bluewave

Yeah, the day 11-15 EPS looks like a classic 0z to 12z run windshield wiper effect. One run tries to pump the Western ridge with more of a MJO 6 influence. The next run leans more on the fast Pacific Jet and tries to flatten the ridge. But the storm track should be similar either way with lows passing through the Great Lakes every several days. Brief warm ups ahead of the lows followed by cool downs behind.

That’s an error caused by the delayed leaf drop keeping thr ASOS in the shade. Even HPN made it to 40°. The temperatures won’t become reliable until the dense canopy finally drops all its leaves. EWR 43 NYC 39 JFK 41 LGA 42 HPN 40

An open field in Central Park would be a great place to measure temperatures in NYC. Before the new ASOS was installed in the mid 90s, the old sensor was in the open. That’s why the NYC high temperatures were more in line with LGA and EWR up through the 1980s. They let the trees grow over the ASOS and put it in deep shade. That’s why there is a continuity break in the NYC observations from the days when the sensor wasn’t in the shade. So the highs became cooler relative to EWR and LGA since the 1990s. Central Park was warmer at times than EWR and LGA like during the July 1977 heatwave. So the lower 90 degree counts at the park since the 90s is just an artifact of the ASOS being in deep shade. If they would allow the ASOS to be moved to one of the open fields in Central Park, then you would immediately see an increasing 90 day count closer to EWR and LGA like the old days.

Another top 5 warmest fall across the Northeast.

Yeah, I think the PNA trying to go positive again is a result of the MJO slowing in phase 6. MJO812 posted the composite for a La Niña a few posts back. The link that has the ENSO specific MJO phases is below. The phase 6 during a La Niña in December has more of a +PNA and trough near the Northeast. But since we have such a fast Pacific flow with a +EPO, it may end up favoring New England more while we still remain in phase 6. The big question is how long the MJO lingers in phase 6? At the very least, it may slow down any transition to a more zonal flow during the 2nd week of December. https://www.frenchscotpilotweather.com/mjo

The stations that I posted are closest to the core of the heat island. Places like JFK and TEB are more on the periphery. My comparison was about the low temperatures within the central areas of the heat island. Not a comparison of low temperatures between the heat island and more suburban or rural areas.

Plants developed their own version of the internet long before we did.

It’s amazing how intelligent and interconnected nature is.

That’s not what the raw data says. The minimums and maximum departures have been running lower than the surrounding ASOS sites. NYC has also been running colder than many of the micronet sites. The first freeze in NYC was much closer to the recent average date than areas away from the heat Island. POU had one of their latest first freezes on record. While NYC wasn’t even close to its latest first freeze. NYC had the lowest temperature on the coldest morning this week for surrounding urban sites 11-24 low temperatures EWR…32 NYC…30 LGA….33 Corona….32 Queensbridge….32 East 40th Manhattan….33

Some of the rooftop gardens around Central Park are gorgeous.

Urban environments can cool at night with enough of a tree canopy when it’s very dry like November has been in NYC with only 1.00”. https://www.sciencedirect.com/science/article/abs/pii/S1618866716303776 Highlights • Urban trees are incorporated into an advanced single-layer urban canopy model. • Shading effect of trees is enabled by a Monte Carlo ray-tracing algorithm. • The fully-integrated WRF-urban modeling system with trees was applied to simulate. • Urban hydroclimate in an arid city. • The cooling effect of urban shade trees is found to be more prominent in nighttime.

With the unusually calm winds this month, it almost looks like all the foliage near the sensor is creating a very localized radiational cooling effect. We can see how much cooler the highs are than the other stations that are in open sunlight. But the cold departure is much lower than any of the other urban sites. EWR…max….+2.4….min….-0.5 NYC…max….-0.1…..min…..-1.8 LGA….max…..+1.1….min….+0.3 JFK….max…..+1.6….min….-1.2 ISP…..max…..+1.9…..min….-2.2

Looks like the delayed leaf drop keeping the NYC ASOS in deep shade has allowed it to have a colder departure this month so far of the major ASOS sites. The other stations are -0.2 to +0.9. While the departures will decline with colder temperatures to close out the month, NYC will be artificially low. EWR…+0.9 NYC….-0.9 LGA…..+0.7 JFK….+0.2 ISP…..-0.2

