2024-2025 La Nina

[snowman19]

14 hours ago, bluewave said:

It’s possible that the rapid reduction of shipping aerosols due to the new regulations that went into effect in 2020 is boosting the marine heatwaves in the mid-latitudes. One of these record marine heatwaves is driving the record SSTs east of Japan leading to the record -PDO values. The ongoing record marine heatwave in the Atlantic are driving the record +AMO. We will probably need further studies to confirm the exact reason for this sudden global temperature rise above model forecasts in recent years. But one of the uncertainties in climate modeling is how changes in clouds and aerosols affect global climate sensitivity to CO2 forcing. 
 

 

@bluewave Might be playing a role in the record low arctic sea ice too you think? 

[Stormchaserchuck1]

shipping aerosols? lol 

[40/70 Benchmark]

5 hours ago, Stormchaserchuck1 said:

Still just a monster N. Pacific ridge here.. subtropical jet making it up to Alaska

https://ibb.co/q7ggFZy

Then hr384 on the ensemble mean has another round of -PNA 

https://ibb.co/88Cpx49

My guess is that subsurface-ENSO will strengthen cold anomalies during this time in July.   They are pretty weak right now, looking like a Weak or low-end Moderate surface La Nina peak. 

Per ONI, I agree....but that isn't what's important.

[40/70 Benchmark]

2 hours ago, bluewave said:

It’s possible that the rapid reduction of shipping aerosols due to the new regulations that went into effect in 2020 is boosting the marine heatwaves in the mid-latitudes. One of these record marine heatwaves is driving the record SSTs east of Japan leading to the record -PDO values. The ongoing record marine heatwave in the Atlantic are driving the record +AMO. We will probably need further studies to confirm the exact reason for this sudden global temperature rise above model forecasts in recent years. But one of the uncertainties in climate modeling is how changes in clouds and aerosols affect global climate sensitivity to CO2 forcing. 
 

 

I thought reducing aerosols should temper global warming? Its among it worse, or is this is a shorter term reaction?

[Stormchaserchuck1]

3 minutes ago, 40/70 Benchmark said:

Per ONI, I agree....but that isn't what's important.

Subsurface has a higher correlation to the N. Pacific pattern than ONI, RONI, Nino 1, 2, 3.. but since 1999 the relative value (RONI) has correlated more with the Hadley Cell/Mid-latitude Cell, by even as much as -0.5/6 difference (ex: ONI is -0.6, global pattern acts like it's -1.2). 

[40/70 Benchmark]

2 minutes ago, Stormchaserchuck1 said:

Subsurface has a higher correlation to the N. Pacific pattern than ONI, RONI, Nino 1, 2, 3.. but since 1999 the relative value (RONI) has correlated more with the Hadley Cell/Mid-latitude Cell, by even as much as -0.5/6 difference (ex: ONI is -0.6, global pattern acts like it's -1.2). 

Your NAO theorem flipped +, correct? We're about halfway home on that...

[Stormchaserchuck1]

16 hours ago, 40/70 Benchmark said:

Your NAO theorem flipped +, correct? We're about halfway home on that...

38% of the way through it's +0.05.. 

I do think we could have some -NAO periods this Winter, but that's because it's had such a big correlation to the -PNA in the last 11 years.  If the central-Atlantic warmth migrates north to off the coast of New Foundland though, it could run the index more positive since it runs out to Aug-Sept, and +TNA often migrates to +AMO from the Winter to that time...

Edit: We are really blasting this thing + right now. https://ibb.co/styNwm6 I was looking at the 5/1-6/25 composite. 

[snowman19]

11 hours ago, Stormchaserchuck1 said:

38% of the way through it's +0.05.. 

I do think we could have some -NAO periods this Winter, but that's partially because it's had such a big correlation to the -PNA in the last 11 years.  If the central-Atlantic warmth migrates north to off the coast of New Foundland though, it could run the index more positive since it runs out to Aug-Sept, and +TNA often migrates to +AMO from the Winter to that time...

