bluewave

The summer of 2017 to 2023 +PNA run was the longest on record since 1950 lasting 7 years. This June so far is a continuation of the streak. Everyone will be tracking the pattern next winter to see if the unprecedented 9 warmer to record warmer winters in a row around the Northeast makes it to 10 years.

Today may be the warmest day of the whole week with parts of NJ away from the sea breeze trying to make it to 90°.

Being driven by that ridiculous marine heat wave to the east of Japan and north of Hawaii. https://x.com/extremetemps/status/1797596879703908370 May 2024 in #Japan had a temperature anomaly of +0.67C above normal and was the 16th consecutive warmer than average month. Tokyo hasn't seen any colder than average month since late 2022. Maps by JMA. https://x.com/MercatorOcean/status/1795090981810819261 This week's Marine Heatwave Bulletin is online! For more data and forecasts, click here https

Newark has had at least a T of rain on every weekend since the beginning of March. Newark Jun 1-2……….T May 25-25…..T May 18-19…..0.04 May 11-12…0.38 May 4-5…..0.31 Apr 27-28…0.11 Apr 20-21…0.05 Apr 13-14…0.04 Apr 6-7…….T Mar 30-31…0.01 Mar 23-24….3.10 Mar 16-17…..T Mar 9-10….1.46 Mar 2-3…..1.31 THE NEWARK NJ CLIMATE SUMMARY FOR JUNE 2 2024... CLIMATE NORMAL PERIOD 1991 TO 2020 CLIMATE RECORD PERIOD 1931 TO 2024 WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST VALUE (LST) VALUE VALUE FROM YEAR NORMAL ................................................................... TEMPERATURE (F) YESTERDAY MAXIMUM 86 112 PM 93 1989 77 9 91 2000 MINIMUM 62 406 AM 48 1945 59 3 64 1946 AVERAGE 74 68 6 78 PRECIPITATION (IN) YESTERDAY T 2.96 1946 0.15 -0.15 0.00 MONTH TO DATE T 0.31 -0.31 0.00 The models are hinting at some shower and thunderstorm potential next weekend with the upper low closing off over the Great Lakes.

https://x.com/WeatherProf/status/1797385397422432279 The black line on top is the 2024 sea sfc temp in mid FL Keys reef. The solid horizontal purple line is the bleaching threshold. We’ve already reached it, ~1 month ahead of 2023 - the worst mass bleaching event ever. To bleach, it would need to be sustained, but not a good sign

It also seems like our winter blocking episodes during the 2020s have shifted the strongest 500 mb anomalies further west into the AO domain. So we are getting weaker -NAO responses and ridging closer to Iceland. Even when the -AO was near record lows like in December 2022 closer to Greenland. So this has been allowing the further west blocks to link up with Southeast ridge. You can see the big difference between the La Niña Decembers of 2022 and 2010. December 2022 featured a -2.719 AO and -0.15 NAO with lower heights near Iceland. December 2010 had a -2.631 AO along with a much lower -1.85 NAO. My guess these shifts along with more south based -AOs in recent years are related to the global land and SST warming altering the way the teleconnections and 500 mb patterns manifest. The -PNA was even lower in December 2010 at -1.78 than the -0.66 PNA in December 2022.

Yeah, the +PNA -NAO tendency has been increasing during the summer. Winters have featured an increasing +NAO pattern. So while this winter was technically +PNA, the undercutting trough near the Western US functioned more like a -PNA. So we have had more of a -PNA 500MB look most winters since the 15-16 super El Niño.

Yeah, this would have been a great pattern last winter. Very impressive +PNA -NAO blocking for June. We’ll need to see exactly where the upper low closes off in order to know where the surface lows and rainfall chances will be the highest.

Yeah, right in cue the ridge is returning to the Western US as we start June. This has been the dominant summer pattern since the 15-16 super El Niño. But the winter pattern has been the opposite with more of a trough over the Western US and record ridging and warmth over the Northeast. So that record NE PAC block during the 13-14 and 14-15 winters shifted to the summer. And the winters have had trouble maintaining any type of ridging In these areas as a trough has been dominating out West. The recent exception was during January 22. That was the result of the MJO 8 pattern. But most of the winter MJO activity has been in the phase 4-7 range since the 15-16 super El Niño.

