bluewave

I don’t think we can blame the disappointing pattern last December completely on the -PNA trough in Western North America. The actual 500 mb trough wasn’t as deep as we used to see under previous -PNA -AO patterns from the 50s to early 70s. The big issue was with how far south the -AO Greenland block built down into New England. No room for 50/50 low development and colder high pressure to build in behind it like was common in the earlier era. That being said, this wasn’t always the best pattern for snow even in an earlier era for the Northeast. But there was more cold available back then making a difference in marginal situations. Also less tendency for the stronger height rises east of New England to steer the storm tracks further west. Many of those earlier seasons with such a strong -AO month along with a -PNA had more snow in NYC than last winter did. Last winter also had the lowest snowfall production for NYC with any winter month featuring an AO reading lower than -2.5.

Yeah, but I have seen versions of this from the Euro since after its hot streak around the time of Sandy. Sometimes it seems to get locked into a suppression forecasting pattern with storms that correct west over time. On other occasions, it’s way too far west and amped up. So I am not sure what is going on. I always read the latest ECMWF reports on performance. But seldom do we see regional skill forecasts for an area like the East Coast. It’s always very generalized with hemispheric or continental skill scores. But there was one write up in the January 2015 storm which the Euro had too far west. The Northeast Corridor is the most densely populated part of North America. So generalized skill scores for much wider geographic areas don’t tell the full story. Something seemed to happen with the model around one of the updates after Sandy.

Yeah, the correction below is definitely what you want to see from a 3 run trend. But I would really like to know why the initial 102 hr forecast was so suppressed. There are people programming that model with some very advanced physics and math degrees. So it would be nice for one of them to join the forum and tell us what the challenges are with East Coast storm tracks. Perhaps interactions between the polar Jet and Gulf Stream just are too hard for the state of the art technology to resolve. Maybe we can get luckier when the Euro upgrades to 4-5 km resolution and improves their convective schemes. And I hope AI can make some real advances with correcting model biases.

I am a bit disappointed in the Euro in recent years with regard to storm tracks. How a model goes from stellar performances with Sandy, Nemo, and Joaquin to the poor showing with Lee is hard to decipher. Plus it’s over amped bias at times makes it erratic. The suppression with the January 2016 record snowfall and too far west with January 2015 wasn’t very good.I know it’s the top rated model based on statistics, but not sure how that calculation is made when we see so many struggles with storm tracks in our area.

I don’t think that most on here raising questions on how much coupling we get, how strong the El Niño gets, and how much influence the WPAC exerts are doing so in the interest of a cold winter. It’s more like trying to figure out what the actual flavor of the winter pattern may be. We have had warm El Niño’s, warm uncoupled El Niño’s, and warm La Ninas over the last 8 years. So going cold for a winter forecast regardless of the ENSO state hasn’t payed off for your clients. If we want a cold winter, we would probably need some extreme version of the -EPO blocks from 13-14 and 14-15. But the forcing since then has only resulted in sporadic cold months which couldn’t sustain. So one of these days we will eventually get another cold winter, but I may not be easily attributable to the specific ENSO state. The one common denominator to all our scattered cold months since 15-16 has been extreme blocking. So the cold winter fans will need a sustained and record blocking regime to lock in. How you forecast that before the winter starts is beyond our current technology. Plus the warming background state makes a colder winter less likely. But that doesn’t mean impossible.

The Euro is probably too far west like it was with Lee. But all the other models focus the heaviest rains over eastern sections. So my guess is that western sections may end up saying what nor’easter while coastal sections to the east cash in.

Pretty cool how the early season nor’easter now forecast for Monday was missed by earlier model runs. So wet and cool pattern to start the new week. We’ll take anything that resembles an actual fall pattern. Eastern sections should be favored. So if this was the winter, better snows east with western areas missing out. New run now has our first nor’easter of fall on Monday Old run just a frontal passage

This is a great presentation on how the Northeast and adjacent coastal waters have seen some off the fastest regional warming on the planet. Just remember that there can always be future shifts to the rates of warming and future decades could vary from the most recent one. Just acknowledging our rapid warming doesn’t guarantee that we will know how things will change in the future. The rates of future warming can vary over the shorter decadal time scales.

