donsutherland1

I agree concerning Antarctic ice melt accelerating. I was focused on the Arctic. Australia remains on a bad climate and bad policy course (still expanding coal production). It remains uncertain whether this season's historic fire season will prove to be a political game-changer there.

Under partly sunny skies, readings across the region topped out in the upper 40s and lower 50s. The first week of the month remains on track to average 5° or more above normal across much of the region. A short-duration cold shot is possible late in the first week of January into part of the second week. This cold shot could provide a window of opportunity for at least some snowfall in the region and especially across central/upstate New York and New England. Based on the forecast strongly positive AO, the probability of a significant (6" or greater snowstorm) for the major cities of the Middle Atlantic region during the first 10 days of January is low. Since 1950, the biggest snowfall for that region when the AO was +2.000 or above during the January 1-15 period occurred during January 14-15, 1954 when Philadelphia received 3.0" snow and New York City picked up 2.0". Boston has had numerous 6" or greater snowstorms during such cases, including one 10" or greater snowstorm. Therefore, the risk of significant snow would likely be greatest over New England assuming this relationship holds (no significant offsetting variables). Such a scenario does not preclude the possibility of a light snow event across parts of the region during this timeframe, particularly during the January 5-9 period. Afterward, a tendency for ridging with warmer than normal temperatures prevailing will very likely develop during the latter part of the second week of the month and persist through at least mid-month. The ENSO Region 1+2 anomaly was +0.3°C and the Region 3.4 anomaly was +0.4°C for the week centered around December 25. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -17.42 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.596. No significant stratospheric warming event appears likely through January 11, but a temporary period of warming will very likely develop in the upper stratosphere and approach or reach 5 mb toward the end of the first week of January. Wave 2 activity will remain relatively muted following the first week of the month. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 1, the MJO was in Phase 8 at an amplitude of 0.564 (RMM). The December 31-adjusted amplitude was 0.748. Since 1974, there were five cases when the MJO was in Phase 6 at an amplitude of 1.500 or above during the December 20-31 period, as has been the case this year. The temperature anomalies were closely tied to how much time the MJO spent in Phase 8 during the January 1-15 timeframe. The mean temperature for January 1-15 for cases with more than 5 such days was 29.0° in New York City. The mean temperature for those with 5 or fewer such days was 36.1°. The overall 1981-2019 mean temperature for January 1-15 is 33.8°. January 2019 will very likely fall into the latter, warmer subset.

Abstract: For generations, climate scientists have educated the public that ‘weather is not climate’, and climate change has been framed as the change in the distribution of weather that slowly emerges from large variability over decades. However, weather when considered globally is now in uncharted territory. Here we show that on the basis of a single day of globally observed temperature and moisture, we detect the fingerprint of externally driven climate change, and conclude that Earth as a whole is warming. Our detection approach invokes statistical learning and climate model simulations to encapsulate the relationship between spatial patterns of daily temperature and humidity, and key climate change metrics such as annual global mean temperature or Earth’s energy imbalance. Observations are projected onto this relationship to detect climate change. The fingerprint of climate change is detected from any single day in the observed global record since early 2012, and since 1999 on the basis of a year of data. Detection is robust even when ignoring the long-term global warming trend. This complements traditional climate change detection, but also opens broader perspectives for the communication of regional weather events, modifying the climate change narrative: while changes in weather locally are emerging over decades, global climate change is now detected instantaneously. The paper can be found at: https://www.nature.com/articles/s41558-019-0666-7

IMO, that record is almost certainly safe. The least snow during the January-April period is the 2.8" that was recorded during winter 1972-73. NYC would need just 0.2" during that period to break the record and no season has come close to such a minimal amount during January-April.

My initial thinking on the system is that a window of opportunity continues to exist. This hasn't been in doubt. The base case is that the potential for a light accumulation in the NYC/EWR area exists with a higher probability of a moderate or possibly even significant accumulation in parts of New England, including Boston. The pattern has some similarities to that when a storm affected the region on January 16-17, 1965, but with some differences (a far less impressive and weakening PNA ridge is forecast) and the 500 mb trough placement differs, too. These differences could result in a somewhat "too late, too little" scenario for NYC/EWR. Cold air would arrive, but by then the heaviest precipitation would be off to the east. Parts of Long Island, particularly Suffolk County, could see higher accumulations as the storm begins to rapidly develop on its approach to the New England coastal waters or when it is over those waters.

