December/January 2019/20 Winter Speculation Thread

[John1122]

Just now, Mr. Kevin said:

John, i am just trying to think how we can salvage some winter before time runs out instead of us wishcasting lol. 

 

I understand that! At this point I think our best hope is a rogue ULL. Those can strike Valley wide anytime between now and April 1st.  The odds of lasting winter weather  are not very high. 

[Carvers Gap]

7 minutes ago, Mr. Kevin said:

Im not sure if yall are aware of this, but the CPC made February below normal, which i find incredibly shocking. Not sure what they are seeing. I would like to see some changes to somehow salvage some winter so we can perhaps have a better chance at a winter storm.

 What is crazy...both times for January and February the models flipped on literally the next run or right as it was published.  Within hours of the forecast, modeling switched.

I doubt the CPC was wishcasting.  LOL.  They had the same thoughts as most everyone who was seeing the modeling.  I don't think you have folks on this sub-forum wishcasting.  I certainly hope that was not implied by your last comment.

 

[Mr. Kevin]

10 minutes ago, Carvers Gap said:

 What is crazy...both times for January and February the models flipped on literally the next run or right as it was published.  Within hours of the forecast, modeling switched.

I doubt the CPC was wishcasting.  LOL.  They had the same thoughts as most everyone who was seeing the modeling.  I don't think you have folks on this sub-forum wishcasting.  I certainly hope that was not implied by your last comment.

 

Not what I was saying. I haven't seen the CPC go below normal in a long time, which is shocking to me. All i am trying to figure out what we need to see to salvage some winter in the pattern to perhaps shift things.

[Carvers Gap]

6 minutes ago, Mr. Kevin said:

Not what I was saying. I haven't seen the CPC go below normal in a long time, which is shocking to me. All i am trying to figure out what we need to see to salvage some winter in the pattern to perhaps shift things.

Need the MJO and Pacific to cooperate.

[weathertree4u]

Looks like we are headed back to the same pattern after a brief pause first of the week; cold, warm up, rain, then cold again. As long as the same players on the field - SER, craziness to expect the plays to be different. 

[Carvers Gap]

It is not the same pattern, but it is still a lousy pattern which gets similar result here. The ridge in the north central Pacific will be gone, but to quote the MA forum, there is more than one pattern that can be bad for winter.  Looks like the EPS is going to stick a trough in the Southwest and then leave unsettled weather under a ridge downstream where we live.   The storm just under 200 on the Euro actually takes a good track with little cold available...we probably need to get used to that.  Honestly, it is almost zonal in some ways when one looks at the 500 map and not the 500 anomaly map.  That Southwest trough could be an error, but I doubt it this time.  Synoptically, it looks right.   Storm track looks to be suppressed by the Hudson Bay AN height anomaly which is also a new feature.  It is a pattern that would unlikely produce snow, but is not without its chances as Jeff and John have noted.  Overall, going to keep one eye over my shoulder at the storm inside of 200 and then HOPE that some transient cold shots can hook-up with the STJ.   Of note, we don't want the BN heights over AK to set-up shop.  If this turns out to be a non-winter(growing more likely by the day), I think two main attributes will have contributed, an active MJO/IO and a strong polar vortex.  Pretty unusual pair, but there they are.  With just over four workable weeks of winter left IMBY, going to have to hope early February has some cold.  

[weathertree4u]

2 minutes ago, Carvers Gap said:

It is not the same pattern, but it is still a lousy pattern which gets similar result here. The ridge in the north central Pacific will be gone, but to quote the MA forum, there is more than one pattern that can be bad for winter.  Looks like the EPS is going to stick a trough in the Southwest and then leave unsettled weather under a ridge downstream where we live.   The storm just under 200 on the Euro actually takes a good track with little cold available...we probably need to get used to that.  Honestly, it is almost zonal in some ways when one looks at the 500 map and not the 500 anomaly map.  That Southwest trough could be an error, but I doubt it this time.  Synoptically, it looks right.   Storm track looks to be suppressed by the Hudson Bay AN height anomaly which is also a new feature.  It is a pattern that would unlikely produce snow, but is not without its chances as Jeff and John have noted.  Overall, going to keep one eye over my shoulder at the storm inside of 200 and then HOPE that some transient cold shots can hook-up with the STJ.   Of note, we don't want the BN heights over AK to set-up shop.  If this turns out to be a non-winter(growing more likely by the day), I think two main attributes will have contributed, an active MJO/IO and a strong polar vortex.  Pretty unusual pair, but there they are.  With just over four workable weeks of winter left IMBY, going to have to hope early February has some cold.  