More like a much warmer climate influences the anomalies differently than a cooler one. So the expression of the natural variability shifts over time. It loads the dice toward warmer outcomes than cooler ones. As to the recent La Niña background state since 15-16, we just don’t know if this may eventually shift to something else. But if it eventually does and we get a whole new winter pattern, doesn’t mean that the warming wasn’t responsible for the last 8 winters. But other changes from the warming asserted themselves for a new winter pattern should it emerge.

Gorgeous hurricane sunset here at KHVN.

The most egregious left of track bias with the GFS was with Joaquin while the Euro was consistently OTS and correct. The one truism is that while the GFS tends to have some right of track bias, it’s usually wrong when it’s the furthest west. This works with both snowstorms and hurricanes. https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/10/06/what-the-european-model-win-over-the-american-model-means-for-weather-forecasting/

Was referring to last winter which was one of the strongest Niña background states and worst winters around NYC metro. 07-08 was a stinker around NYC but got progressively better the further into New England you went. The raging La Niña pattern in 10-11 was tamed by the tail end of the greatest blocking pattern in hundreds of years. So the blocking was calling the shots and not the La Niña. It was game on once the historic December Greenland block pushed back against the hostile Pacific with vigor raising the PNA during that epic retrogression. So our winters always come down to a balance of competing forces. The dominant player tips the scales and the rest is history. Pick the dominant winter factor ahead of time and you come out like a weather rock star.

The one NAO study that has really stood the test of time published back in 2009 was that NAO extremes have been found to increase along with the warming climate. Much larger amplitude and variation between positive and negative states since the Industrial Revolution as the climate has warmed. So a record number of both highs and lows. But one state hasn’t been favored over another. So in effect, the more negative state in 09-10 and 10-11 and more positive in the early 90s or even 11-12, 14-15, and 19-20 are both a function of a warmer atmosphere. The most violent NAO swings on record occurred shortly following the publication of this study. There were multiple seasons with very large swings with in about a month of each other like we saw from December 2015 to January 2016. Same goes for other years like 2017-2018. And other years since 2010. https://www.whoi.edu/press-room/news-release/study-links-swings-in-north-atlantic-oscillation-variability-to-climate-warming/ January 13, 2009 Using a 218-year-long temperature record from a Bermuda brain coral, researchers at the Woods Hole Oceanographic Institution (WHOI) have created the first marine-based reconstruction showing the long-term behavior of one of the most important drivers of climate fluctuations in the North Atlantic. The North Atlantic Oscillation (NAO) is a wide-ranging pressure seesaw that drives winter climate over much of North America, Europe and North Africa. Past reconstructions of the NAO have relied mainly on terrestrial, or land-based records, such as tree ring chronologies combined with ice cores and historical climate data. Those records do not fully capture oceanic processes linked to NAO variability, and short instrumental records from relatively few locations limit the understanding of ocean–atmosphere dynamics with regard to NAO behavior. “By analyzing the coral, we were able to look at changes in the ocean relative to changes on land,” said Nathalie Goodkin, lead author of the study published in the December issue of the journal Nature Geoscience. “Because they are slow growing and have long life-spans, corals can provide high resolution records that are well dated and centuries long.” As they grow, corals accrete seasonal and annual growth layers, similar to tree rings. The proportions of trace elements versus the major element (calcium) found in the layers of the skeleton largely depend on the temperature of the seawater in which it was formed. By analyzing the strontium to calcium ratio in the Bermuda brain coral, Goodkin and colleagues — WHOI scientists Konrad Hughen, Scott Doney and William Curry — were able to reconstruct monthly changes in ocean temperatures and evaluate variability of the NAO during both cold and warm periods from the Little Ice Age (1800–1850) to modern day. The research team found the variability of the NAO decade-to-decade (multi-decadal scale) has been larger, swinging more wildly, during the late twentieth century than in the early 1800s, suggesting that variability is linked to the mean temperature of the Northern Hemisphere. This confirms variability previously reported in past terrestrial reconstructions. “When the Industrial Revolution begins and atmospheric temperature becomes warmer, the NAO takes on a much stronger pattern in longer-term behavior,” said Goodkin. “That was suspected before in the instrumental records, but this is the first time it has been documented in records from both the ocean and the atmosphere.” The North Atlantic Oscillation is described by the NAO index, calculated as a weighted difference between the polar low and the subtropical high during the winter season. In a positive phase, both the low-pressure zone over Iceland and high pressure over the Azores are intensified, resulting in changes in the strength, incidence, and pathway of winter storms crossing the Atlantic. In a negative phase, a weak subtropical high and a weak Icelandic low results in fewer and weaker winter storms crossing on a more west-east pathway. The NAO index varies from year to year, but also exhibits a tendency to remain in one phase for intervals lasting more than a decade. An unusually long period of positive phase between 1970-2000 led to the suggestion that global warming was affecting the behavior of the NAO. “Anthropogenic (human-related) warming does not appear to be altering whether the NAO is in a positive or negative phase at multi-decadal time scales,” said WHOI paleoclimatologist Konrad Hughen. “It does seem to be increasing variability. Clearly, this has implications for the future.” “As temperatures get warmer, there’s potential for more violent swings of the NAO — the phases becoming even more positive and even more negative,” Hughen added. “If the NAO locks more into these patterns, intense storms will become more intense and droughts will become more severe.” The climatic influence of the NAO extends from the eastern United States to Western Europe, impacting human activities such as shipping, oil drilling, fisheries, hydroelectric power generation and coastal management. Improving the ability to predict shifts in the phase and intensity of the NAO is a prerequisite to mitigating the economic impacts of future climate change. While additional modeling and palaeoclimatic studies are needed, a broad distribution of marine records could advance our knowledge of NAO variability and serve to improve future projections, said Goodkin, now an assistant professor in the Department of Earth Sciences at the University of Hong Kong. A WHOI Ocean and Climate Change Institute Fellowship, and grants from the National Science Foundation and Woods Hole Oceanographic Institution supported this work. The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans’ role in the changing global environment.