My guess based on what's happened from 2000 onward and the climate papers I've read is that a general decline will continue at varying rates. The average rate might slow somewhat from the most rapid average rate seen during the last 10 years, but the 2012 minimum extent figure will be surpassed during the 2020s, and maybe more than once. Arctic warming will continue with aggressive feedbacks. I don't see a plausible mechanism that might materially slow the rate at which it is warming right now, though maybe others can identify one if it exists.

Penn State climate scientist Michael Mann's op-ed from Australia where he will be conducting research: The brown skies I observed in the Blue Mountains this week are a product of human-caused climate change. Take record heat, combine it with unprecedented drought in already dry regions and you get unprecedented bushfires like the ones engulfing the Blue Mountains and spreading across the continent. It’s not complicated. The warming of our planet – and the changes in climate associated with it – are due to the fossil fuels we’re burning: oil, whether at midnight or any other hour of the day, natural gas, and the biggest culprit of all, coal. That’s not complicated either... Australians need only wake up in the morning, turn on the television, read the newspaper or look out the window to see what is increasingly obvious to many – for Australia, dangerous climate change is already here. It’s simply a matter of how much worse we’re willing to allow it to get. Australia is experiencing a climate emergency. It is literally burning. It needs leadership that is able to recognise that and act. And it needs voters to hold politicians accountable at the ballot box. https://www.theguardian.com/commentisfree/2020/jan/02/australia-your-country-is-burning-dangerous-climate-change-is-here-with-you-now And a link to commentary by Nerilie Abram, investigator at the ARC Center of Excellence for Climate Extremes and an associate professor at the Research School of Earth Sciences at the Australian National University. https://blogs.scientificamerican.com/observations/australias-angry-summer-this-is-what-climate-change-looks-like/ 2019 was Australia's warmest and driest year on record.

I believe there is a relationship. I am not aware of literature demonstrating that they are manifestations of a larger phenomenon.

Today's AO value of +3.653 was the highest such figure since December 23, 2016. Unfortunately, it was timed for January, not some month outside of winter. Moreover, since January 1950, there are only 8 prior cases where the AO reached +3.500 or above in the January 1-10 timeframe. Five of those cases went on to have a predominantly positive AO in February. 1976 was one such case. Three, however, saw a predominantly negative AO. One such case was 1983. Perhaps, because of the "sacrifice" that has been made, something closer to 1983 will play out. Hopefully, once the MJO departs from the Maritime Continent, its travel plans will exclude any quick returns there.

Congratulations Wxdude and Rodney. Many thanks again to Roger for conducting this fun contest.

January started with readings averaging above normal. The first week of the month will likely average 5° or more above normal across much of the region. A short-duration cold shot is possible late in the first week of January into part of the second week. This cold shot could provide a window of opportunity for at least some snowfall in the region and especially across central/upstate New York and New England. Afterward, a tendency for ridging with warmer than normal temperatures prevailing will likely develop during the latter part of the second week of the month and persist through mid-month. Based on the forecast strongly positive AO, the probability of a significant (6" or greater snowstorm) for the major cities of the Middle Atlantic region during the first 10 days of January is low. Since 1950, the biggest snowfall for that region when the AO was +2.000 or above during the January 1-15 period occurred during January 14-15, 1954 when Philadelphia received 3.0" snow and New York City picked up 2.0". Boston has had numerous 6" or greater snowstorms during such cases, including one 10" or greater snowstorm. Therefore, the risk of significant snow would likely be greatest over New England assuming this relationship holds (no significant offsetting variables). Such a scenario does not preclude the possibility of a light snow event across parts of the region during this timeframe, particularly during the January 6-9 period. The ENSO Region 1+2 anomaly was +0.3°C and the Region 3.4 anomaly was +0.4°C for the week centered around December 25. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -7.16 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.653. This is the highest figure since December 23, 2016 when the AO was +3.807. No significant stratospheric warming event appears likely through January 10, but a temporary period of warming will very likely develop in the upper stratosphere and approach or reach 5 mb toward the end of the first week of January. Wave 2 activity will remain relatively muted following the first week of the month. Overall, most of the stratosphere is forecast to remain cold on the EPS. On December 31, the MJO was in Phase 8 at an amplitude of 0.756 (RMM). The December 30-adjusted amplitude was 1.069. Since 1974, there were five cases when the MJO was in Phase 6 at an amplitude of 1.500 or above during the December 20-31 period, as has been the case this year. The temperature anomalies were closely tied to how much time the MJO spent in Phase 8 during that timeframe. The mean temperature for January 1-15 for cases with more than 5 such days was 29.0° in New York City. The mean temperature for those with 5 or fewer such days was 36.1°. The overall 1981-2019 mean temperature for January 1-15 is 33.8°. January 2019 will very likely fall into the latter, warmer subset. At the start of January, based on sensitivity analysis applied to the latest guidance, there was an implied 70% probability that New York City would have a warmer than normal January. Such a probability is exceptionally high for the start of a monthly period.

