donsutherland1

Arctic Sea Ice Extent: September 18, 2019 vs. September 18, 1989: Source: NSIDC

I provided one paper earlier that dealt with the accuracy issue. The temperature data can be relied on with a very high degree of confidence. At 2 sigma (> 95% confidence), the error is around 0.1°C (e.g., for GISS). Thus, for example, the decadal average mean anomaly during the last 10 years on GISS (+0.78°C) clearly was warmer than that during the 1990s (+0.39°C). The difference between the two 10-year periods was so great that one was dealing with > 99.9% confidence. Statistically, arguments that the 1990s were just as warm (or warmer) are inaccurate.

Global average temperatures and anomalies are not a single area temperature/anomaly. They are measured in thousands of areas on land and in the ocean. Thus, the hypothetical scenario, which was meant to illustrate the concept of averages in thousandths of degrees, is spot on.

Temperatures approached daily record low figures in parts of the Northeast this morning. Overall, many areas in the Middle Atlantic and southern New England regions experienced their coldest readings so far this fall. Low temperatures included: Albany: 42° (lowest since May 14); Binghamton: 42° (lowest since June 4); Boston: (lowest since May 29); Bridgeport: 47° (lowest since June 4); Danbury: 36° (lowest since April 29); Islip: 46° (lowest since June 4); New York City: 52° (lowest since May 16); Newark: 49° (lowest since May 15); Philadelphia: 53° (lowest since June 15); Poughkeepsie: 38° (lowest since April 29); Providence: 45° (lowest since May 15); and, White Plains: 43° (lowest since May 15). In the wake of this recent fairly sharp cool shot, temperatures will rebound starting tomorrow. A warmer to much warmer than normal weekend lies ahead. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI value was -35.30 today. Often an SOI figure at or below -30.00 during the second half of September has been followed by a warmer than normal October. 2002, which saw severe October blocking during which the Arctic Oscillation fell to as low as -5.098 on October 18, was an exception. Today, the preliminary Arctic Oscillation (AO) figure was -1.061. A sharp rebound will very likely commence tomorrow. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. On September 18, the MJO was in Phase 8 at an amplitude of 1.561 (RMM). The September 17-adjusted amplitude was 1.201. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 79% and the probability of a monthly mean temperature of 70.0° or above is near 50%.

Averaging can lead to numbers in tenths, hundredths, thousandths of degrees even if the averaged numbers are whole numbers. For example, assume there is a hypothetical 1,000 stations. All but 1 record 50 degree readings. One registers a 51 degree reading. The average is 50.001 degrees, even as no thermometers measure temperature in thousandths of degrees.

Monthly and annual temperature errors within a greater than 95% confidence interval were very small 0.1 to 0.2 degrees C back in 2013. http://static.berkeleyearth.org/memos/robert-rohde-memo.pdf Since then, better ocean measurements have become available and the averaging errors are even smaller. Even at the earlier figures, one could reject the null hypothesis that the global climate had not warmed at a 95% level of confidence.

The issue doesn’t mean measuring sea ice extent or area is not science. The issue concerns limitations of satellite-based measurements and the concept of margins of error. Statistically, when error is considered, measurements within 40,000 km2 are treated as being the same.

More inaccurate information on the climate change denier front. From twitter: One of the biggest flaws in AGW theory are increased heavy rain events. Rain comes from clouds, which form when warm, moist air rises, and cools. This only happens if there's a steep drop in temp with altitude to force the temp to reach the dew point, otherwise, NO clouds form. https://twitter.com/ChrisMartzWX/status/1174553165745786880 The problem with the above claim is that the dew point is not a fixed value. That both the surface and troposphere are warming does not mean that atmospheric temperatures can no longer reach the dew point. What the literature shows is that the warmer atmosphere, which remains capable of cloud formation, holds more moisture. As a result, the frequency of intense precipitation events in parts of the world increase. Such an increased frequency has also shown up in some of the data. https://science2017.globalchange.gov/chapter/7/ Some attribution analyses related to a number of extreme precipitation events can be found at: https://www.worldweatherattribution.org/analysis/rainfall/

On September 18, Arctic sea ice extent increased by 14,600 square kilometers (JAXA) to 3,978,839 square kilometers.

