Carvers Gap

West Virginia is up to 47” at 232. @tnweathernuthas 26” of snow to this point.

Second storm is La boomba.

The 12z GFS looks like an inland runner or lee side low which develops and causes lift over E TN 10-12” over TRI and much more in the mountains.

From MRX, and when I read about Cove Mountain...I always think about @Math/Met Wind: With the 850mb jet pushing north into the area later this morning, wind gusts will increase across the higher elevations of the east TN mountains. Wind gusts from 35 to 40 mph will be common from around 12Z through 18Z. Latest HREF probs not too excited about reaching advisory criteria, with only isolated areas of 30 to 40% probs. Cove Mountain will most likely see a 40 to 50 mph gust during this time, but most areas will likely stay just below advisory criteria. Winds then pick up again behind cold front tonight into Sunday, with northwest flow around 30 to 40kts at 850mb. This will be another period where near advisory level gusts will be likely for the higher elevations of the east TN mountains. A Wind Advisory may be needed with the next forecast issuance. Storms: Nothing has changed too much with the severe threat. Instability continues to remain elevated with only very low probabilities of some SBCAPE later today just ahead of the cold front. With surface based CAPE unlikely, the main threat will continue to be isolated damaging wind gusts with any stronger shower or thunderstorm. Tonight into Sunday morning, additional moisture moves in with the trough axis and any precip should mainly be in the form of snow. Light snow showers are probable across portions of northeast TN into Southwest VA. No impacts expected as snowfall amounts will be very light if any. High pressure then builds in Sunday into the new work week, with a period of dry and cooler conditions through Tuesday. Downstream from a amplified ridge over the PNW, troughing will deepen across the Ohio and Tennessee Valleys mid week. The return of moisture and cold temperatures may lead to light snow accumulations across higher elevations of the east TN and southwest VA mountains Wednesday night into Thursday. High pressure then begins to build back in on Friday and into the weekend with moderating temperatures.

Kind of a medium to long range update. Thankfully, we have some nickel and dime stuff to track in the shorter range. Just looking at the app on my phone...real feel temps should be in the upper teens by this time tomorrow. Quite a big change incoming. LR modeling did a decent job w/ the 500 pattern for this. Cold air will arrive about 12 hours ahead of what has been modeled as a transition timeframe for several weeks. We will likely roll a ridge through Jan 21-23, though that is not set in stone. The 6z GEFS is very aggressive in keeping the eastern trough in place. The 6z AI EPS gives us enough of a cold air tap that should be serviceable. I think the idea that cold dives into the Canadian Prairies and then rules the roost...that looks like a plausible if not probable idea as of now. Part of the TPV being trapped over NA by HL blocking also looks likely. Sneaky important. They key is going to be the cold being centered over NA and not retrograding into Canada. Most ensembles have the cold in the Canadian Prairies, but the Euro is more retrograded into the Yukon. A good blend is the 0z GEPS which looks about right to me at 500.

The 6z Euro AIFS has a decent snow mean. Models are all over the place w/ the track placement of coastals right now...so huge grains of salt. I would think eastern areas of the forum and the Apps have a shot at coastal enhanced snows w/ clippers up for grabs by everyone. The coastal storms will largely dictate the clippers which follow, and if they can get to our latitude. Remember, clippers generally trend sharply north at the last minute. So, we want them south of us on modeling. As for the coastal opportunities themselves, they are still a bit too far to the east, but...the northern stream interaction w/ the southern stream may still accentuate snowfall over areas of the forum which are favored by phasing or partial phasing of vortices. I would suspect a northwest jog w/ phasing, but that rule sometimes doesn't work out as modeling often under estimates blocking and cold air. As Holston noted yesterday, models are exiting the 5-7 day window where they will lose storm intensity for storm 1. I would think during the next 24-36 hours that we see some more fireworks along the coast w/ phasing.

Ya'll need to see where the 18z GEFS ended its run...nice trend. We saw that once or twice yesterday, and now it's back.

I grabbed a couple of these from CPC...the MA forum has also posted these.

Powell, I hate to hear that. Hang in there.

The Euro Weeklies this afternoon definitely support that CFS MJO map. Get a good window from say Jan15-22nd-ish. Then, we roll a ridge complex through to end the month, then do it again to start February. The interesting thing will be if the cold can actually retreat or if it gets trapped under a HL block. The Euro control had the EC cold throughout the run. Just kind of seems like it is going to be difficult to push the cold out of the pattern for long periods of time, but I could be wrong! Ripe, ripe, ripe for an ice storm if we push a 500 ridge into the SE but the surface doesn't respond to the AN heights, ie stays cold.

Put about a 5-7 day lag on that CFS map, and we are looking at big easter trough by the end of week 1 of Feb or the very beginning of week 2.

Good 12z suite. In the meantime, some beneficial rains will occur before the cold moves in on Sunday. I think everyone has pretty much taken care of the 12z disco...not much to add from me!

We were a heat island before heat islands were cool.

Model of choice at 18z....AIFS Euro deterministic.

The 18z ensembles roll a ridge through as expected right around the 21s....and then they bring the trough almost immediately back East as the EPO rebuilds. 12z GEFS w/ the coup if that is how it works out - yes, wow. Crazy day today...and I have been out of pocket for most of it. Tomorrow should be the same. Don't assume my absence means bad things!

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.