December/January 2019/20 Winter Speculation Thread

[jaxjagman]

19 minutes ago, weathertree4u said:

Too early to start a thread for Winter 2020/2021?

 Its not that bad yet

[Carvers Gap]

2 hours ago, weathertree4u said:

Too early to start a thread for Winter 2020/2021?

Going to go with a +NAO, active IO, un-cooperative MJO, a rising QBO,  a developing drought, and a developing La Nina.  Might throw in a extremely -EPO at times which produces record cold, collapses, then record warmth and rebuilds.  Wash, rinse, repeat.  Might even make a call for a BN December followed by AN Jan/Feb for that winter.  Summer of 2021 should be an outright scorcher.

[Carvers Gap]

Impressive...and also a massive miscalculation by modeling that was depicting a -NAO for much of December at one time.  If you see a sustained -NAO on global forecast models...beware.  Likely not a run that will verify - a least not yet.  

 

[Holston_River_Rambler]

Still a lot of conflict in the tropics this AM, but the W Pac has the most convection I've seen in a while:

Without that TC near the Philippines, the MC would look pretty docile. 

Western 3rd of the Indian Ocean still looking hoppin'

The above is a longer loop to show how that area's convection has changed in approx. the last month. You can see the little break we got there and then convection move back in. Not sure what to make of it other than to say I feel like when convection there was more beneficial earlier, there appears to have been more over Africa at the time. 

 

Meanwhile we have our own OLR stoppage and maaann it's a beaut:

 

[Carvers Gap]

Indeed, the overnight models are now depicting only a relaxation in the pattern that will be measured in days(maybe even 48-72 hours) centered around the NY with a very narrow potential for frozen precip.  The EPS shows BN heights over Alaska that are locked into place during the d10-15 range.  Looking forward to the Weeklies tonight to see if they flip back warm - I suspect they will.  If not, they may well signal a way out of this mess.  So really trying to see if they revert back to last Monday's look(likely trend I think) or double down on Thursday.  If the Alaskan vortex moves into place, large chunks of January could potentially be warm...but, when it finally heads south(and it likely will) the flip will be impressive.  That is brutally cold air.  Bad thing?  We may well have things in full bloom when it happens...IF modeling is correct about the warmth in the LR.  Right now, I am riding with the EPs that shows periodic intrusions of seasonal cold in a base pattern that is above normal to much above normal for the next 3 weeks at least.  Right now, the biggest feature change over the past 24 hours is the signal for a significant Southeast Ridge.  That does not fit climatology, but the feature does teleconnect well to the Alaskan cold.  

So, instead of morning updates that are just repeating information about warm weather...going to hold off on my morning discussion unit the LR changes and we begin to get a consistent look again.  Again, we have a small window for winter weather around the New Year.  I do suspect this warm pattern breaks around mid-late January.  Climatology supports this.  However, in order to provide balance to those comments, know that some Nino winters during the late 90s featured very little cold(maybe one window during a couple of those winters) and very little snow at TRI.  Warmth during Nino winters is nearly a given(excluding a few notable exceptions).  Just going to have to ride this out.  Hate to lose weeks during the heart of winter, but indeed, that looks like a real possibility.  I suspect this head fake was a precursor to the pattern actually changing, but that could be 2-3 weeks into January, and I lean towards the longer time frame.  

As a reminder, I am only talking about temps.  It CAN and DOES snow during warm, Nino patterns.  That is why some actually like weak Nino patterns.

[Carvers Gap]

This is how bad the pattern is(if you like snow)...we are simply hoping that we can just get a cold/cool front or two to drive eastward and bring temps to at least seasonal for a couple of days at a time during the next 16 days.  That should change, but the atmospheric pattern isn't driven by past climate data banks that say it should.  I would not be surprised to see readings in the 70s in some forum locations during the next 7-10s day before we see some seasonal temps early in the New Year.  I don't see many teleconnections or indices that hint at this pattern breaking, but pattern flips do occur...and the best we can do right now is to see if we can find when/if this occurs prior to spring.

[PisgahNCWeather]

I know it is a waiting game again but it will be interesting to see just how cold Alaska gets with this setup. I hope they break their records. We can then live vicariously thru them.

[Carvers Gap]

51 minutes ago, PisgahNCWeather said:

I know it is a waiting game again but it will be interesting to see just how cold Alaska gets with this setup. I hope they break their records. We can then live vicariously thru them.

If we wanted to go old school....we could just root for pieces of the AK vortex to break off and head SE every few days.  The GFS at 6z and 12z has this, but again, not going to find myself in a foxhole with that model.  Looks like a Nina pattern on the GFS in how extreme the swings are.  I agree...It is pretty fun to see wicked cold temps in Canada and Alaska though!  Lots of hot pink on those Tropical Tidbits maps.  Just very few delivery mechanism options in place to get it here.  The way we could steal a snowstorm out of that is to have a big, powerful storm cut and pull a quick shot of that cold into the lower 48.  Then, another system would have to be on its tail and hit the cold.  Timing would have to be perfect, but that is how we could score a storm in a very warm pattern punctuated by a couple of strong cold fronts.

