40/70 Benchmark

Its due to the Hadley Cell configuration, as the ridging in the upper levels over the equatorial PAC induces a lower heights in the mid latitudes (Aleutian low). Anyway, here is some stuff that I have written with respect to the tropical PAC in the past: Tropical Convection as a Global Driver Forecasting at extended lead times is inherently difficult due to the high degree of chaos at play within the planet earth's complex system of land, sea and atmospheric oscillations. Thus remaining ever mindful of both the global atmosphere's primary function, as well as its primary means of carrying out said function is crucial to the successful completion of any season outlook because we can utilize this information to identify the primary driver. The atmosphere in its truest essence is the oft delayed feedback between the land, sea and air that serves to budget the immense degree of solar energy that is concentrated around the equator by redistributing it upward. First in altitude via the convergence and upward ascent of air due to convection, which is a term referring to concentrated areas of showers and thunderstorms. Then eventually poleward by both major storms such as hurricanes, which are essentially spinning gyres of convection, as well as ocean currents and oscillations. This epitomizes how the cycle of ocean and air processes act to budget heat around the globe. Since the primary function of the atmosphere has been identified as the utilization of tropical convection as a vehicle for the redistribution of heat upward and poleward, it is prudent to assume that tropical convection should be the focal point of any long term forecast. The Pacific ocean is by far the largest body of water on the planet, thus it is the convection over the tropical Pacific that is most pervasive within a global context. Madden Julian Oscillation The Madden Julian Oscillation is a broad wave of convection centered on the equator that acts to impart forcing around the entirety of the globe. It has a great deal of utility in long range forecasting because it allows us to identify where tropical deep convection interacts with the general atmospheric circulation at one month leads. This is the point of origin for the synoptic layout spanning the globe, as each of its eight phases represents different locations of the convective wave along a progression mainly in a sector spanning the Indian and Pacific oceans. The more amplified, the more pervasive its influence as a driver of the global pattern. Each phase is teleconnected to disparate upper level patterns around the globe that are dependent upon the time of season, as wave lengths wary. Paul Roundy developed a plot that illustrates this and allows for sorting by MJO phase and time of year, which can be found here. The upper level pattern that is favored across the globe for the pertinent period of time between the months of November and March is obviously dependent upon the location of the MJO wave, which can be located by finding the greatest concentration of outgoing longwave radiation resulting from energy emitted by convection. These are as follows: In crude terms, if we consider the atmosphere akin to a garden hose of balancing down stream forces, which create a series of troughs and ridges through a series known as anticyclonic wave breaking. The location of the MJO is the location where the "hose" is originally shaken. This feature is typically initiated over the Indian Ocean, and usually advances steadily eastwards, as areas of relatively organized convection, bringing a significant enhancement of rainfall, followed in their wake by much less active convection due to sinking air at the surface. The enhanced convection along the MJO wave is created by converging and rising air, which sinks both further up into the atmosphere, as well as downstream in longitude. This is why the MJO is marked by both negative vertical potential near the top of the atmosphere, at the 200mb level, and sinking air in association with a dearth of convection downstream. Different locations of the MJO, or phases, teleconnect to different phases of the respective oscillations spanning the globe. Note that under ENSO neutral conditions, the push of warmer water in association with westerly winds, and the thrust westward of cooler waters from the coast of Peru is relatively even, and largely modulated by seasonal changes (second, middle image). This is a normal Walker circulation. However when changes in global pressure patterns dictate that stronger westerly winds advect warmer waters eastward more readily than can be countered by trades, the resultant ocean-atmospheric coupling associated with el nino and westerly wind bursts feedback on one another to continue thrusting warmer waters further to the east than normal (third, bottom image). Since the primary function of the Walker cycle is to initiate the upwelling of cooler, deep sea surface water, el nino is facilitated by an anomalously weak Walker Cycle, and la nina stronger than normal Walker cycle. Thus conversely, w hen variations in global pressure patterns strengthen the Walker cycle sufficiently as to allow stronger easterly trade winds advect cooler waters further westward than usual, the resultant ocean-atmospheric coupling associated with al nina and easterly trades feedback on one another to continue thrusting cooler waters further to the west than normal (first, top image). Walker Cycle Serves to Budget Solar Energy Focused Near the Equator by upwelling Cooler Subsurface Water and Distributing it Westward via Easterly trade Winds The lower part of the loop flows east to west across much of the tropics near the surface; the upper part flows west to east at higher altitudes. This is because convergence associated with convection at the surface creates divergence aloft once the air rises, thus the flow is opposite at high levels of the atmosphere. Rising air in the west and sinking air in the east near the surface connect the flow in one big, continuous loop. When the Walker cycle is altered due to global pressure