Winter 2021/22 December Thread

[Carvers Gap]

Add the 12z Canadian to the mix as it is now picking up significant AN heights over Greenland.  So that is the GDPS and the GFS which are now picking up blocking which forms around d8.  Again, a lot of this is speculation until we can get it inside of d7 where skill will increase with each day at that point.  The NAO is NOT a given and is notorious for head fakes, but to have it on two models with cold air already in place over NA...this raises the chances for an eastern trough amplification after the 19th.  I am not saying this is a pattern change as I am not sure what pattern we are changing at this point.  We have noted many times that mega ridge in the East during winter are often precursors to strat warming and cold air getting into the Lower 48.

[Mr. Kevin]

2 hours ago, Carvers Gap said:

Two words...NE TN.  Location matters.  A lot of folks outside of TRI won't think about 14-15, even on the Plateau.  I probably had almost 30" of snow here in January and February alone - and that is in Kingsport which is less snowy than the other TRI.   We score a bit differently than the rest of the forum area.  SE KY and SW VA folks can relate to the differences of the micro climates.  Kingsport does not do well with NW flow events(Bristol and JC do well), but does very well with events along the Atlantic provide we can get under a deformation band west of the Apps.  Usually when it is colder in western areas of the forum, it is often warmer here.  Last winter was an extreme example.  Memphis got hammered for days.  We saw very little.  

We have both been on good ends and bad ends of the spectrum. Such strong neg -epo that winter 13-14 regardless. Ao and nao were both super positive but didn't matter because Pacific was so favorable. Or it possibly would have been 10x colder.

[Mr. Kevin]

1 hour ago, Carvers Gap said:

Add the 12z Canadian to the mix as it is now picking up significant AN heights over Greenland.  So that is the GDPS and the GFS which are now picking up blocking which forms around d8.  Again, a lot of this is speculation until we can get it inside of d7 where skill will increase with each day at that point.  The NAO is NOT a given and is notorious for head fakes, but to have it on two models with cold air already in place over NA...this raises the chances for an eastern trough amplification after the 19th.  I am not saying this is a pattern change as I am not sure what pattern we are changing at this point.  We have noted many times that mega ridge in the East during winter are often precursors to strat warming and cold air getting into the Lower 48.

Get the ecmwf on board, then I am more of a believer. Pattern recognition especially with ensembles 

[Carvers Gap]

1 hour ago, Mr. Kevin said:

Get the ecmwf on board, then I am more of a believer. Pattern recognition especially with ensembles 

Modeling has been awful this fall at catching trough amplifications.  Ensembles will likely miss the troughs embedded in this pattern at range.  I don’t use them as a primary source in order amplification as they smooth it out at range.  Ensembles will be last on board.  What I am looking for is not a flip to long term cold which I think is unlikely thought not implausible.  So, same plan as last year.  Trying to find cold shots within the pattern.  As PSU noted in a great post yesterday in the MA forum, we live in an area where snow is the anomaly.  It is easy just to say it is doing to be warm and not snow.  The “not snowing part” is true for 95% of the days of winter or more.  So, it is house money to go warm-up and rain.  That is the norm.  Tough part is being able to spot a trough amplification before ensembles do.  So, I don’t see myself as a hobby forecaster, but someone who is hunting winter wx.  

[Daniel Boone]

3 hours ago, Carvers Gap said:

Two words...NE TN.  Location matters.  A lot of folks outside of TRI won't think about 14-15, even on the Plateau.  I probably had almost 30" of snow here in January and February alone - and that is in Kingsport which is less snowy than the other TRI.   We score a bit differently than the rest of the forum area.  SE KY and SW VA folks can relate to the differences of the micro climates.  Kingsport does not do well with NW flow events(Bristol and JC do well), but does very well with events along the Atlantic provide we can get under a deformation band west of the Apps.  Usually when it is colder in western areas of the forum, it is often warmer here.  Last winter was an extreme example.  Memphis got hammered for days.  We saw very little.  

Good points Carvers !  Yes, 2014-15 had a very sharp demarcation line in who got alot of snow and who got mix or cold rain. Wound up with 34" Jan-Feb. Total at my local. 33" Feb. alone. Northern Lee County 50" ! That wasn't highest elevations either. 

