December 2019 Med/Long Range Disco

[LurkerBoy]

8 minutes ago, Bob Chill said:

A lot of signs on the ens that we lose the Pac in a couple weeks. Not saying I think we flip warm and stay there but it sure looks like (to me) a relax is coming for north america in general. 

This contradicts CAPES latest post. Time will tell!

[Bob Chill]

Just now, frd said:

 

I know this is speculation, however, do you think the CFS is seeing beyond the moderation period with the outlook that CAPE just posted  ? 

 

 

One thing that has been very consistent so far this season is the medium range rarely ends up looking like what the long range says. So far things have broken in our favor more often than going the wrong way. 

Medium range blocking we're seeing now was never even advertised in the long range. Being honest, I really have no clue how the second half of the month goes. Doesn't look like prime deep winter nor does it look like a toaster bath. However, we pretty much always have a warm spell (5+/- days) in Dec. I don't think this month will avoid it. 

[Bob Chill]

2 minutes ago, WxUSAF said:

Lol, just as the pole and Atlantic look to shift better, the Pac wants to take a crap. I’m still skeptical until it happens since this has been advertised a few times in the last 6 weeks only to either not happen or be very transient.

Eps and gefs really open up a mid latitude flood of pac air. The idea is gaining consensus. Prob temporary and nothing to freak out over if it happens at all but if a full latitude trough crashes into the west in 1-2 weeks and pumps the pac into the conus (or NA) nobody should be surprised. 

[CAPE]

8 minutes ago, frd said:

 

I know this is speculation, however, do you think the CFS is seeing beyond the moderation period with the outlook that CAPE just posted  ? 

 

 

I posted the third week of the month. CFS craps up the Pac some beyond that, but it has what looks to be a -AO and a neutral NAO, so the EC still looks to be in decent shape.

[frd]

7 minutes ago, Bob Chill said:

Eps and gefs really open up a mid latitude flood of pac air. The idea is gaining consensus. Prob temporary and nothing to freak out over if it happens at all but if a full latitude trough crashes into the west in 1-2 weeks and pumps the pac into the conus (or NA) nobody should be surprised. 

The solstice warm up has been par for the course the last 8 years.

Seems to be getting ready for another run this year. Not the end of the world as you mention, but it is uncanny how this happens every year, more so after mid-month, and even more so near 12/24.  

[Maestrobjwa]

1 hour ago, frd said:

The solstice warm up has been par for the course the last 8 years.

Seems to be getting ready for another run this year. Not the end of the world as you mention, but it is uncanny how this happens every year, more so after mid-month, and even more so near 12/24.  

And even in the blockbuster 2009-10 year...didn't it warm up by Christmas? (I remember a mildish rain washing away most of the snow, lol)

[CAPE]

Looking at the 12z GEFS, any significant degradation of the Pacific pattern looks brief. The deep trough off the west coast progresses east, and heights are building behind it, with lower heights near the Aleutians and hints of ridging over AK at the end of the run. Looks like a general continuation of a progressive, changeable pattern.

[psuhoffman]

5 minutes ago, C.A.P.E. said:

Looking at the 12z GEFS, any significant degradation of the Pacific pattern looks brief. The deep trough off the west coast progresses east, and heights are building behind it, with lower heights near the Aleutians and hints of ridging over AK at the end of the run. Looks like a general continuation of a progressive, changeable pattern.

I haven’t seen the 12z but even the last run at the end the Aleutian low was reforming which would be the end of the pac puke shortly after. So far the pac has been progressive but with a definite trend and bias towards a reformation of the Aleutian low/epo ridge and no prolonged deviations from that.  That pattern is supported by the sst look there right now as well. I expect that base state to continue. 

[CAPE]

Just now, psuhoffman said:

I haven’t seen the 12z but even the last run at the end the Aleutian low was reforming which would be the end of the pac puke shortly after. So far the pac has been progressive but with a definite trend and bias towards a reformation of the Aleutian low/epo ridge and no prolonged deviations from that.  That pattern is supported by the sst look there right now as well. I expect that base state to continue. 

Yeah I like the persistence of the key features thus far. We have remained generally cold, with some brief warm-ups over the last month or so. No hints of a prolonged shutout pattern. Just keep that going heading into peak climo and we should be in good shape.

[Ji]

4 hours ago, Bob Chill said:

One thing that has been very consistent so far this season is the medium range rarely ends up looking like what the long range says. So far things have broken in our favor more often than going the wrong way. 

