NOAA climate model known as the CFSv2 is predicting a La Nina event (boxed region) for the upcoming winter season of 2021-2022. Source NOAA/CPC
Paul Dorian
Overview
La Nina conditions (cooler-than-normal water) developed early last year in the equatorial part of the Pacific Ocean and then intensified some during the past winter season. In the first several months of this year, water temperatures in the tropical Pacific Ocean have trended towards neutral, but there are signs of a resurgence in La Nina as we head towards autumn. In fact, there are signs right now that suggest the resurgence may already be underway in the central Pacific Ocean. The return of La Nina could have implications on global temperatures and also on the upcoming winter season of 2021-2022.
Warm (red, none shown) and cold (blue) periods in this table are based on a threshold of +/- 0.5oC for the Oceanic Niño Index (ONI) [3 month running mean of ERSST.v5 SST anomalies in the Niño 3.4 region (5oN-5oS, 120o-170oW)], based on centered 30-year base periods updated every 5 years. La Nina conditions developed in the spring of 2020 and continued into the spring of this year, but has been trending towards neutral in recent months. Data source: NOAA/CPC
The Pacific Ocean and signs of a resurgence in La Nina
The Pacific Ocean is the largest on the planet, covers more than 30 percent of the Earth’s surface, and is bigger than the landmass of all the continents combined. The warm waters of the equatorial Pacific Ocean store a great amount of latent heat compared to cooler waters and breed a great deal of convection which impact downstream ridging and troughing in the atmosphere. As such, its sea surface temperature (SST) pattern has a tremendous influence on all weather and climate around the world and the more anomalous the sea surface temperatures, the more the impact can be on the atmosphere around the world. The El Nino-Southern Oscillation (ENSO) is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean. El Nino warmer-than-normal water) and La Nina (colder-than-normal water) are the extreme phases of the ENSO cycle; between these two phases is a third phase called ENSO-neutral.
The plot shows forecasts made by dynamical and statistical models for sea surface temperatures (SST) anomalies in the “Nino 3.4” region for nine overlapping 3-month periods. Many of the models suggest the current nearly neutral conditions transition into a resurgent La Nina episode as we into the upcoming fall and winter seasons. Data source: IRI/CPC
Several independently-made computer forecast models support the idea of a change in the central part of the tropical Pacific Ocean by the fall of 2021 from the current near neutral conditions to one featuring La Nina once again. The plume of El Nino Southern Oscillation (ENSO) model forecasts (see plot) generated in mid-June indicate a resurgence of La Nina conditions is likely to take place by later this summer and continue through autumn. Indeed, some models (e.g., NOAA’s CFS v2) are predicting La Nina will last right into the winter of 2021-2022 with sea surface temperatures as much as 1.0°C below-normal in the “Nino 3.4” region (i.e., central tropical Pacific Ocean) during December/January/February.
The trend of the Southern Oscillation Index (SOI) is up for the last 30 days signaling that a resurgence of La Nina may already be underway in the central Pacific Ocean. Source: The Queensland Government (Australia), The Long Paddock
Teleconnection indices are suggesting a resurgence in La Nina conditions across the equatorial Pacific Ocean may already be underway. Specifically, these types of indices can be tracked to provide information on pressure patterns across the Atlantic and Pacific Oceans which, in turn, can directly impact winds and sea surface temperatures. Specifically, the magnitudes of these indices which can be in positive or negative territory can provide clues about upcoming wind changes and sea surface temperature patterns. Two closely-related teleconnection indices that provide clues about the North Atlantic Ocean are known as the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO).