https://www.washingtonpost.com/outlook/2019/10/15/reframing-climate-change-story-human-evolutionary-success/ The narrative we’ve grown used to on this subject is one of blame, casting humanity as a virus destroying an Earth that now needs saving (from us). But there is a very different story we can tell, one that recognizes climate change not as a marker of shame but as a story of an astonishing success that has led humanity to a moment of great peril, yet also of profound possibility. This new narrative emerges from interdisciplinary studies connecting humanity’s project of civilization with Earth’s own multibillion-year project of life and evolution. The central point is that climate change is the dire but unintended result of our species’ thriving. Humans are not a greedy plague on Earth but simply the latest experiment in planetary-scale evolution. Any species that flourished to the extent we humans have would have to seek out energy sources on a massive scale — and in doing so would change the global ecosystem. It took centuries for the downsides of carbon-based fuels to become apparent. But now that we have figured that out, it’s incumbent on us to change course, and do so quickly. That’s not an anti-business argument. Nor is it even an indictment of humans’ initially developing an economy around oil, before we knew about the implications. By stripping away the self-flagellating rhetoric and reorienting the story in this way — a longer timeline, a broader canvas — new alliances in the fight become possible. Some climate change activists are already rethinking their rhetoric; they’re debating, for instance, whether to use the phrase “climate catastrophe” or “climate crisis,” recognizing that harsh rhetoric may push people not to action but to desensitization or even despair. But the narrative revision I’m talking about is far more sweeping. The first implication of a planetary-scale view of the problem is that humans shouldn’t be considered as a force set in opposition to nature. From the “blue-green bacteria” that created a breathable oxygen-rich atmosphere on to dinosaurs, grasslands and large hairy mammals, our planet has been relentlessly inventing new versions of itself. Humans, and our globe-spanning civilization, simply represent the latest round of innovation. We are who’s at-bat right now — and that’s largely an accident of fate and evolution. When it comes to living organisms changing Earth, humans are not fundamentally different or special. This has happened before. A second implication, the most contentious, is that climate change is not our fault. Don’t get me wrong: Human activity absolutely has caused the rise in temperature that our scientists are hard at work documenting — and without doubt, those who continue to drive climate change denial are deeply and profoundly worthy of blame. I mean, rather, that all human history is the attempt to harvest new forms of energy to power our cherished project of civilization. We triggered climate change by mistake when we tripped over fossil fuels as part of that long effort. It wasn’t because we are evil or unworthy. From a planetary science perspective, global-scale technological civilizations and climate change go together. Any society as successful as ours, emerging anywhere in the universe, is going to have a hard time not triggering climate change. That’s just how planets work when you harvest buckets of energy from them. Viewed that way, changing a world’s climate marks the end of your civilization’s adolescence. At that point, you then face a very strict planetary driving test. Pass it — build a long-term sustainable version of your civilization — and you can go anywhere. Fail and you might die. So, yes, we changed the atmosphere of the entire planet. Not bad for a bunch of hairless monkeys. Now we must meet the existential challenge that success has created. Thinking about climate change in the context of eons of evolution, and as a curse of success, makes the burden of guilt hovering over every individual daily action (paper towels or electric bathroom hand dryers?) seem beside the point. Once humans recognize that triggering climate change was an inevitable consequence of a civilizational project we began 10,000 years ago, it follows that combating climate change, too, must also be a collective process, requiring all the ingenuity our species can muster. By shifting from blame to possibility, people are freed to imagine climate change as a challenge full of risk andpossibility, rather than just a death sentence from accrued guilt. Many people who don’t consider themselves environmentalists get more engaged when the conversation turns to human success and capacity for innovation, I find. Skeptics don’t suddenly “convert,” but space for conversation opens up. Stressing human ingenuity in this context carries risks, for sure. Focusing on our technological prowess — on an evolutionary timeline as well as in the present — risks steering the conversation toward “solutions” like geoengineering, whose unintended consequences may well be even worse than the unintended climate change we drove with fossil fuels. The true game-changing point of the planetary perspective is to convince people we are not above the biosphere — we’re part of it. Our complex global project of civilization must be rewoven into the complex global network of life in ways that allow both to thrive, in new and as-yet-unimagined ways. Left vs. right, Democrat vs. Republican, corporate capitalism vs. socialism. All these polarities of public life and public debate were built before Earth began responding to our civilization-building efforts. Each in their own way carries the baggage of a 19th-century smokestack world whose imperatives don’t align with the urgencies and possibilities of a world in which the climate is changing. The cliche is that history repeats itself, but humanity has simply never been here before. That means we will need to invent something new. New technologies and new policies are one front in that fight, from local-scale projects protecting freshwater sources to investment strategies that ensure capital makes it quickly to technologies such as large-scale energy storage (essential for the full switch to renewal power). But stories were humanity’s first technology. For any of the new approaches to become fully deployed and fully effective, they will have to be grounded in a new way of understanding ourselves and Earth. And if some people question whether a story is enough to move the world, one can ask: What else ever has?

The models want to continue the record breaking fall +EPO pattern that we have been discussing. They also are intensifying the the polar vortex and taking the AO and NAO positive. The record +EPO and Pacific Jet seem to be stronger than any of the individual MJO and La Niña composites suggest.

The GFS has a pretty fast mover. Looks like this will be a less amplified system than models were showing a few days ago. Probably related to the models continuing to underestimate the strength of the Pacific Jet. But we’ll take any snow we can get this early in the season. New run faster Pacific Jet and flatter +PNA ridge Old run

It’s been colder compared to September and October, but there has been no record cold Arctic air like we got in 2017. That early November Arctic outbreak signaled the very cold end of December and early January before the record warmth arrived. If you want Arctic cold, then you generally need a -EPO. This fall the +EPO has been running the table.

This fall so far is much more Pacific dominant than 2017 was. We had the record early November Arctic outbreak that year. This year is all Pacific and continental air masses with no Arctic cold.

