2023-2024 Winter/ENSO Disco

[weatherwiz]

6 minutes ago, ORH_wxman said:

There's a vortex over the Davis Strait though....that's the opposite of the December blocking episode last year. There's also a weak Aleutian low in the N PAC....opposite of the ridge last year. Longer wavelengths in winter prob is a lot colder look

 

Seems like much of the ridging in the east here is driven (or enhanced) by the energy which breaks off the jet early in the week across California and digs into the southwest United States? I'm wondering if that does not happen if this ridging would be much less pronounced. 

[ORH_wxman]

2 minutes ago, weatherwiz said:

Seems like much of the ridging in the east here is driven (or enhanced) by the energy which breaks off the jet early in the week across California and digs into the southwest United States? I'm wondering if that does not happen if this ridging would be much less pronounced. 

It's a fairly common pattern when you get a -EPO block that kind of folds over....but the placement of these features would probably be a bit different int he winter with extended wavelengths. We'd prob see more of an Aleutian ridge poking into AK from further west than we see here to get that negative height response in the PAC NW.

If you had an Aleutian low with a -EPO in winter, all of that response to the east would look different than it does here in October. You prob have the lower height response occur much further east.

 

This is all speculative anyway. Who knows what the N PAC will look like in winter...but I'd be surprised if we got a lot of -PNA patterns this winter. I'd expect -PNA patterns with this strength of El Nino to be transitory.

[Typhoon Tip]

Most often when a -EPO onsets the initial Rossby signal is a shorter wave length. 

This initially forces an undercut jet to torpedo underneath the block.  It may wiggle the PNA negative when that happens … but transitory. The normal progression of the mature -EPO is to neutralize it by dumping the geo-p surplus (figuratively) into PNA’s eastern  domain —> +D(PNA)

This is the idealized model … variations on this theme take place. For ex, rapid relays can move the EPO so quickly that the merge with and forcing a rising PNA are almost seamless. Other times the EPO hangs around and the split/and or “torpedo jet” (flow bifurcation) can last longer. 
 

 

[ORH_wxman]

11 minutes ago, Typhoon Tip said:

Most often when a -EPO onsets the initial Rossby signal is a shorter wave length. 

This initially forces an undercut jet to torpedo underneath the block.  It may wiggle the PNA negative when that happens … but transitory. The normal progression of the mature -EPO is to neutralize it by dumping the geo-p surplus (figuratively) into PNA’s eastern  domain —> +D(PNA)

This is the idealized model … variations on this theme take place. For ex, rapid relays can move the EPO so quickly that the merge with and forcing a rising PNA are almost seamless. Other times the EPO hangs around and the split/and or “torpedo jet” (flow bifurcation) can last longer. 
 

 

Yes agreed....it's why so many here often hear us say "the cold may initially dump into the plains/rockies but could ooze over the top before we get more established cold X days later".....when the cold leaks over the top before the motherload later on, that's frequently an opportunity for an overrunning/gradient type event....

[Typhoon Tip]

13 minutes ago, ORH_wxman said:

Yes agreed....it's why so many here often hear us say "the cold may initially dump into the plains/rockies but could ooze over the top before we get more established cold X days later".....when the cold leaks over the top before the motherload later on, that's frequently an opportunity for an overrunning/gradient type event....

Yeah, I stopped short of mentioning that split flow is a precursor to icing and stuff but yeah

[40/70 Benchmark]

Just now, 40/70 Benchmark said:

Latest IRI suite does nothing to sway me from the 1.6-1.9 range that I honed in on early last summer.

That is the final update before I issue.

[NEPASnow]

 

[Typhoon Tip]

45 minutes ago, NEPASnow said:

 

I have my doubts on it intensifying very much further (seeing as you asked me LOL )  Just a hypothesis, but we may have already peaked. 

I have a notion I'm working on that the Aerosol-related/theorized global temperature spike cast an allusion of stronger drive. 

