Winter 2021/22 December Thread

[Carvers Gap]

Blizzard warnings for the higher elevations of Hawaii right now.  Let that sink in for a minute.    Someone wake-up Jim Cantore.  Incredible forecast.  See below...

[Carvers Gap]

Tonight

Snow showers likely. The snow could be heavy at times. Some thunder is also possible. Cloudy, with a low around 24. Wind chill values as low as -2. Strong and damaging winds, with a southwest wind 95 to 100 mph, with gusts as high as 125 mph. Chance of precipitation is 60%. Total nighttime snow accumulation of 2 to 4 inches possible. 

Sunday

Occasional snow showers. The snow could be heavy at times. Some thunder is also possible. High near 40. Wind chill values as low as zero. Strong and damaging winds, with a south southwest wind 65 to 75 mph decreasing to 47 to 57 mph in the afternoon. Winds could gust as high as 90 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible. 

Sunday Night

Occasional snow showers. The snow could be heavy at times. Some thunder is also possible. Low around 31. Strong and damaging winds, with a south southwest wind 40 to 47 mph, with gusts as high as 55 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible. 

Monday

Occasional snow showers. The snow could be heavy at times. Some thunder is also possible. High near 40. Strong and damaging winds, with a south southeast wind 37 to 47 mph decreasing to 24 to 34 mph in the afternoon. Winds could gust as high as 55 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible. 

Monday Night

Snow showers likely before 8pm, then scattered rain showers. The rain and snow could be heavy at times. Cloudy, with a low around 28. Strong and damaging winds, with a south southwest wind 24 to 29 mph increasing to 35 to 40 mph in the evening. Winds could gust as high as 49 mph. Chance of precipitation is 60%. New snow accumulation of around an inch possible. 

Tuesday

Scattered rain showers before 2pm, then scattered rain and snow showers. The rain and snow could be heavy at times. Mostly cloudy, with a high near 41. Very windy, with a south wind 30 to 33 mph, with gusts as high as 40 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible. 

Tuesday Night

Scattered rain and snow showers before 2am, then scattered rain showers. The rain and snow could be heavy at times. Mostly cloudy, with a low around 32. Very windy, with a south southeast wind 26 to 31 mph decreasing to 20 to 25 mph after midnight. Winds could gust as high as 38 mph. Chance of precipitation is 30%.

Wednesday

Scattered showers. Mostly cloudy, with a high near 44. Windy, with an east southeast wind 20 to 30 mph, with gusts as high as 37 mph. Chance of precipitation is 30%.

Wednesday Night

Scattered showers before 8pm. Clear, with a low around 33. Windy, with an east southeast wind 21 to 30 mph, with gusts as high as 37 mph. Chance of precipitation is 30%.

[John1122]

All overnight models have an Eastern Valley snow event. The Euro was the biggest of them all and got the mid Valley involved as well. 

 

[Carvers Gap]

Yeah, that was a good look, John.  

Looks like we have two timeframes to watch....Wednesday and next Sunday.  Wednesday looks marginal, but it is there on modeling.  Maybe a dusting for some areas?  Next Sunday is one to watch.  Long way to go, but this appears to be a low that cuts followed by a potential second low.  Just how far that boundary gets south is going to be key.

In the LR, the CFSv2(notable cold bias) seems to like some cold around the Christmas timeframe, another warm-up, and then much colder.  I would not disagree.  Base warm for the next few weeks as others have noted with cold interludes.  However, I suspect that we see a more prolonged cold pattern(2-3 weeks) at some point this winter.

  

[PowellVolz]

