bluewave

The near record low multiyear ice is one of the reasons that a favorable summer for sea ice retention can’t come close to pre-2007 levels. https://nsidc.org/arcticseaicenews/ Multiyear ice near record low http://nsidc.org/arcticseaicenews/files/2021/08/Figure4a-week31-350x254.jpg Figure 4a. This graph shows the near record-low amount of multiyear ice in the Arctic as of week 31 (July 30 to August 5) of the 2021 melt season, comparing this year to the same week in previous years of the satellite record that began in 1979. Historical data through 2020 are provided by Tschudi et al., 2019a and quicklook data for 2021 by Tschudi et al., 2019b Credit: Robbie Mallett High-resolution image http://nsidc.org/arcticseaicenews/files/2021/08/Figure-4b-MYI-350x265.jpg Figure 4b. This graph compares the area of multiyear ice in the Arctic between 2021, 2020, and the average from 2008 to 2019 as it melts out throughout the spring and summer. The grey lines depict previous years for general comparison. The area is calculated by adding all pixels in the Arctic that are older than one year based on the NSIDC ice age data product, and multiplying by the area per pixel of each grid cell. Historical data through 2020 are provided by Tschudi et al., 2019a and quicklook data for 2021 by Tschudi et al., 2019b Credit: Robbie Mallett High-resolution image While the multiyear ice that advected into the Beaufort Sea has helped to stabilize ice loss in that region, multiyear ice for 2021 in the Arctic as a whole is at a record low. Based on ice age classification, the proportion of multiyear ice in the Arctic during the first week of August is at 1.6 million square kilometers (618,000 million square miles). The loss of the multiyear ice since the early 1980s started in earnest after the 2007 record low minimum sea ice cover that summer, and while there have been slight recoveries since then, it has not recovered to values seen in the 1980s, 1990s, or early 2000s. This loss of the oldest and thickest ice in the Arctic Ocean is one of the reasons why the summer sea ice extent has not recovered, even when weather conditions are favorable for ice retention.

Several variables for the models to decipher. How strong will Henri get? 12z Euro looks too weak again with forecast while the UKMET is too strong. All models handle the upper low over the Delmarva differently. Some are closed and others more open. The CMC almost looks like a middle ground between the various guidance today. We may not know an exact track until we see how much deepening occurs east of the Carolinas and where the upper low ends up.

It does look like the UKMET pressures are too low. But the NAM with higher pressures was west also. The GFS has been very volatile from run to run. The 0z Euro was more west than 12z but the pressures were too high. The stronger EPS members were further west than the OP. So we’ll see what the 12z Euro and EPS comes up with. But this forecast may come down to the wire since these upper low capture scenarios are really complex.

South America is the latest region to experience these big weather swings.

The 75° dew point up at White Plains ties the August monthly record high for 6 am. White Plains LGT RAIN 76 75

While we got the high humidity today, the most impressive heat went to our north.

75° dew point at JFK. This is the first 6 year stretch with 10 or more days reaching the 75° dew point mark. Just another part of our more subtropical climate. Kennedy Intl CLOUDY 81 75

Just show him this…. Yeah, I would be curious to see how they respond to a simple analysis like we have done on this forum. JFK has seen a similar rise in JJA temperatures as the other stations. You can see the big giveaway that the NYC ASOS went from the sun to deep shade. Notice how the average minimum JJA temperature rose in line with the other stations since 1951-1980. But the average high from 1951-1980 to 2011-2020 is virtually unchanged. JJA 1950-1981 to 2011-2020 temperature change NYC max….83.0…83.2….+0.2 min…..66.0…68.2….+2.2 EWR max…83.4…85.3…..+1.9 min….65.8….67.8…..+2.0 LGA max…82.0….84.4…..+2.4 min….66.8….69.9…..+3.1 JFK max….80.5….82.5…..+2.0 min…..65.4….67.7……+2.3

Looks like the Euro keeps the overrunning west and we get into the warm sector severe potential like the NAM.

