bluewave

This drought will allow portions of the East to challenge all-time October high temperatures next week.

The developing flash drought is impacting areas to our SW the hardest.

Light rainfall events are par for the course in an expanding flash drought situation.

Newark continuing to climb the highest number of 80 degree days during the last 10 days of September list. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 80 Sep 21 to Sep 30 Missing Count 1 2017-09-30 7 0 - 1959-09-30 7 0 2 1986-09-30 6 0 - 1970-09-30 6 0 - 1968-09-30 6 0 - 1961-09-30 6 0 - 1945-09-30 6 0 3 2011-09-30 5 0 - 2007-09-30 5 0 2019-09-30 5 4

Another high temperature guidance beat with the expanding flash drought conditions in the East. The 85 at Newark is 12 degrees above normal for 9-26.

Rapid expansion of the flash drought across our region on the latest update. https://droughtmonitor.unl.edu

Very impressive intensity for so far to the east in the Atlantic.

September 2019 is a continuation of the 2010’s endless summer pattern. 9 out of 10 years featuring above normal temperatures. SEP....EWR...NYC...LGA 2019...+1.5...+1.3...+2.0.....so far 2018...+3.2...+2.7....+3.7 2017...+2.7...+2.5....+2.4 2016...+3.6...,+3.8...+4.7 2015...+5.2....+6.5...+5.0 2014..+1.6....+1.7....+1.3 2013...-1.0....-0.1.....-1.0 2012...+1.3...+0.8....+3.4 2011....+3.0..+2.0....+1.6 2010...+3.4....+3.1...+3.4

Let’s hope that they keep to that promise. We have seen past model upgrades before the bugs were worked out. It does look like it could be a very challenging task. Launching new models isn’t easy. https://vlab.ncep.noaa.gov/web/environmental-modeling-center/fv3-convective-allowing-forecast-system While the NAM does very well with low temperatures and CAD, it runs too cool with the high temperatures like we saw yesterday. The Euro seems to have a better handle on high temperatures. But it was even a few degrees too low yesterday with the strong WAA and dry conditions ahead of the front.

The Euro may become even more the go-to model once the NAM stops running. Could be quite a challenge for the new model to handle the NAM’s strengths. Just look at the new biases that poped up when the GFS was recently upgraded. https://www.washingtonpost.com/weather/2019/02/14/weather-service-prepares-launch-new-prediction-model-that-many-forecasters-dont-trust/ https://mobile.twitter.com/jhomenuk/status/1171950138698473478

The 93 max at Newark today was the 2nd highest temperature during the last 10 days of September. https://mesonet.agron.iastate.edu/wx/afos/p.php?pil=CLIEWR&e=201909232042 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Sep 21 to Sep 30 Missing Count 1 1970-09-30 94 0 2 1959-09-30 93 0 1931-09-30 93 0 2019-09-30 93 0

Yeah, the flash drought has helped. Very unusual blocking ridge from the Arctic down into the US this month.

Funny how Newark couldn’t reach 90 on Memorial Day, Independence Day, and Labor Day. But had no problem making it to at least 91 on the first day of fall. Wonder if this has happened before? 5-27....82 7-4......89 9-2......77 9-23.....91 so far

NSIDC extent dropped to the second lowest minimum on record. 2019 was effectively tied with 2016 and 2007. https://nsidc.org/arcticseaicenews/ Table 1. Thirteen lowest minimum Arctic sea ice extents (satellite record, 1979 to present) RANK YEAR MINIMUM ICE EXTENT DATE IN MILLIONS OF SQUARE KILOMETERS IN MILLIONS OF SQUARE MILES 1 2012 3.39 1.31 Sept. 17 2 2019 2007 2016 4.15 4.16 4.17 1.60 1.61 1.61 Sept. 18 Sept. 18 Sept. 10 5 2011 4.34 1.68 Sept. 11 6 2015 4.43 1.71 Sept. 9 7 2008 2010 4.59 4.62 1.77 1.78 Sept. 19 Sept. 21 9 2018 2017 4.66 4.67 1.80 1.80 Sept. 23 Sept. 13 11 2014 2013 5.03 5.05 1.94 1.95 Sept. 17 Sept. 13 13 2009 5.12 1.98 Sept. 13 Values within 40,000 square kilometers (15,000 square miles) are considered tied. The 2018 value has changed from 4.59 to 4.66 million square kilometers (1.80 million square miles) when final analysis data updated near-real time data, dropping 2018 to a tied ninth position with 2017.

