Carvers Gap

January 2019 would be the other (glass half empty) SSW. I "think" both of those winters had some La Nina characteristics(both Feb10, and Jan19). 2019 did have an SSW event - debatable what it did to the TPV. I did go back and check this morning on the site below about 2019. That was the January that had a great look and went to pot due to the SSW(maybe partial or mostly unsuccessful split...think that split had small twin vortices at the TPV off the top of my head but the main vortex held) https://csl.noaa.gov/groups/csl8/sswcompendium/

Interesting stuff, Holston. January 1985 in terms of cold is what March 1993 is in terms of storms for NE TN. It is the Holy Grail of winter patterns. I think right now this is a very different era in terms of weather. Not sure the usual analogs apply - and that could be good or bad. We will see. Certainly not going to complain if the weather goes that direction. Will be tough to reverse the temps AN anomalies for the first two weeks of January I think. The one possible good scenario which I mentioned a few days ago(and this AM), is that if the cold were to dump into that trough forecast mid-month, that would be a well-timed strat split. SSWs in my experience are just terribly tough to predict. Truly hate that we are substituting what looked like a decent pattern for a flat unknown(leaning warm) pattern. "IF" this is going to be in our favor, we should begin to see that on modeling quite soon. The past couple of SSWs have resulted in cold dumping into the Rockies after a head fake eastward. Second half of the month of January would be our chance. My bigger concern is there is very little cold on this side of the hemisphere to even tap should the SSW behave favorably - takes some time to resupply Canada. I do think we are likely at least one more cold shot that would be a good winter storm window, even if the pattern flips to a western trough. Very much looks like the West is about to get winter after a quiet month in December which followed a great November there. @Holston_River_Rambler, see what you think about February 2010. If I was going with a glass half full attitude, that would be my choice in terms of similarities. Very similar in terms of set-up - even had a late December snow in NE TN.

A warm to very warm pattern is beginning to show up in the medium to long range ensembles, and beginning by midweek of this week. The 12z EPS has moved the eastern ridge flip to this Tuesday w one slp passing through it afterwards. The eastern ridge will likely get stronger during the next 7-10 days. This is the time of year when the EPS begins to rule the roost, but is not infallible either. It does provide some relief around d14 with a ridge redeveloping out West. We saw a similar look last year. As with this last year, the cold air supply will be likely lacking. My confidence is increasing that we are about to enter at least a two week time from from from say Dec30-Jan15 of AN to much AN temps w a seasonal day or two thrown in. After that, comes the game we have played for the last two winters....waiting for the pattern to come back. Is this trough out West a pattern relaxation or a new pattern. Don't know, but I do know that trough has been tough to move (during the past two winters) once in place regardless of EPO ridges(tucks under that ridge) and SSW events. The -NAO looks to be a consistent feature, but connects with the eastern ridge. There are signs this current pattern could return during the second half of January, but if I had a dime for every time I said that during the past two years, I would be a wealthy man. The MJO this morning is now forecast to go into phase three and likely four(with a warm tour likely), and I wouldn't be surprised to see it loop back through those phases once finished...the OLR maps show very little movement from the phase 3-4 regions. The MJO is now driving the bus, though the -NAO does sit in the passenger seat. I think the greater concern is that NA is going to be completely devoid of cold air for the foreseeable future. Now, it can still snow in a warm pattern, but is much more difficult. This year would be a possibility for exactly that with the -NAO in place and storms tracking south. The wild card which I hate to depend upon for cold weather is the strat warm. Yet again, it has fouled what looked like was a nice pattern on the horizon in modeling. Right now we are either looking at a potential pattern change to an eastern ridge/western trough or a long relaxation of the December pattern which was decent(not exceptional but decent). During the next 2-3 days, if we are still looking at the western ridge holding in the d14-16 range on the EPS, then we know the drill. So, hopefully (and I have low expectations for this)...we see the western ridge pop mid-month and the -NAO holds(there is some evidence in LR modeling that it may be leaving the playing field later in January according to the 6z CFSv2 run) - if so that is cold pattern IF cold air can be supplied to NA. (The once strongly forecast -NAO for the end of this month - it is positive today on the CPC site.). Maybe we can steal a storm in a warm pattern coming up. Last note, when the SSW hit in 2018, modeling flipped from warm to cold in one, single run for March. I am not holding my breath on that one, but that is on the table as an option. For now the SSW looks to impact East Asia and Western Europe. That could change. So January thaw or pattern change? That is the real question for me.