[Holston_River_Rambler]

12z Euro has blessed us with another rainy southern upper low!

However, does appear to be finally reeling in to OP range the first (even if transient) cold shot the EPS has been showing. 

Might even be trying to give us a little Upper Low help to go with it:

 

[Holston_River_Rambler]

EPS waaayyyy out there is trying to show some light at the end of the tunnel. As Carver's pointed out this AM, all that cold air is at least on our side of the globe and not in Siberia (no sloshing necessary) 

 

So if things do change and the TPV heads towards Hudson's Bay as its showing at 12z today, there will be no trouble finding a source of the cold. 

 

 

[Carvers Gap]

This will be my last weeklies update until(if) things change on that model.  Indeed, the Weeklies reverted back to a western trough much like they did last Monday.  They have a perpetual SER, sometimes weak and sometimes very strong, through the run after the second week in January.  Looked very much like September and October - but less extreme(unless the extreme is simply being washed out).  At this point, if the Weeklies are right(HUGE if)...the pattern we are seeing is the winter pattern.   Really nothing more to say or belabor the point.  When I am having to look at d14 on a model for any signs of change...we are in a very warm time frame.  It can still snow in a warm pattern.  We saw that during the 90s from time to time.  At this point(and that could easily change), I see no signs of a flip to sustained cold.  We do have a wintery window around the New Year, and then it warms.  

As for the PV, the Hudson Bay is sort of the lesser of two evils.  Having the PV over NAO territory is only slightly better for us than having it over Alaska.  If one is looking at higher latitudes, it is blue where it should be yellow and yellow where it should be blue.  

I no longer am calling for a flip to a cooler pattern.  There is no evidence of that on modeling.  Climatology says it is possible and maybe even probable.   That is our hope.  However, there are Ninos during the 90s where the pattern never turned cold for sustained time.  I do suspect a flip will come...just not seeing it anywhere on modeling at all today.  Other than about 72 hours of cold...it is a base above normal pattern on multiple models.  The other rule of thumb that supports a flip is that the pattern should change after 4-6 weeks which is around or just after mid-January.  

I doubt the Weeklies are correct after week 4 as they are usually just a continuation of their derived run.  However, many other models depict little sustained cold in the SE.  So, tough to toss the Weeklies at this point.

[John1122]

Most mets I've seen keep saying the active STJ will not allow for a SE ridge. We might still be warm but it will be due to Pacific air in the pattern. The PV not being in Alaska is a huge improvement, it tends to get stuck there when it goes there and it quashes any -EP0 and also floods more pacific air into the pattern.

[Carvers Gap]

This is when you know the GFS has bought a one-way ticket to crazy town.  Don't see this every day on modeling.

 

[Carvers Gap]

Now, I do post the above model snapshot for a reason...systems that dig that far into the GOM have to be watched - even during a warm pattern.  It is a good example of how things can amplify with good timing.  Do I think Jacksonville and Savannah get a blizzard?  No.  And if it does, just time to hang it up this winter!!!!  But in the middle of all of this warm talk...pretty hilarious run!  So the Vols wanted to go to Florida for a warm football game?

[John1122]

GEFS goes BN at hour 174 and stays there all but about 48 hours all the way til day 16. Much better look over Alaska at 500mb on there. Just have to see if it's a head fake or not. But modeling in general has looked much better over Alaska the last few runs vs a couple days ago when the EPS and GEFS sat the polar vortex over interior Alaska and just left it there smashing the attempted ridging in the EPO region. 

[John1122]

Euro flipped from 5-15 AN valley wide for New Years Eve morning to 3-6 BN for the same time frame from the 12z to 00z run.  A step towards the GEFS bringing in cooler air. Euro is a warm bias model too. 

[Holston_River_Rambler]

Convection looking better in the MJO regions this AM

nice, colder clouds near the dateline 

SOI has dropped nearly 12 points in response.

 

 

Indian Ocean looks tamer this AM too. Most of the convection is south of the equator and looks like it is associated with a TC:

 

[Holston_River_Rambler]

You can see the TPV being pushed toward Alaska this AM (red arrows are the flow that is rolling the TPV (look in the white circle)).

But wait, what is that??? 

Dohhh

Now I know why all this is going on!!

Santa needed that extra umph to jump start his trip toward the dateline to begin delivering presents. Hopefully by the 26th it will start to roll back our way. 

[Carvers Gap]

0z EPS has reverted to the PV being over AK.  I could find only one cold front that made it through at 850, and it is around NY.  Its trough configuration is improving slightly relative to the shut out pattern that had been shown.

6z GEFS has a +AO, +NAO, -PNA, and +EPO(might be slight debate on that one due to the eastern PAC location).  PV looks really wrapped up tight.  Of note, the GEFS until recently has been perpetually cold in the d10-15 for most of December...TRI will finish much above normal once this week is done.  The GFS operational did sniff out the pattern change in November about 2-3 days prior to the Euro.  Back then though, the Euro couldn’t catch up.  Now, seems like the GFS is struggling.  

If we are going to flip mid-month we will likely see an oddball run now and again on operational modeling.  Would be awesome to see modeling flip on Christmas Eve or Christmas Day.  