I think of it more as changing background conditions leading to new probability distributions. Not that we can’t get the older patterns from time to time in the future. Just that the combinations leading to warmer outcomes will have a greater chance of occurring now. Kinda of like playing with a loaded set of dice in a casino or using steroids in baseball to hit more home runs. So a warmer climate changes the character of the anomalies and extremes. Like power hitters will hit more and longer homers with steroids. Not that there would be no anomalies or home runs absent increased warming and steroid usage. So some of the very cold seasonal forecasts issued in recent years are overlooking the fact that the game is getting rigged in favor or warmer outcomes.

Not really. All these theories have played out in some way shape or form. The 500 mb pattern that produced the warm blob most likely had its roots in the WPAC warm pool at around 15N. While it turned out to be a two winter wonder in 13-14 and 14-15, it shifted seasonality after that point. Plenty of historic droughts, heatwaves, and ridges over the Western part of North America since then during the warm season. As for the Arctic, many people were focused in on 2012. But the big shift to warmer and thinner sea ice occurred back in 2007. Some would say why haven’t we become ice free after 2012? Recent studies have identified the much younger ice packs as the culprit. This has lead to slower extent changes overall as this type of pack behaves differently. We are still waiting for the recovery to the pre-2007 Arctic to play out. The question about small sample sizes and relative short duration for weather patterns to establish new trends is a good one. We know how the climatology community likes to look at longer term averages for trends. But sometimes this takes time for shorter term changes to register in the weather forecasting psyche. Many changes are only recognized while looking back in the rear view mirror. But using changes on shorter term time scales has proven effective in seasonal forecasting during recent years. So it can still be of value even before some of the longer term climate purists begrudgingly accept it.

I would probably take a route closer to these studies in explaining the last 8 winters. As to why this became so much more pronounced now could be related to the interactions with other weather patterns along with changes in the AMOC. Plus some potential background patterns in the climate system that may respond in a tipping fashion. But as to whether these elements permanently tip or switch back or another state in the future with further warming remains to be seen. Posted Wednesday at 12:41 PM https://repository.library.noaa.gov/view/noaa/32935 Twofold expansion of the Indo-Pacific warm pool warps the MJO life cycle https://iopscience.iop.org/article/10.1088/1748-9326/ac5edf/meta Abstract The Indo-Pacific warm pool (IPWP) has warmed and expanded substantially over the past decades, which has significantly affected the hydrological cycle and global climate system. It is unclear how the IPWP will change in the future under anthropogenic (ANT) forcing. Here, we quantify the human contribution to the observed IPWP warming/expansion and adjust the projected IPWP changes using an optimal fingerprinting method based on Coupled Model Intercomparison Project phase 6 (CMIP6) simulations. We find that more than 95% rapid warming and 85% expansion of the observed IPWP are detected and attributable to human influence. Furthermore, human activities affect IPWP warming through both greenhouse gases and ANT aerosols. The multiple model ensemble mean can capture the ANT warming trend and tends to underestimate the ANT warming trend. After using the observation constraint, the IPWP warming is projected to increase faster than that of the ensemble mean in the 21st Century, and the Indian Ocean warm pool is projected to expand more than previously expected. The rapid warming and expansion of IPWP over the rest of the 21st century will impact the climate system and the life of human beings.

