets dominated by the NS making for more of a miller b screw job setup. BUT...that wave wasn't even picked up at all until recently. We just need a SLIGHT adjustment there and boom. The pattern has been screaming for that window. The longwave setup is absolutely perfect in every way. We just need a somewhat healthy STJ wave to come along during a 48-72 hour window and it will likely work out. 12z GFS/EURO were very close just not quite a strong enough wave to get it done. But its so close.

They lit up like a christmas tree