ENSO Discussion

[Phil]

You talking about the cooler than normal water along the Equator in the Atlantic? Never heard that term, "Atlantic ENSO".

 

 

Yeah, it's not something commonly discussed in the online community but that's the technical term used within the scientific community. It runs on a higher frequency than the Pacific ENSO but it can have implications when it shares a sign with the EPAC.

[Phil]

For example, back in 2014, we had the opposing signs at work which focused convection in the east-central Pacific, which was partially responsible for the development of a weak +ENSO low frequency state.

 

http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomnight.7.14.2014.gif

[Phil]

Another example, during the development of the super Niño in 2015. Convection was shifted away from the Atlantic/IO ITCZ and focused over the Pacific. It's all part of a single system, really.

 

http://www.ospo.noaa.gov/data/sst/anomaly/2015/anomnight.6.18.2015.gif

[Geos]

Another example, during the development of the super Niño in 2015. Convection was shifted away from the Atlantic/IO ITCZ and focused over the Pacific. It's all part of a single system, really.

 

 

Interesting. Do you think that during the predicted multi year Pacific La Nina you've mentioned, will it correlate to a cooler Atlantic?

[snow_wizard]

For example, back in 2014, we had the opposing signs at work which focused convection in the east-central Pacific, which was partially responsible for the development of a weak +ENSO low frequency state.

 

 

That brings back bad memories.

[Phil]

Some westerly anomalies developing in the EPAC as the Walker Cell retracts westward w/ WHEM forcing.

 

Enhanced intraseasonal variability like this is something typically associated with weaker ENSO states, possibly indicative that this event won't reach "moderate" in trimonthly status.

 

http://www.atmos.albany.edu/student/ventrice/real_time/timeLon/u.anom.30.5S-5N.gif

[stuffradio]

Some westerly anomalies developing in the EPAC as the Walker Cell retracts westward w/ WHEM forcing.

 

Enhanced intraseasonal variability like this is something typically associated with weaker ENSO states, possibly indicative that this event won't reach "moderate" in trimonthly status.

 

http://www.atmos.albany.edu/student/ventrice/real_time/timeLon/u.anom.30.5S-5N.gif

That's probably better for us snow wise, isn't it?

[stuffradio]

Someone posted on Twitter "Although SST's are looking E-based #LaNina, the equatorial atmosphere still sticks to a W-based look, more in line with 2008/2009"

[Phil]

That's probably better for us snow wise, isn't it?

I don't think it makes a difference in the grand scheme of things.

[Phil]

Someone posted on Twitter "Although SST's are looking E-based #LaNina, the equatorial atmosphere still sticks to a W-based look, more in line with 2008/2009"

I'd say it looks more "east-based" to me there as well. The IPWP uplift is about 10 degrees east of last year at this time.

[Front Ranger]

Someone posted on Twitter "Although SST's are looking E-based #LaNina, the equatorial atmosphere still sticks to a W-based look, more in line with 2008/2009"

 

I knew this wasn't Phil.

[Geos]

That sure does look east based right now.

 

 

[Geos]

ENSO region 1+2 has really tanked in the last week to 10 days.

 

 

[Black Hole]

In regards to this winter, I have been noticing many similarities to 2007/2008. The ENSO situation is similar with a late blossoming la nina coming on. Further, the observed weather at least in my part of the world is similar with a very long and hot summer, followed by a switch to cool/wet weather in Sep/Oct. That year was the last time it snowed in Sep (I had some on the 21st this year). 

So in many ways the observed weather is following well. 

[Phil]

In regards to this winter, I have been noticing many similarities to 2007/2008. The ENSO situation is similar with a late blossoming la nina coming on. Further, the observed weather at least in my part of the world is similar with a very long and hot summer, followed by a switch to cool/wet weather in Sep/Oct. That year was the last time it snowed in Sep (I had some on the 21st this year).

 

So in many ways the observed weather is following well.

That winter was so d**n windy here. I think we had ~ 25-30 days without power from December - March.

