bluewave

It’s not a leap of faith on my part since there were studies published about the +PDO shift around 2013 to 2015 and the jump in global temperatures. Initialized decadal prediction for transition to positive phase of the Interdecadal Pacific Oscillation https://www.nature.com/articles/ncomms11718 The negative phase of the Interdecadal Pacific Oscillation (IPO), a dominant mode of multi-decadal variability of sea surface temperatures (SSTs) in the Pacific, contributed to the reduced rate of global surface temperature warming in the early 2000s. A proposed mechanism for IPO multidecadal variability indicates that the presence of decadal timescale upper ocean heat content in the off-equatorial western tropical Pacific can provide conditions for an interannual El Niño/Southern Oscillation event to trigger a transition of tropical Pacific SSTs to the opposite IPO phase. Here we show that a decadal prediction initialized in 2013 simulates predicted Niño3.4 SSTs that have qualitatively tracked the observations through 2015. The year three to seven average prediction (2015–2019) from the 2013 initial state shows a transition to the positive phase of the IPO from the previous negative phase and a resumption of larger rates of global warming over the 2013–2022 period consistent with a positive IPO phase.

The big difference was that we didn’t have any effective +PDO and super El Niño anywhere near the magnitude of 2015-2016 from the late 1940s into 1970s. So while we may be seeing some weak echoes or reflections of the way the last cycles played out, I stand by my observation that the 2015-2016 event was a full blown +PDO cycle even though is was greatly reduced in duration. But the effective magnitude was stronger when we combine total EPAC warmth along the West Coast and the ENSO SSTs than 82-83 and 97-98 which were in the same defined common +PDO era.

While it has been windier in recent years, this year is the new high average wind gust leader from January through April at nearly 35mph for the first time. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=140&network=NJ_ASOS&station=EWR&syear=1900&sday=0101&eday=0429&varname=avg_wind_gust&w=none&thres=1&year=2025&_r=t&dpi=100&_fmt=png

Yeah, in a warmer world the troughs are becoming weaker. So the SSTs below haven’t been cooling as much. The cold pool couplet of the +PDO back in 2015 over the Central Pacific was much weaker than we saw back in 1997 due to the much weaker Aleutian Low. But the warm pool and 500 mb ridge near the West Coast was much stronger. So using the older calculation method doesn’t yield as strong of a +PDO. This raises the interesting question about future +PDOs in a warming world. Will there ever be an extended +PDO like we saw from the 1970s to 1990s again if we continue to see so much SST warmth from the CP back to the WP? Maybe this is why the +PDO cycle back in 2010s was so short. The other observation is that this recent -PDO has been more defined by the warm pool over the Western to Central Pacific than the cold pool near the West Coast. This is due to the much stronger Aleutian Ridge and weaker -PNA 500 mb trough than we saw from the 1950s to 1970s during that -PDO era. So the calculation method actually helped the -PDO values in recent years rival or match the older values from the 1950s to 1970s. Even though the trough near the West Coast was weaker than past -PDOs and SSTs warmer. I think we are just going to have to take a wait and see approach to the lengths of these PDO phases going forward. As a much warmer Western Pacific from the Maritime Continent to the south of the Aleutians loads the dice for more -PDOs than +PDOs. We will have to see if there is some possibility of the Eastern Pacific seeing an accelerated warming while the Western Pacific cools in the coming years. But if the Western Pacific continues to stay warm and increase the warmth, then +PDOs may be harder to come by. A clue as to if this can happen could be the unusual warming last few years in the Nino 1+2 region and rapid rise in global temperatures. But we recently saw how that shallow warm pool could connect to the warm pool over the WP. So the stronger trades cooled it off and slowed a return to El Niño. But historically as least since 1950, we haven’t seen such a fast return to El Niño following such a strong El Niño like we had in 23-24.

I remember days like this living back in Long Beach. Would be hearing about 80s to the west. But wind gusts over 30 and blowing sand at the beach with 50s. I always had to hose down my bike after getting sandblasted riding the Long Beach board walk.

