bluewave

It was nearly as deep in the mid-Atlantic. 2nd lowest June and July heights on record there. But the aerial coverage of the trough was much smaller due to the steadily expanding 500 mb heights since 2009. The ridges were much more expansive this time around leaving smaller and warmer troughs.

That’s the point that I have been making. While the trough in the mid-Atlantic was nearly as deep this June and July as 2009, there was much less cool air available. This is due to the expanding 500 mb ridges pressing in around the smaller troughs. So record 500 mb heights are leading to much less colder air available for the shrinking downstream troughs. This is a very important aspect of a warming climate which gets little discussion. Troughs decades ago were much more expansive and colder.

Case and point this summer. Should have been much cooler in the U.S. this summer with the near record -NAO-EPO+PNA pattern. 2009 featured roughly similar teleconnections and we were significantly warmer than that summer was. Troughs have been getting crowded out by ridges as the 500mb heights keep rising.

I think we are probably on the same page with our concerns about another mild winter coming up. But we arrive at that potential from two different directions. I believe your concern is that the eastward lean to the SST anomalies finally pulls the forcing east as we head into the winter. I am wondering if the El Niño peaks a little early and the forcing stays near the dateline. Then if there are coupling issues like we have seen this summer, the MJO 4-6 forcing which is also warmer could factor in at times. Plus strong enough dateline forcing in itself could be mild if the PNA ridge rolls over into the Northeast. So it may come down to whether we can get some snowfall luck in a mild pattern and a well timed STJ and blocking overlap. Let’s face it, there are more warmer potential forcing scenarios than cold as we have seen every winter since 15-16. 14-15 was such a freak event with the mega -EPO block overpowering the record +NAO. It was a Modoki with a raging +NAO. Since the climate has warmed so much since then, not even sure if similar modoki forcing scenario would even yield a very cold winter again.

If Philly can hit 100°, then Newark most certainly will. Record heat building into Philly usually makes it up to Newark. So there should be at least one day with favorable winds and highs from 97° to around 100°. Same goes for big Philly snowstorms making it to around Newark with the rare exception of 2-6-10. But we won’t have a 5 SD block this week like back then.

All we can say is that Euro seasonal for the summer from May was off on the EPAC forcing that never materialized. So I am even more cautious at looking at a longer range seasonal forecast for the winter which is much further out than the summer forecast issued in May. That would be like the November forecast being off for winter. But at least the Euro still had some WPAC forcing in the forecast even though it was too weak. http://seasonal.meteo.fr/content/PS-previ-cartes?language=en&TSPD_101_R0=0804515747ab2000ad872a2e9ddcbfd2ff2748fbec26c8047ff69e03f9b0255746c3a2ce239aa065080ec81b72143000ab7a63d4629fcacb295da78c52aa3c7ee66c63462d17216940f510f6a9555384b49970c27218ff6e6d1108718d8fc5d8 Forecast Verification

We got a record MJO 4-6 during the super El Niño in December 2015 once the IOD faded. That combination with the Nino forcing resulted in a super-Niña like +13 December in Northeast. But the blocking coming on strong in January and February saved the winter once the MJO 4-6 influence weakened. There was an interesting paper written on this effect. Plus every El Niño attempt since then has encountered interference from the WPAC warm pool . So I am even more cautious at looking at extended model output when Ninos are involved. Just look at how much further west the forcing was displaced this summer versus the strongest events. Many models missed this and had EPAC forcing in their seasonal outlooks for the summer. https://link.springer.com/article/10.1007/s00376-020-0261-x Distinctive MJO Activity during the Boreal Winter of the 2015/16 Super El Niño in Comparison with Other Super El Niño Events

I guess the hope is we don’t get an early El Niño peak and a quickly fading IOD which allows maritime continent forcing back into picture in time for winter. Then we are pretty much at the mercy of whether blocking shows up or not. Not even sure how much Nino 3.4 needs to warm for a strong enough Nino response to mute the lingering Niña background state of recent years. I would be happy with a milder forcing pattern near the Dateline provided some blocking and and an active STJ.