Edit: We are really blasting this thing + right now. https://ibb.co/styNwm6 I was looking at the 5/1-6/25 composite. 

I figured when I saw the tropical SSTs around New Foundland that was going to happen. There hasn’t been anything even remotely resembling an Atlantic tripole this entire month 

[bluewave]

12 hours ago, 40/70 Benchmark said:

I thought reducing aerosols should temper global warming? Its among it worse, or is this is a shorter term reaction?

Aerosols have been masking global warming over the years. But they have no idea how much since each model gives them a different answer. In addition to shipping places like China have cleaned up the sulphur emissions also. I think the scientific community is pretty much scrambling to figure out why the temperature increase was so much beyond expectations in recent years. Clouds and aerosols are very uncertain since the models have such a wide range of results. 

 

 

[so_whats_happening]

11 minutes ago, bluewave said:

Aerosols have been masking global warming over the years. But they have no idea how much since each model gives them a different answer. In addition to shipping places like China have cleaned up the sulphur emissions also. I think the scientific community is pretty much scrambling to figure out why the temperature increase was so much beyond expectations in recent years. Clouds and aerosols are very uncertain since the models have such a wide range of results. 

 

 

Yep and an increase or decrease in cloud cover plays a very important part in radiative balance. Even something as small as 2% can make a large difference, cloud height also plays such an important role. Was discussing with one of my colleagues on the situation (he works with NOAA) they are not even sure what is going on with the rather abrupt increase over the last decade or so. To be higher continuously from a warming average is something we surely have not recorded take place.

Truly something interesting to see happen.

[40/70 Benchmark]

Fire up the aresols again.

[GaWx]

20 minutes ago, 40/70 Benchmark said:

Fire up the aresols again.

I still wonder about the true impact of the Hunga Tonga underwater eruption and the huge amount of water vapor emitted up into the stratosphere, which supposedly will linger for several more years.

[Stormchaserchuck1]

GFS ensemble mean now pinches off a 594dm ridge over the Aleutian islands of Alaska July 5-6.. should be record breaking if it verifies.  Looking like a very hot July in the N. Pacific, which is usually has something to do with La Nina impacting.. 

Subsurface continues to look like a Weak Nina though

[bluewave]

7 hours ago, Stormchaserchuck1 said:

GFS ensemble mean now pinches off a 594dm ridge over the Aleutian islands of Alaska July 5-6.. should be record breaking if it verifies.  Looking like a very hot July in the N. Pacific, which is usually has something to do with La Nina impacting.. 

Subsurface continues to look like a Weak Nina though

The record breaking 500 mb heights and surface high pressures just keep coming out there. 
 

 

 

[snowman19]

10 hours ago, bluewave said:

The record breaking 500 mb heights and surface high pressures just keep coming out there. 
 

 

 

This is only going to serve to drop the PDO and PMM even more. Also going to really strengthen the ENSO region trade winds. Becoming very confident that we see a big uptick in the La Niña in July, also with Maritime convection starting to fire, we very likely also see a rapid rise in the SOI

[bluewave]

6 hours ago, snowman19 said:

This is only going to serve to drop the PDO and PMM even more. Also going to really strengthen the ENSO region trade winds. Becoming very confident that we see a big uptick in the La Niña in July, also with Maritime convection starting to fire, we very likely also see a rapid rise in the SOI

The best the PDO has been able to do has been a rise back to around -1.5 before dropping again to the -2 to -3 range. 
 

[snowman19]

1 minute ago, bluewave said:

The best the PDO has been able to do has been a rise back to around -1.5 before dropping again to the -2 to -3 range. Regardless of what the La Niña details are for next fall and winter, my guess is that this -PDO is enough for our 10th warmer winter in a row for the Northeast since 15-16. Not sure on snowfall details yet which usually don’t get revealed until the October MJO early indicator. I just hope we can do better than the last 2 years. 
 