Well, in my opinion, it is close enough to the same pattern to categorize it as the same, but splitting hairs at this point; I too am still hopeful that can pull something off but modeling does not provide much to be hopeful for honesty and like you stated yesterday, once we reach the third week of February, essentially, we are done with any appreciable winter weather. Just anxious to see ultra long range to see if there is any guidance that might suggest next year could be a different year with regards to overall winter patterns. The west has had several consecutive very good years, which have essentially erased the California drought but then have a contributing influence on the eventual fire season being rough as a result of all the growth. Anyway, rambled on more than usual lol 

[John1122]

The 6z GFS does something I don't remember seeing by having a gulf low and a cutter at the same time. 

[Carvers Gap]

24 minutes ago, John1122 said:

The 6z GFS does something I don't remember seeing by having a gulf low and a cutter at the same time. 

It is an odd look for sure.  Seems like we would either get a cutter or get GOM slp/wave.

[Holston_River_Rambler]

2 minutes ago, John1122 said:

The 6z GFS does something I don't remember seeing by having a gulf low and a cutter at the same time. 

It's a weird pattern. Kind a like Space Invaders with pieces of energy shooting at warp speed across the country from a split flow. 

[Carvers Gap]

23 minutes ago, Holston_River_Rambler said:

It's a weird pattern. Kind a like Space Invaders with pieces of energy shooting at warp speed across the country from a split flow. 

Yep.  Systems are getting pushed under the developing HB block.  But there is nothing to really force narrowing confluence. Important to recognize this pattern is not a big ridge in the Southeast.  The AN heights  are over Hudson Bay.  That is normally a good setup for big EC snowstorms.  The problem is that there is a ridge(new feature) east of Hawaii which is digging a Southwest low.  The SER over the SE has been replaced by slightly BN heights but there is nothing in the Atlantic to block storms as they approach the East.  Need a 50/50 low to act as a pseudo block if the NAO is going to stay positive.  Probably the bigger problem is a strong PV which is preventing cold from rotating often into the pattern.  There are some good things to like about the upcoming pattern as storms are being forced south.  Problem is our cold source is iffy.  Ensembles this AM look like a Niño pattern with those marginal temps and slightly BN heights rotating under that HB block.  But yeah, the storm track is a mess.  Any changes on the MJO?

[Carvers Gap]

@Holston_River_Rambler, about the only hope I have is that this pattern is a replay of the transition during October and early November.  The Euro did not handle that well but the GEFS did.  I sort of think it probably is not...but there are some similar elements to that transition.  The MJO is notably worse this time around which is why I think we have to watch it for clues if we are going to see enough of a pattern for cold.

[Carvers Gap]

FWIW, the ICON at 0z had marginal temps but a near perfect track for the storm being discussed.

[Holston_River_Rambler]

4 minutes ago, Carvers Gap said:

Any changes on the MJO?

Not hardly any convection in the West Pac now, relative to recently:

A flare up over Indonesia, which is obviously not great, but it isn't a big one yet. Although there is some still in the 6 region, it's south of the equator. 

Still some in the western Indian Ocean, but a little too far south as of now, I would say, to help the N Hemisphere:

 

 

Crankyweather has been looking at the big storm over the Canadian Maritimes as a possibility to shake things up in the N. Hemsiphere and I agree, since there isn't much else for now. It's phasing with a piece of the TPV. 

It's pulling some ridging north, wish it was a little more meridional though.

Will be interesting to see how things shake out after it starts to wind down. 

That storm might have done more to change things, but the big but failed EPO ridge that is sliding down into Canada is also forcing a new piece of TPV to take the place of the one that was over Baffin Bay, lol and guiding the ridging its pumping up further east. 

I don't know if you saw it or not @Carvers Gap but psu and isotherm had a discussion about MJO and base state resonance in the NYC subforum last evening. Interesting thoughts on why things are unfavorable. 

 

[Holston_River_Rambler]

I get the feeling now that maybe isotherm and raindance (who are questioning some of their conclusions because of how bad its been), may still turn out to be right for Feb. Hard to blame them for worsening their outlooks though, even if only slightly.

 

Cranky's take is that if we can get the TPV uncoupled with the SPV and keep the N Hemisphere more "chaotic" we will have some of the same reprisals we had in late autumn. Otherwise there isn't going ot be a lot to shake it up, until we get a final strat warming, and by them it's probably too late for us. 

Of course all this, for everyone reading, is regarding the broader pattern. Not impossible with the wonky suppressed flow to get a surprise Upper low,. 

