December 2019 Med/Long Range Disco

[MJO812]

1 hour ago, Rtd208 said:

Boy this guy Webb is really something else. He is posting at the 33 forum at 3:30 am about the 00z GEFS/EPS being warmer to support his ideas which may or may not be correct but he just has this inherent need to be right and prove everyone else who doesn't support his ideas is wrong. He even seems to get a bit argumentative at times. I mean wow.

I mean the models are  starting to go the wrong way in the long range. Of course they can change .

[Rtd208]

Just now, Snow88 said:

I mean the models are  starting to go the wrong way in the long range. Of course they can change .

My issue is not really with what the models are showing or if they will be right or not but he just has this inherent need to be right, he makes it so obvious.

[Rtd208]

DT (WxRisk). Winter weather lovers won't like it but there may be some hope for the second half of December which is discussed in the last few minutes of the video.

 

[frd]

1 hour ago, Rtd208 said:

My issue is not really with what the models are showing or if they will be right or not but he just has this inherent need to be right, he makes it so obvious.

The MJO depictions, and recent model trends support his notion, as does the typical warmer than average December Nino here in the East, but there is one difference .  That difference is progression, and what may happen is a change to a more winter-like pattern occurring sooner, versus later in December, which indeed would be remarkable. 

Reading Webb's posts does indeed make him sound like an embittered snow weenie going to the dark side. As for the Nino talk he does, I have been reading his posts for several years, and I believe he does focus on the Pacific/tropical weather patterns. I think he knows his stuff. 

 

[CAPE]

6 minutes ago, frd said:

The MJO depictions, and recent model trends support his notion, as does the typical warmer than average December Nino here in the East, but there is one difference .  That difference is progression, and what may happen is a change to a more winter-like pattern occurring sooner, versus later in December, which indeed would be remarkable. 

Reading Webb's posts does indeed make him sound like an embittered snow weenie going to the dark side. As for the Nino talk he does, I have been reading his posts for several years, and I believe he does focus on the Pacific/tropical weather patterns. I think he knows his stuff. 

 

GEFS currently has the MJO forcing moving briefly into phase 2, then into the COD by early Dec. Who knows what happens beyond that. Looks like it may do a loop in the COD, but it could reemerge in a favorable phase or stay neutral. If early Dec is going to be on the mild side, I am not sure the MJO state will be a primary reason. As for the Nino correlation, well we don't really have Nino conditions currently. Do we typically have warmish Decembers when ENSO is warm-neutral?

[WxUSAF]

Based on the Pacific SSTs we might not be in a Nino, but the atmospheric ENSO indices I’ve seen all clearly say it’s a weak nino. 

[frd]

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

GEFS currently has the MJO forcing moving briefly into phase 2, then into the COD by early Dec. Who knows what happens beyond that. Looks like it may do a loop in the COD, but it could reemerge in a favorable phase or stay neutral. If early Dec is going to be on the mild side, I am not sure the MJO state will be a primary reason. As for the Nino correlation, well we don't really have Nino conditions currently. Do we typically have warmish Decembers when ENSO is warm-neutral?

Well, I will bring over one of Webb's post  and you can check it out. Me doing so does not mean I endorse his thoughts, but more so because it is interesting. Of note is that the atmosphere is acting to a degree as it is a Nino. A weak Nino though. 

Webb also mentioned we are ahead of the typical Nino/seasonal  progression. BAMMWX stated we are ahead in terms of the PV evolution, from their webinar. 

Webb specifically said " This winter appears to be well ahead of schedule vs the stereotypical backloaded NINO progression thus far but that doesn't take away from my idea that December will probably end up significantly milder than avg. I think we're more likely to get this party started in January instead of waiting til February this winter, especially if this wave 1 SSWE is successful."

Here is Webb's post form 33 :

<<

The MJO entering the "circle of death" does not automatically mean the tropical forcing signal automatically goes away, but I do think it will enter the COD before reaching phase 3 because of the NINO/+IOD. In grand scheme of things, it honestly doesn't matter in this instance whether the MJO goes into the COD or stays outside w/ amplitude the entire time, the end result will be largely the same in the extratropical northern hemisphere.