For the Pacific Ocean, there is a metric known as the Southern Oscillation Index (SOI) which is directly correlated with the pressure differences between Tahiti and Darwin. This index can signal changes in wind flow and sea surface temperature patterns providing us with clues on the potential development and/or intensification of El Nino or La Nina. Sustained negative values of the SOI lower than −7 often indicate El Nino episodes are underway. These negative values are usually accompanied by a decrease in the strength of the Pacific Trade Winds and sustained warming of the central and eastern tropical Pacific Ocean. Sustained positive values of the SOI greater than +7 are typical of a La Nina with waters in the central and eastern tropical Pacific Ocean becoming cooler during this time. In recent days, the SOI has increased noticeably while in positive territory – perhaps a significant early sign of a resurgent La Nina.
In general, an El Nino episode in the tropical Pacific Ocean tends to cause a spike in global temperatures and there is often a noticeable drop off with La Nina as has occurred during the past several months. Data source: Dr. Roy Spencer, University of Alabama at Huntsville (UAH)
Impact on global temperatures
What goes on in the Pacific Ocean in terms of sea surface temperatures (i.e., El Nino, La Nina) can indeed have an impact around the world with respect to global temperatures in the lower part of the atmosphere. In recent years, the number of El Nino episodes have surpassed the number of La Nina events and global temperatures have often reacted with noticeable spikes. For example, temperatures spiked in 2016/2017 following a strong El Nino event and they had a secondary peak in 2019 associated with a second El Nino episode in the tropical Pacific. Prior to that, strong El Nino events that centered on the years of 1997/1998, 2009/2010 and 2015/2016 were associated with sharp upticks in lower atmosphere global temperatures. In times of La Nina such as during 2007/2008 and 2010/2011, there have been noticeable downturns in global temperatures of the lower atmosphere.
Since the most recent El Nino incident of 2018/2019, La Nina has taken control and global temperatures have responded accordingly. In fact, there has been quite a noticeable drop in global temperatures over the past several months to the point that levels are nearly normal on a worldwide basis as of the latest reading in June 2021. If La Nina does indeed have a resurgence later this year, global temperatures could respond by holding at nearly normal levels or perhaps even falling to below-normal levels.
In a typical La Nina winter, there is a strong polar jet across Canada and the US and colder-than-normal conditions from Alaska to the Northern Plains. In addition, La Nina winters are often warmer and drier than normal in much of the western and southern US. As a word of caution, there are other factors that can play important roles in winter weather across the nation including sea surface temperature patterns across the North Atlantic Ocean and also stratospheric temperatures at high latitudes. Source NOAA/NCEI
Potential impact on the upcoming winter season
In terms of the upcoming winter season of 2021-2022, La Nina could be an important factor depending on its magnitude, longevity and specific location. Typically, this type of oceanic sea surface temperature pattern leads to a strong polar jet across Canada and the US and colder-than-normal conditions from Alaska to the Northern Plains. In addition, La Nina winters are often warmer and drier than normal in much of the western and southern US. One word of caution, however, is that while the Pacific Ocean sea surface temperatures are potentially very important in terms of impact on winter weather across the US, other factors play a role as well. For example, sea surface temperatures pattern in the North Atlantic are often critical; especially, across the central and eastern US and even stratospheric temperature anomalies in high latitudes can play a crucial role.
The winter of 2020-2021 can be characterized as a “La Nina type” of season, bit the temperature anomalies (left) were rather atypical with warmer-than-normal conditions across the Northern Plains and colder-than-normal in the south-central states. Precipitation anomalies (right) has some likeness of a “typical” La Nina winter with generally drier-than-normal conditions in California, Texas and Florida. Source: NOAA/NCEI
Last winter can be safely characterized as a “La Nina” winter season and some of the “typical” results actually did take place in terms of precipitation anomalies. However, the temperature pattern across the US turned out to be somewhat “flipped” from the typical La Nina winter. Specifically, there were drier-than-normal conditions last winter from Florida-to-Texas-to-California as is typical, but temperatures were actually above-normal in the Northern Plains and below-normal in the south-central US – contrary to the usual La Nina pattern.
In the Mid-Atlantic region, any impact on snowfall in the Mid-Atlantic region from La Nina last winter was very dependent on location. While snowfall was well above-normal in most areas to the north of the PA/MD border such as the northern and western suburbs of Philly and New York City, it was generally below-normal south of the Mason-Dixon Line including in and around the Washington, D.C. metro region.