The 3km NAM is further west than the 0z Euro. So we get into the warm sector severe part of Fred. Probably need to see what the 12z Euro does with the track.

Hard to believe that it has been 30 years since a hurricane maintained such solid tropical structure this far north.

In reality, we will never know for sure what the exact storm categories were at each location. But a strong trough interaction and rapid forward motion probably helped maintain intensity longer than usual. So it could have been a cat 2 around NYC and still had a cat 3 surge from earlier in the day.

Water levels with Sandy were the highest on record for NYC and Western Long Island. The storm surge peaking at high tide made the difference. 1821 had stronger winds and a greater surge. But the arrival at low tide with lower sea levels of the era resulted in lower water levels than Sandy. https://www.nature.com/articles/srep07366?proof=t%C2%A0 In summary, an inundation record covering the past ~300 years was reconstructed from sediment cores taken from New York City, NY. Deposits in the record correspond to storms known to have affected New York Harbor, including early historic storms in 1693, 1788 and 1821. Sedimentary analysis reveals only two deposits, those of Hurricane Sandy and the 1821 hurricane, with a median grain size in the sand range (>63 μm). While the Hurricane Sandy deposit was much thicker than the 1821 deposit, it had a smaller maximum grain size. This is consistent with historic accounts and SLOSH model results that suggest that the 1821 hurricane was a smaller (radius of maximum winds of 40 km) but significantly more intense storm (maximum 1-minute sustained wind speed of ~210 km/hr), compared to Hurricane Sandy with a radius of maximum winds of 160–200 km and 130 km/hr sustained winds at landfall. Sea-level rise and peak surge occurring at high tide combined to give Sandy record-breaking water levels, but the 1821 hurricane probably had a significantly larger overall storm surge. Our results indicate that extreme flood events like Hurricane Sandy are not uncommon within sedimentary records and that the true return interval for such extreme events to New York City is probably significantly shorter than current estimates.

Sandy not crossing Long Island made the storm all that much more severe around NNJ, NYC and Western LI. The record blocking and trough phase put us in the stronger RFQ for two high tide cycles. Our area got the weaker side of the 1938 hurricane since it tracked across Central Long Island up into New England. NYC also was in the RFQ (right front quadrant) with the 1821 hurricane. But that hurricane arrived at low tide.

Sandy had much more impact than the other hurricanes of the last 100 years from the Jersey Shore to Western Suffolk. The 1938 hurricane really focused its worst damage from Central and Eastern Suffolk up into New England. There was a long gap in hurricanes directly landfalling from Long Island to New England between 1893 and 1938.The period from 1938 to 1961 had a high amount of directly landfalling hurricanes on Long Island and New England. So we have seen extended periods when landfalls concentrated in certain areas. The big challenge is tying to figure out a shift before it actually occurs.

The one thing that stands out since the mid 90s is how consistent the storm tracks have been. All our tropical systems since then have made landfall first to our south before impacting our area. This was the case last year and again this year with Elsa. Fred’s remnants will impact the region this week after coming ashore in the Gulf. Sandy was one of the most extreme events in our local history making the sharp left turn into Southern NJ. Long Island and New England haven’t seen a hurricane eye cross our shoreline since Bob in 1991 and Gloria in 1985. Before that we had Belle in 1976 and all the storms from 1938 into the 1950s. The main question is why this type of hurricane track has become so rare? Maybe the WAR and blocking has become so strong, that this has forced storms more to our SW for landfalls. So it will be interesting to see when this type of hurricane track makes a return.

The interruption from earlier in the season was MJO related. Now the MJO has now come around to the more active phases for the Atlantic Basin. Last year it took until we reached the L storm for the first major hurricane.

The SSTs across the tropical development areas of the Atlantic are still well above normal. The map I posted was just in reference to the local SSTs and more cooling sea breezes than last year. We are already off to another much faster than normal start to the tropical season.