IMO, today's political leaders lack the courage, foresight, and capacity to take on big problems. They are terrified of challenges, pessimistic about the human capacity to innovate, and tied to the status quo. Past generations took on big problems over shot time frames when the existing technology did not yet exist. That's the story of the Manhattan and Apollo Projects. Had today's political leaders been in positions of authority during either project, both would never have been attempted. The world would likely be a vastly different place for such failure to lead.

That's so far in the future, there's essentially no skill with any dynamical or statistical tool. That doesn't mean it can't happen, but such an outcome is far from a high confidence one.

Ok. That makes more sense. Let's hope that doesn't happen.

It does. Some MJO passages through the Maritime Continent (Phases 4 and 5) at very high amplitude have produced a bout of near-record to record warmth. So one or two days where the temperature spikes is certainly within the realm of possibility.

Phases 4-5 by around 1/10 is what many here have been talking about for days. There is very strong support on the guidance for such a move and at high amplitude. It's the reason the development of a period of ridging near 1/10 and for at least a week is now likely as per the major global operational models and their ensembles.

New Year, New Decade, Old Story... Despite the change in calendar to a new year and new decade, time seems stuck. The region started the first morning of the 2020s with above normal temperatures, much as 2019 concluded. Morning low temperatures into southern New England were generally several degrees above freezing. The week ahead looks mild overall, even as some cooler air could arrive late in the period. There remains some possibility of a light snow event in parts of the Middle Atlantic region and maybe a light-to-moderate event in parts of New England afterward before a warmer pattern reasserts itself. Based on the sensitivity analysis applied to the latest guidance, there is an implied 64% probability that the January 1-7 temperature in New York City will average 40.0° or above. 74% of the 23 prior cases went on to record a warmer than normal January and nearly half had a monthly mean temperature of 35.0° or above.