variations, anomalously cool or warm sea surface temperatures within the band of water of the ENSO region are the result. The precise location of the warmest SSTs can act to favor the concentration of the aforementioned convection in association within the MJO wave that modulates the complex system of land, sea and air interaction, in position for several months at a time. This is known as the Hadley cell, named after George Hadley, which is a global scale tropical atmospheric circulation that features air rising at the surface near the Equator due to convection. The air flows poleward at a height of 10 to 15 kilometers above the earth's surface, descending in the subtropics, and then returning equatorward near the surface. Rising Air Near the Surface in Vicinity of Hadley cell Creates Sinking Air at Both Higher Latitude and Altitude This is why we often see the development of an Aleutian low due north of the area of convection associated with the Hadley cell across the central Pacific during an el nino, and an Aleutian high due north of the subsidence and sinking air in the equatorial Pacific during la nina conditions. The MJO wave will often accelerate through unfavored phases, and sometimes essentially stall in favored phases in alignment with the rising air in association with the Hadley cell. This interaction then feeds back upon itself (SSTS and conditions near the ground that can reenforce stable atmospheric regimes) in order to strive towards an atmospheric equilibrium across the globe. Properly diagnosing the ENSO region is often crucial to the success of any winter outlook since it is often the temperature of the water and in this region that dictates the progression of the MJO convection and position of the Hadley cell that is so curial to shaping the atmospheric processes across the earth. It was noted somewhat vaguely that "changes in global pressure patterns" can provide the impetus for variations with respect to the intensity of Walker cycle, which then regulates changes within the ENSO region that can shift the greatest sea surface temperature anomalies in either direction. Elaborating on said global pressure alterations is crucial since it is in large part the position of the greatest SST anomaly that determines the placement of the strongest convective forcing and attendant Hadley cell that sets the global circulation for a given season. The term “southern oscillation” refers to the relationship of sea surface pressures between Darwin, Australia and the island of Tahiti that modulates both the Walker cycle, and by extension the stripe of sea surface temperatures referred to as ENSO. The measure of this is called the southern oscillation index (SOI), and it is one of the most prominent indicators to be considered when forecasting the overall state and intensity of ENSO for the ensuing winter season. Utilizing SOI Data to Anticipate ENSO State and Intensity When the southern oscillation is in its positive phase, as it is currently, there is above normal pressure over Tahiti, below normal pressure over Darwin and the disparity between the pressure at the respective stations is larger. This intensifies the Walker cycle and lends itself to a cooler than normal strip of Pacific waters to the west of South America, called “La Nina”, which is the feminine version of the term “El Nino”. This means “baby of Christ” in Spanish, referring to its tendency to really begin to manifest itself into the global weather regime around Christmas time. This is because the Walker circulation is created by the pressure gradient force that results from a semi permanent area of high pressure area over the eastern Pacific Ocean that is owed sinking air downstream from a low pressure system over Indonesia due trades pooling warmer waters in the western Pacific. El Nino is fueled by below normal sea level pressure over Tahiti, above normal sea level pressure over Darwin and a smaller pressure difference between the two stations, which serves to weaken the Walker cycle and ultimately leads to an above average strip of waters off of the coast of northern South America. This is because the pressure pattern characteristic of the negative phase of the Southern Oscillation Index (SOI) usually dictates that more frequent westerly wind bursts will traverse eastward across the equatorial Pacific owed to the more diffuse Walker cycle. These westerly bursts of wind act to transport warmer water eastward because they send downwelling perturbations upon their passage, known as "kelvin waves", which act to stifle the normal upwelling of cooler waters from below, thus inhibiting the primary purpose of the Walker cycle. This largely constitutes the phenomena responsible for the development of el nino, and why it is so intimately intertwined with both the SOI and the Walker cycle. Knowing what we know about the complex system of atmospheric and oceanic circulations around the globe, surely there must be an equal and opposite reaction, which represents an attempt by the earth to maintain balance. This is represented by what are termed as "rosby waves", which are more commonly referred to as "trade winds". These trade winds often counter the advection of the warmer water eastward by the kelvin waves near the equator and throughout the ENSO regions with the upwelling of cooler waters to the west, just to the north and south of the equatorial region via the Walker cycle. This is why warm subsurface waters are often crucial to the maintenance and continued development of warm ENSO events. The rosby waves then continue their westward paths just to the north and south of the equatorial ENSO regions, until they deflect off of the western end of the tropical Pacific, near the Indonesian islands (land feedback portion of the system known as delayed oscillation ), and begin to curl back to the westward along the equator. This was outlined previously when detailing the Walker cycle. The passage of the rosby wave incites upwelling, which acts to advect potentially cooler subsurface waters up to the surface, back to the west and into the