High dew points return on Tuesday as the next 594 dm ridge flexes. But clouds and convection will keep the high temperatures more modest than we typically see with such a strong WAR. Several days of higher dew points in the forecast.

https://phys.org/news/2021-08-ocean-steady-temperature-20th-century.html In estimations of ocean heat content—important when assessing and predicting the effects of climate change—calculations have often presented the rate of warming as a gradual rise from the mid-20th century to today. However, new research from UC Santa Barbara scientists Timothy DeVries and Aaron Bagnell could overturn that assumption, suggesting the ocean maintained a relatively steady temperature throughout most of the 20th century, before embarking on a steep rise. The newly discovered dynamics may have significant implications for what we might expect in the future. There wasn't an onset of an imbalance until about 1990, which is later than most estimates," said DeVries, an associate professor in the Department of Geography, and a co-author on a paper that appears in the journal Nature Communications. According to the study, the period from 1950 to 1990 saw temperature fluctuations in the water column but no net warming. After 1990, the study continues, the entire water column switched from cooling to warming. These findings are the result of the addition of a largely underexplored factor in ocean heat content (OHC): Deep ocean temperatures. Prior studies didn't consider the deep ocean," said Bagnell, a graduate scholar in DeVries's laboratory and the paper's lead author. Because of the challenges involved in getting temperature measurements in the deep ocean (below 2,000 meters) that region has gone largely unaccounted for, and data has been sparse. "There is some existing data, from research cruises and autonomous floats," he added. The researchers used an autoregressive artificial neural network (ARANN) and machine learning methods to connect the dots between data points and "produce a single consistent estimate of the top-to-bottom OHC change for 1946 to 2019." The result was a trend that delays warming by decades over previous models. There are two main possibilities for why the effects of global warming took so long to reach the ocean, De Vries said. "One is that anthropogenic warming might have been weaker than previously thought during the 20th century, perhaps due to the cooling effects of aerosol pollution," he said. The other is that the deep ocean may still be exhibiting the effects of climate events long past. "It can take centuries for climate signals to propagate from the surface to the interior," he said. Thus, the effects of a cooling event such as the Little Ice Age might be deep history to us on the surface, but the echoes of the event may have continued to resonate in the deep oceaninto the 20th century, providing a buffer to the warming Earth. The delayed cooling effect ended in 1990, after which ocean temperatures, according to the study, have been accelerating upward. "The lag is catching up and the ocean is warming more strongly now," Bagnell said. The Atlantic Ocean and Southern Ocean are currently where most of the warming is, with the Pacific Ocean and Indian Ocean not far behind. Ocean warming is a concern on many levels, as it can cause changes in circulation, reduce its ability to absorb carbon and fuel more intense storms, in addition to causing sea level rise and creating inhospitable environments for undersea life. If the trend continues, the effects might last centuries, thanks to the same lag that kept the oceans cool until the last 30 years. "The ocean remembers," DeVries said. https://www.nature.com/articles/s41467-021-24472-3 Abstract The historical evolution of Earth’s energy imbalance can be quantified by changes in the global ocean heat content. However, historical reconstructions of ocean heat content often neglect a large volume of the deep ocean, due to sparse observations of ocean temperatures below 2000 m. Here, we provide a global reconstruction of historical changes in full-depth ocean heat content based on interpolated subsurface temperature data using an autoregressive artificial neural network, providing estimates of total ocean warming for the period 1946-2019. We find that cooling of the deep ocean and a small heat gain in the upper ocean led to no robust trend in global ocean heat content from 1960-1990, implying a roughly balanced Earth energy budget within −0.16 to 0.06 W m−2 over most of the latter half of the 20th century. However, the past three decades have seen a rapid acceleration in ocean warming, with the entire ocean warming from top to bottom at a rate of 0.63 ± 0.13 W m−2. These results suggest a delayed onset of a positive Earth energy imbalance relative to