bluewave

I think it’s also a test of how reliable our ENSO models are. With the exception of 15-16, many have had fairly significant errors with their El Niño forecasts as late as September. My guess is that this is a result of the semi-permanent La Niña background state in recent years with strong WPAC warming. 12-13 was never able to develop and models didn’t catch on until October. 14-15 was forecast to go super early on but verified as much weaker. The super El Niño got delayed a year. 18-19 couldn’t fully couple and the Euro completely missed the winter forecast. This year we are continuing to verify under some of the more aggressive ENSO forecasts which had September near +2.0 in Nino 3.4. In addition, we are seeing historically low MEI readings for an event which nominally registered around +1.5 in September. Also unusually weak WWBs for most months since the spring with the exception of August. That was our only month with rapid warming in Nino 3.4 https://www.nature.com/articles/s41558-023-01801-6#:~:text=The results from large ensemble,relative to the central Pacific.

This thread has all the 10” months around the area since 2003. But some were in as short a period of hours to a day like in August 2011 and 2014.

Radar estimates of 4.00+ in the Rockaways.

https://cyclonicwx.com/sst/

I just mean so long after the landfall on Saturday. This may be one of the most delayed post tropical remnant systems that we have had.

The HREF output looks more like something we see soon after a tropical system makes landfall. The mean would be significant enough. But that max potential would really be tough for any locales than can even come within a few inches of that.

You are probably right about the NAO since that cold blob has emerged in the North Atlantic. But most of our DJF blocking episodes since the 15-16 super El Niño have been more weighted to the AO rather than NAO. The other change is that the volatility between extreme -AO and +AO states has been increasing. So the seasonal means often hide the very wide swings. The AO weighted blocks have also become more south based at times leading to warmer outcomes than during past blocking events. JAN 2016…AO…-1.449…..NAO….+0.12 DEC 2017...AO…-0.059……NAO….+0.88 JAN 2018...AO….-0.281……NAO….+1.44 JAN 2019…AO….-0.173……NAO…..+0.59 DEC 2020…AO….-1.736……NAO….-0.30 JAN 2021….AO…..-2.484…..NAO….-1.11 FEB 2021…..AO……-1.191……NAO…..+0.14 DEC 2022….AO…..-2.719……NAO…..-0.15 JAN 2023….AO….-0.674…….NAO…..+1.25

It would be nice if some of this record summer blocking found its way over to the winter.

The -NAO has been negative most of time since June 1st.

Plenty of PNA volatility which leads to big model shifts from run to run. So the models can’t figure out whether the El Niño or -PDO will be running the show leading to big swings from run to run.

But we had hints. The OHC decline and the lack of WWBs were working against El Niño strengthening. Also the extremely Niña-like -PDO and associated trade wind pattern. We can remember the very strong -PDO in September 2012 and trades staying up that caused all the models to miss the decline. We still got the backloaded El Niño February with NEMO so all was forgiven.

The daily -2.52 -PDO is lower than any readings with the La Niña from last fall into winter. I believe it’s also the lowest -PDO reading for a Nino 3.4 reading near +1.4. https://s2s.worldclimateservice.com/climatepanel/

Nino 3.4 back to moderate levels near +1.4 as the Niña-like lack of any appreciable WWBs continues. The much lower RONI and MEI isn’t allowing the trades to fully relax like we typically see during Ninos. So the competing influences are currently acting as brake on El Niño development.

September matches a -PDO El Niño composite blend.The strong Aleutian ridge NW of Hawaii is classic -PDO in September. The ridge over Southern Canada is indicative of El Niño. There is some overlap in Northern Canada between the two composites also. The lower heights in Alaska also have a -PDO flavor.

We got lucky in Long Beach since Gloria hit a low tide instead of high tide. It had a higher storm surge than Irene but Irene came in at high tide. So the actual tide levels for both storms in Long Beach were the same. The wind gusts over portions of Eastern Long Island were estimated at 100+.

Low of 46° this morning here at KHVN is coldest of season so far. https://www.weather.gov/wrh/timeseries?site=khvn

Off course, and we have all been saying this. Competing influences and degree of coupling adds more uncertainty going forward.

Yeah, what we actually said is that the summer composite matched a weaker +MEI composite and that the Aleutian low was on the weaker side for a developing El Niño. Plus we are seeing mixed influences early on so far during the fall. These are very important distinctions in how the summer forecast did. A warmed up weaker MEI composite was a better summer forecast that the other stronger ones relying solely on the warmer 3.4s and a quieter hurricane season. So acknowledging the competing or overlapping patterns would have resulted in a better summer forecast had it been issued. Strong MEI composite… strong Aleutian low less blocking Weak MEI composite more blocking..less expansive Aleutian Low 2023 warmed up weak MEI worked

That’s what I have been saying for a while now. The subsurface cooling from a June peak of +1.4 to under +1.0 now has never happened with any strong to super event we have subsurface records of. While the sample size of super events is smaller, they were all near +2 during this time of year. So we are at 50% of those levels.

While the CFS may be exaggerated in its decline, the drop in OHC may be we we see the slight decline and leveling off effect. Not many cases to draw from with and OHC decline from 1.4 in June to under +1.0 in late September. Not sure how much warmer we can get with a break in momentum like this.

October is another rapidly warming month from the old days like September has been. The monthly temperature increases from 81-10 to 91-20 have been more pronounced during certain months. Newark and Islip are compared below. The +1.0 or warmer months for either station were bolded. ……….EWR…..ISP Dec…+1.5….+1.5 Jan….+1.2…+1.3 Feb….+0.5….+0.5 Mar….+0.4….+0.6 Apr….+0.5…..+0.6 May...+0.6….+0.9 Jun….+0.3….+0.6 Jul…..+1.4…..+1.1 Aug...+0.6….+0.9 Sep….+1.0….+1.3 Oct…..+0.9..+1.4 Nov….+0.2..+0.5

Relative to the historic rankings, the warmest departures shifted over closer to the Dateline in August. Some areas in that zone had the warmest August SSTs on record. Same goes for the warm pool east of Japan. But the overall warmth of the entire WPAC is still there. We have seen month to month fluctuations across different zones of the WPAC in recent years. Big decline with the IOD in the fall of 2019 followed by rapid rebound in the winter. So this part of the basin keeps finding ways to maintain its heat even with short term fluctuations. Quite an extensive reservoir of +30C SST warmth.

It’s no secret that the warmth imbalance to the west is keeping the trades up and letting the Nino 3.4 SSTs decline a bit in recent days.

The resolution on those charts is pretty poor. The WPAC is very warm for this time of year. Plus it’s much warmer than all the previous very strong El Niño years. Also notice the unusual -PDO signature for such warm ENSO SSTs. Nino 4 is close to all-time record warmth for this time of year.

That historic marine heatwave east of Japan is probably helping to push the -PDO to even lower values than we saw during last fall. A daily reading of -2.6 must be near the record lows for this date. Hoping we don’t see some odd combo going forward of higher Canadian heights from the Nino and a Western Trough tucked underneath like we see with -PDO patterns. That would lead to a stronger NPAC Jet pushing the +PNA ridge too Far East and possibly overshadowing the STJ. Want to see the STJ dominate with some decent blocking for the NE snowfall fans. https://s2s.worldclimateservice.com/climatepanel/