Biggest problems(and they are big) this AM are a very wrapped up PV and teleconnections opposite of the values that we need.

The GFS has shown some cracks in the armor as John has noted.  Let’s see if the dam will break.  The 6z GFS showed a piece of the PV break off and head SE.  Thst is a legit way to scrounge up some decent winter wx if the PV stays locked over Alaska, but releases cold from time to time.  Need the EPS to crack or show some signs of doing so.  

[Carvers Gap]

Also, the MJO this AM(RMM1/RMM2) heads back for phase 5.   Not a good look, but the other models have not updated on the CPC site. And a glimmer of hope, the SOI has fallen to ~ -21.  Big drop.  

[Carvers Gap]

I should note that the MJO does go through 7 prior to looping back which does fit its cool down around the New Year.  If we wanted to see a flip...it would never loop back and be a false loop.

[Carvers Gap]

1 hour ago, Holston_River_Rambler said:

Convection looking better in the MJO regions this AM

nice, colder clouds near the dateline 

SOI has dropped nearly 12 points in response.

 

 

Indian Ocean looks tamer this AM too. Most of the convection is south of the equator and looks like it is associated with a TC:

 

Just watched JB's video today.  He is pretty distraught.  His winter forecast is about to go up in smoke again if models are correct.  Now, here is an interesting nugget.  The convection over the western Pacific is very much phase 6 of the MJO.  However, the convection over the western Indian Ocean correlates to phases 1 and 2 which are winter/cold phases.  If the western Indian Ocean convection collapses, then the phase 6 look becomes the dominant phase in the long run.  

[weathertree4u]

4 minutes ago, Carvers Gap said:

Just watched JB's video today.  He is pretty distraught.  His winter forecast is about to go up in smoke again if models are correct.  Now, here is an interesting nugget.  The convection over the western Pacific is very much phase 6 of the MJO.  However, the convection over the western Indian Ocean correlates to phases 1 and 2 which are winter/cold phases.  If the western Indian Ocean convection collapses, then the phase 6 look becomes the dominant phase in the long run.  

Well, he always goes ice cold for his forecasts 

[Holston_River_Rambler]

16 minutes ago, Carvers Gap said:

The convection over the western Pacific is very much phase 6 of the MJO.

 Looks to me to be phase 7 - 8. If this diagram is right, 6 would be over New Guinea. 

 

But I guess this diagram could be wrong. Is there an official CPC one to reference?

 

[Carvers Gap]

1 minute ago, weathertree4u said:

Well, he always goes ice cold for his forecasts 

Most years, yes.  However, his daily stuff is usually pretty good.  I know a bunch of folks don't like him, but I like they guy.  His seasonal forecasts have not been great, and one could make a case that is to drive clicks.  That said, seasonal forecasting is a total crapshoot for pretty much anyone.  For example, I bet very few foresaw the PV tightening up over Alaska.  His mistake this year was cooling his December forecast at the last minute which was warm.  January will likely be warm due to some really warm days during the first ten days of the month - would take some serious cold to reverse that.

Was going to post this anyway(not a response to weathertree) so will post it here.   The QBO was negative yesterday.  That is significant in that it "might" mean that the PV is going to see some disruption.  Now, the value itself is not significantly negative by the trajectory seems like it is.  I am not sure what kind of lag there is regarding the negative value and PV disruption.  It is a "newer" index in terms of forecasting use, and we don't understand it as well as we need to.  When strongly negative, it has a tendency to correlate to PV displacement and high latitude blocking.  Not strongly negative yet, but something to watch.  I suspect it is not a driver at this point so it likely would have to act in concert with other drivers of which not many point to cold.  That said, if the MJO were to finally sneak over and hold in the negative phases...then, the -QBO(as long as it doesn't stall...been hovering at this value for a few days)might actually have an enhanced effect on blocking.  

So, if we are looking for positives(and they are few), there are a couple of big hitters that are in our favor:  deeply negative SOI along with a sharp drop yesterday and the QBO being negative at both 50mb and 30mb.  The SOI can sometimes foreshadow flips on modeling with big drops.  The MJO provides a counter to any flip.

 

 

[Holston_River_Rambler]

 

[Holston_River_Rambler]

Is that going to translate to anything other than more of the same? I don't know, but I do think it is at least in more favorable phases for now.

[Carvers Gap]

10 minutes ago, Holston_River_Rambler said:

Is that going to translate to anything other than more of the same? I don't know, but I do think it is at least in more favorable phases for now.

Here is a screenshot from the CPC site (https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjoupdate.pdf).  Looks convection near the dateline is a phase 6 on this graphic and on current satellites.

[Carvers Gap]

One can see why the MJO is a pain to forecast right now...The western Indian Ocean convection does not teleconnect to the convection just west of the dateline.  So, the MJO values are bouncing all over the place.  For those that are not sure what they are looking at...the green on the graphic above is in the western Indian Ocean for phases 1 and 2 which indicates rising air.  The region near the equatorial dateline is brown which signifies sinking air.  But right now, we have rising air in both the dateline and western Indian Ocean regions.  

[jaxjagman]

Destructive signals continues with the MJO