The La Nina suppressed the atmospheric thermal response to the reduction in aerosols...spanning a few years of its unusual longevity. It seemed that as the La Nina first began empirically weakening earlier this last spring, the global spike phenomenon, both air and sea and amid every latitudes (shocking actually) ... all left the launch pad and ascended almost lock step.  These changes were prior to the warm ENSO foot being established.    

There are El Nino mechanics going on, but these disparate aspects are very difficult to parse out from one another.  

There's been too many baseline canonical mechanics insufficient for an El Nino destined to an exalted dimension, and that's been pretty evident all along. 

 

[MJO812]

 

[NEPASnow]

what would a +PDO do for winter on east coast in our current setup.  It appears the -PDO is getting erased currently.

 

[Typhoon Tip]

Winter arrives in early November ... (close to making a thread?, but hold off for now) 

Not sure of the longevity there after - in fact, I wouldn't be shocked if the continent handsomely reverses deeper in the month - perhaps transiently, prior to a cyclic -EPO autumn. 

Ensuing daily deterministic guidance (i.e., your GGEMs to ECMWF's et al) solutions begin manifesting LE/Lakes and NW el flow snows as a minimum, amid an atmospheric anomaly easily supportive of a synoptic winter profile event(s).  The period Halloween through 10th, particularly near the end of that first week - timing and specifics are too nebular at this range to be very specific (obviously). 

We're negotiating this idea between guidance sources and techniques, but the common denominator below the noise has been and continues to be an extraordinarily deep -WPO. This aspect (and the leading Asian torque foot) has erstwhile been bouncing off a -PDO basal N Pac circulation (AA mode).

In other words, there's likely been erstwhile destructively interference between the two.  However, using the SST metric ... there is apparently a 'bending' if not break point where the WPO forcing is on the threshold of winning.  There is a pretty dramatic -PDO collapse - one that I suggest is partially obscured by a general N Pac that's got a 'thermal hangover' from the global spike phenomenon during this last spring and summer...  These changes in NE Pac SST distribution suggest a N Pac atmospheric mode is being more receptive to WPO.

That will likely result in a -WPO bursting through/-EPO (AB phase), a hand shake that is manifesting spatially in the ensemble means as early season cross polar construct roughly centered on D12   We're just not doing this at Christmas so we get what we get out of it...  

There's are some interesting suggestions from basement, too...The MJO has been drilling a hole in space, stuck, for almost 3 weeks, right around phase 8. It is very low amplitude, but present nonetheless. An indirect indicator for its momentum in the total manifold ...there has been modeled a W 850 mb wind over the north side of the NINO 1+2 region, which has both assisted in spinning up far E Pac TC activity, but also occasionally triggering the formulation of CAG circulation over the western Caribbean.  It is less important this latter aspect actually materializes for us up here throughout the OV/NE/SE Canada; the model physics have been 'detecting' forcing that is consistent with a MJO phase 8-1-2 space correlation.  In other words ... it's there lurking so these tell us not to ignore its contribution to this thing. 

In the more convention usage:

-- the -EPO is both correlated to early season warm ENSO

-- modeled to exist now

-- is forecast by all ensemble sourced derivatives to relay the above into a +PNA ...OR (and this is important!) a neutral PNA with a +PNAP across mid latitudes of the N/A continent.  This is the canonical tendency.  We can see 850 mb temperature anomalies flooding Canada while we are basking in a short lease warm up during this mid next week. 

I'm not firing off a thread for this out of deference to the stochastic model performance during transition seasons. More over, these above changes in the hemisphere happening, whilst the atmosphere has already got teenager changes-induced mood swings going on already ...should nicely assist even ensemble weighting to swing too far left or right - so to speak. 

But I'll tell ... it is honestly a refreshing journey to have something legit in the relative coherency of scaled indicators to finally write about. It's been probably 3 years since I've had this chance.  Lord

[Typhoon Tip]

Another cycle and edging yet more impressive...

That is a particularly deep signal for an extended range ensemble mean wrt to temperature anomaly/distribution signal.  That's cold folks!  

 

[Itryatgolf70]

1 hour ago, Typhoon Tip said:

Another cycle and edging yet more impressive...