Unusual goings on with the stratosphere as such a strong -AO +PNA block isn’t what we typically see during El Niño to La Niña transition summers. Very comfortable early June temperatures for us. Almost looks like the Arctic pattern change around March 20th was so strong that it got stuck in place into the early summer. But now we have the +PNA to go with the -AO https://x.com/judah47/status/1795928965883826606

https://www.washingtonpost.com/climate-environment/2024/05/25/mexico-city-water-day-zero/#:~:text=Supplying water to 22 million,significant sinking around the city. MEXICO CITY — Raquel Campos’ water issues started in January, when her condo building’s manager sent residents a message saying that the city hadn’t delivered water to its cistern. Four days later, taps in the upscale residence went dry. Campos has lived in the wealthy Polanco neighborhood for 18 years and said she has never experienced water issues like this. Her husband paid to shower at a nearby hotel and she called water delivery companies that were overwhelmed with a sudden deluge of requests from the neighborhood. The water in Campos’ building came back within a few days, but with much lower pressure. Water is now delivered about every two weeks. Each unit has paid to cover the cost, increasing their monthly condo expenses by 30 percent. Water scarcity has long been an issue in Mexico City, with the brunt of the shortages happening in lower-income neighborhoods on the outskirts of the city center. But recently, residents in some of the city’s wealthier neighborhoods have also been running out of water as hot temperatures, low rainfall and poor infrastructure have converged to create a crisis across the sprawling metropolis.

Where is the plain text option since it doesn’t seem to show up for me?

https://twitter.com/wxjerdman/status/1796132632549339572

When I do the same thing it comes out as a link. https://x.com/wxjerdman/status/1796132632549339572

32° this morning up in Saranac Lake. https://www.weather.gov/wrh/timeseries?site=KSLK

Yeah, I haven’t been able to get it to work. But I see that other posters have found a way since there are embedded posts in the last few days showing up in the various threads.

How do we get the twitter X links to fully display rather than just show a link? I am seeing posts around the forum with it both ways. It just used to automatically embed before a few weeks ago.