[Carvers Gap]

Great couple of posts, Holston.  I will have to go read their discussion.  I hadn't looked.  I think the key is the MJO.  It looked noticeably worse on the ECWMF today.  The lack of convection in the western IO is bad, bad, bad.  That is an area where phase 1 and 2 of the MJO(cold here) reside.  That means that phase 6 might be about to win again and would explain the Euro's trip towards the warm phases.  The CFS is on an island right now with a nice trajectory.  Problem is...it lost that battle a few weeks ago.  So, I have low confidence that the CFS scores a coup, but it is not out of the realm of possibility.  The Euro has been taking all other models to school for about seven weeks regarding the MJO.  

Yeah, never hurts to have an Atlantic storm jar the PV.  Big storms can shake up patterns for sure.  When in a bad pattern, a big storm is never a bad thing.  Problem is the pattern has been shaken up already and is being changed as we speak.   As I noted earlier...the pattern at 500 is about to be much different than it has been for the past many weeks.  It is just that the new pattern is only slightly better than the old, crappy pattern.  Sort of like there are just a few ways to bake a really good cake...but there are many, many ways to make a bad cake.  One can overcook it or under cook it or measure the ingredients poorly or try to take it out of the pan at the wrong time or not mix it well enough or the icing won't stick.  Same result is a bad cake.   There are many ways to have a warm EC.  So, the new pattern gets the same result but with a much different pattern at 500.   Long story short, we got our shake-up and the new pattern is only marginally better.  

I am really pulling against an SSW at this point.  So, I roll with Holston on that sentiment.  If we get one, it won't matter unless it happens about right now.  Otherwise, spring may be miserable.  Once we get an SSW, as a general rule it takes like two weeks to work its way down to the TPV and affect our latitude.

 

[Holston_River_Rambler]

Just for speculation, let's assume Raindance is right:

"The patterns have been operating in repeat mode nationally at about a 3.5 month lag, so the H2 November storminess should come back about March, for two weeks. The 1/16 storm in New Mexico roughly corresponded timing wise to the 10/4 storm in New Mexico. The idea is 9/16-10/15 is roughly January, so 11/16-12/15 is roughly March."

So that would put us at around October 6th's pattern as of now, if Raindance's approach pans out. 

 

Here's a quote form Jeff on Oct. 15 (not picking him for any reason other than it was a succinct summary of where we were at then):

"Front parade continues. Looks like midweek and again early next week; warm in between."

Sounds familiar, but with the difference that we are in January now. 

Looks like the Euro OP first showed the final push that flipped November around Oct. 18th, so that puts us 12 days (lol) from seeing a potential shake up, again, if Raindance's approach works. 

Now, interestingly enough, this big storm off the Canadian Maritimes, correlates almost perfectly if I extrapolate Raindance's approach, to Hurricane Lorenzo, a storm that started to shake up the hemisphere in October. 

 

 

Not going to spend a ton of time talking about it, because Cranky has a nice recap of Lorenzo and what it did:

http://www.stormhamster.com/entry2/lorenzo.htm

His conclusions for the TL/Dr crowd:

Visual of it:

Sorry if I'm pushing cranky a lot today, but since the tropics aren't helping right now, gotta look north and up in the atmosphere and say what you will about him, he sticks to that sort of an approach. 

 

[Holston_River_Rambler]

9 minutes ago, Carvers Gap said:

The CFS is on an island right now with a nice trajectory.

TBH I'm not sure what it even sees. Euro and GFS both show some flare ups around S America in the days 7 - 10 window, but that's about it. 

[Holston_River_Rambler]

I don't have the V Pot anomalies for the Euro OP, but I do for the Control.

and looking at that, I'm not really sure what the Euro sees to send it back to 5/6. Looks to me like it still favors 1/2

I know OLR isn't the only thing that goes into the MJO RMM plot calculation, but you'd think it would show more convection over the MC for that RMM plot. 

 

 

Indian Ocean though:

Some of it there even looks like to would be N of the equator. 

[Carvers Gap]

@Holston_River_Rambler, do you have a link to isotherm's and PSU's discussion?

If the pattern comes back from November, I will be giving John credit for that as he has done extensive research on that correlation dating  back several seasons.  Anyway, I think our forum is way ahead of that curve regarding November repeating itself later during winter.  People on this forum have speculated for weeks that there is potential for a repeat of the October/November pattern evolution.  That is rooted in John's work.

Isotherm and Jeff have forgotten more than I will ever know.  Their arguments(even during rare misses) are well constructed with sound reasoning.  They often get both the outcome and reasoning correct.  Gotta have both of those.  

[Holston_River_Rambler]

@Carvers Gap

True, John has been on that. 

Here is the page: https://www.americanwx.com/bb/topic/52870-january-2020-general-discussions-observations-thread/page/63/

Starts about 3/4 of the way down. Just scroll until you see psu's pic, and it takes off from there. 

