donsutherland1

An Arctic front moved across the region this afternoon triggering snow showers and even snow squalls that coated the ground in places. Following the frontal passage, parts of the region will likely experience their lowest temperatures so far this season. New York City will likely see the temperature fall into the middle or upper teens tomorrow morning with a high temperature only in the middle and perhaps upper 20s. The ENSO Region 1+2 anomaly was +0.5°C and the Region 3.4 anomaly was +0.5°C for the week centered around December 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.05°C and the ENSO Region 3.4 anomaly has averaged +0.53°C. These recent conditions are consistent with a weak El Niño. Nevertheless, a neutral ENSO remains the base case for Winter 2019-20. The SOI was -7.94 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.376. No significant stratospheric warming event appears likely through December 27, but some warming above 3 mb could develop near the end of the forecast period. Moderate Wave 2 activity could occur after December 20, likely leading to some upper stratospheric warming. Overall, most of the stratosphere is forecast to remain cold into the middle of the fourth week of December on the EPS. On December 17, the MJO was in Phase 3 at an amplitude of 0.770 (RMM). The December 16-adjusted amplitude was 0.850. For the December 20-27 period overall, the temperature in such cities as Washington, Philadelphia, and New York will likely average above normal despite the cold start to the period. There is a chance that colder air could return near the end of December or the beginning of January. Based on sensitivity analysis applied to the latest guidance, there is an implied 56% probability that December will wind up colder than normal in New York City.

Some photos of the ice this morning:

It's a difficult situation. Externalities e.g., the cost of carbon emissions and their consequences, aren't captured in the pricing mechanism of fossil fuels. That's part of the reason at least some economists favor a carbon tax. In addition, certain governments have little or no meaningful commitment to addressing the great challenge of climate change (or even recognition of the science). Yet, the time left to avoid making what amounts to an almost irrevocable commitment via emissions to temperature increases above 2.0 degrees C or 1.5 degrees C is shrinking.

Thanks for this information. The 12/13-16 data has now been pulled and replaced by "M." Given the temperatures at Sitka, I suspect based on what you found and the lower temperatures there than a few days ago, the sensor was, in fact, malfunctioning.

I don't think such a model is practical given the risks that such power could be abused given human nature as it is. However, the issue of ignorant leaders or those who put narrow interests (e.g., Russia and oil) ahead of even serious global challenges are a real problem.

I believe I was quoting Vice Regent. We agree about living in a more sustainable way. The former almost certainly won't be broadly supported. The latter could and should be.

A widespread 0.10"-0.25" freezing rain event affected areas just to the north and west of New York City earlier today. Parts of eastern Pennsylvania, northwestern New Jersey, New York State, and Connecticut picked up 0.30" or more freezing rain. Some freezing rain totals included: Allentown: 0.29"; Bridgeport: 0.39"; Center Valley, PA: 0.50"; Highland Lakes, NJ: 0.30"; Islip: 0.19"; Monroe, NY: 0.44"; Stockholm (1 WNW), NJ: 0.40"; and, Westhampton: 0.19". In the wake of the departing ice storm, a short but sharp shot of cold will push into the region tomorrow, possibly accompanied by snow showers and even a snow squall. Tomorrow night, parts of the region could experience the lowest temperatures so far this season. New York City will likely see the temperature fall into the middle or upper teens Thursday morning with a high temperature only in the middle 20s. The ENSO Region 1+2 anomaly was +0.5°C and the Region 3.4 anomaly was +0.5°C for the week centered around December 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.05°C and the ENSO Region 3.4 anomaly has averaged +0.53°C. These recent conditions are consistent with a weak El Niño. Nevertheless, a neutral ENSO remains the base case for Winter 2019-20. The SOI was -13.44 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.370. No significant stratospheric warming event appears likely through December 26, but some warming above 2 mb could develop near the end of the forecast period. Moderate Wave 2 activity could occur after December 20, likely leading to some upper stratosphere warming. Overall, most of the stratosphere is forecast to remain cold into the middle of the fourth week of December on the EPS. On December 16, the MJO was in Phase 3 at an amplitude of 0.849 (RMM). The December 15-adjusted amplitude was 1.127. For the December 20-27 period overall, the temperature in such cities as Washington, Philadelphia, and New York could average somewhat above normal despite the cold start to the period. There is a chance that colder air could return near the end of December. The potential for a full-fledged Arctic outbreak could be available during the first week in January if some of the guidance has correctly forecast the pattern evolution heading into January. Based on sensitivity analysis applied to the latest guidance, there is an implied 62% probability that December will wind up colder than normal in New York City.