[Mr. Kevin]

9 minutes ago, Carvers Gap said:

Modeling has been awful this fall at catching trough amplifications.  Ensembles will likely miss the troughs embedded in this pattern at range.  I don’t use them as a primary source in order amplification as they smooth it out at range.  Ensembles will be last on board.  What I am looking for is not a flip to long term cold which I think is unlikely thought not implausible.  So, same plan as last year.  Trying to find cold shots within the pattern.  As PSU noted in a great post yesterday in the MA forum, we live in an area where snow is the anomaly.  It is easy just to say it is doing to be warm and not snow.  The “not snowing part” is true for 95% of the days of winter or more.  So, it is house money to go warm-up and rain.  That is the norm.  Tough part is being able to spot a trough amplification before ensembles do.  So, I don’t see myself as a hobby forecaster, but someone who is hunting winter wx.  

Orangeblood at storm2k made a good post today about the pattern. Supposedly the coldest air on the planet will be to our nw. Getting a mechanism to bring it south. Epo/wpo may do it if they are negative enough. 

[Carvers Gap]

10 minutes ago, Mr. Kevin said:

Orangeblood at storm2k made a good post today about the pattern. Supposedly the coldest air on the planet will be to our nw. Getting a mechanism to bring it south. Epo/wpo may do it if they are negative enough. 

Yep, that is what we have been saying on this forum for several days.  Debatable about the coldest air being over here.  Yesterday, that was the general trend.  Today, though very cold in NA, the coldest remained in Siberia for most of the models I could find.  Nothing set in stone at all.  I look for one of two mechanisms to drive it both, -EPO or -NAO or a cutter which wraps cold air in behind it.   I am probably missing something.  Teleconnections looked good this AM after d12 or so.  I think we are likely looking at an amplification which doesn't hold.  However, if we can get 4-7 days of good, cold Arctic air...we have a shot. 

[Carvers Gap]

15 minutes ago, Daniel Boone said:

Good points Carvers !  Yes, 2014-15 had a very sharp demarcation line in who got alot of snow and who got mix or cold rain. Wound up with 34" Jan-Feb. Total at my local. 33" Feb. alone. Northern Lee County 50" ! That wasn't highest elevations either. 

That is insane!!!!

[John1122]

I seem to recall that 14-15 had big event winter for nearly everyone and several for some of us. It's the year of collapsed boat docks here due to heavy snow and ice that came in several waves.  Knox had a 6 inch snow and a monster ice storm. Chattanooga had a 6+ storm. West Tennessee had blizzard conditions and widespread 12 inch snows. Nashville may have missed out, but I know they got 3 inches in the 1st week of March event. 

[PowellVolz]

Orangeblood at storm2k made a good post today about the pattern. Supposedly the coldest air on the planet will be to our nw. Getting a mechanism to bring it south. Epo/wpo may do it if they are negative enough. 

Storm2K?


.

[John1122]

Saw a post from GAWx/Larry, who is an encyclopedia of weather history. He noted for Atlanta (and likely here by extension here, though we aren't always cold in the same way) that the MJO in low amplitude/near or just inside the cod phase 8 was the absolute coldest for the area in January. It was -6, -4 in low Ph 7, -3 in low 1,2, and 3. Surprisingly, phase 6 cod/low was -2.  Oddly, phase 7 high amplitude was -1 in Jan, normal in phase 8 high, and above average in all other phases in high amplitude. 4/5 were above normal low or high but way above normal high 5.

[Holston_River_Rambler]

27 minutes ago, PowellVolz said:

Storm2K?


.

Yeah I saw that and was like "Ooooh some new forum I can haunt!!" lol 

[Holston_River_Rambler]

Some of y'all may have already seen this, but Webb posted the BOMM MJO RMM forecast today (It seems like its link has been dead at the CPC MJO site since mid 2020):

 

I think like Jeff mentioned these tropical critters are going to slow its progression down even more and this BOMM forecast seems to show that well. Not happy to see it forecast to collapse into the COD as it moves into 8, but I think most of us would be happy to see it make it there. 