previous estimates, although large uncertainties remain. Discussion The ARANN reconstruction of full-depth OHC provides an internally consistent framework for monitoring EEI over time, showing that the Earth energy budget was in quasi-equilibrium, with substantial decadal variability, for the four decades from 1950 to 1990. The warming rate from the ARANN does not differ from that derived by objective mapping methods with statistical significance, and previous studies already support a slower ocean warming rate for the 1950–1990 period relative to the 21st century (Fig. 5). However, due to the combination of a smaller estimated change in 0–2000 m OHC for 1950–1990 and the contribution of deep ocean cooling, the ARANN implies a stronger and later shift toward accelerated EEI than previously recognized, and raises the question as to what may have caused this climate shift. Anthropogenic radiative forcing has remained positive and continued to grow in magnitude over the past century1, so the lack of global ocean warming implied by the ARANN results over the period from 1950 to 1990 may seem counterintuitive at first. However, Earth’s climate system is not currently at equilibrium. Due to the timescales of overturning in the ocean, propagating the entire forced climate signal from the surface to the interior may require decades to centuries to manifest as signals in the deep OHC8,10, implying that the EEI is modulated by changes in external forcing on multi-decadal time-scales. In the deep ocean, cooling of the Pacific and Indian over much of the 20th century could result from a past climate event such as the Little Ice Age10. A cooling trend that derives itself from long-term modes of climate variability49 would not be reflected in any of the components of the external radiative forcing budget for the 20th century. Nonetheless, deep ocean cooling does not entirely account for the near zero warming trend in OHC prior to 1990, especially when considering that the 0–2000 m interval shows minimal change in the ARANN OHC estimate as well, averaging just 0.03 ± 0.09 W m−2 from 1960 to 1990. The difference between the ARANN and the IAP reconstruction11 of OHC in the upper 2000 m, is similar in magnitude to the ARANN estimate of deep ocean cooling (Supplementary Fig. 15), and in general the spread across OHC estimates in the top 2000 m is larger than the deep ocean cooling trend estimated by the ARANN (Fig. 1b–c). This spread indicates large uncertainties related to methodological differences in estimating OHC over the latter half of the 20th century. However, if the ARANN estimate of minimal upper ocean warming prior to 1990 is correct, it could indicate that anthropogenic or volcanic aerosol effects are larger than currently estimated for this time period50 or that the transient climate response to anthropogenic forcing is affected by regional feedbacks arising from the pattern of ocean heat uptake51,52. Changes in the ocean overturning can also affect the EEI by modifying the rate of ocean heat uptake53, which could also lead to discrepancies between radiative forcing and upper ocean warming. The recent accelerated warming since 1990 implied by the ARANN is consistent with the dominant effects of anthropogenic greenhouse gas forcing and negligible volcanic aerosol forcing1,54, as well as estimates of increased radiative forcing55 during the past three decades. Due to improved ocean temperature sampling over the past several decades, there is high confidence that the top 2000 m of the ocean have been gaining heat at an accelerating rate, as indicated by the convergence of OHC estimates across methodologies during this time period (Fig. 1b–c). In addition, the ARANN results suggest that the deep ocean below 2000 m has added 48 ± 19 ZJ since 1990, or about 10–28% of the ocean warming above 2000 m during this period, significantly contributing to the accelerating EEI in recent decades. This contribution is larger than that from non-ocean components of the Earth energy budget, including the land surface, cryosphere, and atmosphere, which together account for ~27 ± 8 ZJ of warming since 199056. In all, the results presented here show that deep ocean cooling during the latter half of the 20th century has given way to deep ocean warming over the past three decades, contributing to a delayed response of the EEI to contemporary radiative forcing effects. If this recent shift toward warming of the deep ocean continues, it will have implications for Earth’s climate for decades to centuries to come due to the long overturning timescales of the deep ocean. Continued monitoring of the global OHC, and improved resolution of deep ocean temperature changes, will be key for developing accurate forecasts of Earth’s energy budget and future climate change.