Five photos from today’s ice storm: Larchmont, NY New Rochelle, NY Bronx, NY Bronx, NY Bronx, NY

It's not far from Van Cortlandt Park. From there northward into Yonkers, there was quite a bit of ice. Farther south and east, the ice was much less.

Bronx, NY: 32° with freezing rain

Your location shows as Bolton Landing. Probably 1"-3" snow with 2"-4" in the Albany area. White Plains less than one inch and then sleet/freezing rain (probably 0.10"-0.20" freezing rain).

Sleet is currently falling in Larchmont, NY.

Variability will likely continue to define to weather into the closing week of December. As a result, much of the region could see perhaps additional snowfall through December 26, along with periodic intrusions of cold air. A short but sharp shot of cold will follow the system that will impact the region tonight into tomorrow with snow, sleet, freezing rain and rain. Parts of the region could experience the lowest temperatures so far this season. New York City will likely see the temperature fall below 20° with one day where the high temperature remains in the middle or upper 20s. Another window of opportunity snowfall could be available during the December 21-23 timeframe. During that time, the Arctic Oscillation (AO) is forecast to be negative. However, some of the latest guidance now shows a weakly positive NAO in combination with a negative PNA. As a result, the synoptic pattern looks less promising than it did a few days ago. Since 1950, 33% of storms that brought 4" or more snow during December 16-31 to just one city from among Philadelphia, New York City, or Boston had an AO- and 19% had an AO-/NAO-. However, from among the storms that brought 4" or more snow to at least two of those cities, 77% occurred with an AO- and 54% occurred with an AO-/NAO-. For the December 20-27 period overall, the temperature in such cities as Washington, Philadelphia, and New York could average somewhat above normal despite the cold start to the period. The ENSO Region 1+2 anomaly was +0.5°C and the Region 3.4 anomaly was +0.5°C for the week centered around December 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.05°C and the ENSO Region 3.4 anomaly has averaged +0.53°C. These recent conditions are consistent with a weak El Niño. Nevertheless, a neutral ENSO remains the base case for Winter 2019-20. The SOI was -15.00 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.986. No significant stratospheric warming event appears likely through December 25. Wave 2 activity is forecast to remain relatively weak. Overall, the stratosphere is forecast to remain cold into the middle of the fourth week of December on the EPS. On December 15, the MJO was in Phase 3 at an amplitude of 1.130 (RMM). The December 14-adjusted amplitude was 1.292. Differences for the closing days of December between the EPS and GEFS are narrowing. Consistent with the colder idea having prevailed more often than not since late autumn, the EPS has begun to move toward a colder solution for the end of December. When it comes to New York City's 4" or greater snowstorms during the second half of December, the AO is highly important. Since 1950, December 16-31 has seen 15 storms bring 4.0" or more snow to New York City. 73% occurred with an AO-. Further, 80% of the 6" or greater snowstorms during this timeframe occurred when the AO was negative. Even as the PNA and NAO had a lesser impact on the 4" or greater snowstorms, an NAO- was present in 70% of the 6" or greater snowstorms during that timeframe and a PNA+ was also present during 70% of the 6" or greater snowstorms. Based on sensitivity analysis applied to the latest guidance, there is an implied 63% probability that December will wind up colder than normal in New York City.