Watch this little critter to the east of New Guinea:

In the past few years we've seen the MJO try to progress past 6/7ish and it gets sapped by a tropical critter in this area. I think it is the SPCZ (South Pacific Convergence Zone). 

 

Masiello noted this as well a few days ago, in dialogue with Webb. On his gif you can see a mirror cyclone developing N of the equator as the Equatorial Rossby waves associated with the MJO pulse head east:

 

Found this while trying to puzzle out the connections between Rossby Waves/ Kelvin Waves/ and the MJO:

http://kejian1.cmatc.cn/vod/comet/tropical/MJO_EqWaves/navmenu.php_tab_1_page_2.2.2_type_text.htm

I thought It might be of interest to some. 

 

Happy Hour GFS has a nice suppressed storm track:

In no way trying to connect this gif to the tropical stuff above, but thought it was a pretty pattern for fantasy land. Looks to me like HL Blocking funneling energy and cold from the pole. 

[Mr. Kevin]

1 hour ago, Holston_River_Rambler said:

Some of y'all may have already seen this, but Webb posted the BOMM MJO RMM forecast today (It seems like its link has been dead at the CPC MJO site since mid 2020):

 

I think like Jeff mentioned these tropical critters are going to slow its progression down even more and this BOMM forecast seems to show that well. Not happy to see it forecast to collapse into the COD as it moves into 8, but I think most of us would be happy to see it make it there. 

Watch this little critter to the east of New Guinea:

In the past few years we've seen the MJO try to progress past 6/7ish and it gets sapped by a tropical critter in this area. I think it is the SPCZ (South Pacific Convergence Zone). 

 

Masiello noted this as well a few days ago, in dialogue with Webb. On his gif you can see a mirror cyclone developing N of the equator as the Equatorial Rossby waves associated with the MJO pulse head east:

 

Found this while trying to puzzle out the connections between Rossby Waves/ Kelvin Waves/ and the MJO:

http://kejian1.cmatc.cn/vod/comet/tropical/MJO_EqWaves/navmenu.php_tab_1_page_2.2.2_type_text.htm

I thought It might be of interest to some. 

 

Happy Hour GFS has a nice suppressed storm track:

In no way trying to connect this gif to the tropical stuff above, but thought it was a pretty pattern for fantasy land. Looks to me like HL Blocking funneling energy and cold from the pole. 

I guess we all know this, but 4-6 phases aren't cold here. That chart that webberweather posted, is from two days ago. Hopefully it will be updating soon. I hope we get some cold pattern sooner or later. 

[Daniel Boone]

2 hours ago, John1122 said:

I seem to recall that 14-15 had big event winter for nearly everyone and several for some of us. It's the year of collapsed boat docks here due to heavy snow and ice that came in several waves.  Knox had a 6 inch snow and a monster ice storm. Chattanooga had a 6+ storm. West Tennessee had blizzard conditions and widespread 12 inch snows. Nashville may have missed out, but I know they got 3 inches in the 1st week of March event. 

NE TN. wasn't that fortunate as records indicate there John. Carvers and myself can attest to that. Look at KTRI for instance compared to Carvers Totals. Mine compared to Rogersville just to my South. Quite a sharp difference.

[Mr. Kevin]

I'm curious which mjo rmm chart has the most accuracy? Does anyone know? I saw the bamm that webber posted. 

[Carvers Gap]

So the Euro Weeklies are wonky again.  Literally, the mean ensemble repeats the exact same look through the end of January with almost the exact same details repeating week after week.  That has always been a red flag to me, because that isn't real life.  It doesn't go below normal at any point.  Here is the wonky part.  The control goes below normal during the last week of December and stays BN for the entire run!  The entire run....

On a sad note, the last two runs of the CFSv2 have left the cold camp.  It will probably be back.  That is why I don't share a foxhole with that model.  It is a waffler.  LOL.  But I like it on cold runs. 

The GFS operational and Euro control are the keep in the castle of cold.  Those are our holdouts.  Stay strong, 0s and 1s.   

[Carvers Gap]

3 minutes ago, Mr. Kevin said:

I'm curious which mjo rmm chart has the most accuracy? Does anyone know? I saw the bamm that webber posted. 