Meteorologist Paul Dorian
Peraton
peratonweather.com
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Here in NH, we had an unusually warm and dry June. The dryness was a continuation of state wide, (although variable in intensity) drought conditions of over a year duration. This, of course was due to “Global Heating”. Then this month we have had the opposite – cool, and very rainy. So rainy in fact, that it is probably close to third place in the record books so far, and there are still 10 days to go. The drought has been obliterated in a matter of a few short weeks. This, of course, is due to “Climate Change”. Science.
someone give the ENSO meter a kick its going the wrong way for aus as it appears right now
What is a “normal” level? Is it the level prevailing for four-and-a-half billion years before SUVs?
Many comments on this thread about ENSO processes and aftereffects are blatantly wrong. It would be impossible for me to address them all, and based on past experience, it would be a waste of my time. So I won’t bother.
Regards,
Now, now, Mr. Tisdale. Don’t get upset about comments. Whadaya expect? Instead, please give us your informed opinion/prediction of the next 12 months of the ENSO. Thank you.
Bob,
Good that you are still taking an active interest.
It is true that there are a lot of misconceptions about ENSO.
I do not think it is a waste of your time to address some of the blatant errors by myself and others.
You have done posts in the past for Anthony and I would see this as an opportunity to do a piece on some of our said misconceptions.
I hold fairly firm views and may not want to take it all in but unbiased and informative opinion is always worth being presented.
Cheers.
Comment disappeared can it be reinstated please?
As interesting as these – and virtually all – conversations on WUWT are, we each miss the central point.
We have lost the argument, several years ago. By focusing on the facts (Bravo!), we ignore the environmental argument to feelings.
These people seek to instill fear.
Very simple.
No amount of factual commentary, as luscious as each may be, can satisfy the hunger created by fear.
The argument from facts is correct. And useless.
We have lost the debate folks.
The AGW storyline has evolved into a religious creed. Or should we say Screed?
Universal guilt is applied, thick as Marmite, on the unsuspecting public. We decry the salty flavor and they gobble it up.
With all due respect to ‘les marmitons’, this is how an addiction begins.
Of course you are fearful. We can help you. Confess your carbon sins and repent. Send money, blood and treasure.
Amplify this tens of thousands of times over the past two decades and we have Marmite World, where everything tastes the same and everyone eats the same.
Fear (salt) drives us back to the trough. We absolve ourselves (acknowledge our carbon sins). We are confessed and live again (pay your taxes and listen closely for the next Faustian bell).
Example. As a member of the USCGA, I heard a meteorologist present hurricane preparation info last night. He was accurate and articulate – and had clearly drank at the climate change hotel; where you can get in but can never get out.
His five word preface?
‘Despite the climate change deniers…’
Thanks for all the work done by the WUWT team and contributors.
Unfortunately, we are all rehashing eggs and ham while the world has moved on…to marmite.
Soon we will be in prison, eating our own…
Hey John not everyone who likes marmite has adopted the “environmental argument to feelings.”
Despite what sometimes seems like overwhelming odds against the Truth about the climate being not only not in “crisis” mode but actually being perfectly fine, the Climate Liars are not “winning”, and they know it. Thus the desperation and increasing shrillness of their alarmist cries. We must soldier on. Rage, rage against the dying of the light, and do not go gentle into that good night. To paraphrase Bob Dylan. Hee hee.
More La Nina would be bad news for the western USA. The weather has been unusually dry in Salt Lake City since about March 2020, and we could use a wet El Nino winter (we need the water).
When it’s dryer, the warmunists claim it’s climate change … when it’s wetter, the warmunists call it climate change … when it’s warmer, the warmunists call it climate change … and when it’s cooler, the warmunists call it climate change.
The rest of us just call it “the weather”.