Another great resource from the NWS-MRX in regards to snow totals. I like this product.... https://noaa.maps.arcgis.com/apps/opsdashboard/index.html?fbclid=IwAR0QYePy3pyZYuuIS0jbRay_ZTOsakNgNxnZaAoB2TsaN0mHV2zxZ1c-btU#/4fe985838e464fb9bb980799443e01b6

Again, the 18z GEFS (or some variation) is a possibility for continued winter or a tough that extends from say Calgary to Kentucky. Those two set-ups have some prior precedent with a -NAO be a constant.

Would about have to be...I think.

The 18z CFSv2 Extended has flipped back to cooler for the last three weeks of January...but it has a much different MJO. Good point, @John1122. Yeah, this pattern would have been gold in Jan, @Daniel Boone. Let's hope this is one of these winters where the warm just never shows up in real time. It may well be that the pattern we move to would be that of 95-96(lite) where the cold stretches from MT to TN...models just aren't there yet. GEFS extended does hint at that after a couple of weeks of ridging in the East for weeks 2-3 of Jan.

Yeah, the GEFS extended has flipped warm with a ridge along the eastern seaboard after the first week of Jan. I would imagine there would be intrusions of cold west of the Apps...colder the further west one goes. Maybe a Montana to Tennessee special at times. Overall, warm look(after Jan 7th) w a maybe one trough rolling through after the 7th. Pretty big changes, but it does bounce around some.

See what you can find. Seems like opinions are split(pun intended) on whether this is good for eastern NA. Watching the GEFS extended run right now. Look like a very warm week 2 of Jan with some hope for week 3. Will update in a bit. Watching Liberty and Coastal Carolina. Thanks for your updates!

Areas of "blue" for the SPV don't necessarily imply cold at the surface - sometimes it is the opposite right? I was looking at the GFS with its split at 18z....looks like the cold in NA is under the warmer strat anomalies. . 50mb will tell us a little better where the split goes, but for now...we need to be hoping this doesn't couple with the TPV IMHO. Again, there can be great years with TPVs and modeling could flip cold at the last minute. IMHO(and it is only an opinion) is that this SSW would not be an improvement to the pattern which we are currently in. It might be time to get my seed order prepped ASAP if this SSW goes the way I think it could. I will still hold out hope that it goes the way of some great winters. Be a tough pill to swallow if this SSW ruins this pattern.

What we want to see is what the 18z GEFS did. The eastern ridge fires during week 2 of January, but a trough sneaks in underneath it. That allows a western ridge to fire. Once could imagine that allowing very cold air during the second half of January to slide into that trough. That said, I am not chasing cold into the second half of January this year. If it happens, it happens...but I won't be tracking that(not after last year's persistent fail on that). The worst case scenario is the 12z EPS and 12zCVSv2 extended....-NAO connects to an eastern ridge and never relents. Like Boone, runs counter-intuitive for a summer pattern to develop during winter, but I have seen it happen. However, La Nina climatology favors a trough in the West. Enough Grinch from me this evening. LOL. Needless to say, I don't like the trends after d10, but as we know...that can still change. This will flip quickly if it is going to change. That flip might not be seen for another week or two(speaking of cold if the split occurs).

I think the 18-19 coupled with the TPV - is that the year we got the twin vortices or was that last year? ....Very much looks like the lobes of the TPVs go to western Europe and the other rotates into Alasks(and then retrogrades back into eastern Siberia). I really cannot overstate my disdain for what I am seeing with this SSW. Ugh.

SSW is going to be a real pain in the butt from a model standpoint. The GFS successfully forecast an SSW split in March of 2018 from 16 days out. March was frigid. Think the following winter (18-19), we had a good pattern forecast at some point that winter...the SSW "split" and we lost that look in the LR. We had a great start to winter in 2018 here in TRI, and then the pattern evaporated. All of that said, early season strat splits in late December and early January have led to some great winter patterns in the East which featured very abrupt changes. Right now, we are about to substitute a decent pattern(like early Dec 2018) for one that could be great or could be spring. I have seen modeling flip on a dime to really cold or really warm. They are quite random in where they place the lobes of cold which break off - like going to Vegas. I really don't like the trends of LR modeling during the past 36 hours. They could flip back once the strat warm is "felt," but I lost my enjoyment of SSW stuff in 18-19. LOL. Give me March 2018 in January...but not a fan of LR modeling trends right now. That said, if the SSW is going to be felt, count forward a couple of weeks from the SPV split(assuming the TPV also splits), and that should be when we see changes at our latitude. @Holston_River_Rambler, when is the exact time frame of that split.