Yeah, I agree with the authors description of the first and second EOFs of the PDO undergoing a remarkable evolution since 2014. Remarkable Changes in the Dominant Modes of North Pacific Sea Surface Temperature https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101078 The second PC is mostly positive from 1990 to 2021 and strongly positive from 2014 to 2021 (Figure 6b), reflecting the positive SSTa across much of the North Pacific that EOF 1 alone does not capture. The weak negative lobe in the second EOF lessens the warming near the coast of North America. As EOF 2 describes less of the variance than EOF 1, it might be expected that its shape is more variable when calculated over different time periods, interestingly, the positive lobe in EOF 2 has grown steadily when calculated over successively longer time periods (Figure 6b, x-ticks). The positive lobe of EOF 2 filled up 98% of the North Pacific when calculated over the period 1950–2018 and similarly for HadISST data at 93% (Figure S1.6 in Supporting Information S1). While EOF 2 has not been invoked as often as the PDO as a measure of SST variability, the robust evolution since 2014 is still worthy of note. Figure 6 Open in figure viewerPowerPoint (a) The second EOF of SST over the PDO region for the entire time series (1950–2021). (b) The principal component for the second EOF is shown on the left y-axis using colored bars. The right y-axis (x symbols) shows the percentage of data points greater than zero in the second EOF from 1970 to 2021. 5 Conclusions The fundamental result of this study is that the first EOF of SST in the North Pacific has changed starting in 2014. For more than 20 years, the PDO has been used to describe the state of the North Pacific. However, since the marine heatwave of 2014, there have been remarkable changes to the dominant mode of SST in the North Pacific. The spatial pattern of the first EOF of SST from 1950 to 2021 is notably different from the PDO, suggesting that though the PDO served as a useful metric of SST variations until 2014 (Johnstone & Mantua, 2014), it may no longer be as effective a climate index for the North Pacific. From 1950 until the 2014 MHW, the first EOF remained consistent in its proportion of positive and negative regions with both taking up roughly half the area of the North Pacific (and with the positive region taken to be the eastern Pacific). When EOFs are calculated from 1950 to endpoints after 2014, the first EOF has a maximum positive region covering 77% of the North Pacific, with a PC indicating the largest anomalies on record. These changes to the first EOF/PC of North Pacific SST are nothing short of remarkable. In concert with these changes, the second EOF/PC of SST has also undergone profound evolution since 2014. This second EOF now accounts for approximately 18% of the variability, growing from 13% during the 1950–2013 period. The spatial structure of the second EOF now is positive over almost the entire basin, with a PC that has grown strongly positive in the last several years. Thus, the second EOF/PC describes warming over much of the Pacific not in the positive lobe of the first EOF. A relevant aspect of our analysis is that we did not remove a trend from the data before calculating the EOFs and PCs. This is consistent with the original calculations of EOFs in the North Pacific (Davis, 1976) and more recent analysis by Johnstone and Mantua (2014), but inconsistent with the definition of the PDO which did have a global mean trend removed (Mantua et al., 1997; Zhang et al., 1997). Whether or not a trend was removed had little effect on the first EOF, and thus the PDO, until 2014. Two of our results lead to this conclusion: first, our first PC calculated between 1950 and 1993 agreed with the PDO with a correlation coefficient of 0.97; and second, our first EOF calculated with successively longer time series did not change in shape until 2014. There are many approaches to removing a trend from time series (Deser & Phillips, 2021; Frankignoul et al., 2017; Solomon & Newman, 2012). We investigated two of these approaches: first we removed a least-squares fit of a line to the global average temperature as in the original definition of the PDO (Figure S2 in Supporting Information S1), and second, we removed a least-squares fit of a line from each grid point in the North Pacific (Figure S3 in Supporing Information S1). In each case the EOF analysis reproduced the PDO spatial pattern and index, suggesting that the PDO remains a good measure for the variability relative to the trend. In general, removal of a trend (as by least-squares fitting of a line, e.g.,) tends to deemphasize the ends of a record. In our analysis, the inclusion of the trend highlights the fact that the warming in the eastern Pacific has increased notably in recent years, a fact that would be obscured if a linear trend had been removed. The PDO is recognized to be a result of many processes that may cause temperature variability (Newman et al., 2016) rather than any singular phenomenon. The many processes that affect SST have apparently combined to create both this era of frequent marine heatwaves beginning in 2014 and a fundamental change to the first mode of SST. The persistence of the marine heatwaves was studied by Di Lorenzo and Mantua (2016) who also invoked a number of interacting processes, suggesting that the variance described by the PDO would increase in a warmer climate. Di Lorenzo and Mantua (2016) explicitly removed a trend before calculating the EOFs of SST, so that their EOFs described variance relative to the trend. The PDO is based on a constant spatial pattern defined by the EOF that described the most variance of SST through the mid 1990's. However, there is no guarantee that the EOFs of SST will remain constant as climate change continues. This concern about indices based on EOFs applies also to the North Pacific Gyre Oscillation (Di Lorenzo et al., 2008), which describes variance in sea surface height. The PDO is widely used as a measure of temperature in the eastern boundary upwelling system along the west coast of North America (e.g., Weber et al., 2021). The period of persistent marine heatwaves since 2014 has made the PDO less useful as an index of temperature in this region because it does not reflect the recent increase. In general, using PCs from a basin-wide analysis as indices of temperature for specific regions may be problematic because the influences from distant parts of the basin affect the PCs. Options moving forward may include: (a) updating the definition of the first mode of temperature variability, as we have done here, (b) explicitly accounting for the trend in addition to the PDO for a measure of temperature, or (c) defining a new temperature metric in a specified area in the region as is done for the various measures of El Niño (Trenberth, 1997) or more recently as in the NEP index (Johnstone & Mantua, 2014). Interestingly, the NEP was first published just before the recent period of MHWs, and the value of the approach championed in Johnstone and Mantua (2014) has only increased. The wide-ranging effects of the recent period of MHWs are likely to be seen in continuing studies of the eastern North Pacific.

