February 2022 Obs/Disco

[40/70 Benchmark]

East-based la nina events have always been more prone to poleward Aleutian ridging....I noted numerous examples spanning back decades in my work last fall. Again, not doubting the Hadley cell research, but cold ENSO episodes of this ilk have always strayed from the la nina baseline, historically speaking.

[40/70 Benchmark]

East Pacific (EP) La Ninas

East Pacific events are "characterized by the cooling SST anomaly center confined to the EP

 east of 150°W and relatively weak SST anomaly observed over the CP". They decay

 more quickly overall. These canonical la nina events are theorized to be relegated

 largely to the eastern Pacific due to the fact that they are a byproduct of the

 thermocline dynamics present in the Walker Cycle", which is explained  in the

 ENSO & Tropical Background addendum.

 

Here is a composite of cool ENSO events meeting this criteria:

 

 

 

 

 

Note that the warmer anomalies near the dateline ensure that forcing remains over the central and western Pacific,

 similar to the weaker la nina composite. Sinking air that discourages convective forcing is focused well east of the dateline. Also evident is that the Aleutian ridge focuses more to the northwest relative to the modoki, cp event, which will be illustrated when that particular composite is reviewed. 

This often entails a protrusion of said ridge into the polar region at times, which likely contributes to the lower heights

 over the mid latitudes:

 

 

 

Note again the similarities to the weak la nina H5 composite that was comprised in the intensity segment of the discussion. 

Obviously that is because all of these events were weak, however, there are some stronger basin wide events that were still decidedly biased east. Two such events there were referenced earlier are the strong la nina events of 1955-1956 and 2010-2011, which were both fairly cold across the eastern US and featured a great deal of blocking. Both of these have been designated as mixed-type "hybrid" events.

[WinterWolf]

2 hours ago, Damage In Tolland said:

I don’t think the whole month looks wintry. There looks like a 2 week window first half of month to me.

Well that also would go along with, and favors climo too.  In most cases, if March is gonna be wintry, it’s usually during the first half.   

[40/70 Benchmark]

I think what we have this season is an eastward biased cool ENSO overlaid onto spiking solar, so we have the favorable PAC interludes, with tempered blocking due to the rising solar.  The strat vortex has remain robust due to the sun IMO....so when the tropo vortex was somewhat dysregulated early on, it wasn't well coupled, but now that its recovered they have aligned.

[rimetree]

Just ordered a new snow blower last night. Winter is over. 

[CoastalWx]

Euro with Pina Coladas first half of next week.

[Great Snow 1717]

10 minutes ago, rimetree said:

Just ordered a new snow blower last night. Winter is over for the next decade.

FYP

[Typhoon Tip]

6 minutes ago, 40/70 Benchmark said:

East-based la nina events have always been more prone to poleward Aleutian ridging....I noted numerous examples spanning back decades in my work last fall. Again, not doubting the Hadley cell research, but cold ENSO episodes of this ilk have always strayed from the la nina baseline, historically speaking.

That correlation may be so ...

but in present practice, it makes it hard to know if that is causing this or not when as noted by CPC analysis, the atmospheric circulation has been decoupled in recent weeks.  If it is decouple, that can't be the forcing mechanism -

But that may be fine in the discussion.  Because, it's just as plausible that eastward biased cool SST anomalies typically do disconnect/'uncouple'     It's an interesting question/topic no doubt.  That would take a tedious atmospheric reanalysis effort comparing all historical La Nina's that fell within 90% tolerant analogs to this one, by some red-eyed brain flogged grad student thinking they might've bitten off more than they can chew in their chosen thesis directive.   I mean it's like... 'was the La Nina analog in x-y-z year'  Then compare circulation modes then and now as to their uncoupled states.... I guess you could do it.  But it would be too levels of research.  Amassing suspect seasons, than calculations/mathematical physics to prove it.   AI/super computing would be helpful in the latter.   digressing -

The HC stuff is speculative, btw -     I only push that across ( as a posit) because I like cause and effect?   I don't believe things just happen for the sake of their existence.  Everything is caused by an event, or an aggregate of events in constructive(destructive) interference, in nature - in reality really.  The atmosphere is no different.  There's a reason for these ENSO disconnects.  There's a reason for the faster than normal atmospheres. If the boreal winter heights are still deep enough, and the HC lingers into mid latitudes even fractionally... that increases gradient -->  speed takes place.   And here's the the thing that I think would be critical in that assertion- I don't believe the initial HC studies have it right that the expansion is only happening in the summer.  That's suspect ... Firstly, the radiative forcing in the tropics doesn't dim below the threshold where the atmosphere would no longer gain diabatic energy, below 23 1/2 deg of latitude winters.  It's not that it is not happening, it is being expressed via wind velocity.  The compression of the heights speeds up the flow, and that is the machinery that conserves the energy of the expansion - it's just being converted into stronger winds.

[Brian5671]

54 minutes ago, CoastalWx said:

More clown maps.

have any of these ever verified on winds?!?!?

[Great Snow 1717]

1 hour ago, RUNNAWAYICEBERG said:

Will you be awake and sober to see yours fly off?