I generally like the Australian.  Nah, LOL.  It is the coldest which is why I say that.  I talk about the MJO, but I truly hate to look at it on modeling - meaning going to the MJO region and looking at charts for convection.  

@nrgjeff, which model is it the handles the western Pac and IO better?  I would guess Euro but not sure that is a slam dunk answer.

[Carvers Gap]

24 minutes ago, Daniel Boone said:

NE TN. wasn't that fortunate as records indicate there John. Carvers and myself can attest to that. Look at KTRI for instance compared to Carvers Totals. Mine compared to Rogersville just to my South. Quite a sharp difference.

We bough a 4WD after that winter as a family vehicle and haven't had to use it since!!!!   LOL.  Our van was useless for two months in 14-15.  

[Daniel Boone]

28 minutes ago, Carvers Gap said:

We bough a 4WD after that winter as a family vehicle and haven't had to use it since!!!!   LOL.  Our van was useless for two months in 14-15.  

Yeah, was a fun February for sure. Forgot to mention recorded -20 in Pennington gap on the 20th. -16 at my home in Jonesville with a high of 12.

    That was a Winter where Kingsport outdid Bristol and Johnson city by quite a margin irt snowfall. I know you rubbed that in Carvers, lol

[John1122]

2 hours ago, Holston_River_Rambler said:

I think like Jeff mentioned these tropical critters are going to slow its progression down even more and this BOMM forecast seems to show that well. Not happy to see it forecast to collapse into the COD as it moves into 8, but I think most of us would be happy to see it make it there. 

 

From what Larry noted, we apparently do want it to hit the COD in 8. He said it was even more wintry if it hit the COD there and went counterclockwise into 7. 

[Carvers Gap]

16 minutes ago, Daniel Boone said:

Yeah, was a fun February for sure. Forgot to mention recorded -20 in Pennington gap on the 20th. -16 at my home in Jonesville with a high of 12.

    That was a Winter where Kingsport outdid Bristol and Johnson city by quite a margin irt snowfall. I know you rubbed that in Carvers, lol

LOL.  Man, I am afraid to go look at those threads - I was living large that year!  

 As you know, Kingsport normally gets hosed when it comes to snowfall in the TRI.  @Holston_River_Rambler, the EB?  LOL.  Seriously, our elevation is lower due to being right on the river.  My house sits about 100-150' higher than the river plain, and I prob get 25% more snowfall than downtown.  Then again, I am upwind of the heat dome. 

[Holston_River_Rambler]

Lawsy Mercy. I woke up and saw I had 3 (count that 3!!) notifications. Made me a little nervous, lol ! 

Mr Kevin, you will be happy to note that the BOMM chart has updated and now reflects one day later, Dec 8:

 

A loop'd loop in 8 forecast!?! What's the world coming to? 

I mean that looks like a pretty solid bet of at least some time in 8. Of course assuming that BOMM's RMM forecast has the right idea. 

The Euro has it, but is a wee bit slower: 

Even ye olden GFS looks pretty solid:

Even the worst case scenarios on the GFS take it to the "off the charts" territory in 6 and the last time we went there, it facilitated a SSW, originating over N. Asia:

 Jan - March 2018:

 

Hmmmm 2018... That seems to have had a similar ENSO look:

(Blue = La Nina; Red = El Nino) source: https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php

I may be misremembering, but wasn't 2018 the year we had the SSW in late Feb. and then that put the squoosh on Spring until late May? Actually I went back and looked and I think that SWW was in late Feb (22nd?) 2017. We did however have a SSW in early 2018 a pretty good chance around March 12 of that year.

Here are some relevant images and comments from that March:

 

 

Some how one of the gifs of the HRRR's take on the system survived the 3.5 years:

 

Yeah it doesn't look great, but the ground truth was a little south.

I think there are some hypotheses we can throw out based on the above, but simply suggesting these "if this, then thats" do be all I haz energy for this AM. 

 

 

 

Also, High Latitude Blocking of some sort looks like a pretty safe bet to me too, between Christmas and New Year, its just a question of where it develops and how it evolves. Does it develop and evolve in favorable areas for the TN Valley, or no? 