Warmest first day of fall this decade. Newark first day of fall high temperatures since 2010 9-22-10...90 9-23-11...75 9-22-12...78 9-22-13...72 9-22-14....73 9-23-15....80 9-22-16....84  9-22-17....85 9-22-18....75 9-23-19....91 and rising

One of the more impressive flash droughts to impact the region during September in a while. What a difference a year makes.

Today could be the first time since 2010 that fall started with a 90 degree day at Newark. Newark first day of fall high temperatures since 2010 9-22-10...90 9-23-11...75 9-22-12...78 9-22-13...72 9-22-14....73 9-23-15....80 9-22-16....84 9-22-17....85 9-22-18....75

+15 high temperature departure at Newark today. MAXIMUM 89 200 PM 94 1970 74 15 https://forecast.weather.gov/product.php?site=NWS&issuedby=EWR&product=CLI&format=CI&version=1&glossary=1&highlight=off

It’s tough to say which one of these many competing factors will win out for the winter.

That’s a remarkable stat. Just saw it posted on twitter. Record warmth and high pressure over the Arctic since May. https://mobile.twitter.com/AlaskaWx/status/1175034044578295808 https://mobile.twitter.com/ZLabe/status/1170022132216029185

Very impressive Arctic Amplification this September with so much open water. https://www.arctictoday.com/arctic-sea-ice-is-close-to-its-annual-minimum-extent-but-thats-just-part-of-the-picture/?wallit_nosession=1 As the autumn equinox looms and winter darkness approaches, Arctic sea ice has dwindled to what appears to be one of the lowest minimums in the satellite record. “We are basically right now in a dead tie for second place,” Mark Serreze, director of the National Snow and Ice Data Center, said on Wednesday. Ice extent — defined as the area where there is at least 15 percent ice coverage — dropped to 4.1 million square kilometers on Tuesday, matching minimums set in 2007 and in 2016, according to the Colorado-based NSIDC. It will take a few more days to know whether this year’s minimum has been set and the freeze season has started, Serreze said. Total ice extent can waver up and down at this time of the year because of shifting winds and a contest between freeze at the highest latitudes and continued melt in the more southern parts of the Arctic, he said. This year’s minimum extent has no chance of matching the record-low 3.4 million square kilometers (1.32 million square miles) hit in 2012, Serreze said. Still, it fits into a trend to more open water over longer periods of the year, he said. All that open water reinforces the warming cycle in the far north, strengthening the phenomenon known as Arctic Amplification, he said. When waters lack ice cover, they absorb more solar heat, he said. “You’ve got to get rid of all that heat,” he said. “Where does that heat go? Up into the atmosphere.” While annual minimums are useful markers for long-term trends, the expanding durations of open water are turning out to have more immediate significance, said Rick Thoman, climate scientist with the Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks. That is especially the case for the waters off Alaska — the Bering, Chukchi and Beaufort seas — where ice has been especially scarce, even in the past winters, he said. The official Arctic-wide minimum extent is only part of the picture, he said. “For Alaska, it doesn’t make much of a difference if it’s No. 1 or No. 4. There hasn’t been any ice anywhere near Alaska for a very long time and the water that’s there is extremely warm,” Thoman said. In the waters off northern and northwestern Alaska, sea-surface temperatures were generally running 3 to 6 degrees Celsius (5.4 to 10.8 degrees Fahrenheit) above normal during the second week of September, according to data gathered by ACCAP. That sets the stage for a delayed freeze season, he said. “We can be absolutely certain that freeze-up in the Beaufort, Chukchi and at least the central Bering will be late,” he said. Delayed freeze likely means a warmer-than-normal fall and, when the winter freeze arrives, ice that is thin and more susceptible to midwinter meltdowns similar to those that occurred in the past two years in the Bering and the Chukchi, he said. The past years’ winter ice loss may have been highly unusual, but repeat occurrences could become more common if southerly winds return, Thoman said. “I think you’ll see the big collapses like we’ve had in the past two years. That requires that sustained southerly flow. We won’t see that every year,” he said. Thoman noted that with the exception of the extreme low in 2012, annual minimums over the past decade have been generally in the same ballpark. That is because the very high-latitude ice, unlike ice at lower Arctic latitudes, has relatively brief period of the year when there is direct sunlight shining on it and causing melt from above, he said. “We have melted all the easy, low-latitude ice now,” he said. Melting out ice at the highest latitudes will require a different process, he said. “That’s going to come from the ocean. That’s going to come from underneath,” he said. Serreze, too, said the highest-latitude ice has lingered despite widespread melt elsewhere in the Arctic. At those very high latitudes — for now — there is still multiyear ice that survives melt seasons, he said. But more changes are expected in the future, he said. “We are kind of in new territory,” he said. “We have not been here before, so every year we’re learning.” https://mobile.twitter.com/ZLabe/status/1175055129290010624 Well above average temperatures over nearly the entire #Arctic Ocean so far this September. This is especially found in areas where there is a lack of sea ice cover.