The high temperatures at Yakutat, Alaska for the past three days and for today (preliminary value) were: December 13: 56° (old record: 49°, 2017) December 14: 58° (old record: 49°, 2017) December 15: 61° (old record: 48°, 2005) December 16: 57° (old record: 50°, 2005) All four days exceeded the previous December record high temperature of 52°, which had been set on December 8, 1960. The 61° temperature yesterday broke the meteorological winter record of 58°, which was set on January 19, 1930 and tied on December 14, 2019 and was also above the November monthly record of 59°, which was set on November 1, 1947. Prior to yesterday, the latest 60° temperature on record occurred on October 13, 1969 when the temperature reached 60°. Daily records go back to May 1, 1917.

It's beginning to feel a lot like... spring?

According to the GISS dataset, November 2019 ranked as the second warmest November on record with a +1.02°C anomaly. Only 2015 with a +1.06°C anomaly was warmer. As a result, 2019 has a year-to-date anomaly of +0.97°C, which is the second warmest at this point in time. 2019 is extremely likely to wind up as the second warmest year on record on that dataset. To wind up cooler than 2017 (+0.92°C annual anomaly), which currently ranks as the second warmest year on record, December would need a temperature anomaly of +0.37°C. The last month with a temperature anomaly of +0.37°C or less was January 2008, which had a temperature anomaly of +0.30°C. The last time December was at least as cool occurred in 2000 when the monthly anomaly was +0.28°C. The coolest anomaly so far this year is +0.86°C, which occurred in May.

Yes. It's possible. It will be interesting to see how things evolve this afternoon and evening.

Winter Forecast Update... Over the past 6 weeks, the ENSO Region 3.4 anomaly had averaged +0.53°C. Gradual cooling of that region is forecast for the remainder of the winter. As a result, the base case idea of a neutral-warm ENSO remains on track. At the same time, the cool anomaly in ENSO Region 1+2 has largely disappeared (-0.05°C average anomaly over the past 6 weeks). Persistent warmth in this region could have an adverse impact on seasonal snowfall in parts of the eastern United States. The NAO had been positive for 100% of the first 15 days of December before falling to -0.069 on December 16. The core assumption of a predominantly positive NAO remains on track. During the December 1-15 period, the Arctic Oscillation (AO) averaged +1.584 with a peak figure of +3.059on December 3. Nevertheless, a portion of the northern Middle Atlantic and southern New England regions had colder than normal temperatures on average. Since 1950, there were 13 prior cases where the AO averaged +1.000 or above during the first fifteen days of December. Such outcomes have typically been followed by somewhat less than normal snowfall in parts of the Great Lakes Region, Middle Atlantic States, and southern New England. These figures are modestly below those in the winter idea posted at the beginning of this thread. However, the differences are sufficiently small to suggest that the overall idea remains on track. What could lead to higher snowfall amounts: 1. Prolonged deep blocking (AO of -1.000 or below) 2. The MJO's persistently being in Phases 7, 8, 1 and 2 at a high amplitude 3. The ENSO Region 3.4 anomaly falling to somewhat negative values as the winter progresses 4. A mainly negative NAO What could lead to lower snowfall amounts: 1. A persistently positive AO coupled with a strongly negative SOI 2. The MJO's persistently being in Phases 4, 5, and 6 at a high amplitude 3. Dramatic warming in ENSO Region 1+2

The latest guidance suggests the potential for significant freezing rain not too far north and west of New York City. Based on the latest guidance, it is likely that an area stretching from West Milford, NJ across White Plains and to Danbury could pick up 0.10" to 0.25" freezing rain with the potential for more, especially in northwestern New Jersey. Some of the local media outlets (radio forecasts I heard coming into work this morning) are downplaying the freezing rain risk (the specific mention concerned not more than a few hundredths of an inch). However, those outlets may be using dated guidance and/or relying on the much warmer GFS to reach a conclusion that understates risk of icing. The 3 km NAM, 12 km NAM, and RGEM are very aggressive, both with amounts and the southern extent of the freezing rain.

I don't think one can be certain about how much of the needed CO2 can be absorbed. IMO, until the risks are better understood, society should probably avoid such approaches unless absolutely necessary.