 

 

[Holston_River_Rambler]

Actually I was wrong, scroll until you see Isotherm for the first time. 

[Carvers Gap]

Skimmed some of that.  My initial reaction would be that we have to be careful comparing years during a +AMO to those found during a -AMO.  And then my next reaction is that seasonal forecasting right now requires us to juggle too many plates at times.  Everything is ok as long as one understood driver is at work.  When one driver is dominant, those winters have great model verification.  But really, I don't think one has to think too hard about this winter.  The MJO and IO have been active along with a tight PV.  The QBO was positive until just recently.  One of those(the QBO) variables was a known quantity while the MJO, IO, and PV states were not known until winter was underway.  So in hindsight, the reasons are fairly clear.  I actually think many forecasts identified the correct variables that were drivers.  It was identifying their subsequent values that was tricky.  IMO, being a good seasonal forecaster requires one to identify the drivers AND then identify their values. 

I think what we need is to have a strong La Nina in order to remove the positive SSTs from the Pacific.  That would waste a winter here, but would bring the Pacific basin back to a more normal base state.  A volcanic eruption at the right latitude would also do the trick.  Will be interested to see if the theories of solar min blocking lags verify during the next two winters.  

Lastly, I do think the term "weak El Nino" gets tossed around a bit to loosely my many, many folks.  I am guilty of that as well.  A weak positive is often still a neutral ENSO state.  I think this winter will actually be classified as a La Nada.  La Nada winters are pretty "meh" IMBY.  That Pacific water off the coast of South America that is cool is sometimes underestimated.   The misnomer (referring to neutral positives as weak El Ninos) can cause false conclusions.  In other words, we can't refer to this winter(in the future) and say that weak El Ninos are no longer good when in fact it may not be a weak El Nino at all.  

 

[Carvers Gap]

Back to weather model watching for the 12z suite.

1.  The ICON is a warm Miller A

2.  GFS is now just a cutter.

3.  Will be interesting to watch the Euro trend on that system.

[Holston_River_Rambler]

On the bright side 12z GFS gives E KY and SW VA a flurry fest for almost 3 days:

[Holston_River_Rambler]

UKMET looked good for a few frames anyway, for that storm we've been discussing:

If we could just get that southern energy to move out on its own. 

[Holston_River_Rambler]

Longwave pattern the 12z GFS showed at the end of its run was a way to work with the +EPO. Not going to post it since it is the GFS and probably has a 1.42096998% chance of verifying, but it does show how what the EPS has been showing could roll forward and be at least a decent look with a +PNA.

 

[Carvers Gap]

23 hours ago, Coach B said:

I  agree. I've been going back through the historical NOW data for Jan and Feb when I have time the last several days. As Carver's has pointed out, it was just much colder with more snow from 1960 thru about 1985. People who grew up in that era in TN say things like, "we used to get at least a couple 2-4" snows every year, and they hung around for a week or more." They were generally right, even for non elevated areas throughout the state. The number of days with snow cover for Nashville in the winters of 1977-1979 alone is astounding compared to now. I didn't even look at the 60s, as I'm sure they were similar. Sometime around 86 that changed. I think some big events for the following 15 years or so kind of masked the change. We had the slider in 88, the Superstorm in 93, the massive ice storm in 94, big events in otherwise not really cold years in 96 and 98 and so on. Interestingly, as has been pointed out by others, the 1920s thru the 1950s stunk for winter as well, so a decades long bad stretch cannot be fully blamed on man made GW. It's pretty neat to dig back into the historical record. So its my hope that we shift back into a more favorable period before I get to old to enjoy it!

Great post.  I used to judge how good the winter was going to be by how early it snowed in a season - and Knoxville folks, I lived in Knoxville when I used that rule.  Grew up(till I was ten) behind West Town mall for a while and then off Ebenezer.  If it snowed in late December, I always felt good about my chances.  LOL.  And then I lived in Florida for two years................................................no amount of climatology could save me in central Florida.

[Holston_River_Rambler]

Just to see teh true depth of the EPS's flip:

one week ago

 

today:

[Carvers Gap]

@Holston_River_Rambler, I think the EPS is likely correct and other models will have a similar and drastic flip.  That said, should we at least consider the idea that the EPS is wrong.  Man, I don't knowhow much time you have on your hands...but would be interesting to the the GEPS, GEFS, and EPS evolution on their 12z ensembles.  Right now the EPS is either the trend setter(likely due to its superior MJO modeling) or it is an outlier.  It is kind of fun to watch the heat retrograde across Canada.  Going to get some great low tracks with no cold with that look.  LOL.