bluewave

The thermometer needs to be in a fan aspirated radiation shield which all ASOS, NCDC, and mesonet weather stations have. But the sensor itself can’t be located under a dense canopy of trees which will keep it several degrees cooler than surrounding open grassy fields. The NY mesonet site has a great video on the proper sitting of weather sensors near heavily wooded areas away from tall trees. NYC ASOS violates official sitting rules http://www.weather2000.com/ASOS/NYC_ASOS.html You can imagine how much denser the canopy has become since the 2013 photo and 2003 story. Central Park Weather: Vegetative Overgrowth Affecting Weather Readings - WABC-TV (New York-WABC, August 22, 2003) - Forecasting the weather is not easy. Government equipment can often be blamed for giving faulty weather information. As Bill Evans explains, a big culprit may be some of the equipment buried in Central Park. Rainfall, snowfall, and the temperature are all vital information recorded 24 hours a day at the weather station located in the heart of Central Park. But meteorologists like Michael Schlacter have serious concerns about the accuracy of the stations data. It sits amid overgrown vegetation and he says thats the problem. The leaves can trigger snow gauges and trees can warp rain and wind measurements. On this hot day, a temperature gauge is in the shade instead of direct sunlight. Michael Schlacter, Weather 2000: "Its kind of like driving a car without a speedometer, odometer, and gas gauge. You are running with false information." The weather instruments at Belvedere Castle have long adorned the top. There used to be a government meteorologist here in the city to keep an eye on them. But now the nearest meteorologist is 60 miles that way. But National Weather Service meteorologists say they knew the weather readings in the park would never be as keenly accurate as the ones at the airports where guidelines prevent foliage from being within 100 feet of the station. Schlacter: "We knew that at times we would have flaky readings, that leaves would fall in gauges, that we would have problems with visibility sensors." [NWS Meteorologist-in-Charge Michael] Wyllie says the weather station is there because it was historically significant to maintain its presence in the park. He says theres been a lot of growth because of the wet spring at so much in fact that temperatures have routinely been recorded lower in the park than at the airports. Wyllie: "We are actually having a micro climate system there because of the vegetation." Imperfect perhaps but nonetheless the system provides the official record of weather for the country's largest city. And Michael Schlacter says its a city that deserves better. Schlacter: "I think New Yorkers deserve a lot better, and I think they deserve the best weather station money can buy." Copyright 2003 ABC Inc., WABC-TV Inc.

The MJO 6 is building the ridge over the West while the fast Pacific Jet tries to flatten it out. So the trough can’t dig into the Southeast. We end up with the gradient favoring New England. There is a parade of storms crossing the Northern Tier. This results in warm ups for us ahead of the Great Lakes lows and cool downs behind.

Changing the NYC temperature measurements to underneath a dense tree canopy in the 1990s has had a big impact on the high temperatures while the trees still have leaves on them. The older NYC thermometer out in the open like the other official stations prior to the 1990s was more in line with EWR and LGA. Once the leaves drop over the next week or so, the highs will be similar to LGA and EWR again. NYC has experienced an artificial reduction in annual 90° days since the 1990s due to the foliage blocking the sensor. But winter 50° days have increased at similar rate to EWR and LGA. Those bare trees during the winter don’t block nearly as much sun as the fully leafed out trees do. So open areas of Central Park probably have closer to 23 to 25 days reaching 90° as opposed the 17 located in the deep shade. That’s how big a difference it makes when you take temperatures under a dense tree canopy instead of an open field. EWR 90° days 1961-1990…..23……1991-2020…..28……+5 NYC 1961-1990…..18……1991-2020…..17………-1 LGA 1961-1990….14…….1991-2020….22……..+8 EWR winter 50° days 1961-1990….16……1991-2020…..23…….+7 NYC 1961-1990….16…..1991-2020…..22……..+6 LGA 1961-1990….14……1991-2020…22………+8

I posted the recent photos of the delayed Manhattan leaf drop a few days ago. You probably don’t remember when the Central Park high temperatures were on par with EWR and LGA. They installed the new ASOS under a stand of trees in the 1990s that grew into a dense canopy over the last 30 years. The old thermometer used to be in the open area near the castle with no trees shading the sensor. So when you take high temperature readings under a dense canopy of trees, it can be several degrees cooler than in a nearby open field depending on the weather conditions. That’s why you can’t take official temperature measurements directly underneath trees. Even rural weather stations like at the NWS in Upton are located in a clearing away from trees. They would never place their equipment out there underneath the dense natural pine barrens in that area. All part of the standardization process of how official weather measurements are taken.

First flakes of the season here in SW Suffolk. Light dusting earlier on the rooftops and cars. Temperature at 37° now.

You can see the gradient favoring New England at least in early December.

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.