The court transcript related to Mann v. Ball is now available. Key excerpts: There have been at least two extensive periods of delay. Commencing in approximately June 2013, there was a delay of approximately 15 months where nothing was done to move the matter ahead. There was a second extensive period of delay from July 20, 2017 until the filing of the application to dismiss on March 21, 2019, a delay of 20 months. Again, nothing was done during this period to move the matter ahead... The evidence is that the defendant intended to call three witnesses at trial who would have provided evidence going to fair comment and malice. Those witnesses have now died. A fourth witness is no longer able to travel. Thus, in addition to finding that presumption of prejudice has not been rebutted, I also find that there has been actual prejudice to the defendant as a consequence of the delay... Turning to the final factor, I have little hesitation in finding that, on balance, justice requires the action be dismissed. The parties are both in their eighties and Dr. Ball is in poor health. He has had this action hanging over his head like the sword of Damocles for eight years and he will need to wait until January 2021 before the matter proceeds to trial. That is a ten year delay from the original alleged defamatory statement. Other witnesses are also elderly or in poor health. The memories of all parties and witnesses will have faded by the time the matter goes to trial. I find that, because of the delay, it will be difficult, if not impossible, for there to be a fair trial for the defendant. This is a relatively straightforward defamation action and should have been resolved long before now. That it has not been resolved is because the plaintiff has not given it the priority that he should have. In the circumstances, justice requires that the action be dismissed and, accordingly, I do hereby dismiss the action for delay. https://www.bccourts.ca/jdb-txt/sc/19/15/2019BCSC1580.htm In sum, the lawsuit was dismissed on grounds of delay. The delay had nothing to do with Mann's failure to provide materials related to his "hockey stick" analysis and had nothing to do with the substance of climate change. The lawsuit was dismissed on procedural grounds.

After another fall-like day, the coolest night of the season lies ahead courtesy of an air mass that brought several daily record low temperatures to parts of Quebec this morning. Outside New York City, widespread 40s are likely. A few areas where radiational cooling is typically strong could even see readings dip below 40°. However, warmer air will begin to return by Friday. Unseasonable warmth will likely prevail during the upcoming weekend. In Texas, Galveston picked up 6.17" rain from the remains of tropical storm Imelda. That smashed the daily rainfall record of 2.47" from 1979 and was that city's largest daily rainfall since Hurricane Harvey brought 8.64" on August 29, 2017. The two-day figure of 10.65" was the highest since August 28-29, 2017 when 12.43" rain fell from Harvey. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI value was -20.97 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.883. A sharp rebound will very likely commence tomorrow. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. The latest EPS weekly data shows widespread warmth across the CONUS during October. On September 17, the MJO was in Phase 8 at an amplitude of 1.200 (RMM). The September 16-adjusted amplitude was 1.078. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 75% and the probability of a monthly mean temperature of 70.0° or above is near 50%.