December concluded with widespread warm anomalies. Despite having a monthly temperature anomaly of 2.7° below normal on December 21, New York City finished with an anomaly of 0.8° above normal. Snowfall was also generally below normal in much of the coastal plain and larger Middle Atlantic region. The preliminary December 2019 temperature anomalies for select cities were: Baltimore: +3.2°, Boston: +2.5°, Islip: +1.2°, New York City: +0.8°, Newark: +1.1°, Philadelphia: +1.2°, and Washington, DC: +2.4°. Through December 31, total snowfall in New York City was 2.5". In Philadelphia, it was 0.1". In Washington, DC, it was 0.4". Since 1888, there were 29 prior cases when seasonal snowfall through December 31 was less than 1" in Philadelphia and Washington, DC and less than 4" in New York City. Mean seasonal snowfall amounts by the end of the winter were: New York City: 20.6" (median: 15.1"); Philadelphia: 16.1" (median: 13.4"); and, Washington, DC: 12.1" (median: 9.5"). In New York City, 59% of such winters wound up with less than 20" snowfall, but an equal share wound up with less than 10" and more than 40". In Philadelphia, 66% of such winters had less than 20" snowfall. In Washington, DC 79% of such winters recorded less than 20" snowfall. January will begin on a generally mild not with the first week averaging 5° or more above normal across much of the region. A short-duration cold shot is possible late in the first week of January into part of the second week. Afterward, a tendency for ridging with warmer than normal temperatures prevailing could develop during the latter part of the second week of the month. Based on the forecast strongly positive AO to start January, the probability of a significant (6" or greater snowstorm) for the major cities of the Middle Atlantic region during the first 10 days of January is low. Since 1950, the biggest snowfall for that region when the AO was +2.000 or above during the January 1-15 period occurred during January 14-15, 1954 when Philadelphia received 3.0" snow and New York City picked up 2.0". Boston has had numerous 6" or greater snowstorms during such cases, including one 10" or greater snowstorm. Therefore, the risk of significant snow would likely be greatest over New England assuming this relationship holds (no significant offsetting variables). Such a scenario does not preclude the possibility of a light snow event across parts of the region during this timeframe, particularly during the January 6-9 period. 2019 was, by far, the warmest year on record in Utqiagvik (formerly Barrow) with an annual mean temperature of 20.9°. The previous record was 18.9°, which was set in 2016. Anchorage also capped off a record warm year with a record high daily temperature of 46°. The previous record was 44°, which was set just last year. The previous warmest year on record was 41.5°, which occurred in 2016. The ENSO Region 1+2 anomaly was +0.4°C and the Region 3.4 anomaly was +0.6°C for the week centered around December 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.56°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -4.00 today. Today, the preliminary Arctic Oscillation (AO) figure was +2.726. The AO has now risen 5.1 sigma in 4 days and nearly 5.5 sigma in 5 days. The preliminary December average was +0.391 (55% days positive and 45% days negative). No significant stratospheric warming event appears likely through January 9, but warming will very likely develop in the upper stratosphere and approach or reach 5 mb toward the end of the first week of January. Wave 2 activity will remain relatively muted at 30 mb through most of the first week of January, but a moderate Wave 2 hit could occur at or above 10 mb leading to the upper stratospheric warming. Overall, most of the stratosphere is forecast to remain cold through the first week of January on the EPS. However, the upper stratospheric warming will need to be watched for possible downward propagation. On December 30, the MJO was in Phase 7 at an amplitude of 1.069 (RMM). The December 29-adjusted amplitude was 1.259. Since 1974, there were five cases when the MJO was in Phase 6 at an amplitude of 1.500 or above during the December 20-31 period, as has been the case this year. The temperature anomalies were closely tied to how much time the MJO spent in Phase 8 during that timeframe. The mean temperature for January 1-15 for cases with more than 5 such days was 29.0° in New York City. The mean temperature for those with 5 or fewer such days was 36.1°. The overall 1981-2019 mean temperature for January 1-15 is 33.8°. January will likely be warmer than normal across the Middle Atlantic region and southern New England. The likely anomalies will range from 1.5° to 2.5° above normal (around 2.4°above normal in New York City).

During the afternoon, clouds broke for sunshine on occasion. The temperature topped out at a mild 44°. Three photos, one of which shows the aftermath of yesterday’s pounding waves. At the end, winds gusted past 50 mph yesterday.

Using the base normal figure skews things, as 2.4 degrees above normal was once around freezing, meaning a greater tendency of snowfall. Using temperature averages is more meaningful. January Mean: 34.0-34.9: Mean: 7.5"; Most: 27.9", 2016 January Mean: 35.0-35.9: Mean: 4.5"; Most: 13.3", 1964 January Mean: 36.0-39.9: Mean: 2.8"; Most: 7.9", 2017 January Mean: 40.0 or above: Mean: 1.5"; Most: 6.5", 1937 That data is from Central Park.