Medium range blocking we're seeing now was never even advertised in the long range. Being honest, I really have no clue how the second half of the month goes. Doesn't look like prime deep winter nor does it look like a toaster bath. However, we pretty much always have a warm spell (5+/- days) in Dec. I don't think this month will avoid it. 

What's broken in our favor?. We havent seen a flake yet

[CAPE]

1 hour ago, Ji said:

What's broken in our favor?. We havent seen a flake yet

Its Dec 8th dude, and there have been "flakes" in many locales.

Even some accumulation in places- like Richmond and Salisbury.

[Mr. Kevin]

I think most should focus on the eps because it usually has a better idea of patterns instead of the gefs imo. Overall better track record. 

[Bob Chill]

We better hope ens guidance is wrong leading into the holidays. I won't mind a warm Christmas as long as a quick end is in sight. If the gefs/eps upper level pattern is right then we might end up in an extended shutout pattern. No way to sugarcoat the upper air pattern the gefs and eps are showing. 

[LP08]

30 minutes ago, Bob Chill said:

We better hope ens guidance is wrong leading into the holidays. I won't mind a warm Christmas as long as a quick end is in sight. If the gefs/eps upper level pattern is right then we might end up in an extended shutout pattern. No way to sugarcoat the upper air pattern the gefs and eps are showing. 

Just pretend this is the GEFS and all is well lol

[CAPE]

40 minutes ago, Bob Chill said:

We better hope ens guidance is wrong leading into the holidays. I won't mind a warm Christmas as long as a quick end is in sight. If the gefs/eps upper level pattern is right then we might end up in an extended shutout pattern. No way to sugarcoat the upper air pattern the gefs and eps are showing. 

The way to sugar coat it is to not buy it, and/or believe it will be transient. At least the look up top is respectable as the PAC shifts to an unfavorable look on guidance. Another few runs and we will have a better idea if this is just a reshuffle and the pattern rolls forward, or if it will stick for awhile. I am inclined to go with persistence at this point.

[WinterWxLuvr]

19 minutes ago, C.A.P.E. said:

The way to sugar coat it is to not buy it, and/or believe it will be transient. At least the look up top is respectable as the PAC shifts to an unfavorable look on guidance. Another few runs and we will have a better idea if this is just a reshuffle and the pattern rolls forward, or if it will stick for awhile. I am inclined to go with persistence at this point.

Is there a reason we would believe anything beyond a short window of time?

[Maestrobjwa]

1 hour ago, Bob Chill said:

We better hope ens guidance is wrong leading into the holidays. I won't mind a warm Christmas as long as a quick end is in sight. If the gefs/eps upper level pattern is right then we might end up in an extended shutout pattern. No way to sugarcoat the upper air pattern the gefs and eps are showing. 

Oof...What is it with that? That would be a carbon copy of last winter! (where even you had a very slight meltdown at the end of the month due to the pac air, lol) Why does this keep repeating itself?

Now, personally...I never expect any snow events between Christmas and mid-January (because it literally never happens down here for whatever reason...only exception was the Blizzard of 96! And I think that was linked to the La nina somehow). So, if we get into a shutout pattern, I could bear it...as long as it doesn't extend past that...because then you're cutting into prime climo with that crap!

[Bob Chill]

48 minutes ago, C.A.P.E. said:

The way to sugar coat it is to not buy it, and/or believe it will be transient. At least the look up top is respectable as the PAC shifts to an unfavorable look on guidance. Another few runs and we will have a better idea if this is just a reshuffle and the pattern rolls forward, or if it will stick for awhile. I am inclined to go with persistence at this point.

I think some version is coming. Seeing too much agreement. Could be wrong and it could be nothing but having a full latitude trough along the west coast of any kind starts a process that almost always takes 5+ days minimum to reverse. 

Again, I'm not saying I think anything is locked in and anything and everything can change. It's an important feature to watch over the next week. 

Just now, Maestrobjwa said:

Oof...What is it with that? That would be a carbon copy of last winter! (where even you had a very slight meltdown at the end of the month due to the pac air, lol) Why does this keep repeating itself?

It's not a carbon copy. I never said that. It's completely normal for north america to get filled with maritime air at times during a winter. Sometimes it's short lived and other times it never goes away. But it always happens so don't expect any winter to not have some pac floods. 