Such a geoengineering approach, not withstanding other risks that may or may not be known, would only capture a fraction of the annual CO2 emissions per year (around one-eighth). That assumes one could produce enough iron sulfate for maximum effect. https://www.theguardian.com/environment/2012/jul/18/iron-sea-carbon

I'm not as pessimistic, though I have worries given how impotent and unwilling today's generation of leaders (political and business) are in addressing the challenge of anthropogenic climate change. Addressing climate change should not require "phasing out civilization." It does entail some significant changes. Among those changes are a transition to cleaner fuels, increased energy efficiency, a carbon tax/elimination of subsidies for fossil fuels, etc. In my view, were the same leaders involved in tackling the problem of anthropogenic climate change today, credible, binding, and concrete commitments would have been undertaken. They understood what today's leaders don't, namely that today's choices have consequences for tomorrow. Consequently, they were not paralyzed by the suffocating short-term thinking that defines today's leaders.

Variability will likely continue to define to weather into the closing week of December. As a result, much of the region could see additional snowfall through December 26, along with periodic intrusions of cold air. Whether the major cities see a 6" or greater snowstorm could depend, in large part, on the state of the teleconnections at the time of any storminess. The first system will likely bring a light snowfall to the coastal plain and light to moderate snowfall to interior sections before transitioning to sleet, freezing rain, and then rain during tomorrow into tomorrow night. This could be the kind of system that brings 2"-4" across northwestern New Jersey/northeastern Pennsylvania north and eastward to Albany. However, such locations as Islip, New York City, and Newark will likely pick up 1" or less snow. That storm will be followed by a short but sharp shot of cold. Parts of the region could experience the lowest temperatures so far this season. New York City could see the lowest temperature approach 20° and perhaps one day where the high temperature remains below 30°. Another window of opportunity could be available during the December 21-23 timeframe. During that time, the Arctic Oscillation (AO) is currently forecast to be negative. However, some of the latest guidance now shows a weakly positive NAO. Since 1950, 33% of storms that brought 4" or more snow during December 16-31 to just one city from among Philadelphia, New York City, or Boston had an AO- and 19% had an AO-/NAO-. However, from among the storms that brought 4" or more snow to at least two of those cities, 77% occurred with an AO- and 54% occurred with an AO-/NAO-. Meanwhile, the temperature reached 51° in Anchorage on December 9. That set a new record high temperature for December and meteorological winter. The previous December record was 48° (December 1-2, 1992 and December 26, 1999). The previous record for meteorological winter was 50°, which was set on January 19, 1961 and tied on January 27, 2014. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.3°C for the week centered around December 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.23°C and the ENSO Region 3.4 anomaly has averaged +0.67°C. These recent conditions are consistent with a weak El Niño. Nevertheless, a neutral ENSO remains the base case for Winter 2019-20 and the recent cooling in Region 3.4 suggests that the base case remains viable. The SOI was -14.90 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.037. For the December 1-15 period, the AO had a preliminary average of +1.584. Since 1950, 13 years saw the AO average +1.000 or above for the first 15 days of December, which is very likely this year. Only 3 (23%) wound up with a colder than normal December in New York City (which appears likely at present). The most recent such case was December 1988 when New York City had a mean December temperature of 35.9°. Following a December 1-15 average AO value of +1.000 or above, 85% of winters went on to record less than 30.0" seasonal snowfall in New York City and Newark. One notable exception was winter 2013-14 when 57.4" snow was recorded in New York City and 61.1" in Newark. No significant stratospheric warming event appears likely through December 24. Wave 2 activity is forecast to remain relatively weak. Overall, the stratosphere is forecast to remain cold into the fourth week of December on the EPS. On December 14, the MJO was in Phase 2 at an amplitude of 1.296 (RMM). The December 13-adjusted amplitude was 1.297. Large differences between the EPS and GEFS persist beyond Day 10. The GEFS is notably colder than the EPS with much of North America and the Northern Hemisphere covered by cold anomalies. Both show the coldest anomalies over a portion of northern Asia. The colder idea has more often than not prevailed since late autumn. When it comes to New York City's 4" or greater snowstorms during the second half of December, the AO is highly important. Since 1950, December 16-31 has seen 15 storms bring 4.0" or more snow to New York City. 73% occurred with an AO-. Further, 80% of the 6" or greater snowstorms during this timeframe occurred when the AO was negative. Even as the PNA and NAO had a lesser impact on the 4" or greater snowstorms, an NAO- was present in 70% of the 6" or greater snowstorms during that timeframe and a PNA+ was also present during 70% of the 6" or greater snowstorms. Based on sensitivity analysis applied to the latest guidance, there is an implied 65% probability that December will wind up colder than normal in New York City.