Last time I checked no one on this forum lives in one of these....lol

[40/70 Benchmark]

10 minutes ago, Typhoon Tip said:

That correlation may be so ...

but in present practice, it makes it hard to know if that is causing this or not when as noted by CPC analysis, the atmospheric circulation has been decoupled in recent weeks.  If it is decouple, that can't be the forcing mechanism -

But that may be fine in the discussion.  Because, it's just as plausible that eastward biased cool SST anomalies typically do disconnect/'uncouple'     It's an interesting question/topic no doubt.  That would take a tedious atmospheric reanalysis effort comparing all historical La Nina's that fell within 90% tolerant analogs to this one, by some red-eyed brain flogged grad student thinking they might've bitten off more than they can chew in their chosen thesis directive.   I mean it's like... 'was the La Nina analog in x-y-z year'  Then compare circulation modes then and now as to their uncoupled states.... I guess you could do it.  But it would be too levels of research.  Amassing suspect seasons, than calculations/mathematical physics to prove it.   AI/super computing would be helpful in the latter.   digressing -

The HC stuff is speculative, btw -     I only push that across ( as a posit) because I like cause and effect?   I don't believe things just happen for the sake of their existence.  Everything is caused by an event, or an aggregate of events in constructive(destructive) interference, in nature - in reality really.  The atmosphere is no different.  There's a reason for these ENSO disconnects.  There's a reason for the faster than normal atmospheres. If the boreal winter heights are still deep enough, and the HC lingers into mid latitudes even fractionally... that increases gradient -->  speed takes place.   And here's the the thing that I think would be critical in that assertion- I don't believe the initial HC studies have it right that the expansion is only happening in the summer.  That's suspect ... Firstly, the radiative forcing in the tropics doesn't dim below the threshold where the atmosphere would no longer gain diabatic energy, below 23 1/2 deg of latitude winters.  It's not that it is not happening, it is being expressed via wind velocity.  The compression of the heights speeds up the flow, and that is the machinery that conserves the energy of the expansion - it's just being converted into stronger winds.

I think its both....depends on which season, but generally speaking, east-based la nina events, like modoki el nino events, tend to be less pervasive forces in the atmosphere (though this one was very prominent early on)....so it makes sense that some of the disconnect from la nina climo may be a byproduct of that. But its also due to the fact that the forcing tends to make it farther to the east, closer to the dateline in east-based la nina events, like Scott was illustrating via VP image.

Anyway, just as you say that everything is caused by an event in the atmosphere, I am of the opinion that there is rarely one "silver bullet" or "smoking gun", so to speak. In fact, its usually an agglomeration of factors working in concert and vying for proxy.

The HC stuff totally makes sense to me...my aim wasn't to dispute that in any way....just want to be careful not to overattribute phenomena to it.

[ORH_wxman]

23 minutes ago, CoastalWx said:

Euro with Pina Coladas first half of next week.

Got a lot flatter with that wave though…not far from something more wintry. We’ll have to see if it tries to pull a 2/4

[jbenedet]

5 hours ago, dendrite said:

Yeah if we pop some sun I think I agree for S NH. That weak inversion is pretty low and could be somewhat mixed out easily. Model 2m temps are already u50s. 

I'd be pretty surprised if it doesn't, MHT - South/east. The warm front lifts through around sunrise and moves north/east, unmitigated. 

[jbenedet]

MHT up to 42F. Nice day for Feb

[WinterWolf]

10 minutes ago, ORH_wxman said:

Got a lot flatter with that wave though…not far from something more wintry. We’ll have to see if it tries to pull a 2/4

What day are you talking about? 

[TauntonBlizzard2013]

As usual, I’ll sell on the high winds tomorrow night 

[ORH_wxman]

11 minutes ago, WinterWolf said:

What day are you talking about? 

Next Tuesday.

[CoastalWx]

26 minutes ago, ORH_wxman said:

Got a lot flatter with that wave though…not far from something more wintry. We’ll have to see if it tries to pull a 2/4

Yeah saw EPS is cooler. Sell the op.

[CoastalWx]

8 minutes ago, TauntonBlizzard2013 said:

As usual, I’ll sell on the high winds tomorrow night 

Will be typical 50-60 stuff I think.

[TauntonBlizzard2013]

11 minutes ago, CoastalWx said:

Will be typical 50-60 stuff I think.

Meh

[HoarfrostHubb]

1 hour ago, Lava Rock said:

32.4F. That'll be the last sub 32 for awhile. bye bye pack.

Saturday morning... 

[HoarfrostHubb]

That was a 10 m map as well.   High roofs in Tolland

[40/70 Benchmark]

4 minutes ago, HoarfrostHubb said:

That was a 10 m map as well.   High roofs in Tolland

Maybe 10m from sea level, so you're ripping at 1000'  in the Tolland Alps.

[CoastalWx]

EPO gone wild on EPS. 

[Damage In Tolland]

Eye popper 

[brooklynwx99]

thing of beauty

[40/70 Benchmark]

2 minutes ago, brooklynwx99 said:

thing of beauty

Looks like GEFS. 

#nudityinbrooklyn

[MJO812]

3 minutes ago, 40/70 Benchmark said:

Looks like GEFS. 

#nudityinbrooklyn

Already in my squad car

[40/70 Benchmark]

Just now, MJO812 said:

Already in my squad car

Lights and clothing off, siren on.

[Typhoon Tip]

It's annoying and unpleasant outside right now here in Ayer.   There's just enough high clouds to dim the sun to a glow and not really warm feeling. Meanwhile, it's windy.   So 42 may as well be 24 ...  Helluva way to kick off a warm spell. 

heh anyway, not surprised.  It didn't look "nice" out in the charts scoping this prefrontal environment. It looked to windy then.