Yeah, plenty of back and forth especially in regard to high temperatures this spring. While the average and minimums were solidly near the top throughout,the maxes haven’t been as impressive since March 18th. We probably could have challenged the warmest spring on record had the pattern not shifted to more blocking and onshore flow after St. Patrick’s Day. So Newark was only able to reach 90° for a max once this spring which was on the cooler side for the spring max and only on 1 day. The most impressive record warmth occurring through March 17th was a little too early to add to the 90° count. So the spring was the 3rd warmest on record at Newark even while having the lowest max and #90 days for other such high ranking years. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Max Temperature Mar 18 to May 29 Missing Count 1 2010-05-29 69.6 0 2 1985-05-29 68.8 0 3 2021-05-29 68.5 0 - 2012-05-29 68.5 0 4 2023-05-29 68.1 0 5 1986-05-29 67.9 0 6 1945-05-29 67.8 0 7 1991-05-29 67.7 0 8 1994-05-29 67.5 0 9 1977-05-29 66.7 0 10 1993-05-29 66.6 0 11 1949-05-29 66.5 0 12 2015-05-29 66.4 0 - 1981-05-29 66.4 0 - 1941-05-29 66.4 0 13 2006-05-29 66.3 0 - 2004-05-29 66.3 0 - 1998-05-29 66.3 0 14 2024-05-29 66.2 0 - 1976-05-29 66.2 0 - 1962-05-29 66.2 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Max Temperature Mar 1 to Mar 17 Missing Count 1 2024-03-17 59.2 0 2 2016-03-17 58.8 0 3 1973-03-17 57.8 0 4 2012-03-17 57.5 0 5 2000-03-17 57.4 0 6 1977-03-17 57.0 0 7 2020-03-17 56.9 0 8 1990-03-17 56.7 0 9 1946-03-17 56.4 0 10 1945-03-17 54.6 0 Spring average March 1st through May 29th Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Spring max and #90 days 1 2012 57.6 92…2 2 2010 57.4 95…3 3 2024 56.6 90…1 4 1985 56.2 92…3 5 1991 56.0 93…8 6 2023 55.5 93…3 7 1977 55.3 91…4 8 2022 54.9 98…4 - 2016 54.9 96…3 - 2011 54.9 92…1 - 1945 54.9 90…1 9 2021 54.8 96…4 10 2004 54.7 92…2 - 1998 54.7 90…2 - 1986 54.7 95…6

There are a few ways that a warming climate can manifest in our our weather patterns. The first way is linear by which the winters gradually become warmer and snowfall decreases. But there will still be colder and snowier winters in the mix along the way. I think this gradual shift is what most people are more familiar with. But the second way is more non-linear or threshold dependent. The climate models don’t really do well at picking out these temperature thresholds in advance. So they usually don’t become obvious until after a certain period of time has passed. It does appear that we may have crossed a temperature threshold during the 15-16 super El Niño. But we still probably need to see how winter temperatures progress through 2030 in order to know whether it was a shift or just loading the dice for warmer winters with some colder ones still mixed in. The snowfall experience has been different for us. From 93-94 through 17-18 we saw a steady increase in snowfall. But the off seasons like 97-98, 01-02, 06-07, and 11-12 fell near the bottom of the list. So it was an all or nothing snowfall pattern and lacking the median snowfall seasons which were more common from the 60s to early 90s. While the better seasons were more frequent, we traded the median seasons for near record low seasons. Since the most recent downturn only began in 18-19 for snowfall, more time is need to know if we entered a longer term declining phase or passed a threshold where the much lower seasons replace the higher ones as the norm. In any event, the 2010s record snowfall decade would be a tough act to follow even in a more stable climate absent the warming trend.

The interesting thing is that the La Niña winters with the lower RONI since 2010 in the multiyear groupings had better snowfall around NYC than the higher RONI ones. This works for the ONI also. It seems to be why each multiyear La Niña since 2010 there was at least one season which stood out with better snowfall than the others. But this hasn’t worked for temperatures with every La Niña winter since 11-12 having above normal temperatures NYC and the Northeast. https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt NYC SON…..23…..RONI….-1.08…snow…..2.3” NDJ…..21……RONI….-1.24…snow…..17.9” OND... 20….RONI……-1.52…snow….38.6” NDJ…..17…..RONI…..-1.25….snow…..40.9” SON….16…..RONI…..-1.09….snow…..30.2” OND….11…..RONI…..-1.05…..snow…..7.4” OND….10…..RONI…..-1.70…..snow….61.9” http://www.bom.gov.au/climate/mjo/ There is another interesting pattern which has worked out since 2010. All the snowiest La Niña winters which included 10-11, 17-18, and 20-21 had the most amplified MJO phases 4-6 in October. The less snowy winters had weaker MJO 4-6 activity. I will update this post after October to see how the MJO pattern did. So maybe we could get some clues for the winter snowfall around NYC. But the one caveat is that all these relationships since 2010 may not continue to work.