Tonight Snow showers likely. The snow could be heavy at times. Some thunder is also possible. Cloudy, with a low around 24. Wind chill values as low as -2. Strong and damaging winds, with a southwest wind 95 to 100 mph, with gusts as high as 125 mph. Chance of precipitation is 60%. Total nighttime snow accumulation of 2 to 4 inches possible.  Sunday Occasional snow showers. The snow could be heavy at times. Some thunder is also possible. High near 40. Wind chill values as low as zero. Strong and damaging winds, with a south southwest wind 65 to 75 mph decreasing to 47 to 57 mph in the afternoon. Winds could gust as high as 90 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.  Sunday Night Occasional snow showers. The snow could be heavy at times. Some thunder is also possible. Low around 31. Strong and damaging winds, with a south southwest wind 40 to 47 mph, with gusts as high as 55 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.  Monday Occasional snow showers. The snow could be heavy at times. Some thunder is also possible. High near 40. Strong and damaging winds, with a south southeast wind 37 to 47 mph decreasing to 24 to 34 mph in the afternoon. Winds could gust as high as 55 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.  Monday Night Snow showers likely before 8pm, then scattered rain showers. The rain and snow could be heavy at times. Cloudy, with a low around 28. Strong and damaging winds, with a south southwest wind 24 to 29 mph increasing to 35 to 40 mph in the evening. Winds could gust as high as 49 mph. Chance of precipitation is 60%. New snow accumulation of around an inch possible.  Tuesday Scattered rain showers before 2pm, then scattered rain and snow showers. The rain and snow could be heavy at times. Mostly cloudy, with a high near 41. Very windy, with a south wind 30 to 33 mph, with gusts as high as 40 mph. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.  Tuesday Night Scattered rain and snow showers before 2am, then scattered rain showers. The rain and snow could be heavy at times. Mostly cloudy, with a low around 32. Very windy, with a south southeast wind 26 to 31 mph decreasing to 20 to 25 mph after midnight. Winds could gust as high as 38 mph. Chance of precipitation is 30%. Wednesday Scattered showers. Mostly cloudy, with a high near 44. Windy, with an east southeast wind 20 to 30 mph, with gusts as high as 37 mph. Chance of precipitation is 30%. Wednesday Night Scattered showers before 8pm. Clear, with a low around 33. Windy, with an east southeast wind 21 to 30 mph, with gusts as high as 37 mph. Chance of precipitation is 30%.

With winds that strong you wonder how snow would even reach the ground


.

[Mr. Kevin]

2 hours ago, Carvers Gap said:

Yeah, that was a good look, John.  

Looks like we have two timeframes to watch....Wednesday and next Sunday.  Wednesday looks marginal, but it is there on modeling.  Maybe a dusting for some areas?  Next Sunday is one to watch.  Long way to go, but this appears to be a low that cuts followed by a potential second low.  Just how far that boundary gets south is going to be key.

In the LR, the CFSv2(notable cold bias) seems to like some cold around the Christmas timeframe, another warm-up, and then much colder.  I would not disagree.  Base warm for the next few weeks as others have noted with cold interludes.  However, I suspect that we see a more prolonged cold pattern(2-3 weeks) at some point this winter.

  

Carver, I guess we can stay optimistic, but in reality we got a long ways to go before any type of cold regime sets in. I'm rooting for it to happen, because most like winter weather and not warm weather all winter lol. I believe that it will be later in winter if we see anything other than a few cold days. Front loaded just dont see logical at this point imo.  Would like to get a sustained cold pattern however way we can get it. 

[jaxjagman]

Models are all over the place for next weekend.But even if does turn cold there seems to be no mechanics that would logically lock in any cold/Just a roller coaster ride upcoming seemingly..Best thing to get any decent snow right now would be from  some ANA front like system but i hate watching snow over night and melts the next day

[Holston_River_Rambler]

OP Euro wants to make sure we are good and soaked :

[Carvers Gap]

3 hours ago, PowellVolz said:

With winds that strong you wonder how snow would even reach the ground


.

Hurricane force winds and snow.  Somebody's dream scenario somewhere.  LOL - not mine.  I definitely could enjoy a blizzard, but not touching 125mph winds!

[Carvers Gap]

1 hour ago, jaxjagman said:

Models are all over the place for next weekend.But even if does turn cold there seems to be no mechanics that would logically lock in any cold/Just a roller coaster ride upcoming seemingly..Best thing to get any decent snow right now would be from  some ANA front like system but i hate watching snow over night and melts the next day

Yeah, I don't see cold locking in before Christmas for more than a day or two.  Think our best chance for snow next weekend is for the cold to crash into the back of the system while a slp or wave buckles it, thus slowing it down.  Long shot, but not impossible at all.  Tough to know as modeling was nearly blind to the amplification.