[Geos]

In regards to this winter, I have been noticing many similarities to 2007/2008. The ENSO situation is similar with a late blossoming la nina coming on. Further, the observed weather at least in my part of the world is similar with a very long and hot summer, followed by a switch to cool/wet weather in Sep/Oct. That year was the last time it snowed in Sep (I had some on the 21st this year). 

 

So in many ways the observed weather is following well. 

 

Back in the Midwest it was quite a snowy winter with just over 100" where I lived. I'll always remember that winter - the winter that it wouldn't quit snowing.

[Guest happ]

In regards to this winter, I have been noticing many similarities to 2007/2008. The ENSO situation is similar with a late blossoming la nina coming on. Further, the observed weather at least in my part of the world is similar with a very long and hot summer, followed by a switch to cool/wet weather in Sep/Oct. That year was the last time it snowed in Sep (I had some on the 21st this year). 

 

So in many ways the observed weather is following well. 

 

2007/08 was a decent rain year here [over 20"]. A hot summer followed by a cooler than average September.

[Black Hole]

Back in the Midwest it was quite a snowy winter with just over 100" where I lived. I'll always remember that winter - the winter that it wouldn't quit snowing.

Yeah in Utah it was very snowy, a storm train that just wouldn't quit. 

[Front Ranger]

Sep 2007 was quite a bit different here. Nothing close to the ongoing cool stretch. Didn't have any notable cool weather until mid October, and nothing sustained until around Thanksgiving.

[Geos]

Yeah in Utah it was very snowy, a storm train that just wouldn't quit. 

 

It wasn't particularly cold there either, just really wet. Almost the entire winter was snow covered in the area I lived.

[snow_wizard]

In regards to this winter, I have been noticing many similarities to 2007/2008. The ENSO situation is similar with a late blossoming la nina coming on. Further, the observed weather at least in my part of the world is similar with a very long and hot summer, followed by a switch to cool/wet weather in Sep/Oct. That year was the last time it snowed in Sep (I had some on the 21st this year). 

 

So in many ways the observed weather is following well. 

 

Looks a bit more blocky than 2007 though.  Just a tiny difference in blockiness could have huge implications for the NW winter.

 

BTW the solar was perfect match also.  This winter will probably have somewhat of a 2007-08 look, but as I said small variations would be huge for us.

[Geos]

Got a little warming to the east and some cooling going on to the west right now.

 

 

[TT-SEA]

Got a little warming to the east and some cooling going on to the west right now.

 

 

 

That is significant warming in the east.  

[Phil]

Some MJO interference with the Niña cell/background state, which remains quite weak/unstable (for the time being).

 

http://www.atmos.albany.edu/student/ventrice/real_time/timeLon/u.anom.30.5S-5N.gif

[TT-SEA]

Some MJO interference with the Niña cell/background state, which remains quite weak/unstable (for the time being).

 

 

Yeah... the Nina is suddenly look pretty weak.   Lots of warming over the last week.

 

[SilverFallsAndrew]

Yeah... the Nina is suddenly look pretty weak.   Lots of warming over the last week.

 

 

This has been shown on the models for a few weeks.

[Jesse]

People have such high expectations for this Niña it seems........................................... ,

[Kayla]

People have such high expectations for this Niña it seems........................................... ,

 

I've heard we don't want a strong Niña anyway..................

[Guest happ]

The La Nina of 2010/11 produced great rain years [22.73 in 2010 & 32.88 total in 2011]. The El Nino of 2015 started off great during summer but failed miserably in winter. Climatologists predict a warm winter for California.  

[Phil]

The La Nina of 2010/11 produced great rain years [22.73 in 2010 & 32.88 total in 2011]. The El Nino of 2015 started off great during summer but failed miserably in winter. Climatologists predict a warm winter for California.

La Niña winter rainfall in the SW US depends heavily on the state of the AO/NAM. The winter of 2010/11 had a strong polar block and equatorward jet.

[Phil]

In fact, I would go farther, and claim that the long term drying trend in the SW US is a direct consequence of the overall trend towards a boreal winter +NAM (+AO) since the 19th century.