Notice how wide the band of +PDO SST warming was from Mexico all the way to Alaska with the +PDO super El Niño event in 15-16. It far surpassed anything we have ever seen from a +PDO and El Niño combo before. The reason the raw index you posted was underdone was due to the much smaller cold pool to the west of the +PDO horseshoe. So the footprint of the historic +PDO was larger leading to the normally cold regions to the west being smaller. This why the SST charts below are a better indicator of the strength of the event. As the raw index was too narrowly defined to capture the sheer volume of historic SST warmth near the coast. So we need to update the way we calculate these indices in a rapidly warming world with more extreme marine heatwaves. We have seen this same process at work with the raw telconnections struggling to capture the totality of events which have more often been defined by the record 500mb heights.

The SSTs along the West Coast were the warmest on record during the 2014-2015 +PDO event. Those raw indices values you posted were only a small piece of the total event. As those raw indices can often miss the totality of events. Like we often see between the 500mb versions of the teleconnections and the surface pressure versions. My analysis involves a bigger picture view rather than the more narrowly defined approach that you are taking. Notice how much wider the band of record SST along the West Coast warmth was in the 15-16 event than 97-98 and 82-83.

Big Ambrose Jet day coming up. 80s west of the sea breeze to 50s along the South Shore. Then SSW gusts later over 30 mph again. So our strong winds pattern continues.

My point was about the duration of the PDO cycling. I have posted numerous papers further back on how the length of the phases was different during different climate epochs. The period around 2015 was one off the most extreme +PDO and super El Niño couplets that we have ever experienced. I posted papers on this further back on how there was a model used which forecasted this shift. But the amplitude of the shift in the model was much weaker than what verified. So the period from around 2015 to the late 2010s was indeed a +PDO phase. But we cycled back to more -PDO into the 2020s. There was more research that the ENSO cycle has become more extreme using corals going back hundreds of years as the climate has warmed. This has been confirmed by how extreme the swing was between the super El Niño and +PDO was in 2015 and the -PDO and multiyear La Niña -PDO in the early

If you didn’t continually misstate my conclusions based on your incorrect perceptions of them, then we wouldn’t have to keep going back and forth and diverging from the main discussion. Maybe this format just is too incomplete to enable you to get the full gist or meaning of the ideas that I am trying to convey. We could probably come to a much better understanding if we ever had a meeting in public like at a conference if something. If you ever met me in person, then you would probably come away from the meeting with a completely different view as my in person persona can often be more stand up comedian like. As these forums can come off as overly dry. I get that you have a pretty good sense of humor and so do I. But it’s not always easy to convey that in these posts. These back and forth interactions I take in stride. Almost like when players are off the field the relationship is less intense what is seen on the field. But unfortunately, these forums miss the the off field antics.

Something human I see about your posts is that they involve a large degree of projection. I can tell you are bothered about the lack of cold and snowy winters and it’s leading to you being very critical of anyone that is pointing out the obvious. Viewing scientific principles through political filter usually doesn’t lead to success. But sometimes people are willing to sacrifice forecast accuracy in service to holding onto outdated beliefs which provide emotional comfort. What you classify as superiority is actually maintaining focus on the big picture. I have worked very hard to eliminate biases over the years. It’s actually been easier to do with weather statistics and patterns which hold no emotion for me. Maybe this is what you are perceiving as superiority. I try not to get emotional about the weather and climate.

The Euro updated seasonal forecast for the summer will be out on May 5th. It actually has been one of the better periods for seasonal forecast skill of summer temperatures and 500 mb patterns. My guess is that this dry pattern will generally continue into the summer as it has been very persistent especially in Eastern PA into NJ. The last time we had a dry pattern heading into the summer was 2022. This is when NJ reached 100° over 5 times but the areas further east had more onshore flow and less 100° heat than NJ. So our first hints on summer wind direction will probably come with the Euro update on May 5th.

My only agenda has been getting the pattern correct. I have to chuckle when I see posts such as yours which often use the term agenda. Since agenda is generally a political term that has nothing to do with weather and climate forecasting.