It’s a bit of a challenge to try and time the peak since the progression has been so different this year. So if everything about the evolution has been new, then can we rely on the timing and magnitude of the peaks of other events? It’s a good question. I guess the one constant is the westward lean to the forcing continues into September. While Dateline forcing during the winter could still be quite mild, at least we could up our chances for a better snowfall outcome than last winter. But the bar is pretty low. Just give me a decent STJ and some well timed blocks and I will tolerate a milder winter like we have had for the last 8 years. The cooling that you mentioned in the WPAC may be dampening the MJO 4-5 and upping the 6-7. Even though the RMM charts are missing the magnitude of the forcing drifting toward the Dateline which the VP anomalies more clearly show.

Thanks for posting. That gives us a clearer picture why the upper ocean heat anomalies have gone to around +1.2 recently. Looks like the +2 regions above 150 meters have expanded westward. Probably need to see what happens following this more Niña-like interval to know when the next warming spike at the surface occurs like we just saw. This evolution since last winter has been pretty unique. So we don’t have a collection of analogs to compare it to. The big question is what the ENSO regions need to warm to for the forcing to shift further east than we have seen?

It would fit with the theme this year with the greatest daily departures outside summer like we saw in April. But the potential is there if we can keep the UL far enough offshore. Very difficult in these parts to keep record heat away for more than several months at a time. So we’ll see if the Newark thermometer which has been underperforming all summer can finally register a +10 daily departure. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Avg Temperature Departure 2023-09-01 -4.3 2023-08-31 -2.1 2023-08-30 4.7 2023-08-29 1.0 2023-08-28 0.3 2023-08-27 3.1 2023-08-26 4.9 2023-08-25 0.7 2023-08-24 -3.9 2023-08-23 -2.1 2023-08-22 -1.7 2023-08-21 4.6 2023-08-20 -0.5 2023-08-19 -3.7 2023-08-18 1.2 2023-08-17 1.6 2023-08-16 1.0 2023-08-15 1.3 2023-08-14 4.7 2023-08-13 3.6 2023-08-12 2.0 2023-08-11 0.4 2023-08-10 -0.2 2023-08-09 2.7 2023-08-08 0.1 2023-08-07 -0.9 2023-08-06 0.0 2023-08-05 1.4 2023-08-04 -2.2 2023-08-03 -5.3 2023-08-02 -4.8 2023-08-01 -2.4 2023-07-31 -2.5 2023-07-30 -3.1 2023-07-29 4.9 2023-07-28 7.8 2023-07-27 7.3 2023-07-26 0.7 2023-07-25 0.2 2023-07-24 1.1 2023-07-23 2.1 2023-07-22 0.5 2023-07-21 1.5 2023-07-20 1.5 2023-07-19 -1.0 2023-07-18 1.0 2023-07-17 5.5 2023-07-16 -0.5 2023-07-15 2.5 2023-07-14 1.0 2023-07-13 5.6 2023-07-12 4.6 2023-07-11 1.7 2023-07-10 1.8 2023-07-09 0.8 2023-07-08 3.9 2023-07-07 4.1 2023-07-06 6.7 2023-07-05 5.8 2023-07-04 1.0 2023-07-03 6.1 2023-07-02 4.3 2023-07-01 -1.0 2023-06-30 -0.3 2023-06-29 -0.6 2023-06-28 -0.4 2023-06-27 -1.7 2023-06-26 -1.4 2023-06-25 3.3 2023-06-24 0.1 2023-06-23 -6.7 2023-06-22 -8.4 2023-06-21 -5.6 2023-06-20 -2.8 2023-06-19 -1.5 2023-06-18 0.8 2023-06-17 -0.8 2023-06-16 -1.0 2023-06-15 -1.7 2023-06-14 -1.9 2023-06-13 2.0 2023-06-12 1.3 2023-06-11 3.6 2023-06-10 -0.5 2023-06-09 -2.7 2023-06-08 -6.8 2023-06-07 -3.5 2023-06-06 3.4 2023-06-05 -1.3 2023-06-04 -9.0 2023-06-03 -3.6 2023-06-02 9.2 2023-06-01 5.5 2023-05-31 -3.2 2023-05-30 -3.8 2023-05-29 2.0 2023-05-28 1.3 2023-05-27 0.6 2023-05-26 -2.6 2023-05-25 -4.3 2023-05-24 1.0 2023-05-23 -3.2 2023-05-22 2.1 2023-05-21 1.4 2023-05-20 -0.3 2023-05-19 -2.1 2023-05-18 -11.3 2023-05-17 -3.5 2023-05-16 4.8 2023-05-15 1.6 2023-05-14 5.3 2023-05-13 13.1 2023-05-12 12.9 2023-05-11 6.2 2023-05-10 0.4 2023-05-09 0.2 2023-05-08 9.0 2023-05-07 5.8 2023-05-06 0.1 2023-05-05 -3.6 2023-05-04 -6.8 2023-05-03 -6.0 2023-05-02 -6.2 2023-05-01 -1.9 2023-04-30 -2.1 2023-04-29 -6.3 2023-04-28 -4.5 2023-04-27 -3.1 2023-04-26 -5.8 2023-04-25 -1.9 2023-04-24 -2.1 2023-04-23 4.8 2023-04-22 5.6 2023-04-21 4.5 2023-04-20 -0.6 2023-04-19 -0.8 2023-04-18 -2.4 2023-04-17 9.0 2023-04-16 10.4 2023-04-15 14.3 2023-04-14 24.1 2023-04-13 24.0 2023-04-12 23.4 2023-04-11 9.3 2023-04-10 0.7 2023-04-09 -5.9 2023-04-08 -4.5 2023-04-07 2.4 2023-04-06 15.8 2023-04-05 4.2 2023-04-04 11.1 2023-04-03 2.4 2023-04-02 -3.2 2023-04-01 15.2