[Carvers Gap]

Interesting to see the 12z GEFS begin to allow the eastern ridge complex to decay/retrograde west.  Don't think so?  Switch your model over to surface temp anomalies and let it loop.  Moves east, and then slips back into the West again.  The deep trough which was forecast to go into the West is nothing more than a blip.  Hate that for the ski slopes there as they are suffering now.  

[Mr. Kevin]

1 hour ago, Carvers Gap said:

Interesting to see the 12z GEFS begin to allow the eastern ridge complex to decay/retrograde west.  Don't think so?  Switch your model over to surface temp anomalies and let it loop.  Moves east, and then slips back into the West again.  The deep trough which was forecast to go into the West is nothing more than a blip.  Hate that for the ski slopes there as they are suffering now.  

It's more that it's a dont believe so situation lol. We stay warm If and when we get a -nao/ao things may get colder imo. -Epo/wpo would help also.

[Mr. Kevin]

1 hour ago, Carvers Gap said:

Interesting to see the 12z GEFS begin to allow the eastern ridge complex to decay/retrograde west.  Don't think so?  Switch your model over to surface temp anomalies and let it loop.  Moves east, and then slips back into the West again.  The deep trough which was forecast to go into the West is nothing more than a blip.  Hate that for the ski slopes there as they are suffering now.  

With a -pna its inevitable it warms here for a while. Unless u get strong - nao/ao couplet. Definitely needs some help from mother nature 

[Carvers Gap]

I can say this much, I am not losing a second of sleep about modeled warm weather patterns on December 5th.  LONG way to go.  Could it be a non-winter?  Sure.  But could it be a winter with a memorable cold snap?  Sure.  Saw where JB is worried about the late 90s non-winters as a possibility.  Thing is, that is always a possibility but is about as unlikely as a severely cold winter.  But one look at the CFSv2, and the long term continuation of a warm pattern is no slam dunk - reference MA forum discussion.  We have just come off a November at TRI which was -3F.  So, we already have had a front end cold snap of sorts - the weather doesn't adhere to manmade calendars.  We aren't going to stay below normal forever.  We are right on time for a switch in patterns.  The positive is that we know there is a decent correlation between cold Novembers and winters which are BN.  While there are a few clusters of analogs that produce warm, nearly snowless winters....most second year La Nina winters have some winter.  Many of those winters have extreme cold.  While last year was not a second year Nina, it did produce a memorable period of winter for those in western TN and Texas.  That is the calling card of La Nina.  

[Carvers Gap]

Interesting.  Found this on the MA forum.

 

[Mr. Kevin]

1 minute ago, Carvers Gap said:

Interesting.  Found this on the MA forum.

 

I also feel Carver that if the mjo can make it past the standing wave, we should be in better shape moving forward. Bamwx mentioned that a few days ago.

[nrgjeff]

Models have tried and failed to move the MJO east for weeks. Matt Hugo is missing badly.

I'm in a contest on who's more bearish, Kevin or me. I'll use the ECMWF monthlies as an excuse to go even more bearish, AN temps all remaining months of winter. I am mostly joking, but the clusters are pretty consistent.

Oh wait, I'm not kidding. Updating my long-range for work. Yeah I'm warm every week the rest of the calendar year and every month of core winter. 

Regarding the SCANA index, it's been a miserable failure for North America recent winters. 

[Carvers Gap]

1 minute ago, Mr. Kevin said:

I also feel Carver that if the mjo can make it past the standing wave, we should be in better shape moving forward. Bamwx mentioned that a few days ago.

I think Jeff summed-up Bam's track record of late.  IMO, more of an SST problem where the cooler temps in areas where 8-2-1 reside won't allow impulses to propagate into favorable phases.  That said, we are not really into longer wavelengths associated with winter yet - meaning wavelengths are still changing.  Until those really set-up, not sure where those "standing waves" set-up over the US as well.  SER is definitely favored at times but not guaranteed.   Right now we are seeing three pools of BN heights and three pools of AN heights in the northern hemisphere.  That is extremely stable.  However, I suspect we move to four of each by mid-winter.  See if you can dig up some articles about teleconnections of Scandinavian ridging and/or Ural ridging in relation to patterns over NA during winter.  Might also see if that Scandinavian ridge is a prelude to high latitude blocking setting up(potentially due to an SSW).    Also, some really good information is what John posted earlier about La Nina winters for this area.  I trust his information above all other sources.