I think we can say with a lot of confidence that we see another winter of MJO 4-6 forcing, especially with the Niña and the IOD turning more neutral-negative, which favors eastern IO and Maritime Continent convection. Seasonal snowfall is always a wildcard, since a single event can skew it. The other thing that’s striking right now is the record low arctic sea ice already….that’s only going to decrease even more in July and August 

[bluewave]

21 minutes ago, snowman19 said:

I think we can say with a lot of confidence that we see another winter of MJO 4-6 forcing, especially with the Niña and the IOD turning more neutral-negative, which favors eastern IO and Maritime Continent convection. Seasonal snowfall is always a wildcard, since a single event can skew it. The other thing that’s striking right now is the record low arctic sea ice already….that’s only going to decrease even more in July and August 

It looks like the -PDO has been driving the strong  La Niña background state with the 100° June heat we have just seen in the East. As the actual La Niña has been slower out of the gate than usual. May be related to the ongoing record marine heatwaves slowing the drop in SSTs east of the Dateline. But as long as the -PDO is so negative, we are getting a very strong La Niña background state regardless of what happens east of the Dateline.

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jun
Click column heading to sort ascending, click again to sort descending.

1	2021	103	La Niña
2	2011	102	La Niña
-	1994	102	El Niño
-	1993	102	Neutral
-	1952	102	Neutral
-	1943	102
7	1988	101	El Niño to La Niña
-	1966	101	El Niño to La Niña
9	2024	100	El Nino to La Niña
-	1959	100	El Niño to neutral
-	1953	100	El Niño
-	1934	100

[snowman19]

31 minutes ago, bluewave said:

It looks like the -PDO has been driving the strong  La Niña background state with the 100° June heat we have just seen in the East. As the actual La Niña has been slower out of the gate than usual. May be related to the ongoing record marine heatwaves slowing the drop in SSTs east of the Dateline. But as long as the -PDO is so negative, we are getting a very strong La Niña background state regardless of what happens east of the Dateline.

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jun
Click column heading to sort ascending, click again to sort descending.

1	2021	103	La Niña
2	2011	102	La Niña
-	1994	102	El Niño
-	1993	102	Neutral
-	1952	102	Neutral
-	1943	102
7	1988	101	El Niño to La Niña
-	1966	101	El Niño to La Niña
9	2024	100	El Nino to La Niña
-	1959	100	El Niño to neutral
-	1953	100	El Niño
-	1934	100

I think this slower La Niña progression may end up resulting in a later peak (i.e. the El Niño last year)

[bluewave]

6 minutes ago, snowman19 said:

I think this slower La Niña progression may end up resulting in a later peak (i.e. the El Niño last year)

We are probably better off using the SSTs west of the Dateline in the tropics and subtropics rather than what is happening in the official Nino regions. It seems to me the WPAC warm pool has been driving the bus since 15-16. The RONI has been trying to do this but it still feels incomplete to me. Since the MJO in the 4-7 regions has become so dominant regardless of El Niño, La Niña, or neutral.

[GaWx]

 SOI dailies as expected came up strongly the last few days (avg of +21 last 5 days), largely because of quite high Tahiti SLPs. The peak was 1018.3. Going back to 1991, only 1996 had a higher Tahiti peak in June though 2020 peaked higher in late May. Meanwhile, OISST continues ~+0.4.

[mitchnick]

2 hours ago, bluewave said:

We are probably better off using the SSTs west of the Dateline in the tropics and subtropics rather than what is happening in the official Nino regions. It seems to me the WPAC warm pool has been driving the bus since 15-16. The RONI has been trying to do this but it still feels incomplete to me. Since the MJO in the 4-7 regions has become so dominant regardless of El Niño, La Niña, or neutral.

Warmth out west near or west of the dateline could result in a better Nina winter than a basin wide Nina.

So far, most modeling has been reluctant to venture out of the COD for any period of time. But it's early, so we shall see.

[bluewave]

42 minutes ago, mitchnick said:

Warmth out west near or west of the dateline could result in a better Nina winter than a basin wide Nina.

So far, most modeling has been reluctant to venture out of the COD for any period of time. But it's early, so we shall see.