Whether the usual warm spots in NJ go 95+ this week will come down to how close the offshore cutoff gets. The Euro is the hottest at 95-100° with the low staying further offshore. The CMC is in the middle at 94-98°. The GFS has the low closer to coast and more onshore flow and 90-95°. Not sure if the Euro is over amped with the ridge to the west. None of the models have been doing particularly well recently with big flips in some way from run to run. The summer forecast bias was too warm. But September in recent years has been unusually warm. So who knows which will win out.

Estell Manor COOP edged out Newark and Hightstown for the August 90 day lead. Monthly Data for August 2023 for New Jersey Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 ESTELL MANOR COOP 6 HIGHTSTOWN 2 W COOP 5 NEWARK LIBERTY INTL AP WBAN 5 Newark Area ThreadEx 5 HARRISON COOP 4 MARGATE COOP 4

Thanks. Had family in this area so it worked out easier for me.

I am in a little cooler spot than the LI South Shore used to be for me and it’s down to a crisp 56° here at KHVN.

It does pose the question of how warm the ENSO regions need to get for more of a Nino-like atmospheric response than we have seen? https://psl.noaa.gov/enso/mei/

September and October have been our fastest warming fall months in recent decades. 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. The summer worked out similarly with July posting the greatest warm departure relative to June and August. ……….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

Yeah, actual +30C SSTs from the Dateline to WPAC are much warmer than +1 to +2 or even +3 departures in the ENSO regions. The departures in the eastern regions just don’t have the same bite anymore while the WPAC is so warm. That’s how Nino 1+2 can have such high departures for months and not move the needle on forcing. Back in 1997 we saw the dominant forcing during the summer much further east. But that year didn’t have any competition from the WPAC which was much cooler. https://psl.noaa.gov/map/clim/sst.shtml

Unusually Niña-like MJO action to start September for a El Niño year as the WPAC warm pool is battling the ENSO warming. The IOD looks too weak relative to the WPAC warm pool to have much influence outside that local area.

Big westward lean to the forcing for the first half of September. The forcing plots beyond 2 weeks usually aren’t that reliable. We may see the forcing stall out near the DL again and only some transient EP forcing before the next wave rolls out.

But the subsurface is lagging 1982 at this point when it was getting close to +2 heading into September.

Just looking at the 2nd lowest December -AO last year would have made you think we should have had a KU event.

Provided that the OHC makes a big move upward to the +1.50 +2.00 range from the values only around +1.2 today. Unless the subsurface relationship will do something new like we have seen with many aspects of this event. Plus we just don’t have a big enough sample size of events to account for all the possible variability that may present.

Summer temperatures were close to average for the warmer 1991-2020 climate normals period. Rainfall was above average north and below average south. Seems like the Driscoll Bridge was the dividing line between above and below average rainfall.

This event is unique and nothing like the stronger Pre-1980 evolutions. Just go into the data pages from the strongest events during that era and you can see the differences. Notice how much warmer Nino 1+2 and 3 is along with Nino 4 is now. Nino 3.4 is a little cooler this time. Also take note how much warmer the entire WPAC is now. You can also see the S and W displacement of the forcing away from the equator which was previously the norm.