Carvers Gap

RadarScope is changing over to mix over the northern TRI. It mostly rain, but I can see mix on the windshield. This is early for that.

This if for roughly the same time frame. The 6z GFS, 0z EPS, and 0z CMC. Let's see if the Euro deterministic is leading a change. For now, the ensembles are not there. The 6z Euro looked like it would have been cold. Time will tell. I certainly am no fortune teller!

For ONLY kicks and giggles, let's see if the 6z GFS can hit the half court shot on Christmas Eve.

The 0z EPS has a much different solution than any other global ensemble including the AIFS. The GEFS, GEPS, and AIF still have the cold shot next weekend. The 6z GFS has a the Christmas Eve cold shot(which really could go either way). I think the widely diverse solutions are due to the various MJO solutions. The EURO at range has struggled so far during late fall and winter. It certainly is good enough to score a coup, but it erroneously called for the beginning of December to be warm(after the weeklies had it cold). I would suspect there is a severe cold shot headed into the Lower 48. Things get scrambled when that happens.

The 6z GFS has returned to a much colder look. The 0z Euro is definitely warmer after mid-month. Its ensemble is not as much. Both the 0z GEPS and 0z GEFS are not warm. I think the warm-up looks to be set just after mid month. But there is this on the LR GFS, and take with a huge grain of salt...a major league anafront. This would be a nightmare or travel. You don't have to guess what the weather looks like under that. Lots of uncertainty after the 20th, so we'll see.

Basically, the December 1995 pattern would repeat later that winter, but with better climatology in place for cold air to make it to this latitude and hold. IMBY(not the folks at elevation), we are fighting climatology every step of the way right now. It eases up after Dec 10th or so, and becomes more favorable with each day. When I first started tracking, I rarely tracked during the first 20 days of December. But if this pattern were to repeat during the second half of winter, I think the cold presses more. Now, the STJ is inactive...so northern stream systems are gonna have to do the trick. I still think we have a shot to score before this breaks just short of Christmas. One caveat, this may not break down before Christmas. Some MJO plots are stalled through the end of the month and into early January on the left side of the MJO. Also, modeling tends to break down patterns a bit too early. That said, a New Year's thaw seems realistic. If it is twenty below w/ five feet of snow...you can look back on this comment and thank me for it!

The Euro Weeklies this evening strongly hint at a 95-96 type of progression. Warmup around Christmas. Cold returns mid-Jan or just after. That also fits the pattern of recent winters. The good thing about all of this...eastern portions of the forum have missed w/ the second cold shot during recent Nina winters. I doubt that happens this winter. I think the cold in later January pushes to the coast. Just a hunch.

The talk about the trough being flat and displaced eastward got me to thinking - I know, dangerous! But that displaces western ridge(which leads to a very cold NE) will sometimes retrograde. If it does so slowly enough, we can hit the sweet spot at 500 OR if a system will cut one time. Any type of cutter right now is going to send very cold air south.

Totally got the shaft, man. I would drive home and be amazed. Now, Knoxville wasn't half bad. I remember driving around behind West Town Mall in my front-wheel-drive w/ everything covered in snow. Knox Co had to develop a new snow day, make-up plan after that winter. That extra 30 minutes kids go each day....started that year. But what TRI got was insane. I would see the snow around Jearoldstown Rd on my way up 81, and the parking lots were just stacked with snow piles. After the second storm, it was wild. We will see another winter like that. I can't wait to track it. 14-15 was good though. So, I kind of feel like I got my money back with that winter.

What happens with the above pattern, and I need to look at this more carefully(roll the tape forward if you will), all of that retrogrades. You get a window when a pattern like this retrogrades where we get a goldilocks 500 pattern.

December 1995. Notice the eastwardly displaced ridge and trough setup? This isn't a perfect match, but I found it interesting, even with the Bering Sea hp. Notice the cold in the Yukon? But overall, the similarities are kind of striking. And now look at the 30 day forecasts from the Euro Weeklies, GFS Weeklies, and CFSv2. Now, I am not saying this is going to be 95-96 as a winter, but it could be a light version. That winter didn't mean business until mid-late Jan through mid-Feb. As CoachB noted(think that was him), that winter wasn't overly cold, but it snowed during a four week time frame every, single time it got cold. I pulled this up, because CPC keeps double weighting it in their d8-14 analogs.

I think our next trackable system is around Dec 11th - very light NE TN, SE KY, SW VA, possible Plateau. Then, I think our best chance will be around Dec 14th. As long as that cold front presses into our area w/ full force, I think we likely see frozen precip then. The 18z GFS shows the potential for that one. It is running as we speak.