 

The MJO enters the circle of death when multiple circulation signals act simultaneously, or the MJO interacts with a standing wave like the one over the Indian Ocean. Why?

 

Because the MJO is an eastward propagating subseasonal wave in the tropics coupled to the extratropical circulation. When this normally eastward propagating wave becomes quasi-stationary/stops moving eastward, its amplitude on RMM phase diagrams like the one below decrease. However, this DOES NOT mean that the tropics are not having an huge impact on the mid-latitude wave pattern. If anything, the global impact from subseasonal Indian Ocean convection will be much larger than usual the next few weeks because it's being amplified by & constructively interfering w/ a standing wave. That's not something the RMM diagrams will tell you.

 

 

 

 

>>>>

 

@C.A.P.E. Webb did mention we benefit from the -NAO late month, by delaying or muting any tropical based warming .  

 

 

 

 

[psuhoffman]

3 hours ago, C.A.P.E. said:

GEFS currently has the MJO forcing moving briefly into phase 2, then into the COD by early Dec. Who knows what happens beyond that. Looks like it may do a loop in the COD, but it could reemerge in a favorable phase or stay neutral. If early Dec is going to be on the mild side, I am not sure the MJO state will be a primary reason. As for the Nino correlation, well we don't really have Nino conditions currently. Do we typically have warmish Decembers when ENSO is warm-neutral?

As USAF said the atmosphere is behaving “like” a nino lately. But frankly the climo cycle recently has been a warm December no matter the enso state. I’m not entirely sure if the “warm nino” thing is due to enso or that we have had way more ninos lately which skews the results vs older ninos when colder December’s wasn’t as unusual. We had some pretty cold December ninos in the 1960s and 70s.  The Atlantic and Gulf SSTs have been on fire lately. Add in the lag of sst temperatures cooling and that might have as much or more to do with the prevalence of the SE ridge early in winter lately. In essence we might be losing the early 1/3 of winter due to the current warmer SST cycle there.  Only reason our mean snowfall isn’t dropping faster is we also seem to have a higher hit rate on big storms when the pattern does rarely get right.  Boom and bust cycles seems to be our normal climo now, even more than it was historically.  

 

[CAPE]

2 minutes ago, psuhoffman said:

As USAF said the atmosphere is behaving “like” a nino lately. But frankly the climo cycle recently has been a warm December no matter the enso state. I’m not entirely sure if the “warm nino” thing is due to enso or that we have had way more ninos lately which skews the results vs older ninos when colder December’s wasn’t as unusual. We had some pretty cold December ninos in the 1960s and 70s.  The Atlantic and Gulf SSTs have been on fire lately. Add in the lag of sst temperatures cooling and that might have as much or more to do with the prevalence of the SE ridge early in winter lately. In essence we might be losing the early 1/3 of winter due to the current warmer SST cycle there.  Only reason our mean snowfall isn’t dropping faster is we also seem to have a higher hit rate on big storms when the pattern does rarely get right.  Boom and bust cycles seems to be our normal climo now, even more than it was historically.  

 

Yeah its hard to make a call for a cold December around here. It happens every so often. Still can get a frozen event even if overall the month is 'warm' as long as the pattern isn't hostile, and with climo becoming more favorable moving forward.

[LurkerBoy]

So is the new thinking that dec will be AOAN? Sorry, I’m a noob and it’s harder to parse the more esoteric speech. 

[psuhoffman]

@frd  I do think there are legit signs of a pattern shift in early December. However, his timeline and extent of the effects of the mjo wave propagation through warm phases seems dubious to me.  Last year we had a record stall in warm phases and even that didn’t take a whole month to propagate out. We started to torch mid December due to the mjo and still got back to a colder regime by the end of the first week of January.  So he is expecting another record stall in warm phases to beat last years record?  He may be totally right with his numbers but his tone implies a month long warm pattern and if we do enter mjo hell in early December I find it unlikely we are still battling that come holiday week. Now last year the problem was the mjo would blast through cold phases in a week and cycle back to warm phases but that’s another issue. And there was speculation the SSWE muted the benefits of the one decent cold phase mjo wave as well. Just seems to be a lot not being taken into account. 