As the world's attention focuses on climate change, a matter over which the scientific fundamentals are settled, at least one climate change denier has cited a discredited petition allegedly signed by "31,487 scientists." https://twitter.com/tan123/status/1174432569854705669 The 1997 petition comes complete with a non-peer reviewed paper written by Willie Soon, Arthur Robinson, and Noah Robinson, none of whom have backgrounds in climate science or a related field. But there's more. Just as the paper's conclusions were inconsistent with scientific understanding even then, its conclusions were incompatible with basic physics related to greenhouse gas properties (some findings, of which, go back to the 19th century), its signers are far from authentic. The May 1, 1998 issue of The Seattle Times reported: The petition with 15,000 signatures surfaced shortly before the April 22 Earth Day and quickly became music to global warming's critics. They highlighted it in news releases, at congressional hearings, even on the Senate floor... Several environmental groups questioned dozens of the names: "Perry S. Mason" (the fictitious lawyer?), "Michael J. Fox" (the actor?), "Robert C. Byrd" (the senator?), "John C. Grisham" (the lawyer-author?). And then there's the Spice Girl, a k a. Geraldine Halliwell: The petition listed "Dr. Geri Halliwell" and "Dr. Halliwell." https://archive.is/eQIGW The article also noted: Robinson, who acknowledges he has done no direct research into global warming, said the petition includes thousands of people "qualified to speak on this subject" including biochemists, geophysicists and climatologists. Nevertheless, Robinson felt fit to put his name on a "paper" concerning a matter over which he claimed he had "done no direct research." What does that say about Robinson? More broadly, what does it say about the three authors, none of whom have relevant climate science backgrounds to submit peer-reviewed work on climate change, to essentially manufacture a paper, have it posted on Robinson's organization's website in a font and structure that leaves casual readers with the perception that it was published in a journal? What does it say about those peddling the petition, which was documented to have been riddled with fake names?

So far, Galveston has received 5.96" rain today. That easily surpasses the daily record of 2.47", which was set in 1979. It is also Galveston's biggest one-day rainfall total since August 29, 2017 when 8.64" rain associated with Hurricane Harvey fell.

Arctic sea ice extent registered yet another decline on September 17 on JAXA. Arctic sea ice extent stood at 3.964 million square kilometers assuring 2019 the second lowest minimum extent on record. Based on sensitivity analysis applied to the August 31 figure, the bottom 25% value would be 3.916 million square kilometers. https://www.americanwx.com/bb/topic/48618-arctic-sea-ice-extent-area-and-volume/?do=findComment&comment=5308717 The bottom 10%, which was not listed above, would be approximately 3.850 million square kilometers. The latest minimum extent on record is September 30, which was set in 1995 with a minimum extent of 6.018 million square kilomters. During the 2010-18 period, 2 years had minimum extent figures on September 17 and 2018 recorded its minimum extent on September 21.

Brilliant sunshine and crystal clear skies covered the New York City area today. Temperatures across the Middle Atlantic region ranged from the middle 70s to the lower 80s. By Friday, warmer air should push back into the region. Unseasonable warmth could prevail during the upcoming weekend. Meanwhile, both in the Southeast and France, the fierce summer of 2019 raged on. Records in the Southeast included: Apalachicola, FL: 98° (new monthly record); Atlanta: 98°; Crestview, FL: 100° (tied monthly record); Montgomery, AL: 103°. Records in France included: Aubenas: 94° (new monthly record); Brive: 90°; Carcassonne: 91°; Istres: 88°; and Nimes: 98° (new monthly record); and, Orange: 95°. Nimes has now set 4 monthly high temperature marks this year: February: 76°; June: 112° (all-time record); July: 102°; and, September: 98°. In terms of the Arctic, Arctic sea ice extent fell to 3.991 million square kilometers yesterday (JAXA). That assures 2019 of having the second lowest minimum extent on record. Only 2012 had a figure below 4 million square kilometers. In part due to the large-scale absence of sea ice near Alaska, Utqiagvik (formerly Barrow) is on course for what could become that city's warmest September on record. Through yesterday, that city had seen 83 consecutive days with above freezing temperatures, which is 15 days longer than the previous record. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI value was not available today. Today, the preliminary Arctic Oscillation (AO) figure was -1.362. The AO is forecast to return to positive values in a week or less. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. The latest EPS weekly data shows widespread warmth across the CONUS during October. On September 16, the MJO was in Phase 8 at an amplitude of 1.075 (RMM). The September 15-adjusted amplitude was 0.905. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 81% and the probability of a monthly mean temperature of 70.0° or above is 52%.

I don't believe many here believed the single model showing an August minimum would verify. Having said this, I suspect we either reached our minimum or will do so in the next 3-5 days. It will be fascinating to see how things play out.