As for the medium and LR pattern, ensembles and deterministic modeling still favor some amplification mid-month. Whatever we get is likely going to be northern stream influence.

As an explanation for those who don't live in NE TN, one of the real pains which we(in TRI) have to deal with(regarding modeling) is that models will sometimes smooth the cutoff for elevation snows into regions which don't have elevation. Most people think NE TN is high elevation....we are not, but we are very close to places which are. What is difficult to know about recent model runs...is whether smoothing is playing a role in the strong totals east of I-81. But for anyone who has lived up here for very long, we have had some systems with wild and crazy snow cutoffs regarding accumulation. We had a guy from work one time who said he would be out for the week due to snow. We thought he was just pulling our legs. He was only 20 minutes away. Nope, that man had like 2-3 feet of snow in his yard. We had a dusting. I am NOT expecting that this time, but I could see foothills communities doing well...but modeling is not to be trusted when some have a bunch of snow and others have none. Could bust either way.

Both the 18z RGEM and GEFS hold serve over extreme NE TN. I have strong doubts about snow in TRI, but the GFS is no longer alone w/ the this system as noted above. From I81 to the east, there is snow modeled on almost all models w/ the exception of the Euro. The closer to the foothills one goes, the stronger the totals. This is definitely a trackable system for NE TN and SW VA folks(Abingdon vicinity). It is no slam dunk, but interesting nonetheless to see the GFS pick up support. Now, before folks accuse me of favoring MBY...this, in fact, does not appear to have much of an impact IMBY. In fact, if correct, I will be able to drive 10 minutes to my east and find snow. LOL.

A warming trend is present after hour 300. Is it destined for the reality of the previously modeled LR warmups? I think so. I don't doubt that we could see a warmup, but the MJO is parked on the left side or a bit. Any warmup should be short lived IMHO. As for the minor system affecting NE TN and SW VA tonight and tomorrow? Time of day probably keeps this from being much of a problem in TRI, but.....I am not unconvinced that eastern portions of TRI aren't going to see 1-3" of snow. Bristol, Elizabethton, Roan Mountain City, Unicoi, Erwin, and eastern JC. These are TRICKY little systems to figure out, and modeling supports snow in those areas - 18z 3K NAM, 18z HRRR, 12z RGEM, 12z GFS, 12z CMC. I think west of I-81 the dynamics get here after the best forcing exits. But we need to watch trends this evening. I have seen system like this score in amazing ways.

Just one Arctic air mass after another.

Bonified anafront (second of the run) w/ the second cold front. The Southern Apps will have a foot and a half of snow by the end of this run.

The 18z GFS has a second cold front roaring down the Plains at d12. This one could be colder.

That forms a light anafront and then a Nor'easter. IMHO, that would form a blizzard for the NE.

There is a noticeable and significant uptick in juice w/ the 18z short range models w/ regards to Sunday night. The GFS continues w/ its outlier look in NE TN, but the 18z(edit) NAM has the same deformation band. Almost all short range models now have increased backing over Virginia and/or North Carolina. Can it get west of the Apps??? I don't know about that.

Congratulations, everyone. The HOT donuts sign is on for this thread. Haha! Now, I am gonna go watch some football.

If we see that really cold shot between Dec 14-16, I would say we have a 50/50 shot(or better) at a strong anafront. As for Sunday night, I have no idea...it is interesting to see the GFS hang onto that. Overall, we need that ridge to backup just a bit. I see where several folks on other forums have been talking about -PNA. I don't know if that is a true -PNA. That looks like a +PNA on modeling, and it is centered a bit too far to the east.

Models haven't missed by much with the exception of the 4-5 day SER/feedback hiccup. They really haven't amplified the pattern with just a few exceptions. Mid-month may well change that. I think the wavelengths are just flatter, and that may help us later on as this will be tough to dislodge as climo gets increasingly colder. This has been a pretty cold start IMBY. I do think there is a window for a piece of the TPV to drop into NA to lower latitudes than the GL. Also, you noted that the Pac NW has been pretty active. That Pac flow also might be modifying the colder temps at the base of the trough, and that was shown on modeling. Interestingly, the Sierra Nevadas in California and the Colorado Rockies have been stuck under that ridge, and are way, way BN on snowfall. Lastly, the pattern doesn't really amplify in phase 7 of the MJO, but it can w/ phase 8. I think modeling erroneously tried to loop the MJO, and that made a mess. Now, it is forecast to stall by some models in phase 8. It may just keep on making the circuit, but...it did make a turn(per the EMON) today which could signal a stall. We will know more in a few days. Overall though, this has been a very cold start IMBY.