[frd]

1 hour ago, Bob Chill said:

We better hope ens guidance is wrong leading into the holidays. I won't mind a warm Christmas as long as a quick end is in sight. If the gefs/eps upper level pattern is right then we might end up in an extended shutout pattern. No way to sugarcoat the upper air pattern the gefs and eps are showing. 

Meanwhile the vortex looks to get stronger as we look out a bit. To me just looking over the landscape it would appear that Isotherms, camp 2 outcomes might be gaining traction. Combine that with the recent trend of warm Decembers after the 15 th and you get the much anticipated warm-up. 

How long is the question. If you go by Tom's train of thought it could be a while. To me it is disheartening to possible once again put all my faith into a shortened climo window, yeah, most likely over-reacting, but is wise to .always temper expectations to avoid complete depression over the lack of snow and sustained cold. Getting harder and harder to arrive at a meaningful and durable cold weather period.

Oh, and for the record, the vortex can be stronger than average and we might still get colder periods but we really need -NAM state, I still have some hope the warmer period does not eat too much into our peak climo period.  

  

    

[cbmclean]

9 minutes ago, frd said:

  

    

So while 11 out of 21 members have average or below average vortex strength at the 12/23, but the 10 positive outweigh the -/neutral members?  Is that a valid conclusion?

Oh, and I thought the EPS had 50 members plus control?

[Maestrobjwa]

29 minutes ago, frd said:

How long is the question. If you go by Tom's train of thought it could be a while. To me it is disheartening to possible once again put all my faith into a shortened climo window, yeah, most likely over-reacting, but is wise to .always temper expectations to avoid complete depression over the lack of snow and sustained cold. Getting harder and harder to arrive at a meaningful and durable cold weather period.

For me, a shortened climo window is if something would cut into the Jan 15th-February 20th prime climo window. But if something just pushes things down the road to mid-January...that would be pretty much normal, lol

[cbmclean]

33 minutes ago, frd said:

How long is the question. If you go by Tom's train of thought it could be a while.

Who is Tom?

[Maestrobjwa]

3 minutes ago, cbmclean said:

Who is Tom?

I think that's Iso's real name.

[poolz1]

24 minutes ago, frd said:

Meanwhile the vortex looks to get stronger as we look out a bit. To me just looking over the landscape it would appear that Isotherms, camp 2 outcomes might be gaining traction. Combine that with the recent trend of warm Decembers after the 15 th and you get the much anticipated warm-up. 

How long is the question. If you go by Tom's train of thought it could be a while. To me it is disheartening to possible once again put all my faith into a shortened climo window, yeah, most likely over-reacting, but is wise to .always temper expectations to avoid complete depression over the lack of snow and sustained cold. Getting harder and harder to arrive at a meaningful and durable cold weather period.

Oh, and for the record, the vortex can be stronger than average and we might still get colder periods but we really need -NAM state, I still have some hope the warmer period does not eat too much into our peak climo period.  

  

    

I dont disagree that we may have a milder stretch coming up but the last 30 days have been below normal east of the MIss river.  Fairly persistent since Nov turned colder. 

We just had this same discussion a week ago when models were showing a crap pattern in the 10-15 and then the EPO ridge started showing up and now we are tracking an event. 

Models will waffle with the MJO passing through the COD and remain volatile in the LR, imo.  The PV strengthening over the pole is a concern but an MJO that pushes into another 8/1/2 progression, combined with the background state we have already experienced I still think things look positive for later in Dec. 

If anything...it's not an uninteresting season so far. No consensus is kind of nice after last year.... 

[psuhoffman]

1 hour ago, frd said:

Meanwhile the vortex looks to get stronger as we look out a bit. To me just looking over the landscape it would appear that Isotherms, camp 2 outcomes might be gaining traction. Combine that with the recent trend of warm Decembers after the 15 th and you get the much anticipated warm-up. 

How long is the question. If you go by Tom's train of thought it could be a while. To me it is disheartening to possible once again put all my faith into a shortened climo window, yeah, most likely over-reacting, but is wise to .always temper expectations to avoid complete depression over the lack of snow and sustained cold. Getting harder and harder to arrive at a meaningful and durable cold weather period.

Oh, and for the record, the vortex can be stronger than average and we might still get colder periods but we really need -NAM state, I still have some hope the warmer period does not eat too much into our peak climo period.  