As Don said, it would be a very slow process from such high CO2 levels. Hopefully, we make a great technological leap in how we power the world before CO2 levels get that high. https://www.sciencedaily.com/releases/2019/02/190220112221.htm A new study finds humans are pumping carbon dioxide into the atmosphere at a rate nine to 10 times higher than the greenhouse gas was emitted during the Paleocene-Eocene Thermal Maximum (PETM), a global warming event that occurred roughly 56 million years ago. The results suggest if carbon emissions continue to rise, the total amount of carbon dioxide injected into the atmosphere since humans started burning fossil fuels could equal the amount released during the PETM as soon as 2159. "You and I won't be here in 2159, but that's only about four generations away," said Philip Gingerich, a paleoclimate researcher at the University of Michigan and author of the new study in the AGU journal Paleoceanography and Paleoclimatology. "When you start to think about your children and your grandchildren, and your great-grandchildren, you're about there." Scientists often use the PETM as a benchmark against which to compare modern climate change. But the new study shows we're on track to meet this benchmark much sooner than previously thought, as the pace of today's warming far outstrips any climate event that has happened since the extinction of the dinosaurs. "Given a business-as-usual assumption for the future, the rates of carbon release that are happening today are really unprecedented, even in the context of an event like the PETM," said Gabriel Bowen, a geophysicist at the University of Utah who was not connected to the new study. "We don't have much in the way of geologic examples to draw from in understanding how the world responds to that kind of perturbation." The exact environmental consequences of PETM-like carbon levels are unclear, but the increased temperatures will likely drive many species to extinction with the lucky ones being able to adapt or migrate, according to Larisa DeSantis, a paleontologist at Vanderbilt University who was not connected to the new study. In addition, it will take thousands of years for the climate system cool down, she said. "It's not just about 100 years from now; it's going to take significant periods of time for that carbon dioxide to make its way back into the Earth's crust," DeSantis said. "It's not a short-term event. We're really committing ourselves to many thousands of years of a warmer world if we don't take action quickly."

You are correct. It was our only major station to reach 90 degrees in October since the 1950’s. Looks like a warm offshore flow let JFK get a degree above LGA and EWR. JFK 2007-10-08 90 66 78.0 18.3

The only question is how long it will take to scratch off areas closer to us. Could enhance our warming potential next several weeks before any reversal occurs.