 

 

[Carvers Gap]

40 minutes ago, Holston_River_Rambler said:

Lawsy Mercy. I woke up and saw I had 3 (count that 3!!) notifications. Made me a little nervous, lol ! 

Mr Kevin, you will be happy to note that the BOMM chart has updated and now reflects one day later, Dec 8:

 

A loop'd loop in 8 forecast!?! What's the world coming to? 

I mean that looks like a pretty solid bet of at least some time in 8. Of course assuming that BOMM's RMM forecast has the right idea. 

The Euro has it, but is a wee bit slower: 

Even ye olden GFS looks pretty solid:

Even the worst case scenarios on the GFS take it to the "off the charts" territory in 6 and the last time we went there, it facilitated a SSW, originating over N. Asia:

 Jan - March 2018:

 

Hmmmm 2018... That seems to have had a similar ENSO look:

(Blue = La Nina; Red = El Nino) source: https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php

I may be misremembering, but wasn't 2018 the year we had the SSW in late Feb. and then that put the squoosh on Spring until late May? Actually I went back and looked and I think that SWW was in late Feb (22nd?) 2017. We did however have a SSW in early 2018 a pretty good chance around March 12 of that year.

Here are some relevant images and comments from that March:

 

 

Some how one of the gifs of the HRRR's take on the system survived the 3.5 years:

 

Yeah it doesn't look great, but the ground truth was a little south.

I think there are some hypotheses we can throw out based on the above, but simply suggesting these "if this, then thats" do be all I haz energy for this AM. 

 

 

 

Also, High Latitude Blocking of some sort looks like a pretty safe bet to me too, between Christmas and New Year, its just a question of where it develops and how it evolves. Does it develop and evolve in favorable areas for the TN Valley, or no? 

 

 

There is a wicked cold snap earlier in the 17-18 winter which is hidden because it straddled two months.  End of December and beginning of January saw the N Fork freeze pretty much solid here.   We had nearly a week where we didn't get above freezing.  Don't think it snowed at all as the PNA/EPO was almost to the Arctic(or more).  Was very frustrating to have that much cold and very little snow.  Classic La Nina cold outbreak.  Spring 2018 was crazy.  I need to go look at that thread again.  I may have been in JC picking up a water heater during April with snow showers coming down.  

[Carvers Gap]

@Holston_River_Rambler, I may do a post in the historical winter thread on 17-18.  You are more than welcome to chime in.  The swings that winter were WILD!!!!  We had a stretch of about seven days that were roughly -20F below normal....and then then hit 82 in February...got an SSW....and then there was light, but measurable snow at TRI twice during April.  That is classic La Nina.   Easily one of the most frustrating winters in terms of snow, but watching the GFS nail the strat warm from 16 days out was something to behold. 

[Carvers Gap]

Of note the 0z and 6z GEFS  have cracked - meaning they are no longer repeating the same pattern endlessly.   Of note, a -NAO is now showing up on the model.  If true, it means the operational has led the way.  The 0z GEPS is not too dissimilar.  Good news on the ensemble front.  I can't see the d10-15 EPS on WxBell.

[Holston_River_Rambler]

13 minutes ago, Carvers Gap said:

I can't see the d10-15 EPS on WxBell.

Here ye go feller:

[Carvers Gap]

1 hour ago, Holston_River_Rambler said:

Here ye go feller:

Thanks, Holston.  Progression is slower but smilier.  Like seeing the AN heights in the southwest.  If it continues to connect with the ridge in AK, that forms an EPO.  Big change today was the GEFS with big changes after d10.  Honestly, those are fairly substantial changes on the EPS...just not in ur favor.  Need that ridge out of the Aleutians.  However, some great cold snaps during La Nina winters tend to work around that big high there.  And of course, sometimes it just goes warm!  LOL.  Thanks again.

[Carvers Gap]

1 hour ago, Holston_River_Rambler said:

Here ye go feller:

Holston, do you have the control for d10-15l?  

[Holston_River_Rambler]

1 hour ago, Carvers Gap said:

Holston, do you have the control for d10-15l?  

Yeah, but it ain't the prettiest control run, lol. I don't have the H5 anomalies for the control, but the 300mb winds give a good idea of the pattern.