The only preseason metric which has worked for all La Ninas since 2010 has been the October early MJO indicator. This has helped out with the snowfall potential. But every La Niña since 11-12 has been warmer than average here in the Northeast. 

[snowman19]

16 minutes ago, bluewave said:

The only preseason metric which has worked for all La Ninas since 2010 has been the October early MJO indicator. This has helped out with the snowfall potential. But every La Niña since 11-12 has been warmer than average here in the Northeast. 

10-11 started as a purely east-based event, which is why that early-mid winter did what it did. It was also a solar minimum. Once the Niña migrated west at the end of January, 2011 and was no longer east-based, all of the blocking disappeared in February and it never came back again….not a coincidence. This Niña event is (and never was) definitely not projected to be east-based on any model. In fact, as @GaWx stated last week, some models have actually warmed in region 1+2 on their new runs

[mitchnick]

26 minutes ago, snowman19 said:

10-11 started as a purely east-based event, which is why that early-mid winter did what it did. It was also a solar minimum. Once the Niña migrated west at the end of January, 2011 and was no longer east-based, all of the blocking disappeared in February and it never came back again….not a coincidence. This Niña event is (and never was) definitely not projected to be east-based on any model. In fact, as @GaWx stated last week, some models have actually warmed in region 1+2 on their new runs

As is typical of BWI Niñas, 10/11 winter was paultry for snowfall at BWI with only 14.4", and DCA with even less. I don't think any weenie south of 40N would shed a tear if the 10/11 analog didn't work out. Lol

[GaWx]

37 minutes ago, snowman19 said:

10-11 started as a purely east-based event, which is why that early-mid winter did what it did. It was also a solar minimum. Once the Niña migrated west at the end of January, 2011 and was no longer east-based, all of the blocking disappeared in February and it never came back again….not a coincidence. This Niña event is (and never was) definitely not projected to be east-based on any model. In fact, as @GaWx stated last week, some models have actually warmed in region 1+2 on their new runs

Consensus for Nov shows coolest in 3/3.4 with warmest in 4.

[bluewave]

5 hours ago, snowman19 said:

10-11 started as a purely east-based event, which is why that early-mid winter did what it did. It was also a solar minimum. Once the Niña migrated west at the end of January, 2011 and was no longer east-based, all of the blocking disappeared in February and it never came back again….not a coincidence. This Niña event is (and never was) definitely not projected to be east-based on any model. In fact, as @GaWx stated last week, some models have actually warmed in region 1+2 on their new runs

My is guess is that 10-11 was more about the 150 year -NAO event lingering from the previous year than it was about the La Niña. That historic blocking pattern began during the 09 summer with one of the coolest June-July periods on record around NYC. It carried through the 09-10 winter and reversed in early February 11. So it’s unlikely that we ever see the 09-10 all-time snowfalls in the Mid-Atlantic surpassed during an El Niño or any other ENSO state. Same goes for over 60” of snow in only 33 days around NYC in 10-11 during a La Niña or any other ENSO state. 
 

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL046786

The winter of 2009/2010 was one of the most negative winters of the North Atlantic Oscillation (NAO) during the last 150 years. While most operational extended-range forecasting systems had difficulties in predicting the onset of the negative NAO phase, once established, extended-range forecasts were relatively skilful in predicting its persistence. Here, the origin and predictability of the unusual winter of 2009/10 are explored through numerical experimentation with the ECMWF Monthly forecasting system. More specifically, the role of anomalies in sea surface temperature (SST) and sea ice, the tropical atmospheric circulation, the stratospheric polar vortex, solar insolation and near surface temperature (proxy for snow cover) are examined. None of these anomalies is capable of producing the observed NAO anomaly, especially in terms of its magnitude. The results of this study support the hypothesis that internal atmospheric dynamical processes were responsible for the onset and persistence of the negative NAO phase during the 2009/10 winter.

 

[GaWx]

9 minutes ago, bluewave said:

My is guess is that 10-11 was more about the 150 year -NAO event lingering from the previous year than it was about the La Niña. 
 