Some quick morning thoughts on January: 1. The AO is now rising sharply. It has increased by more than 5 sigma over the past 4 days. It is forecast to remain strongly positive into mid-month. 2. The EPO is currently positive and rising. It could go neutral during the second week of the month. EPO+/AO+ patterns are typically the warmest in January. Such warmth is often amplified when the SOI is negative. 3. There is strong consensus on the guidance that the MJO will move into the Maritime Continent phases at high amplitude. All said, the first week of January could have a mean temperature at or above 40 degrees in NYC and the first half of the month, could be much warmer than normal. Any snowfall during the brief window as a trough swings across the region from late in the first week of January to the middle of the second week will likely be light. No significant snowfalls (6" or above) are likely for the Middle Atlantic region. Central and upstate New York and New England would have a better chance at significant snowfall. Ridging with above to occasionally much above normal temperatures should redevelop around January 10 +/- a few days and could predominate for at least a week and possibly longer. My final guess is that NYC will probably have a January temperature anomaly of 2.4 degrees above normal.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 2.2 2.4 1.3 1.5 1.0 0.0 -1.0 -1.5 0.4

The storm that brought the year's last significant precipitation to the region is now departing. Steady precipitation was falling across eastern Long Island and into eastern New England. Precipitation amounts were in line with expectations. Through 8 pm, amounts included: Allentown: 0.75"; Baltimore: 0.83"; Boston: 1.17"; Bridgeport: 1.39"; Harrisburg: 0.69"; Islip: 1.12"; New York City: 0.99"; Newark: 0.97"; Philadelphia: 0.99"; Poughkeepsie: 1.12"; Providence: 1.44"; and, Scranton: 0.50". Through December 29, monthly anomalies for select cities were: Baltimore: +2.3°, Boston: +2.0°, Islip: +0.7°, New York City: +0.4°, Newark: +0.6°, Philadelphia: +0.7°, and Washington, DC: +1.6°. January will begin on a generally mild not with the first week averaging 5° or more above normal across much of the region. A short-duration cold shot is possible late in the first week of January into part of the second week. Afterward, a tendency for ridging could develop during the latter part of the second week of the month. Based on the forecast strongly positive AO to start January, the probability of a significant (6" or greater snowstorm) for the major cities of the Middle Atlantic region during the first 10 days of January is low. Since 1950, the biggest snowfall for that region when the AO was +2.000 or above during the January 1-15 period occurred during January 14-15, 1954 when Philadelphia received 3.0" snow and New York City picked up 2.0". Boston has had numerous 6" or greater snowstorms during such cases, including one 10" or greater snowstorm. Therefore, the risk of significant snow would likely be greatest over New England assuming this relationship holds (no significant offsetting variables). Such a scenario does not preclude the possibility of a light snow event across parts of the region during this timeframe, particularly during the January 6-9 period. Despite the development of a sustained colder than normal temperature regime, Utqiagvik (formerly Barrow) is nearing the end of its warmest year on record. 2019 will likely conclude with a mean temperature of 20.9°. The existing record is 18.9°, which was set in 2016. Currently, 2017 ranks as the second warmest year and 2018 ranks as the fourth warmest year. The ENSO Region 1+2 anomaly was +0.4°C and the Region 3.4 anomaly was +0.6°C for the week centered around December 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.56°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was +1.09 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.389. No significant stratospheric warming event appears likely through January 8, but warming will very likely develop in the upper stratosphere and approach or reach 5 mb toward the end of the first week of January. Wave 2 activity will remain relatively muted at 30 mb through most of the first week of January, but a moderate Wave 2 hit could occur at or above 10 mb leading to the upper stratospheric warming. Overall, most of the stratosphere is forecast to remain cold through the first week of January on the EPS. However, the upper stratospheric warming will need to be watched for possible downward propagation. On December 29, the MJO was in Phase 7 at an amplitude of 1.262 (RMM). The December 28-adjusted amplitude was 1.265. Since 1974, there were five cases when the MJO was in Phase 6 at an amplitude of 1.500 or above during the December 20-31 period, as has been the case this year. The temperature anomalies were closely tied to how much time the MJO spent in Phase 8 during that timeframe. The mean temperature for cases with more than 5 such days was 29.0° in New York City. The mean temperature for those with 5 or fewer such days was 36.1°. The overall 1981-2019 mean temperature for January 1-15 is 33.8°. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that December will wind up warmer than normal in New York City with a monthly mean temperature near 38.4°. At present, a warmer than normal January appears likely in the region.

Thanks for sharing this.

Unfortunately, yes.