[UniversesBelowNormal]

Pacific pattern is correlating with ENSO subsurface cold wave moving across -200m Nino 3 nicely. Nice correlation from 2017. 

[frd]

23 minutes ago, psuhoffman said:

Last year we had a record stall in warm phases and even that didn’t take a whole month to propagate out. We started to torch mid December due to the mjo and still got back to a colder regime by the end of the first week of January.  So he is expecting another record stall in warm phases to beat last years record?  He may be totally right with his numbers but his tone implies a month long warm pattern and if we do enter mjo hell in early December I find it unlikely we are still battling that come holiday week

That makes sense. So, maybe he ends correct on the apparent turn to milder,  but the duration of any warm up is shortened. I know HM talked about cold at the end of December which matches your thoughts here. 

Along with the general talk lately about warm or mild Decembers bluewave was mentioning the turn of events in the Pac since 2013, and how the recent warmer early Fall seasons turn colder in November and then mild in December.

Here the focus is on massive warming in  Pac this decade, and sea ice melts during the recent summers etc. This makes a lot of sense. Seems we have new players as a consequence of a warming global state and they seem to really impact the period form October to December.  know it effects the entire year, but to us here at this time of year you can see it and feel it.  The effects of a warmer base state promote increased  ice melt but also effect seasonal blocking with warmth in the Pac ( mostly the deep tropics ) effecting the  MJO,  EPO regions, Hadley cell , tropical forcing , snow cover, etc., even SSW and other weather phenomena.   

Then there is feedback on certain ocean locations in the form of anomalies, and these are players to a degree as well.  Looking beyond day 7 is a real gamble these days. models struggle as do forecasters. But, I guess, in this new day and age you have to incorporate these new players on how you decide to forecast the weather in the long range.  

 

[frd]

 

Hot Off The Press , maybe the precursor pattern is working .

 

 

 

 

[poolz1]

14 minutes ago, frd said:

 

Hot Off The Press , maybe the precursor pattern is working .

12z gefs def more bullish but overall it continues the theme it has been advertising.

Some pretty rapid weakening toward the end of the run.

[Ralph Wiggum]

54 minutes ago, poolz1 said:

12z gefs def more bullish but overall it continues the theme it has been advertising.

Some pretty rapid weakening toward the end of the run.

Taking a beating is an understatement. But a SSWE is extremely volatile and unpredictable. Could throw the entire trop into one hostile mess which is anyone's guess which areas that could potentially favor. I guess it is better than one massive stacked SPV/TPV combo over Santa's hometown but I take these SSWE's with a grain of salt. Sometimes they work out beautifully for us but more often then not it lays an egg.

[jaydreb]

EPS still showing low heights for most of CONUS into December.  I assume we would prefer to see blue rather than red just south of the Aleutians though.  

[WxUSAF]

^thats all Pac air though. So maybe slightly below normal temps, but probably not an airmass that can snow in early December.

[Kmlwx]

14 minutes ago, jaydreb said:

EPS still showing low heights for most of CONUS into December.  I assume we would prefer to see blue rather than red just south of the Aleutians though.  

 

@WxUSAF hit the nail right on the head below. Look at the height lines. You're pretty much getting a tsunami of straight Pacific air flowing over the entire CONUS. We want a nice flow of continental polar air to give us good cold air delivery. 

4 minutes ago, WxUSAF said:

^thats all Pac air though. So maybe slightly below normal temps, but probably not an airmass that can snow in early December.

 

[Bob Chill]

5 minutes ago, WxUSAF said:

^thats all Pac air though. So maybe slightly below normal temps, but probably not an airmass that can snow in early December.

Yep. Looks like a typical -PNA period where the western ski areas get dumped on for a couple weeks. Not warm here but still far from a good snow pattern here. However, the PNA typically oscillates so even if the EPS is right it's not unreasonable to expect the PNA to flip back + after the storm cycle. These types of patterns commonly hold for 1-2 weeks. We're still a month away from our climo not fighting us with every little detail. I'm good with everything as is and can easily envision how it could improve at a time when our area stands a chance at a snow event.  