I disagree with your assessment about a cold phase since 1998. The PDO has been shorter cycling than it was prior to the 1990s. So we have been getting alternating +PDO and -PDO cycles since then. This is why the 2010s into the 2020s have experienced such a rapid shift between the record +PDO in 2015 to record -PDO in the early 2020s. Those long 30 year cycles have become a thing of the past. Plus the rapid warming of the Western Pacific has altered the way the PDOs have been relating to our sensible weather. So canonical expectations based solely on PDO phase have not been working out. -PDOs of recent years have been much different from earlier -PDOs due to the 2nd EOF running so warm. So this has lead to much warmer and less snowy -PDOs then were experienced in the past. We also experienced record warmth with the +PDO in December 2015. So not seeing how another +PDO in coming years if it were to evolve would necessarily be any cooler than the recent -PDOs. The colder 13-14 into 14-15 period was more a result of the +TNH and +NPM pattern. But as we saw last winter, the stronger Northern Stream of the Pacific Jet muted that influence. So no cold trough was able to develop in Canada like we saw in 13-14. This is why when I saw the Pacific Jet and storm tracks last December I said early on that we weren’t going to see another 13-14 repeat like some on twitter were calling for.

The very low soil moisture has been pretty persistent as the strong winds quickly dry things out behind the parade of storms through the Great Lakes that have been generally underperforming on moisture.

Yeah, warmer and drier than normal until further notice.

We were in and out of drought quite a bit prior to the precipitation increase since 2003. So those lower totals didn’t really cut it. The good news is that the NYC hasn’t had a drought emergency since then. The dry pattern since last summer has mostly been focused to the S and W of NYC. So the reservoirs to the north are fine. But NJ had had reservoir issues. These strong winds dry things out more as we have seen with the increased brush fires in recent months.

It’s more pronounced to our SW as they are down more than 10 inches since last summer.

I still think it’s too early to be discussing any lasting shift in the Pacific. Since the ridge east of Japan and south of the Aleutians returned right after the winter mismatch ended related to what happened in the tropics last October. Remember, the west Pacific has been having more influence than whether the PDO has been in a positive or negative phase. As the 2nd EOF of the PDO has really been more significant in recent years than the old canonical understanding we used to use.

Here come the wind gusts over 35 mph again to dry things out after the rain. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=140&network=NY_ASOS&station=ISP&syear=1900&sday=0101&eday=0426&varname=avg_wind_gust&w=none&thres=1&year=2025&_r=t&dpi=100&_fmt=png Kennedy Intl PTCLDY 50 33 52 NW26G35

My early guess for next winter is that it’s going to be warmer than this past winter was from Philly to Boston. This is based on past La Niña +PNA mismatches and what happened in the seasons around them. The previous La Niñas with strong +PNA in either December or January were 95-96, 00-01, 10-11, 17-18 and 20-21. The 96-97 and 01-02 winters were milder than the preceding ones. Same went for 11-12 which was warmer than 10-11. 16-17 came before the 17-18 mismatch but I thinks it’s informative of the same general background conditions. We haven’t had a back to back La Niña or a back to back La Niña and a neutral around one of these +PNA mismatches years that were as cold as the first years was. There is always one year in a grouping of La Niñas or La Niña and neutral which is colder than the previous one. 21-22 followed the 20-21 mismatch year with December featuring record warmth in many areas. The MJO 8 in January made January the sole colder and snowier month in a sea of warm that winter. It’s tough to get a two colder La Ninas in a row or a colder neutral following a colder La Niña. But will hold out some hope of at least one decent winter month next winter should we see a 21-22 type mirroring or weak echo. As always, I will wait until we see what the early MJO indicator does in October. This past October we got the strong signal which lead to the +PNA mismatch in December and January which I discussed last October. We haven’t had two in a row before. But you never know if we can get a first time. So I will wait until after October for my 2nd winter guess. Was hoping a few weeks ago that the system could tilt more into El Niño. But this too never happened so soon before going back to at least 1950 following such a strong El Niño. So the EPAC warming still hasn’t become connected to the subsurface further west. And we just saw how the increase in surface winds cooled Nino 1+2. But I still want to see how the summer into fall goes before making a final ENSO call for next winter. Obviously, we saw how the neutral to weak El Niño in 18-19 couldn’t overcome the stronger La Niña background warm pool in the WPAC. So 18-19 had more elements of a La Niña following the 17-18 La Niña mismatch.