[Mr. Kevin]

3 minutes ago, Carvers Gap said:

I think Jeff summed-up Bam's track record of late.  IMO, more of an SST problem where the cooler temps in areas where 8-2-1 reside won't allow impulses to propagate into favorable phases.  That said, we are not really into longer wavelengths associated with winter yet - meaning wavelengths are still changing.  Until those really set-up, not sure where those "standing waves" set-up over the US as well.  SER is definitely favored at times but not guaranteed.   Right now we are seeing three pools of BN heights and three pools of AN heights in the northern hemisphere.  That is extremely stable.  However, I suspect we move to four of each by mid-winter.  See if you can dig up some articles about teleconnections of Scandinavian ridging and/or Ural ridging in relation to patterns over NA during winter.  Might also see if that Scandinavian ridge is a prelude to high latitude blocking setting up(potentially due to an SSW).    Also, some really good information is what John posted earlier about La Nina winters for this area.  I trust his information above all other sources.

If what you're saying is true, guess we hope they don't setup in warm phases for winter. The shorter wavelengths aren't giving us any cold weather with front loaded

[Mr. Kevin]

1 minute ago, Mr. Kevin said:

If what you're saying is true, guess we hope they don't setup in warm phases for winter. The shorter wavelengths aren't giving us any cold weather with front loaded

So what is needed to happen to have some cold this winter and how realistic is it to happening? We don't want to be chasing unicorns all winter lol. 

[Carvers Gap]

1 minute ago, Mr. Kevin said:

If what you're saying is true, guess we hope they don't setup in warm phases for winter. The shorter wavelengths aren't giving us any cold weather with front loaded

Actually that is not true IMHO.  -3F for November.  While that is not a winter month, fits Nina climatology to the T.  Warm start to fall followed by a quick flip to cold late in fall.  Textbook front loaded cold...problem for us is the front load came during a time when we really don't get a ton of snow historically.  

[Mr. Kevin]

Just now, Carvers Gap said:

Actually that is not true IMHO.  -3F for November.  While that is not a winter month, fits Nina climatology to the T.  Warm start to fall followed by a quick flip to cold late in fall.  Textbook front loaded cold...problem for us is the front load came during a time when we really don't get a ton of snow historically.  

I just don't consider November front loaded because it is  not winter lol. 

[Carvers Gap]

Euro monthlies are warm, but when aren't they for winter?  Maybe a few examples, but wicked warm bias in general.

As for Hugo, just thought his information was interesting.  I generally buy into the idea that it is going to be difficult for the MJO to work into 8, but who knows.  I generally try to look at both sides of the coin.

The CFSv2, which I scorn regularly, is not base warm from Christmas week onward.

Again, it is December 5th.  Not unusual for winters to start warm and return to cold, especially after cold Novembers.  It is not out of the realm of possibility that the winter will remain AN either.  There are precedents for both.  I am certainly not going to hang my hat on a wx model which has a know warm bias or a known cold bias.  We will know soon enough.  Winter forecasting can be humbling for us all...and if it hasn't been yet, it will be.

[Carvers Gap]

7 minutes ago, Mr. Kevin said:

I just don't consider November front loaded because it is  not winter lol. 

That was never in question.

[Mr. Kevin]

1 minute ago, Carvers Gap said:

That was never in question.