Bays Mountain Park in Kingsport. Some of the "peaks" there are 2,280-2,400(max) feet. Pretty cool place. There is actually an elevated valley in the middle of two ridges - pretty rare geological formation(valley in the top of a mountain). Just looks like one ridge as you drive by on I-26. It used to be Kingsport's water supply. We were at about 2,000' in the phot. Great place to ride mountain bikes, run, or hike. Also has a nice nature center and planetarium. Most of the arms of the lake were ice covered today.

Headed up to Bays Mountain today for a run(SLOW!) in the snow. Went through anywhere from 3-7" of snow. Got a lot of good climbing in though.

After a decade and a half of really bad winters, the Mountain West had some great winters in the 2010s...stellar type stuff.

Can't remember. We had one winter where it was pushed back and pushed back...then had an and SSW...and had more snow in March than the rest of winter. I am thinking this(the one where the SSW screwed things up) was 17-18 when we had that really cold last half of December. Then, it went to crap. LOL. That said, some truly great winters have had SSWs during early January.

Saw a post on another forum(maybe MA), where the strat warm stuff may be causing some of this for early January modeling. Seems like 2-3 winters ago, we had a January that looked great on LR modeling, and the strat warm pretty much wrecked havoc on that. Makes me wonder if we are about to see large scale changes(could be really good or the opposite) after mid-January. The SSW could have a hand in that look as well. Ah, I remember now(forgive the stream of thought post!)...the MA referenced a tweet about the eastern US being warmer than normal during the events leading up to a strat warm. LOL- heck, I have even talked about it, but always forget when it happens in modeling. When there is a massive ridge along the east coast of NA(basically a WAR on steroids...talking like Cuba to Greenland), that has preceded the last 2-3 SPV splits. Have to admit, I am not excited about this strat split scenario...but it does open the door for very cold air(due to the NAO) to enter the east after the split. Just going to depend on which side of the globe the coldest air goes.

12z CMC has snow in Kansas. True cutter.

The fly in the ointment with this storm is the high near Bermuda is not getting out of the way. It is creating return flow over the SE.

My only concern with the GFS is how quickly it is moving its snow axis westward. During the last four runs, it has moved from eastern W VA to Lexington, KY, at that latitude. Would be nice to see it settle on a track. Let's see where the CMC goes.

Just digging through modeling this morning. Here is the 6z Euro Control. @Holston_River_Rambler, I don't think the operational goes out to 144 and neither the ensemble nor deterministic have precip types at 6z, right? Either way, this is a good look eastern section of middle TN and mirrors the 6z GFS.

I think anytime we have a strong fold front on modeling (during the next couple of weeks), going to have to be watched.

As for the 6z GFS, going to need other modeling come east as the GFS is on the eastern side of the envelope (and trended westward at 6z) for the NYE storm. Still a long way to go on that one. We were fortunate to track the Christmas Eve deal from almost ten days - that is a rarity. The pattern does support 1-2 storms taking the low road during that time frame. The storm immediately after the NYE storm is kind of what I am watching.

The CFSv2 seasonal(which bounces around and changes quite a bit as it runs once per day) illustrates the concern for January, and also illustrates how a -NAO can create a ridge in the East. I think we will see an undetermined period of the look below - might be just a few days, a week, or weeks. Just tough to tell. We are now entering that time frame that is one where I have low confidence as modeling is juggling several plates(see my posts yesterday). The GEFS OLR maps today do depict convection in the IO(Inidan Ocean) region in the phases 3-4 regions and maybe some weaker convection in the phases 1-2 regions as well. We don't want that showing up long term as one only needs to look to last winter to see the consequences of that. The run below kind of shows what modeling is dealing with. The 0z EPS now has a similar look to what is below. The variability is possibly due to the MJO becoming possibly becoming more of a factor on some modeling and even during various model runs...and less on others. What all of this means is that the Atlantic(-NAO) is going to have to be the driver in the LR if we want more cold and snow after the New Year and little help from the Pacific is on the Horizon....and the Atlantic, if too strong, can actually become a thorn as well. Finally, let's see where the EPS goes(the 6z GEFS implies the ridge). I don't like losing it in the LR. Just one run of the EPS which looks bad, so let's see where it goes. Indeed, the 6z GFS has a similar set-up to the Christmas Eve event. The Euro is basically a cutter for that event. CMC is in between the Euro and GFS. Canadian modeling has been pretty good this winter. The window from NYE to maybe around Jan 4th has some potential for the subform. After that time frame...toss-up.