The SSTs off the whole East Coast are much cooler than last year.

The whole area around Newark has been warmer than the rest of the region this summer. The urbanized NE NJ corridor has had 27-32 days reaching 90°. Last summer it was areas further north and east of there that had the most anomalous heat. 90° days Newark………….……33 Caldwell…………...…32 Harrison………………31 New Brunswick……29 Somerset…………….27

The other difference this summer is that the bouys south of Long Island are running about 5° cooler than the last few years. There have been many days of 73°-74° water temperatures. Recent summers featured record peak SSTs around 80°. So the sea breeze has been more effective this year at cooling the South Shore. This is only the 3rd time on record that the highest temperature of the season at JFK was in May. If the JFK summer high of 91° holds, then it will be the 3rd coolest of all-time. Monthly Highest Max Temperature for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Year May Jun Jul Aug Sep Oct Season 1969 99 91 97 97 91 83 99 1996 95 91 87 86 90 77 95 1987 95 92 95 93 84 71 95 2021 94 91 90 91 M M 94 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Jun through Aug Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1967 89 0 2 1951 90 0 3 2021 91 17 - 2014 91 0 - 2004 91 0 - 1996 91 0 - 1985 91 0 - 1960 91 0

The only part of our area that is having a hot summer relative to recent years is NE NJ. The average temperature at Newark through August 14th is 4th warmest. This ranking is mostly based on the record heat experienced back in June. July was cooler and wetter for the whole area than recent years. Due to the strong onshore flow so far, JFK is tied for its 2nd coolest summer since 2010. The high of 94 this year at JFK is the 2nd coolest experienced since 2010. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Jun 1 to Aug 14 Missing Count 1 2010-08-14 79.4 0 2 2011-08-14 78.7 0 3 2020-08-14 78.0 0 4 2021-08-14 77.9 0 5 2012-08-14 77.2 0 6 2016-08-14 77.1 0 7 2019-08-14 76.8 0 8 2013-08-14 76.6 0 9 2018-08-14 76.1 0 10 2015-08-14 75.9 0 11 2014-08-14 75.1 0 12 2017-08-14 74.9 0 Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Jun 1 to Aug 14 Missing Count 1 2020-08-14 79.8 0 2 2010-08-14 79.6 0 3 2016-08-14 78.2 0 4 2019-08-14 77.5 0 - 2018-08-14 77.5 0 - 2012-08-14 77.5 0 5 2013-08-14 77.2 0 6 2021-08-14 77.0 0 7 2011-08-14 76.9 0 8 2017-08-14 75.9 0 - 2015-08-14 75.9 0 9 2014-08-14 75.0 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Jun 1 to Aug 14 Missing Count 1 2010-08-14 77.6 0 2 2011-08-14 76.3 0 3 2020-08-14 75.9 0 - 2016-08-14 75.9 0 4 2015-08-14 75.5 0 5 2012-08-14 75.4 0 6 2019-08-14 75.1 0 7 2013-08-14 74.8 0 8 2021-08-14 74.0 0 - 2018-08-14 74.0 0 - 2017-08-14 74.0 0 9 2014-08-14 73.9 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Jan 1 to Aug 14 Missing Count 1 2011-08-14 103 0 2 2010-08-14 101 0 3 2013-08-14 100 0 4 2019-08-14 99 0 - 2012-08-14 99 0 5 2016-08-14 98 0 6 2020-08-14 97 0 7 2017-08-14 95 0 - 2015-08-14 95 0 8 2021-08-14 94 0 - 2018-08-14 94 0 9 2014-08-14 91 0

It would be nice if all the seasonal forecasts from the Euro were this good. JJA forecast issued on May 1st