https://www.eurekalert.org/pub_releases/2019-09/uom-soa091219.php NEWS RELEASE 18-SEP-2019 Study of ancient climate suggests future warming could accelerate UNIVERSITY OF MICHIGAN ANN ARBOR--The rate at which the planet warms in response to the ongoing buildup of heat-trapping carbon dioxide gas could increase in the future, according to new simulations of a comparable warm period more than 50 million years ago. Researchers at the University of Michigan and the University of Arizona used a state-of-the-art climate model to successfully simulate--for the first time--the extreme warming of the Early Eocene Period, which is considered an analog for Earth's future climate. They found that the rate of warming increased dramatically as carbon dioxide levels rose, a finding with far-reaching implications for Earth's future climate, the researchers report in a paper scheduled for publication Sept. 18 in the journal Science Advances. Another way of stating this result is that the climate of the Early Eocene became increasingly sensitive to additional carbon dioxide as the planet warmed. "We were surprised that the climate sensitivity increased as much as it did with increasing carbon dioxide levels," said first author Jiang Zhu, a postdoctoral researcher at the U-M Department of Earth and Environmental Sciences. "It is a scary finding because it indicates that the temperature response to an increase in carbon dioxide in the future might be larger than the response to the same increase in CO2now. This is not good news for us." The researchers determined that the large increase in climate sensitivity they observed--which had not been seen in previous attempts to simulate the Early Eocene using similar amounts of carbon dioxide--is likely due to an improved representation of cloud processes in the climate model they used, the Community Earth System Model version 1.2, or CESM1.2. Global warming is expected to change the distribution and types of clouds in the Earth's atmosphere, and clouds can have both warming and cooling effects on the climate. In their simulations of the Early Eocene, Zhu and his colleagues found a reduction in cloud coverage and opacity that amplified CO2-induced warming. The same cloud processes responsible for increased climate sensitivity in the Eocene simulations are active today, according to the researchers. "Our findings highlight the role of small-scale cloud processes in determining large-scale climate changes and suggest a potential increase in climate sensitivity with future warming," said U-M paleoclimate researcher Christopher Poulsen, a co-author of the Science Advancespaper. "The sensitivity we're inferring for the Eocene is indeed very high, though it's unlikely that climate sensitivity will reach Eocene levels in our lifetimes," said Jessica Tierney of the University of Arizona, the paper's third author. The Early Eocene (roughly 48 million to 56 million years ago) was the warmest period of the past 66 million years. It began with the Paleocene-Eocene Thermal Maximum, which is known as the PETM, the most severe of several short, intensely warm events. The Early Eocene was a time of elevated atmospheric carbon dioxide concentrations and surface temperatures at least 14 degrees Celsius (25 degrees Fahrenheit) warmer, on average, than today. Also, the difference between temperatures at the equator and the poles was much smaller. Geological evidence suggests that atmospheric carbon dioxide levels reached 1,000 parts per million in the Early Eocene, more than twice the present-day level of 412 ppm. If nothing is done to limit carbon emissions from the burning of fossil fuels, CO2 levels could once again reach 1,000 ppm by the year 2100, according to climate scientists. Until now, climate models have been unable to simulate the extreme surface warmth of the Early Eocene--including the sudden and dramatic temperature spikes of the PETM--by relying solely on atmospheric CO2 levels. Unsubstantiated changes to the models were required to make the numbers work, said Poulsen, a professor in the U-M Department of Earth and Environmental Sciences and associate dean for natural sciences. "For decades, the models have underestimated these temperatures, and the community has long assumed that the problem was with the geological data, or that there was a warming mechanism that hadn't been recognized," he said. But the CESM1.2 model was able to simulate both the warm conditions and the low equator-to-pole temperature gradient seen in the geological records. "For the first time, a climate model matches the geological evidence out of the box--that is, without deliberate tweaks made to the model. It's a breakthrough for our understanding of past warm climates," Tierney said. CESM1.2 was one of the climate models used in the authoritative Fifth Assessment Report from the Intergovernmental Panel on Climate Change, finalized in 2014. The model's ability to satisfactorily simulate Early Eocene warming provides strong support for CESM1.2's prediction of future warming, which is expressed through a key climate parameter called equilibrium climate sensitivity. The term equilibrium climate sensitivity refers to the long-term change in global temperature that would result from a sustained doubling--lasting hundreds to thousands of years--of carbon dioxide levels above the pre-industrial baseline of 285 ppm. The consensus among climate scientists is that the ECS is likely to be between 1.5 C and 4.5 C (2.7 F-8.1 F). The equilibrium climate sensitivity in CESM1.2 is near the upper end of that consensus range at 4.2 C (7.7 F). The U-M-led study's Early Eocene simulations exhibited increasing equilibrium climate sensitivity with warming, suggesting an Eocene sensitivity of more than 6.6 C (11.9 F), much greater than the present-day value. ### The research was supported by a Heising-Simons Foundation grant to Poulsen and Tierney. Link to full paper: https://advances.sciencemag.org/content/5/9/eaax1874 Simulation of Eocene extreme warmth and high climate sensitivity through cloud feedbacks Jiang Zhu1,*, Christopher J. Poulsen1 and Jessica E. Tierney2 See all authors and affiliations Science Advances 18 Sep 2019: Vol. 5, no. 9, eaax1874 DOI: 10.1126/sciadv.aax1874 Article Figures & Data Info & Metrics eLetters PDF Abstract The Early Eocene, a period of elevated atmospheric CO2 (>1000 ppmv), is considered an analog for future climate. Previous modeling attempts have been unable to reproduce major features of Eocene climate indicated by proxy data without substantial modification to the model physics. Here, we present simulations using a state-of-the-art climate model forced by proxy-estimated CO2 levels that capture the extreme surface warmth and reduced latitudinal temperature gradient of the Early Eocene and the warming of the Paleocene-Eocene Thermal Maximum. Our simulations exhibit increasing equilibrium climate sensitivity with warming and suggest an Eocene sensitivity of more than 6.6°C, much greater than the present-day value (4.2°C). This higher climate sensitivity is mainly attributable to the shortwave cloud feedback, which is linked primarily to cloud microphysical processes. Our findings highlight the role of small-scale cloud processes in determining large-scale climate changes and suggest a potential increase in climate sensitivity with future warming.