Under partly sunny skies (deep blue sky coupled with abundant cumulus clouds), the temperature was mainly in the middle 40s this afternoon. There was also a gusty breeze that was continuing to bring cooler air into the region.

In 1987, humanity was confronted with a growing ozone hole over the Southern Hemisphere and the implication of an inevitable and dramatic rise in skin cancer cases. The world's leaders at that time, even while taking on an existential Cold War struggle, came together in Montreal to adopt a solution to address the problem. A binding commitment to completely phase out the use of CFCs and halons was agreed. That treaty was universally ratified. Since then, much progress has been made. NASA recently revealed: Thirty-two years ago, the international community signed the Montreal Protocol on Substances that Deplete the Ozone Layer. This agreement regulated the consumption and production of ozone-depleting compounds. Atmospheric levels of man-made ozone depleting substances increased up to the year 2000. Since then, they have slowly declined but remain high enough to produce significant ozone loss. The ozone hole over Antarctica is expected to gradually become less severe as chlorofluorocarbons— banned chlorine-containing synthetic compounds that were once frequently used as coolants—continue to decline. Scientists expect the Antarctic ozone to recover back to the 1980 level around 2070. https://www.nasa.gov/feature/goddard/2019/2019-ozone-hole-is-the-smallest-on-record-since-its-discovery Then, science carried the day. Political leaders made the kind of decisions that fall with responsible leadership. They made no excuses. They did not embrace defeatist conclusions that acting would be economically harmful, much less that nothing could be done. They did not descend into "denialism" or conspiracy theories aimed at alleviating accountability from their shoulders. They acted with conviction. They put the world on a better path. Just three decades later, when confronted by another global challenge--that of anthropogenic climate change--the world's leaders abdicated their responsibility in Madrid. They proved unable to summon the courage, foresight, and leadership to tackle the global challenge of the contemporary era. They chose timidity at a time when no great struggle comparable to the Cold War is raging. Put simply, they failed the test of leadership. They demonstrated that although they hold positions of authority, they lack the capacity and qualities necessary to lead. Instead, they chose to remain passive bystanders to history. They failed as leaders. They failed as people. In their enormous failure to lead, they have substantially magnified the burden they have already left to today's youth and future generations to come. In doing so, they have defined their generation as arguably the most short-sighted one in modern history. They chose to leave the world a worse place than they inherited. Given the overwhelming body of scientific evidence and range of tools available to launch a credible effort to curb then reverse greenhouse gas emissions, their fateful choice is a deliberate one. Ignorance is not a valid defense. At the same time, they have unequivocally made clear to today's youth that the concerns and futures of those youth are to be sacrificed for the preservation of the short-sighted status quo. Given the urgency and gravity of the challenge of anthropogenic climate change, this is a most sad outcome. Urgent problems aren't punted to the future year after year. Great problems are not routinely ignored, much less cloaked in the packaging of brave words disconnected from concrete and credible measures to evade responsibility. Fortunately, as time passes, those who occupy today's positions of leadership will gradually depart those positions. In their wake, future generations will be left with a tremendous mess. The passage of time will determine whether leadership capacity on the global stage merely skipped today's generation of global leaders or whether the absence of leadership capacity is a new and persistent problem. Considering that human nature has changed remarkably little since the emergence of Homo Sapiens, the odds are still high that the contemporary leadership deficit is merely a temporary phenomenon.