Excerpts: Arctic sea ice freezes each winter after a long summer melt. But surprising warmth during the Arctic winter and spring hampered its build-up — setting the stage for this summer’s dramatic ice loss. The dynamic was especially apparent in the Bering Sea. “From about January to May the sea ice in the Bering Sea just didn’t happen,” says Alice Bradley, a polar scientist at Williams College in Williamstown, Massachusetts. “We haven’t seen that before.” A low-pressure weather system hovered over the sea for much of February, funnelling warm air from the south and pushing the little ice that did manage to form into northern waters. Throughout the spring and summer, Arctic sea ice melted away faster than it usually does in areas such as the Beaufort Sea and the central Arctic Ocean. Ice extent and volume hit record monthly lows in July, and by early August there was no sea ice within 240 kilometres of the Alaskan coast... Between water melting off the ice sheet’s surface and breaking off into icebergs, Greenland likely contributed a little over 1.5 millimetres to global sea-level rise this year, according to polar scientist Xavier Fettweis at the University of Liège in Belgium. When researchers eventually compare the mass lost during this summer’s melt to the mass gained during winter snowfall, Greenland is likely to come out as having lost at least as much in 2019 — or even more — than in the extreme year of 2012. https://www.nature.com/articles/d41586-019-02653-x

Serious scientific debate over climate change has ended. Residual uncertainties persist, but the fundamentals (observed warming; anthropogenic causes; broad increase in heat waves, droughts, and floods, etc.) are widely-agreed. As a result, non-science institutions are increasingly incorporating climate change into their work. One such institution is the International Monetary Fund (IMF). In its April 2019 World Economic Outlook, the IMF observed: There is a need for greater multilateral cooperation to resolve trade conflicts, to address climate change and risks from cybersecurity, and to improve the effectiveness of international taxation... Over the medium term, climate change and political discord in the context of rising inequality are key risks that could lower global potential output, with particularly severe implications for some vulnerable countries... Risks of a somewhat slower-moving nature with serious implications for the medium- and long-term outlook include pervasive effects of climate change and a decline in trust with regard to establishment institutions and political par-ties. The Intergovernmental Panel on Climate Change (IPCC) reported in October 2018 that, at current rates of increase, global warming could reach 1.5°C above preindustrial levels between 2030 and 2052, bringing with it extremes of temperature, precipitation, and drought. Such extremes would have devastating humanitarian effects and inflict severe, persistent output losses across a broad range of economies (Chapter 3 of the October 2017 WEO). The warning from the IPCC comes amid substantial distrust of establishment institutions and mainstream political parties—a distrust often born of rising inequality and entrenched beliefs that existing economic arrangements do not work for all. The accompanying polarization of views and growing appeal of extreme policy plat-forms imperil the medium-term outlook by making it difficult to implement structural reforms for boosting potential output growth and strengthening resilience, including against climate-related risks. Low-income developing countries have also borne the brunt of climate change and potent natural disasters. Lowering the fallout from these events will require adaptation strategies that invest in climate-smart infrastructure, incorporate appropriate technologies and zoning regulations, and deploy well-targeted social safety nets... By adding to migrant flows, climate-related events compound an already-complex situation of refugee flight from conflict areas, often to countries already under severe strain. Box 3.1 of Chapter 3 discussed the price of manufactured low-carbon energy technologies. The IMF recognizes the growing importance of climate change because, among other things, the IMF has member countries that are substantially and adversely impacted by it. For example, earlier this month, the IMF developed a climate change policy assessment for the Federated States of Micronesia. In sum, broad scientific consensus on climate change and its effects are being incorporated outside scientific fields. The IMF provides just one example of how science is beginning to inform the work of such entities.

A warm fall overall appears to be locked in, but the winter outcome is still uncertain. Some recent developments, if things move in the direction suggested, might lead to a warmer than normal winter, but the time-bound uncertainty is too great to have much confidence right now.