ENSO regions, until the SOI and other factors counter by initiating a modifying, westerly wind burst inducing kelvin wave, and the cycle begins a new. The former is the phenomenon has remained prevalent throughout the month of October and into November. The frequency and magnitude of these westerly wind bursts and trade wind surges accompanying rosby waves is positively correlated to the intensity of el nino, and negatively correlated to la nina. It is the precise timing and other nuances of the interminable Walker cycle that determines the behavior of the subsurface, which ultimately dictates the distribution of SST anomalies within the ENSO region. This is crucial because it is the SSTs anomalies that mold the configuration of convection that determines the location of the Hadley cell and modulates the state of the atmosphere around the globe. ENSO Modulates Convective Driver History tells us that the more mature an ENSO event grows, the more likely it is to assume the structure of a traditional "Canonical" event. That is to say, an el nino generally expands eastward with maturity, and a la nina westward. And these respective evolutions can have drastic differences as it relates to the character of winter across the northeast US and mid atlantic, since the vastly different placement of warmest sea surface anomalies has a ripple effect due to associated convective forcing schemes. This is owed to the latent heat release from the convection that builds above the warmest sea surface anomalies, which sets in motion a chain of atmospheric responses that permeates throughout the entire globe, across both disparate latitudes, as well as layers of the atmosphere. Convection in association with the MJO over the warm, moist and tropical Pacific releases latent heat that then rises up into the atmosphere, forming ridges of higher atmospheric air pressure. Since the waters of the Pacific ocean that compromise the ENSO regions breed a great deal of convection, the resultant atmospheric ridging in association with the MJO pulse subsequently forces downstream, balancing alterations to the atmospheric regime via the Hadley cycle. Obviously in a general fashion, the more anomalous the positive sea surface temperature anomalies, the more convection that can exert a stronger forcing mechanism on the adjacent regions of the atmosphere, that then reverberates throughout the globe. This is very evident in the composite of the five strongest el nino events on record below. Weaker el nino events are often more west-based, since the westerly wind bursts are not as prominent and thus the warmest SSTs are not transported eastward as efficiently. These are termed "modoki" el nino events. Weaker and West Events What is also evident is that the GOA low in the weaker el nino composite is displaced to the west, and also more diffuse due the to the lower SST being further west. Thus what is perhaps more important than the intensity of the ENSO event and the attendant forcing is its placement. This relates back to the manner in which the ENSO develops, which is designated along a canonical vs modoki continuum. Canonical ENSO vs Modoki and the Importance of ENSO Structure A few of falls ago, we correctly cited structural nuances as the rationale as to why the 2017-2018 la nina would behave differently than its winter 2016-2017 predecessor, which engendered mild conditions across the east. The coldest anomalies were centered in region 1.2 last season, abutting the east coast of Peru. The cool SST anomalies are focused in the west-central flank, which is encompassed by regions 3.4 and 4, respectively. The sinking air in association with this pool of cooler SSTs means that the Hadley cell, and rising was further to the east. The 2017 event was a central-based la nina event, or a "modoki" la nina. This term of Japanese origin has a meaning akin to "similar, but different", attesting to the fact that this type has some attendant slight variations to the global climate regime. The lesson illustrated via the dichotomy between the consecutive cold ENSO events of the those two years is also applicable to el nino. The definition of the word "canonical" is "according to recognized rules or scientific laws", in contrast to the definition of the term modoki, which is is of Japanese origin, being "similar, but different". One can infer that the canonical el nino is the base state for a mature el nino akin to how the positive AO/NAO couplet is at the higher latitudes. In other words, should the course of development for the warm ENSO event continued relatively unabated, then the warm sea surface anomalies will likely center closer to the eastern region 1.2 with few exceptions. Canonical el niño Canonical el nino cousin of modoki la nina in that coolest SST anomalies focused in the central Pacific, thus somewhat similar forcing regime is possible. Modoki, Central Pacific la Nina This is likely due to the fact the impetus for a mature warm ENSO event is a barrage of significant westerly wind bursts, which negate and reverse upwelling induced by easterly trade winds. The modoki el nino counterpart is the modoki la nina, which focuses the coolest sea surface temperature anomalies over the central Pacific, thus is more reminiscent of canonical el nino forcing in that sense. The most powerful la nina events are in the central Pacific ARE due to rosby wave induced easterly trades transporting cool waters westward. Generally speaking, the most powerful el nino events are east-based due to excessive westerly wind bursts piling warm waters east. Strong, canonical el nino (left) favors are prominent Gulf of Alaska low, which drives the Pacific jet inland, this locking the arctic jet north. Strong modoki la nina (below) favors a major Aleutian high, which teleconnects to a western North American ridge and eastern ridge, which also often locks polar jet north. Since modoki el nino concentrates warmest SSTs in the central Pacific and modoki la nina focuses coolest SSTs in the same region, modoki la nina obviously behaves much differently from modoki el nino.

