Carvers Gap

The 12z GEFS ensembles now lock the EPO ridge in place - that is a one day map, but the 5d for the end of the run looks very similar. It retrogrades the first EPO as we thought it would, and then almost immediately forms a new one. Does this pattern have more staying power than originally thought? Maybe. Some deterministic runs are portraying that scenario now. The EPO can be very difficult to break down once it forms. The 12z GEFS also has the NAO in place as well. Here are the comparison from 6z to 12z. The 12z Euro deterministic looks super similar to the 12z GEFS. That would mean that Larry is about to score the coup if it holds. He called that from November w/ analog forecasting and ENSO climatology. He was adamant. He might be within 7 days of that predicted pattern unfolding and hopefully holding. That look has precedent w/ previous Nina winters...just dig back through our threads. It looks the same as our recent Nina winters but the trough is nudged slightly eastward w/ more cold on the SE portion. That fits the cluster w/ -QBO reading and weak Nina winters. The QBO fell again during December to -26.92, and is a very low reading for that index. This could be a blip, or it could be a shift...but that is a pretty big move. Addendum: The 12z GEPS builds the EPO as well, but is a tad slower w/ the move. But the EPO rebuilding after the first cycle looks like a trend now at 12z. Even the EPS has moved AN height into the EPO region late in the run.

The 12z Euro does provide a path to snowfall for our southernmost areas of the forum w/ snow tracking from Louisiana into north GA/SE TN, and into the Carolinas. There is a lot of snow shower activity. At this range, it is going to be difficult for modeling to sort through all of the energy in the pipeline. Looks like nickels and dimes w/ the potential for a big dog(looking more like the 17th at the moment, but that could change). With such strong amplification, any shortwave is going to have to be watched closely. Just one cold air mass after another on the 12z Euro through the 23rd(end of run). Interestingly, the 12z Euro locks the EPO into place. Now, that would be interesting if that trend holds. I have seen that on some other models recently, but it doesn't budge much at 12z. It just keeps kicking the SER right OTS.

The 12z Euro is rolling. I can't see the surface maps yet, but again, another run w/ closely spaced vortices dropping into a very amplified trough. We might still be 24-48 hours from having a good handle on the 15-17th sequence of systems.

It really is crazy how much energy is in the pattern, but not surprising giving how amplified the trough is. It is antithesis of what we have seen w/ the longwave pattern this winter. The 12z CMC ends up w/ just one minor event after another. One thought as we wait for the Euro....we used to call systems that were back to back the "engine and caboose" setup. Modeling will often head fake w/ one system, string things out, and then consolidate w/ the other. Sometimes, the caboose ends up as the bigger storm, and sometimes the engine. I think modeling isn't sure which storm to phase, the 15th or 17th. It could end up strung out, but I kind of think one of those two ends up bigger depending on spacing. The caboose is stronger at 12z. edit: The 12z GEM gets very close to another system on the 17th as it does form a low which runs the coast as a weak reflection. The trailing northern stream still manages to dump a decent amount of snow on the northern 1/3 of the forum...east of Nashville 2-8" of snow in those areas. The mountains get pounded. The event is still ongoing as the run ended w/ a weak lee side slp forming.

The 12z GEM manages a neutral tilt phase over the TN and OH valleys. I can't see surface maps yet on the 15h, but that might be a Miller B hybrid.

Kind of for fun at this point and in fantasy land at 258, a piece of the TPV is now trapped under a HL block. It is losing latitude like it was dropped off of a building. Could be a cold run for the GL and NE....glancing shot here.

It has been some time since we have seen troughs this amplified on modeling. At 222, the GFS has a trough running from Anchorage to New Orleans. This one sucks the TPV into the pattern(we've talked about that potential), and creates quite a cold front(w/ snow) around the 17th. Again, not sure this second front is being modeled correctly if the mis-phase is an error on the 15th...but it is impressive nonetheless at 500. Either way, we have seen modeling really keying on this time frame for strong amplification.

The 12z GFS avoids the westward trekking slp, and sends a consolidated and highly amplified trough in the East around the 17th. If the GFS is wrong w/ the system on the 15th, and if it is more amplified as I suspect it might be....the rest of the pattern would be more amplified. As is, the trailing trough being the 15th amplification will be every bit as imposing.

The GFS almost got to where the ICON was...just too quick w/ the southern stream to make the phase. Let's see where the other deterministic runs go w/ that. IF It forms a coastal in reality...that is honestly about where we want it on the GFS w/ the westward trend and it missing the phase. If that phases, it could be well west of that.

At 156, the GFS misses the phases. Not unexpected from a model which has a progressive bias. Let's see where ensembles go with that. That said there is still a lot of energy behind the initial front which is dragging its feet.

The 6z AIFS Euro does that crazy deal where the slp cuts off over Idaho and heads to San Fran.. I think that is part of the feedback that we have seen all winter in that part of the world. If that doesn't occur(which I doubt it does), programmers across modeling need to take a serious look at what is going on in the western US w/ storm prediction - it is rough. With many millions of people living downstream of that...it needs to get fixed. There is almost assuredly some shared programming as evidenced by that pinched of low tracking westward over the US.

So far w/ the 12z suite is rolling: 1. The ICON hass a coastal system and could trend much bigger if real... 2. The GFS and RGEM both have pretty decent snow shower activity Sunday.

Yeah, I want the light blue hues over MBY.

The 18z AIFS Euro barely lets the eastern ridge build after the first retrograding cycle. It almost immediately retrogrades again into the Eastern Pac. The cold TPV sitting in the middle of the continent really won't let the ridge build over the East, and it squashes the SER. I am not seeing a tendency to retrograde the TPV into the West, not on the deterministic and not on the ensemble. The SER is going to try to flex, but IF the setup for the TPV is correct, I bet that trough is underdone. I hate to use a 360 map, but this is where models were originally showing the trough dumping into the West. Do you see a trough in the West? This is a TPV dominant pattern if it verifies, and that vortex could possibly rule the roost if real. The other trend I am seeing is the tendency for HL blocking to lock it in place which would prevent a retreat across the pole once in place. Let's see if this verifies. I am making NO promises this is legit as modeling has been "you know what" most of the winter at this range. This look is very common on many models. When modeling starts to key on major patterns like this, it can score at range.

18z GEFS stuff...