[cbmclean]

10 minutes ago, Bob Chill said:

Yep. Looks like a typical -PNA period where the western ski areas get dumped on for a couple weeks. Not warm here but still far from a good snow pattern here. However, the PNA typically oscillates so even if the EPS is right it's not unreasonable to expect the PNA to flip back + after the storm cycle. These types of patterns commonly hold for 1-2 weeks. We're still a month away from our climo not fighting us with every little detail. I'm good with everything as is and can easily envision how it could improve at a time when our area stands a chance at a snow event.  

Still trying to sort out my Pacific teleconnections.  So a -PNA pattern can come and go relatively quickly, but a dreaded +EPO will embed itself for weeks?

[WxUSAF]

It still looks like the AO and NAO are generally favorable for us for the next 2 weeks.  Let's keep that going.  We've seen the last 2+ weeks what that can do with a favorable Pac long wave pattern.  Do that again in a winter month and I think we'll be rockin.  Clearly the models are having a more difficult time figuring out the Pac as we've seen from the +PNA/-EPO look we were getting around Thanksgiving to the -PNA/+EPO pattern advertised now.  Probably not worth looking past D7-8 for much.  

[WinterWxLuvr]

33 minutes ago, jaydreb said:

EPS still showing low heights for most of CONUS into December.  I assume we would prefer to see blue rather than red just south of the Aleutians though.  

Straight zonal though. Not unexpected from a long range mean though. And those heights aren’t really all that low.

[Bob Chill]

Just now, cbmclean said:

Still trying to sort out my Pacific teleconnections.  So a -PNA pattern can come and go relatively quickly, but a dreaded +EPO will embed itself for weeks?

All major teleconnections can be stable or volatile. I'd say the PNA and EPO are similar in their inherent stability/volatility. Sometimes one phase dominates for weeks/months and other times it bounces back and forth. Right now is a transition month so there's too much inherent volatility to predict anything beyond 1-2 weeks. It's entirely possible that the PNA spends more time - than + during met winter. Seeing a -PNA during late fall or early winter is very common and imo isn't a much of a clue for long lead guessing. 

[frd]

Who knows whether the EPS will be correct, however, just two days ago it had the East in a cold pattern at hour 240, but now after losing the  -EPO we are above normal, as are most areas East of the Mississippi River. Not horrible temp-wise, but not a winter-like period.  

Someone here, forget who, mentioned he did not like seeing the ridge North of Hawaii.  I agree, that messed things up last year, responsible partly for the fast Pac Jet, lack of West coast ridging and assisted the SE ridge to show up.  Hopefully if it does come along, it is simply a transient feature. 

Decembers can be, and are typically are transitional months,  asking modeling to pick up correct outcomes a month ahead is difficult.  

A progression to above normal in early December should be taken in stride after the recent cold spell. Whether it is a month long affair as some are saying is really a reach. I prefer to concentrate up to 7 days. It is fun to talk about the possible weather drivers and the pattern but getting stressed over model runs after day 7 is simply not healthy and takes away the fun of this hobby.    

 

[frd]

So much for their hot hand....................( well like they said -   need a few more runs ) 

 

 

 

[CAPE]

@Bob ChiII

EPS weeklies H5 anomalies a week beyond the end of the 0z EPS. Fwiw, 2m temps look average. I would say the look is pretty crappy overall, but ofc it's the weeklies. Always overly  smoothed and ambiguous.

[BristowWx]

Just now, C.A.P.E. said:

@Bob ChiII

EPS weeklies H5 anomalies a week beyond the end of the 0z EPS. Fwiw, 2m temps look average. I would say the look is pretty crappy overall, but ofc it's the weeklies. Always overly  smoothed and ambiguous.

We get through a less than perfect first two weeks Dec and then a flip when it starts to count..glass half full weenie logic.  

[CAPE]

Just now, BristowWx said:

We get through a less than perfect first two weeks Dec and then a flip when it starts to count..glass half full weenie logic.  

Not a bad way to roll. Seems pretty reasonable the beginning of Dec could suck.

[Bob Chill]

Just now, C.A.P.E. said:

Not a bad way to roll. Seems pretty reasonable the beginning of Dec could suck.

As the days go by the less we know about Dec. Lol. I'm not mad at the weekly plot you posted. It's not that far from something that can work. Better than last year's no chance in hell pattern