 

This is because the +NAM system state corresponds to a broadened/poleward-shifted Hadley Cell network, and weakened tropical convection. This also warms the globe in the long run given more solar radiation uptake in the tropical oceans, which further enhances the Hadley Cell expansion and +NAM. The feedback loop can continue for centuries if the external forcings allow it.

[seattleweatherguy]

Possible it will revert to a cold neutral?

[Phil]

Possible it will revert to a cold neutral?

I hope so, since neutral was my original call.

[Front Ranger]

We'll have the answer for summer sometime around the spring equinox. While the aforementioned progression favors an anticyclonic NPAC background state into summer with a downstream western trough, whether it continues depends on whether the PV/NAM breakdown (SSW) and subsequent state-reversal alters the underlying/low frequency tropical convective system, which currently remains under low frequency control of the +QBO. The SSW, or a major volcanic eruption, are the only thing capable of altering this global system state abruptly and permanently, with the last example of such an occurrence being January 2013. Not even the sun can do that so quickly.

 

If the QBO maintains its grip on the thermals and wave state, the developing Niño attempt will fail and the west will experience a cooler than average summer under -PNA and/or generally stronger antiycyclonic NPAC state. If the QBO either cycles back early (very unlikely) or tropical convective domain is altered thanks to the ongoing perturbation via SSW/NAM -> mass circulations/static stability, the Niño attempt will succeed and the west will experience a warmer than average summer under a cyclonic NPAC state.

 

As it turns out, the QBO lost its grip, but the developing Nino attempt failed, and the West had a warmer than average summer...

 

[Phil]

As it turns out, the QBO lost its grip, but the developing Nino attempt failed, and the West had a warmer than average summer...

 

Actually the exact opposite. The -QBO cycled in much faster than expected, which tightened the Walker Cell faster, but didn't provide enough time for the WPAC to cool/ventilate through evaporative feedback once the warm waters left the EPAC. So we were left with a huge WPAC Hadley Cell, and a residual +SIOD/+IOD (enhanced W-IO convection), under a -QBO base state, which is more reflective of an extremely west-based El Niño, if anything.

 

It wasn't until sometime in April that I saw what was happening, and even then I thought the warmth would wait until August. The majority of the heat did hold off until August, however it was such a rapid transition that it caught me napping with regards to the evolution of the June/July wavetrain.

 

This was actually the fastest -QBO frontal cycle since 1960.

[TT-SEA]

Actually the exact opposite. The -QBO cycled in much faster than expected, which tightened the Walker Cell faster, but didn't provide enough time for the WPAC to cool/ventilate through evaporative feedback once the warm waters left the EPAC. So we were left with a roaring/west-shifted WPAC Hadley Cell and enhanced Indian Ocean convection under a -QBO base state, which, for all intents and purposes, is more reflective of an extremely west-based El Niño, if anything.

 

It wasn't until sometime in April that I saw what was happening, and even then I thought the warmth would wait until August. The majority of the heat did hold off until August, however it was such a rapid transition that it caught me napping with regards to the evolution of the June/July wavetrain.

 

This was actually the fastest frontal QBO cycle since 1960.

 

It is being remembered as a warm summer... but July was almost normal and one of the most perfect summer month possible around here.  

[Phil]

It is being remembered as a warm summer... but July was almost normal and one of the most perfect summer month possible around here.

Yeah, I remember it being a warm day/cool night type of pattern, with heat focused along/east of the Cascades.

[Phil]

Yeah, pretty much average west of the Cascades, warm/hot along/east of the Cascades.

 

[Front Ranger]

It is being remembered as a warm summer... but July was almost normal and one of the most perfect summer month possible around here.  

 

It was a warm summer. July was coolish right along the immediate coastline, but was definitely a warm month overall for the PNW. Same with June.

 

The warm season pattern became established halfway through May, and the entire first half of the warm season set the stage for a very similar second half, as far as warm West/cool East.

 

[seattleweatherguy]

I hope so, since neutral was my original call.

Cold neutral or neutral means more widely storms! At least better chance for notable ones.