The low frequency state already is deviating rather significantly from a typical La Nina.
The transition period between La Nina & El Nino onset often comes with more frequent -EPO/+TNH, especially in mid-late winter
Westerly wind anomalies deep into the Indo-Pacific during the fall before El Niño play a *very* underrated role in preconditioning/charging the Warm Pool over the West Pac
The build-up of the West Pac Warm Pool provides the “fuel” for El Niño to grow later in the yr
This yr is a classic example👇
How do our low-level zonal wind anomalies over the Indo-Pacific the past few months compare to the onset years of every El Niño since 1950?
Almost a perfect match overall.
The westerly low-level wind anomalies deep in the Warm Pool are doing a lot of damage already to our current La Nina state
The mean Indo-Pacific Warm Pool last month looks similar to what preceded the 1982, 1997, 2006, 2014, & 2018 El Ninos
The Warm Pool is plenty strong enough for El Niño later this year
Note that 30C SSTs are centered ~160E & extend to nearly the dateline below the equator
Euro weekly 7-day avg precip anomaly fcst for mid Jan (left) vs correlation b/t the CPC’s EP/NH index & OLRa (right)
Note the Eq. Rossby Wave ~150-160E in the Eq. Pacific in both images, where 2 anomalous centers of convective heating straddle the equator. That’s usually how you get -EPO in winter
A lot of the +U is off-equatorial so it’s definitely somewhat a function of box size. However, those off-equatorial westerlies are important too for charging the Warm Pool and forcing a +PMM
Rather unsurprisingly, the easterly trade winds are MIA relatively speaking as this -NPO pattern strengthens its grip on the North Pacific
NDJF N Pacific SLPa 1 year before El Nino (left) vs the Euro weekly forecast thru early Jan (right)
This year has a classic negative N Pacific Oscillation (-NPO) pattern that often precedes El Nino events in the following calendar year
See Vimont et al (2003):
journals.ametsoc.org/view/journal...
The ongoing MJO event in the West Pacific has led to a *gigantic* build-up of westerly momentum in the tropical troposphere, w/ GLAAM anomalies approaching 3 sigma! Very El Nino-like
TAO buoy subsurface animation for this past month
Notice the thermocline is quickly deepening and the subsurface anomalies are beginning to advance eastward over the West-Central Equatorial Pacific.
We likely won't realize the true scope of the ocean response to this MJO event until early Jan or so, but early signs already point to a pretty big ocean response, even before the WWB event in the West-Central Pacific has occurred
La Niña is living on borrowed time in the grand scheme of things
I definitely need to take better care of myself and get more regular exercise and eat healthier. Those things would also certainly help
It really depends on how far the eastern edge of the warm pool is zonally advected towards the central pacific the next few months whether the +TNH is associated with less -PNA or more +PNA late winter.
The current configuration is very favorable to +TNH tho
The thermocline in the West-Central Eq. Pacific is already responding to the Westerly Wind Burst event & -IOD collapse that occurred earlier this month in association w/ the MJO.
A downwelling Kelvin Wave is forming over the West Pacific & will help eventually destroy La Nina in a few months or so.
Hope so too!
That sounds somewhat similar to me though I may have some other compounding factors like pain medication and perhaps some sort of underlying condition (high blood pressure ?). But anxiety during this whole ordeal definitely made it worse.
Thank u!
Thank you Jack!!
Thank you 🙏
Had to check myself into the ER last night with some nasty heart palpitations, felt like I was having a heart attack. 😣
Results came back negative fortunately & I feel better this morning w/ the occasional palpitation still
Hopefully when I see the cardiologist they can diagnose the issue 🙏
It’s so hard to get things to work out in the Desert Lowlands of southern NM & El Paso, even if the longwave pattern is there for a good snow event.
Oth, the pattern is close enough on some guidance to where it‘s legitimately possible (albeit rather unlikely) that they do.
The GEFS and Euro AIFS ensembles trying to give me some hope for snow in early December.
Surely, this must be a trap.
The low-level westerly wind burst in the pacific is what’s really driving the MJO into the Western Hemisphere (phase 8) in Dec (left)
That to me is a very telling of how hard the atmosphere is pushing the ocean away from La Niña & possibly towards an El Niño state this coming spring or summer
A stronger PV is a better downward reflector of upward propagating wave energy. I do expect the PV to strengthen later in Jan or Feb given the east qbo/high solar combo
The warmest water on the entire planet is sitting ~160E in the Equatorial Pacific & a prolonged Westerly Wind Burst event is about to occur here
This will trigger a downwelling oceanic kelvin wave that should destroy La Niña ~3 months from now & begin moving the ocean towards El Niño conditions
We might be in a La Niña at the moment, but the tropical troposphere already looks very El Niño-like with a huge build-up of deep-layer westerly wind anomalies
In the grand scheme of things, El Nino is likely knocking on the door 🚪
For all my S2S junkies out there, here’s another invaluable tool to add to your arsenal:
An annual archive of polar cap geopotential height anomalies going back to 1940 using ERA-5 & a 30-year sliding climatology
👀
hebweather.net/prod/gph_arc...
Cool study came out earlier this yr looking at the dynamical origins of the extreme 2023 Heatwave in the Desert SW
They concluded that the warm Tropical Atlantic was the primary culprit
The partial regression analysis (left) & AGCM forcing (right) are pretty telling
www.nature.com/articles/s41...
Yes for the most part.
I’m interested to see how ENSO evolves going into the next year, esp given what happened after this in 1982.
I still can’t get over how similar this year’s zonal wind anomalies in the tropics are to 1981