Yea, I just don't agree with you. You have strong forcing centered east of the dateline in a robust el nino, it won't end well....in 1856 or 2022.

I'll bet if you examine the colder strong el ninos, they were more west-based. Yes, ALL seasons have been warming, but global warming doesn't explain why canonical el nino events, which the vast majority of stronger events can be classified as, are warmer than modoki seasons. Its two disparate forcing regimes. Stronger events have a more prominent Aleutian low tucked closer to the west coast, which floods the country with PAC air. That feature is less prominent and often displaced east in weaker/modoki events.

Brrrr.....

44 last night, and Sunday night IMBY.

Like we don't already here that every season? lol

I think a warmer climate would be more prone to la nina as the overall global canvass warms, it will be easier for the PAC to feature cooler anomalies..just a hunch. However, what I can tell you is that more modoki el nino events are favored over canonical el nino seasons.

I'm not sure that a strong el nino on average increases chances for cold, although it depends on the structure of it, of course.....higher end storms where you are, sure.

I hooked everyone up at the conference a few years back....there was plenty of damage indeed.

Maybe if we get a bit more humidity, he can enjoy a slippery and slimly coc...just slithering its way into his no-no region.

You are like the inverse of a winter-weenie melting down after Tip acknowledges that we begin "recovery from the solar nadir" around the holidays.

Nuts for around the summer solstice....wish we could get this pattern during winter.

I highly doubt that...the periodicity doesn't line up....they happen about every 10-15 years...'72-'73, '82-'83, '97-'98, '15-'16. I think we are still at least a few to more likely several years away from the next super el nino.

I know what you mean, but I really am not doing that....the band will snap, and we will have el nino next year, if not this season. Like I said, probably next year, which is when we could combine it with an easterly QBO.

The next el nino that we have will be a modoki....take it the bank. We always have a money-shot el nino when we emerge from these multi-season cold ENSO regimes. Probably 2023-2024 season.

Not seeing the el nino anymore, at this point, but warm neutral still has a shot.

I had about 100" on the longer range GEM last winter.

I have a Roth 401K and a state pension...also doing therapy on the side, so should be able to get SS.

An el nino by CPC standards is very unlikely. The MAM ONI is -1.1. Since 1950, the only two seasons to go on to qualify as an official el nino during the subsequent cold seasons following a MAM ONI of -0.5 or lower are 1976 and 2018...both merely -0.5 MAM ONI. They each peaked at +0.9 ONI....still weak. Even a recovery that drastic only takes us to a peak ONI of +0.3, which is warm neutral. Now, this isn't to say that we absolutely can not pull off an el nino like season, as arbitrary thresholds are not the ultimate determinant. There a small chance....as in addition to last December, the other extreme -PDO Decembers are 1955, 1964, 2008 and 2010. We would need to pull off a recovery similar to 2009, on the heels of the extreme 12/2008 PDO, which recovered from a MAM 2009 ONI of -0.3 to +1.6 in NDJ. I do not see that, but this kind of PAC reversal would take us back up to a peak of +0.8 ONI for the cold season, which would be weak el nino.

Yea, all we hear about in December is the impending grinch....before, during and after.

Yea, I can't see a full fledged el nino, either, but I do think that warm-neutral remains on the table.

Yea, I thought the Pacific would end up a hair less favorable, and the Atlantic/polar domain a bit better...in the end, not bad. I def. had the idea of poleward Aleutian ridging owed to east biased la nina. Interesting regarding the correlation....that is one area that I am weak on. I don't really incorporate those, aside from ENSO forecasting. Those correlations are something that I see you and raindance use alot.

I'm sure we'll pay for this on the back nine of summer and early on in fall, but I will take the low dews as long as I can.

71 is fine with me.

And some others may need a mental status check waiting for the weekend warmth. I maybe on call this weekend.