Yeah, the MJO 4-7 pattern has been dominant regardless of El Niño or La Niña since the December 2015 historic +13 departure in the Northeast and record MJO 4-7 amplitude for an El Niño. Every winter since then has been warmer to record warm. But we have still had a few MJO 8 opportunities along the way. January 16 was one which lead to the record late January snowstorm and brief subzero readings on Valentine’s Day around NYC. It was still one of our warmest winters on record due to the ridiculous warm start to the season in December. Our next MJO 8 was in February 17. While it delivered a nice blizzard around NYC Metro in February, it was also one of our warmest winters. The 17-18 winter started showing promise with the Arctic cold and the MJO 8 after Christmas and 950 mb Benchmark blizzard in early January. Then the pattern rapidly turned warmer in mid-January as the near record MJO 4-7 emerged. Record warmth in February followed with 80° warmth around NYC Metro. So the backloaded warmth pushed the winter into the warm column. The strat warm blocking and MJO 8 influence occurred too late into March so the winter finished warm again. The 20-21 winter had just enough warmer MJO activity for the winter to finish above normal. But the amplitude was muted just enough for a really nice snowfall outcome for many especially just inland from the immediate coast. While the 21-22 winter started with more December record +13 warmth this time around DFW with a very amplified MJO 5-7, we saw nice improvement during January with the coldest month for NYC in years near 30°. Very nice snows especially east of NYC to go with the MJO 8. But the winter still averaged warmer than normal. Then more MJO 4-7 issues in 22-23 and 23-24 with two completely different ENSO states and continuing record WPAC warm pool. The Pacific was so hostile in December 22, that it completely overpowered our 2nd lowest December -AO on record. Just when we thought the winters couldn’t get any warmer than 22-23, we finished again with one of our warmest winters in 23-24 with very strong MJO 4-7 forcing for such a strong El Niño. This made it an unprecedented 9 warm to record warm winters in a row for the Northeast. Looking forward to next winter, it appears like La Niña and -PDO will be in the menu yet again. I guess the one hope is we can put together some intervals closer to what we saw in the 20-21 and January 22. And not a repeat of the 22-23 La Niña. But this would require some MJO improvement like we got in 20-21 and January 22.

The interesting part is that we only had that extended pattern during the cold seasons in 13-14 and 14-15. It was associated with very strong blocking over the NE PAC domain. But the paper doesn’t mention the fact that this pattern has shifted to the warm seasons since then and has been largely absent during the winters. Notice how the models are building the ridge over the Western US during the start of June right on cue. Record Western warm season heat and drought have been a dominant feature in recent years. A prime example of this was the historic NE PAC blocking and heatwave in the Pacific Northwest during the summer of 2021.

The warm departure this month is mostly a function of the warmer minimums rather than the maximums. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of May Click column heading to sort ascending, click again to sort descending. Rank Year Mean Min Temperature Missing Count 1 2012 58.4 0 2 1991 58.3 0 3 2018 57.6 0 - 1985 57.6 0 4 2024 57.4 3 - 2011 57.4 0 5 2022 57.3 0 - 2015 57.3 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of May Click column heading to sort ascending, click again to sort descending. Rank Year Mean Max Temperature Missing Count 1 1991 79.5 0 2 2015 79.2 0 3 1965 77.8 0 4 1986 77.5 0 5 1993 77.2 0 6 1985 76.5 0 - 1944 76.5 0 7 2010 76.4 0 8 2018 76.2 0 - 1959 76.2 0 9 1977 76.1 0 - 1964 76.1 0 10 2004 76.0 0 11 2007 75.7 0 12 1980 75.4 0 - 1955 75.4 0 13 2022 75.2 0 - 1936 75.2 0 14 2024 74.9 3 - 1994 74.9 0 - 1941 74.9 0

I an not in the permanent camp yet. But I think next 5 years will give us enough data to make that call one way or the other. A large portion of the Eastern US has had an unprecedented 9 warmer to record warm winters in a row. If this doesn’t change by 2030, then I think we would have to entertain the idea of some type of shift to a new regime. So I will just take it one year at a time to see if there are any deviations from this pattern.