Unfortunately, GW often gets framed as a political issue since there are some that recommend specific policy prescriptions whether they will be effective or not. I look at this as a way to understand how we can better predict and adapt weather patterns that become more frequent as a result. I don’t care much for politics so I completely get how even talking about GW turns some off and makes them less interested. I even saw an interview with Anthony Watts on PBS when he stated that one of his main issues with GW is some are going to use it to force a political ideology on someone else. He hinted that if he didn’t see his political or economic beliefs getting threatened, then he may not have pushed back so hard against GW. So the inability to separate science from politics can be quite a downfall for society. Even more so sometimes than the original challenge like a warming climate.

The other way of looking at the situation is that it becomes more visible when some threshold get crossed more often. So there could have been numerous years when we were close but the threshold wasn’t crossed. The recent years may just look more extreme when the steady march higher wasn’t as noticeable. A bit in a way like the last little push necessary to top a scale in one direction or another. This point isn’t always very obvious until after it has been crossed.

A 7° warmer Gulf Stream is probably playing a role in tandem with more frequent and stronger MJO 4-6 activity with the record WPAC warm pool.

It used to be better especially further to the south of our area when there was more of a vortex near the East Coast rather than a SE Ridge. So these days we have to worry more about cutters. Back then, it was a more suppressed storm track favoring the mid-Atlantic. But it was a colder pattern for us back then with more opportunities snow in what would be marginal -PNA patterns for us today.

We didn’t have the consistently higher 500 heights east of New England back in that era like we do now. Notice how the recent 8 winter average has never occurred. In the past, we would get occasional spikes that would go right down the next season. It could be a mix of the WPAC warm pool MJO 4-6 along with the much warmer Gulf Stream and even the slowing AMOC.

It would have been a much better pattern back in the 50s to early 70s when the blocks weren’t as south based on average as recent years have been. The height rises to the east of New England don’t mix well with -PNA patterns like we saw in December. Even with the +PNA in December 2020, the track was just a little too tucked in near SNJ for Long Island to get into the best Jackpot zone near BGM. Plus just enough ridging to allow the record Christmas cutter a week later.

These are the days that surfers wish for all year.

On the whole, modeling has taken a big leap forward from the 60s and 70s. Now we can use a super ensemble to get a good track on a hurricane at even 5 days out. Plus ensembles can now identify general day 6-10 day patterns fairly well. But we have still been pushing up against the 15 day limit.

Nothing unusual about Newark this summer as some other stations had more 90° days. This was probably the result of the ASOS being so close to the bay and getting cooling breezes. Newark hasn’t had the 90° day lead NJ so far in the 2020s. Data for January 1, 2023 through September 15, 2023 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 ESTELL MANOR COOP 34 HARRISON COOP 33 HIGHTSTOWN 2 W COOP 31 NEWARK LIBERTY INTL AP WBAN 29 Newark Area ThreadEx 29 Data for January 1, 2022 through September 15, 2022 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 SOUTH JERSEY REGIONAL AIRPORT WBAN 52 HIGHTSTOWN 2 W COOP 49 NEWARK LIBERTY INTL AP WBAN 49 Data for January 1, 2021 through September 15, 2021 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 FREEHOLD-MARLBORO COOP 42 NEWARK LIBERTY INTL AP WBAN 41 Newark Area ThreadEx 41 HIGHTSTOWN 2 W COOP 40 Data for January 1, 2020 through September 15, 2020 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 HIGHTSTOWN 2 W COOP 42 FREEHOLD-MARLBORO COOP 40 HARRISON COOP 39 CANOE BROOK COOP 37 CALDWELL ESSEX COUNTY AP WBAN 37 ESTELL MANOR COOP 36 HAMMONTON 1 NE COOP 32 ATLANTIC CITY INTL AP WBAN 31 NEWARK LIBERTY INTL AP WBAN 31 Atlantic City Area ThreadEx 31 Newark Area ThreadEx 31