These dry spells often last a minimum of several years. That means that it is most likely that we will have one more dry winter. Many of the creeks here in Northern California are bone dry right now. Even some of the larger ones. On the plus side it allows for a good look at the bedrock for gold.
I call her “the bitch” to remind me she causes problems !!! Cold is always more damaging than heat so it looks as if we are in for a difficult winter.
Awful news to us in Chile. Yeah the fisheries are booming with the cold sea water but this year has been very dry so far. Not as bad as 2019 yet but we have barely had any rain in July here in Santiago! The temps had been relatively normal but the past 3 days have been unseasonably warm. Hoping we get some rain before the month ends and then more before spring
bdgwx Reply to Chris Hanley July 20, 2021 6:46 pm
“That graphic is from Dr. Spencer’s blog. It has been discussed extensively already. Here is the cliff notes version. First, of those 68 model simulations 50 of them are actually from the CanESM model.
The 68 model simulations are all that is available.
As Nick Stokes admits grudgingly
” the fact [is] that only a small subset of CMIP6 results have yet appeared. Roy (and I) use the results posted by KNMI Explorer”
So when Roy Spencer posts “An Earth Day Reminder: “Global Warming” is Only ~50% of What Models Predict”.
He is using the CMIP6 models available in the form that they are available.
He is comparing the mean of those models with the actual observations .
Global warming is only 50% of what was predicted by all of the the latest models available.
–
When RCP gave 4 base models including the ridiculous 8.5 did anyone complain?
No they all jumped on the gross outlier as “business as usual”
The CanESM model.runs 50 model sims, based on different predicates, accepted by Gavin Schmidt, and they all run shockingly high.
Does he call for a retraction?
No he lauds their work.
The Pacific doesn’t store “latent” heat. It stores sensible heat. Latent heat has to be added to get vaporization, or the sensible heat converted to latent heat.
“In fact, there has been quite a noticeable drop in global temperatures over the past several months to the point that levels are nearly normal on a worldwide basis”
Mr Dorian uses the word normal over and over. What, exactly, is normal?
There’s no NORMAL, the correct word is average.
Did I hit the nail on the head or what. My comment from 27 hours ago “Watch how emerging sunspots will cause temps to shift on TTs 3.4 graph. Imo, this last strong groupings of northern sunspots were the reason for the recent plunge in temps in the 3.4. Now that new large sunspot region in the south has caused a lessening in the rate of the temp drop. Temsp should move sideways over the next several days. It then looks like new northern sunspots will come around the edge after several days. Those groups should cause the 3.4 trend to drop once again in around 2 or 3 days from now.after they emerge, or so goes my concept.”.
That is exactly what has taken place on TTs 3.4 graph since I made that comment. Stay tuned.
Midnight and TTs 3.4 graph warms up slightly. The new sunspots in the north are just coming into view. This should change the direction of the trend in the 3.4 region by the end of today.
So that did not pan out as anticipated. Temps have continued upward on the 3.4 graph every six hours as it is updated. It is possible that the reason for this is due to the strength of southern sunspot 2847 which is still very large comparative to recent sunspots. Plus the northern AR group which came around the edge the other day has yet to form a sunspot. For almost several weeks my concept fit in with every new sunspot. So I will keep watching to see what the future will bring.
Temps have now moved sideways over the last 2 updates on TTs 3.4 graph. I was only off by half a day on the shift. Possibly due to the strength of sunspot 2847 which has been the largest sunspot of this cycle to date.
This is late on the 27th. Temps have continued to drop steadily in the 3.4 region. There is now a new active region in the south which will come into view in several days. Temps in the 3.4 should stop falling around that time. There are no new active regions in the north due to show up in that time.
That last active region in the south ended up almost fading away. There was no change to the trend in the 3.4 region. New larger active regions are now coming around the rim of the sun, and the cooling trend in the 3.4 region has finally abated.
The trend in the 3.4 region has warmed over the last 2 updates. These new active regions are larger than the last small area.