griteater

Potentially more periods of central Pac ridge / trough off or along the west coast than typical mod-str El Niños

None quite like this one. ASO here is Aug-Sep-Oct

On the Roundy tool, one thing I'm seeing that gives it more credence is that the lowpass OLR / -VP signal is showing up there along the dateline....and that makes sense IMO as it matches with what we've seen all summer/fall as opposed to it being farther east like the big east based ninos (it also matches essentially all seasonal forecast model projections for winter)

Dec 30 - Jan 6 on Euro Weeklies

Oh yeah, that pattern is likely in the cards for 2nd-3rd week of Dec Thereafter, Paul Roundy's 100-day lowpass / MJO tool is matching up nicely with the Euro Weeklies Shown here are both in 3-day increments from Dec 5 to 29. E Pac trough in 2nd and 3rd week of Dec, followed by retrograding Aleutian Low into a +PNA pattern in last week of Dec. We've discussed limited / mixed results with Roundy's tools, and I stand by that....but I will say, the concept with this one is really nice, and if one is going to work well, it should be this one as it combines the low frequency / low pass signal (base tropical forcing pattern) with the higher frequency signals running on top (MJO and Equatorial Rossby waves)....his description: "the only predictors included are obtained from OLR data, including 100-day low pass projected, MJO, and equatorial Rossby band signals" And you can see on his loop where the OLR convection lights up along the dateline in weeks 2-3 of Dec before fading (as the signal moves east). Late Dec / Early Jan should be our first big test of a legit El Nino since 15-16 in terms of what wins out....El Nino / -PDO / WPac warm pool....and there will be several more tests thru winter

Just popping in to say that there are separate things being discussed here with respect to SSTs 1 - The max SSTs in the W Pacific warm pool have moved east due to the current WWB and have extended a bit east of the dateline (I should say, the WWB has given the eastward extension a good push). There are also max SSTs in the Maritime Continent (1st image below). You can view this movement of the W Pac warm pool via an image loop of SSTs over the past year: https://psl.noaa.gov/map/clim/sst.anim.year.html 2 - The second thing being discussed are SST anomalies. Via SST anomalies, Nino 3.4 looks fairly basin-wide at the moment (2nd image below). You can view a loop of the SST anomalies over the past year here: https://psl.noaa.gov/map/clim/sst.anom.anim.year.html

November Month to Date temperatures - 2023 vs 1997

From NOAA CPC's Weekly MJO Update...

Surely you can keep your composure and not bring that crap and language in here

Agree with GaWx that the -VP uplift moving from the Central Pacific to the Americas and Africa in the 2nd half of Dec would support the Euro Weeklies forecast, as late December is really the earliest timeframe when an MJO 7-8-1-2 pass becomes favorable for winter in the East.

Added columns for Monthly Peak and Tri-Monthly Peak

NOAA CPC Weekly Nino 3.4 values for November (OISST data): Nov1: +1.8 Nov8: +1.8 Nov15: +1.9 If we estimate the weekly values for Nov22 and Nov29 to both come in at +2.1 (i.e. SSTs continue to rise this week before leveling off next week as the westerly wind anomalies subside), that would yield a November monthly of around +1.94. NOAA uses ERSST for the monthly number and the OISST monthly has been 0.07 lower than the ERSST monthly over the past 2 months. So, let's go with +2.01 for November as an estimate. Here is how that November number compares with other El Ninos...

Oh yeah, agree, they produce similar results, but just thinking of assigning the culprit for each

True, but we should be able to distinguish the difference between the 2 (big east-based Aleutian Low vs. -PDO influenced trough close to the west coast). My opinion is that the big, east-based Aleutian Low pattern won't be very prevalent this winter, but we'll see

IMO ENSO strength is most important, followed by the location of the related base Walker Cell uplift and subsidence regions that become established. There are associations that come from the prior year ENSO state as well. In terms of the timing of ENSO peak...the main thing that maintains El Nino ONI strength is low-level westerly wind anomalies that push out of the W Pac and into the C and E Pac. That same westerly wind push from WPac to EPac is consistent with MJO phases 7-8-1-2. So, I'd say it's a good thing for El Nino to be maintaining and gaining in strength at this point as long as it doesn't go bonkers and get into Super Nino territory from a multi-month ONI standpoint (unlikely this year, but not out of the question)...but based on many prior cases, El Ninos are going to hold their ONI strength at least into early winter (87-88 being one of the rare exceptions as that one faded during fall & winter)

I don't think this kind of warming that we are seeing is unexpected or surprising given the magnitude of this westerly wind burst. IMO the bigger question is what happens going foward, as I believe we're going to need to see additional waves of westerly wind anomalies move across the nino regions in order to maintain / further grow the warming SST anomalies. I will be surprised if this moves closer to a big east-based Nino with the low frequency / base state uplift moving well east of the dateline like 83/98. I think the most likely outcome is a strong nino, but not quite super, with the mean uplift being moderate to strong in strength and hanging close to the dateline....this would yield a promising outlook ENSO-wise for the eastern U.S. Other factors will fight against the promising outlook though: 1) Current year global warmth, 2) Strongly -PDO for a Nino, 3) Early Strat PV is strong - on that front, the good news is that there is no evidence at the moment of it coupling with the troposphere which is big in early winter.

+2.00

09-10 winter had -VP centered in nino 4. 97-98 winter had it centered in nino 3 (and with strong forcing). If we start seeing convection firing in MJO 4-5-6 for more than a quick pass, it's likely due to climate change / those waters wanting to remain warm in spite of a robust nino. But this is base pattern stuff. The windows of wintry opportunity in the E U.S. from a tropical forcing standpoint should be when weak MJO waviness rolls atop the current base state and into the 7-8-1-2 zones in the late Dec-Mar timeframe (more favorable for 7-8-1-2 then). 7-8-1-2 is always favored in the E U.S., but moreso during El Nino.

UKMO OSTIA also had a big jump today in 3.4 from +1.56 to +1.72....so, some strange stuff going on this week with the data.

snowman's dreams are coming true. 3.4 is up to +1.97 on World Climate Service

Nino 4 warming and 1+2 cooling is moving this closer to a basin-wide look

Nino 4 warming should be regarded as a good thing for the East. The bad would be if substantial SST warming occurs in the Maritime Continent (that is what could aid in more MJO 3-4-5, though a stout Nino should overwhelm it) and/or the base -VP uplift moves east into the E Pac.

This current westerly wind burst looks legit and I believe it will lead to warming (subsurface and surface). It may be a good thing though to kick us out of the low AAM state and more into El Nino / +AAM....and agree, unless we see more follow-up WWBs like this one, I don't see how this one event is going to re-configure everything....i.e. flip the base state / low frequency VP signal into a hardcore and east-based situation like the super ninos you mentioned (that's what appears to be forecasted by Webb and Roundy). In terms of the winter overall, I wish the strat PV wasn't starting out on the strong side like it is...would prefer it to be more neutral or weak (looks like it is going to strengthen again after this stretching event around T-Day). But outside of that, I think the parameters for winter look good overall IMO

The varying opinions this year are really wild with respect to El Niño peak / base forcing location / how it impacts the pattern…and especially with how late in the game we are now. Folks are doubling down on their stance too

Nino 3.4 on UKMO OSTIA as of 11-15 is +1.56. That's the lowest value since Oct 12