I know we talk a lot about El Niño and La Nina. But there seems to be another factor that has been influencing the pattern of our monthly departures. A monthly departure pattern that has been regularly repeating since 2010. We are all familiar with how warm September and a October has been over this period. But this turn to cooler has been a regular feature in November. Notice how closely this November has matched the 2010-2020 composite.

The higher extent than recent years around the Chukchi Sea is a result of the record +EPO vortex since the late summer.

A recent study improved MJO forecasts out to four weeks using deep learning. https://www.nature.com/articles/s41467-021-23406-3 Producing accurate weather prediction beyond two weeks is an urgent challenge due to its ever-increasing socioeconomic value. The Madden-Julian Oscillation (MJO), a planetary-scale tropical convective system, serves as a primary source of global subseasonal (i.e., targeting three to four weeks) predictability. During the past decades, operational forecasting systems have improved substantially, while the MJO prediction skill has not yet reached its potential predictability, partly due to the systematic errors caused by imperfect numerical models. Here, to improve the MJO prediction skill, we blend the state-of-the-art dynamical forecasts and observations with a Deep Learning bias correction method. With Deep Learning bias correction, multi-model forecast errors in MJO amplitude and phase averaged over four weeks are significantly reduced by about 90% and 77%, respectively. Most models show the greatest improvement for MJO events starting from the Indian Ocean and crossing the Maritime Continent.

With all the record winter warmth over the last 20 years, getting intervals of blocking and a more favorable Pacific has been key to the record snowfall. This has been true for all the various ENSO states. It’s the few years when the Pacific didn’t relax and the NAO and AO blocking was lacking that snowfall went below normal. With the record blocking patterns since 2002-2003, we have seen an unprecedented number of seasons when stations from around Newark out to Eastern LI recorded 40” or more of snow. This dramatic increase in snowfall has occurred during a steady increase in winter temperatures. Our older winters with 40”+ peak snowfall amounts used to occur with a NYC average temperature around 32°. But many recent 40”+ seasons featured a NYC average DJF temperature in the 35°-40° range. So this is a new combination of warmth and heavy snow for our area. Seasons since 1950 when at least one station from Newark to Eastern LI recorded 40”+ and the NYC DJF average temperature. 35°+ average temperature seasons bolded 20-21….36.1 17-18….36.2 16-17….39.3 15-16….41.0 14-15…31.4 13-14…32.9 12-13…36.8 10-11….32.8 09-10…33.8 08-09…34.2 05-06…37.3 04-05…35.4 03-04…32.4 02-03…31.2 00-01….33.5 95-96…32.2 93-94…31.2 86-87….34.8 77-78….30.8 68-69….32.9 66-67….34.1 63-64…33.2 60-61….31.7 57-58…33.2 55-56…32.8 Yeah, that’s why we have been getting so much record warmth before or after our best snowstorms since the super El Niño in 15-16. Last December it was 60s before and after our best December snowstorm and -AO in years. May 2020 tied for our latest trace of snow following one of our warmest winters. 17-18 featured 30” of snow in March on Long Island after Newark hit 80° in late February. We had the blizzard in February 2017 a day after the 60s. 15-16 went +13.3 in December followed by the 30” snowstorm in January and new #1 NYC snowstorm. Even before the super El Niño, we were getting occasional patterns like this. Nemo in February 2013 following the very warm first few months of winter. The 11-12 lack of winter after the record snowstorm in late October. The February 2006 NYC #2 snow following one our warmest Januaries on record. The late winter 2005 snowstorms following one of the warmest first 2 weeks of January on record. This is a sea level version of spring in the Rockies where snow and warmth have often occurred together.

They didn’t ignore the NAO in their forecasts. But a forecast issued on November 8th for the 22-29 is going to miss a few things. Notice how good a job it did with the colder signal for the end of the month. So I would consider that EPS forecast very good for such a long range forecast. Just understand that it underestimated the big +EPO trough in Alaska. So if we don’t have a -NAO and the long range EPO verifies more positive, then the temperatures could beat expectations to the upside. That’s why you have to be careful when dealing with a record Pacific Jet and long range forecasts. Maybe someday the models will have AI built in and the forecast limit near 2 weeks can get extended further out in time.

The point about the Euro underestimating the +EPO long range is correct. But the EPS always had a colder +PNA -WPO pattern to end the month. It was never forecasting a torch for us. The reason this week was a little colder than the November 8th forecast was due to the stronger -NAO. Notice the stronger +EPO trough near Alaska than the EPS had back on November 8th. EPS forecasts from November 8th Nov 22-29 +EPO is stronger and -NAO more negative

The models can only do so much when we have seen record North Pacific Jet activity this fall. You posted the other day how this will be the most +EPO fall. I posted the record winds in that area during the fall a few days ago. So we see a model history of underestimating the Pacific Jet long range. As to my post yesterday, we have been in a -WPO pattern this month. And that is what the forecasts have been showing going forward. But if that Aleutians ridge is weaker or fades faster, that means the long range will correct warmer. That’s why getting a poleward Aleutians ridge is so important.