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL046786

The winter of 2009/2010 was one of the most negative winters of the North Atlantic Oscillation (NAO) during the last 150 years. While most operational extended-range forecasting systems had difficulties in predicting the onset of the negative NAO phase, once established, extended-range forecasts were relatively skilful in predicting its persistence. Here, the origin and predictability of the unusual winter of 2009/10 are explored through numerical experimentation with the ECMWF Monthly forecasting system. More specifically, the role of anomalies in sea surface temperature (SST) and sea ice, the tropical atmospheric circulation, the stratospheric polar vortex, solar insolation and near surface temperature (proxy for snow cover) are examined. None of these anomalies is capable of producing the observed NAO anomaly, especially in terms of its magnitude. The results of this study support the hypothesis that internal atmospheric dynamical processes were responsible for the onset and persistence of the negative NAO phase during the 2009/10 winter.

 

2009-10 & 10-11 were when sunspots were very low to low and 1-2 yrs after a min. Only 4 other winters since 1979-80 had a DJF averaged sub -0.25 NAO and they also all had low sunspots/were within 2 yrs of a min: 1984-5, 1986-7, 1995-6, and 2020-1. All 6 of these -NAO winters had <35 sunspot #/month. Coincidence? 35 is well under the average/median of upper double digits. All of the last 4 solar mins had either 1 or 2 -NAO winters within 2 yrs of the min.

[bluewave]

1 hour ago, GaWx said:

2009-10 & 10-11 were when sunspots were very low to low and 1-2 yrs after a min. Only 4 other winters since 1979-80 had a DJF averaged sub -0.25 NAO and they also all had low sunspots/were within 2 yrs of a min: 1984-5, 1986-7, 1995-6, and 2020-1. All 6 of these -NAO winters had <35 sunspot #/month. Coincidence? 35 is well under the average/median of upper double digits. All of the last 4 solar mins had either 1 or 2 -NAO winters within 2 yrs of the min.

They didn’t find much relation to the low sunspots in the paper.

suggesting that the unusually low solar activity contributed little, if any, to the observed NAO anomaly during the 2009/10 winter.

17] The origin and predictability of the extremely negative phase of the NAO during the winter of 2009/10 have been explored by means of numerical experimentation. Different possible forcing mechanisms have been tested such as El Niño, the QBO, and reduced solar insolation. However, none of the forcings considered in this study was able to reproduce the negative phase of the NAO, especially in terms of its magnitude. The results of this study, therefore, support the hypothesis that both the development and persistence of negative NAO phase resulted from internal atmospheric dynamical processes. This may explain why most operational seasonal forecasting systems had problems in predicting the negative NAO winter when started in late autumn (e.g., forecasts issued in October and November 2009). The results of this study suggest that internal atmospheric dynamics are an important source of low-frequency atmospheric interannual variability [see also James and James, 1989] including extreme atmospheric circulation anomalies. Furthermore, this study suggests that internal atmospheric dynamics are able to produce extremely persistent atmospheric circulation anomalies which are associated with substantial extended-range predictive skill. From a dynamical point of view it will be interesting to better understand the processes responsible for the persistence of the negative NAO throughout most of the 2009/10 winter.

[snowman19]

2 hours ago, GaWx said:

2009-10 & 10-11 were when sunspots were very low to low and 1-2 yrs after a min. Only 4 other winters since 1979-80 had a DJF averaged sub -0.25 NAO and they also all had low sunspots/were within 2 yrs of a min: 1984-5, 1986-7, 1995-6, and 2020-1. All 6 of these -NAO winters had <35 sunspot #/month. Coincidence? 35 is well under the average/median of upper double digits. All of the last 4 solar mins had either 1 or 2 -NAO winters within 2 yrs of the min.

Back in early November of 2010, HM predicted the incoming historic blocking. He said the stratosphere and troposphere were “talking” and major AO/NAO blocking was on the way. He attributed it directly to the low solar and low geomag