I just had some heavier rains here with this first round.

Looks like some much needed rainfall tomorrow. HRRR has 3 rounds of convection. First batch of elevated convection early tomorrow morning with the warm front. Then another round of storms midday with the cold front which becomes more surface based. Which will be followed by more storms in the evening. Also expect windy conditions again lingering into Sunday.

The composite I posted was both -NAO and -AO at 500 mb as the ridge extended from Baffin Island all the way over to Iceland. So the -AO and -NAO were interchangeable at 500mb on the storm days. The -NAO has linked up with the Southeast Ridge just as much as the -AO. So the recent differences between the indices are more surface pressure related rather than at 500mb where the linkage with the subtropical ridge while the indices were negative has been occurring. March 2023 was the most negative -NAO cold season month in recent years. And the Southeast Ridge had no trouble linking up with the -NAO block that month for the big rainstorm along the coast and interior high elevation snowstorm. https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii 2023 3 1 -0.956 2023 3 2 -1.006 2023 3 3 -1.093 2023 3 4 -1.161 2023 3 5 -1.109 2023 3 6 -1.132 2023 3 7 -1.187 2023 3 8 -1.091 2023 3 9 -0.614 2023 3 10 -0.356 2023 3 11 -0.293 2023 3 12 -0.254 2023 3 13 -0.111 2023 3 14 -0.007

The Ambrose Jet kicked in around 5 to 6 pm. But the afternoon initial SE flow delayed it a bit. Even though the Ambrose Jet typically peaks between 4-7pm JFK hourly data Apr 24, 6:25 pm 64 46 52 S 21G26 10.00 CLR 30.22 30.23 Apr 24, 6:20 pm 64 46 52 S 20G26 10.00 CLR 30.22 30.23 Apr 24, 6:15 pm 64 46 52 S 20G25 10.00 CLR 30.22 30.23 Apr 24, 6:10 pm 64 46 52 S 18 10.00 CLR 30.22 30.23 Apr 24, 6:05 pm 64 46 52 S 17G24 10.00 CLR 30.22 30.23 Apr 24, 6:00 pm 63 44 52 S 18 10.00 CLR 30.22 30.23 Apr 24, 5:55 pm 63 44 52 S 18G24 10.00 CLR 30.22 30.23 Apr 24, 5:51 pm 63 45 52 S 18 10.00 BKN250 1023.70 30.22 30.23 Apr 24, 5:50 pm 63 44 52 S 18 10.00 30.22 30.23 Apr 24, 5:45 pm 63 44 52 S 20 10.00 CLR 30.22 30.23 Apr 24, 5:40 pm 64 44 49 S 21 10.00 CLR 30.22 30.23 Apr 24, 5:35 pm 64 44 49 S 18 10.00 CLR 30.22 30.23 Apr 24, 5:30 pm 64 44 49 S 20G26 10.00 CLR 30.22 30.23 Apr 24, 5:25 pm 64 44 49 S 18 10.00 CLR 30.22 30.23 Apr 24, 5:20 pm 66 45 46 S 20G25 10.00 CLR 30.22 30.23 Apr 24, 5:15 pm 66 45 46 S 18 10.00 CLR 30.22 30.23 Apr 24, 5:10 pm 66 45 46 S 18 10.00 CLR 30.23 30.24 Apr 24, 5:05 pm 66 45 46 S 17G25 10.00 CLR 30.23 30.24 Apr 24, 5:00 pm S 18G24 10.00 CLR 30.23 30.24 Apr 24, 4:55 pm 66 45 46 S 18 10.00 CLR 30.23 30.24 Apr 24, 4:51 pm 67 46 47 S 17 10.00 FEW060 BKN250 1024.10 30.23 30.24 Apr 24, 4:50 pm 66 46 49 S 16G22 10.00 FEW060