  

    

I hope this doesn’t come off as disrespectful to you or Tom because I have the utmost respect for you both, but I think you are letting one person effect your outlook too much.  And I’m not saying I love everything I see right now. My expectations aren’t sky high. Im still where I was a month ago, hesitantly expecting near avg snowfall but with low confidence. But I also don’t see the doom and gloom either. 

First of all wrt Toms seasonal forecast, I respect the hell out of him and he has an exceptional track record, but some years aren’t easy to nail. This year is complicated. I would have low confidence in anyone’s forecast. 

I also question some things that are the foundations of the contingent calling for a mild winter. 

1.  A lot of the December torch calls were based on an mjo tour of warm phases. But that hasn’t happened and instead we enter the middle of the month still cold and an mjo looking to cycle through the COD and maybe head towards cold phases by New Years  

2.  The AO was supposed to become hostile and it did, but now it’s quickly tanking again and then who knows.  But it hasn’t locked in positive. 

3.  The AAM state was used as a basis for a lot of the warm calls. But for starters the AAM has improved significantly since earlier in the fall. And additionally if we did deeper into the AAM im not sure history supports the notion that a low AAM is necessarily a death sentence to cold and snow.  Yes overall there is a correlation  but that’s because most low AAM years were Nina’s and cold neutrals following a Nina and those do suck.  If we were in either of those conditions I would be saying this is gonna hurt!  But if we only look at enso neutral years following warm or neutral years almost all of them were cold and snowy.  So how does that compute?  

4.  The slow qbo progression was cited.  But even if the qbo takes until February to flip negative winter months during a descending qbo between 5-0 were mostly ok.  There is evidence the qbo doesn’t need to get negative to become favorable.  it’s already getting into favorable territory barring a reversal.  

People are saying “this should lead to that” but when I look at actual examples it didn’t play out that way.  Granted I’m simply looking at things from 30,000 feet trying to pick out correlations but I see plenty of evidence to refute typical low AAM expectations.  

 

[Snowy Hibbo]

The latest conclusions from my North American long term outlook:

1. After the New Year, we should see deeper cold risks per the GWO cycle for the Central and Eastern North American regions.
2. The short term good pattern over the Eastern US will dissipate into ridging in the latter half of December. It might get more interesting in the days prior to January, with the aforementioned colder risk in Jan. This doesn’t mean there is no chance of snowfall, rather it is more limited.
3. After the current short term Southern US snowfall risk, chances will be lower until January, or at least the last week of December.

More details here:

https://longrangesnowcenter.net/2019/12/09/north-america-on-the-long-term-9th-december/

[CAPE]

Pretty nice look here. Maybe one last chance to score something before we possibly go mild PAC dominant for a bit.

[frd]

8 hours ago, psuhoffman said:

I hope this doesn’t come off as disrespectful to you or Tom because I have the utmost respect for you both, but I think you are letting one person effect your outlook too much.  

I enjoy hearing both sides of the science. Maybe I am being swayed by concerns that will never take front stage. Not to mention seasonal forecasting is very complex and no one will ever tell you they have complete confidence in their forecasts 

Honestly,  as poolz posted recently, we have been in this cooler regime for a while. We are eventually due for a break. Maybe, this later December moderation period is simply a variation of the January thaw, just several weeks earlier. 

30 years ago in my youth all I would know is generally we warm a bit after a month of frequent cold fronts, I knew nothing of the MJO, Glaam, AAM, tropical forcing, etc.  Sometimes not knowing is better, so much to track and account for. I am still hopeful for a period of winter weather that lasts awhile.  I do feel the base state will deliver us what we want this winter. 

 

[Bob Chill]

2 minutes ago, LurkerBoy said:

So we’re officially going mild...?

Not in the next 10 days and nobody knows for sure what happens after. There is decent agreement for an unfavorable epac trough setting up and filling the conus with maritime air but does it actually happen? If it does, how long will it last? Nodoby knows these answers for certain. Not even the most powerful weather supercomputers in the world. It's something to watch. That is all. 

[Ralph Wiggum]

1 minute ago, LurkerBoy said:

So we’re officially going mild...?

Apparently the old sages have punted December claiming PAC firehose and long recovery period. Not sure I completely agree with the AO poised to tank, ridging developing over Greenland, and 50/50 lows popping up as we enter winter climo but I guess the PAC runs the show anymore in this new climate.