That is a particularly deep signal for an extended range ensemble mean wrt to temperature anomaly/distribution signal.  That's cold folks!  

 

Could you post images or no?

[bristolri_wx]

My two cents (and maybe not even worth that) - however this winter turns out, there should be confidence that it will be different than last year. Whether that ends up being more snow or more cold remains to be seen. What we do know is that from June until now, we’ve been in a much different pattern compared to last year. Maybe we end up both warmer and snowier thanks to the way things end up falling into place. If we “rat” I bet it will be in an entirely different way than 2022-2023.

Not basing this on lots of numbers, just observation and common sense that this years atmospheric chaos seems to be a lot different than last years atmospheric chaos. We shall see! 

[ORH_wxman]

1 hour ago, Itryatgolf70 said:

Could you post images or no?

I’m not Tip but I’ll pinch hit for him on this one…first H5 anomaly (5 day average mean ending 11/5) and then 850 anomaly for the same period…

 

 

 

At the moment, ensembles are keeping the cold relatively transient…lifting it out by the very end of their ensemble runs, but we know the caveats sometimes when changing into a new pattern…sometimes guidance tries to end it too quickly. So we’ll see how it all shakes out. But definitely a colder look coming in around Halloween into early Nov  

 

[40/70 Benchmark]

Just now, 40/70 Benchmark said:

Last Update from me before I publish next month.

https://easternmassweather.blogspot.com/2023/10/final-enso-update-of-fall.html

 

[NEPASnow]

3 minutes ago, 40/70 Benchmark said:

 

are we still looking for more of a central based El Nino?

[40/70 Benchmark]

1 hour ago, NEPASnow said:

are we still looking for more of a central based El Nino?

Looks to be basinwide.

[TauntonBlizzard2013]

Just now, 40/70 Benchmark said:

Looks to be basinwide.

That’s a negative for this region, correct?

[NEPASnow]

10 minutes ago, 40/70 Benchmark said:

Looks to be basinwide.

is the convenction still west along the dateline due to the cold water below Hawaii?

[MJO812]

12 minutes ago, TauntonBlizzard2013 said:

That’s a negative for this region, correct?

Congrats DC?

[RUNNAWAYICEBERG]

12 minutes ago, TauntonBlizzard2013 said:

That’s a negative for this region, correct?

It has to be. No positives allowed. 

[SnowGoose69]

2 hours ago, NEPASnow said:

is the convenction still west along the dateline due to the cold water below Hawaii?

The assumption by some is that is the cause for it.  DT's winter write up showed that cold anomaly has mitigated El Nino impacts in the past, but we have seen so many strange things in recent years with SSTs its possible the convection placement might be a result of something else

[40/70 Benchmark]

17 hours ago, NEPASnow said:

is the convenction still west along the dateline due to the cold water below Hawaii?

I feel like the forcing it being pulled west due to the warmth in the west PAC..this is also keeping el Nino in check.

[40/70 Benchmark]

18 hours ago, TauntonBlizzard2013 said:

That’s a negative for this region, correct?

I wouldn't expect a top 10 snowfall season...just in that sense maybe.

[WinterWolf]

36 minutes ago, 40/70 Benchmark said:

I wouldn't expect a top 10 snowfall season...just in that sense maybe.

He’s expecting a bottom 3 I’m sure lol…..all kidding aside I think average is certainly attainable for most areas in SNE.  And that will seem huge after last year.   

[WxWatcher007]

11 minutes ago, WinterWolf said:

He’s expecting a bottom 3 I’m sure lol…..all kidding aside I think average is certainly attainable for most areas in SNE.  And that will seem huge after last year.   

Average would be a win. Having the season not reside from Feb 15-March 15 would be a massive win. 

[NEPASnow]

 

[WinterWolf]

2 hours ago, WxWatcher007 said:

Average would be a win. Having the season not reside from Feb 15-March 15 would be a massive win. 

Agreed Don…completely. 

[DavisStraight]

26 minutes ago, WinterWolf said:

Agreed Don…completely. 

I'd be happy with 50 inches and at least one 15+ incher.