If the mjo cant make it into 8 1 2 based on sst anomalies, we will need tremendous blocking or SSW event most likely 

[Carvers Gap]

13 minutes ago, Mr. Kevin said:

If the mjo cant make it into 8 1 2 based on sst anomalies, we will need tremendous blocking or SSW event most likely 

I tend to agree with Jeff on the MJO, though I am less bearish for winter.  Jeff pretty much holds court over the IO and western Pacific knowledge.  When in doubt, follow his lead on that one.  I think we are going to need help in the Atlantic as you note earlier.  The CFSv2 is the way out of long term warmth.  No idea if it is right.  I don't share a foxhole with that model at any point!  LOL.  OR....in the really unusual circumstance it gets cold during warm phases.  For me, just too early to tell.  I definitely agree with base-warm for winter.  I just think we see some extreme cold embedded.  My question is do we get 1 or 2(with the second being after mid-winter) cold intrusions.  I do think the ongoing BN precip is likely a more limiting factor for snow.  Makes precip so much harder to connect with colder patterns if there is little precip in the pattern.  The QBO cycle should produce cold.  It is uncanny how well descending QBOs correlate to cold in E TN.  So for now, we are looking for windows for potential snow prior to the potential warm-up.  I like the idea of an eastern ridge from Dec 15-22 at least.  We will see if that continues from that point on.  I would lean that the warmth continues, but again, no slam dunk.  I do think there is a chance for some cold around Christmas or slightly thereafter.  Going to leave you guys to it for a bit.  May check back later this evening.

TN vs Purdue in the Music City Bowl in Nashville....will be fun to track the wx for that one.   

[Mr. Kevin]

2 minutes ago, Carvers Gap said:

I tend to agree with Jeff on the MJO, though I am less bearish for winter.  Jeff pretty much holds court over the IO and western Pacific.  I think we are going to need help in the Atlantic as you note earlier.  The CFSv2 is the way out of long term warmth.  No idea if it is right.  I don't share a foxhole with that model at any point!  LOL.  OR....in the really unusual circumstance it gets cold during warm phases.  For me, just too early to tell.  I definitely agree with base-warm for winter.  I just think we see some extreme cold embedded.  My question is do we get 1 or 2(with the second being after mid-winter) cold intrusions.  I do think the ongoing BN precip is likely a more limiting factor for snow.  Makes precip so much harder to connect with colder patterns if there is little precip in the pattern.  The QBO cycle should produce cold.  It is uncanny how well descending QBOs correlate to cold in E TN.  So for now, we are looking for windows for potential snow prior to the potential warm-up.  I like the idea of an eastern ridge from Dec 15-22 at least.  We will see if that continues from that point on.  I would lean that the warmth continues, but again, no slam dunk.  I do think there is a chance for some cold around Christmas or slightly thereafter.  Going to leave you guys to it for a bit.  May check back later this evening.

TN vs Purdue in the Music City Bowl in Nashville....will be fun to track the wx for that one.   

It would be nice to see two cold blasts this winter. To have a few opportunities at ice/snow. Fun to track when we get them

[Carvers Gap]

Take a minute and look at the analog package graphic of the past 30 years of La Nina's. PSU notes there are two different clusters.  There is a bit of a misconception the the trough is in the West.  Now, also note the ridge just east of Scandinavia and the ridge in the central Pac.  Those features are showing up in some variation in LR modeling.  

 

[Mr. Kevin]

7 minutes ago, Carvers Gap said:

Take a minute and look at the analog package graphic of the past 30 years of La Nina's. PSU notes there are two different clusters.  There is a bit of a misconception the the trough is in the West.  Now, also note the ridge just east of Scandinavia and the ridge in the central Pac.  Those features are showing up in some variation in LR modeling.  

 

Right now, we have the Epo and ao not in our favor for cold air. The SSW event we had last winter took 6-8 weeks to propagate correctly to the troposphere, but all SSW events aren't the same. We definitely need a fundamentally sound shift in the Pacific to really change the pattern among other things. 

[Carvers Gap]

21 minutes ago, Mr. Kevin said:

Right now, we have the Epo and ao not in our favor for cold air. The SSW event we had last winter took 6-8 weeks to propagate correctly to the troposphere, but all SSW events aren't the same. We definitely need a fundamentally sound shift in the Pacific to really change the pattern among other things. 

I don't think the way to colder weather will be via an SSW though a perturbation of the TPV is probably likely at some point this winter season.  Just pointing out that some similar features to those analogs are showing up on current modeling.  Pretty cool I think.  We will see in time where that leads.  I asked in the MA thread if PSU knows how those Decembers looked.  I just don't have time to enter those into reanalyses program.  If you have time, go for it.  Would be interesting to see what a composite of those previous Decembers looked like...