On September 16, Arctic sea ice extent fell to 3.991 million square kilometers on JAXA. That is only the second time on record that Arctic sea ice extent will have a minimum figure below 4 million square kilometers.

NYC reached 77 today.

The near-real time products are not quality controlled. The final data is. From the NSIDC site: The daily and monthly images that we show in Arctic Sea Ice News & Analysis are near-real-time data. Near-real-time data do not receive the rigorous quality control that final sea ice products enjoy, but it allows us to monitor ice conditions as they develop. https://nsidc.org/arcticseaicenews/faq/#average-vs-daily It should be noted that the JAXA data set shows Arctic sea ice extent as second lowest and NSIDC shows it as 3rd lowest. One can probably have a reasonable degree of confidence that Arctic sea ice extent has fallen to at least the 3rd lowest figure on record at least somewhat below that of 2007. Corroboration across data sets adds confidence.

Newly-released GISS temperature data revealed that summer 2019 was the warmest summer on record globally with a mean temperature anomaly of +0.92°C. The old record was +0.89°C, which was set in 2016. 9 of the 10 warmest summers occurred since 2000 and 5 of the last 10 warmest summers occurred since 2015. Weekly ENSO data suggest increased prospects of a neutral-cool wintertime ENSO. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI was -5.76 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.041. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. Overall, September remains on a path that will very likely lead to an above normal monthly temperature. A mean figure of 70.0° or above remains possible for New York City. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. The latest EPS weekly data shows widespread warmth across the CONUS during October. On September 15, the MJO was in Phase 8 at an amplitude of 0.906 (RMM). The September 14-adjusted amplitude was 0.707. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 75%.

Quick update for the larger June 1-September 15 period for Anchorage: 2019 had a mean temperature of 62.0°F (16.7°C). That surpassed the previous record warm figure of 60.0°F (15.6°), which was set in 2016. The 10 warmest June 1-September 15 timeframes occurred as follows: Prior to 1980: 2 cases 2000 or later: 7 cases 2010 or later: 5 cases 2015 or later: 4 cases

Yesterday, National Hurricane Center scientist Eric Blake tweeted that Miami had set the record for the number of days with temperatures of 93° or above at 42 while noting that is "rouglhy double" the 40-year average. Blake's tweet was then retweeted by CBS' Jeff Berardelli, who noted that it provided an example of a "warming trend" and that in terms of such warmth "Miami is trending up quickly." Any serious look at the Miami climate record should have ended the discussion there. Berardelli was on the mark. Miami has had a clear temperature trend. Further, its 30-year moving average figure for annual temperatures reached a record high of 77.5° in 2017 and was tied in 2018. 2019 could lead to a slight increase in that figure. When one looks at Miami's years with a mean temperature of 77.0° or above, there were 26 such cases. 2 occurred prior to 1980. 22 occurred since 1990. 14 occurred since 2000. 8 occurred since 2010. 2019 is on track to become the 27th such case. Overall, there are a total of 119 cases in Miami's climate record. However, Berardelli's observation was questioned in spite of the data supporting it. Roger A. Pielke, Sr. went off on a tangent about dew points. That dew point temperatures are a distinct metric recorded by the NOAA needs to be emphasized. Blake's and Berardelli's observations concerned temperatures. They did not mention dew point figures. So, what happens when dew point data (which goes back to 1980) is included? Miami's dew point data revealed that the average number of days per year with dew point temperatures of 75° or above has generally increased in recent decades (20-year moving averages are in parentheses): 1980-89: 111.7 days per year 1990-99: 131.1 days per year (1980-1999: 121.4 days per year) 2000-09: 126.2 days per year (1990-2009: 128.7 days per year) 2010-18: 139.0 days per year (1999-2018: 130.8 days per year) The most recent 30-year period (1989-2018) averaged 130.7 days with dew point temperatures of 75° or above. That is the highest such average for a 30-year period on record.