donsutherland1

At 11:10 am, snow had moved into Charlottesville. Ahead of the snow, temperatures had risen into the middle 40s in Atlantic City (45°), Baltimore (45°), and Washington, DC (45°). As precipitation arrives this afternoon, temperatures at those locations should fall. Therefore, rain should change to snow. The 12z GFS has come in a little snowier. The 12z RGEM was fairly consistent with the 0z ECMWF. The HRRR is not impressed with the system. Widespread 2"-3" amounts appear possible just to the west of the Baltimore-Washington corridor. As the storm deepens, some periods of moderate snow could also impact eastern Long Island. The potential for a narrow area of 1"-3" amounts in part of New Jersey exists. Therefore, I made some minor adjustments. Overall, my thinking concerning snowfall amounts remains similar to that of last evening: Atlantic City: 1" or less Baltimore: 1"-3" Harrisburg: 1" or less Islip: 1" or less New York City: 0.5" or less Newark: 0.5" or less Philadelphia: 1" or less Sterling: 1"-3" Washington, DC: 1"-3" Wilmington, DE: 1"-2"

Absolutely. That is correct.

December 2019 Temperature Anomalies:

The forecast 500 mb pattern on the 1/7/2020 0z NAM has some similarities to that which was present on January 20-21, 1994. Snowfall amounts on January 20, 1994 were as follows for select locations: Atlantic City: 0.2"; Baltimore: 3.1"; New York City: None; Philadelphia: 0.2"; and, Washington, DC: 1.9". At that time, a bitter Arctic air mass covered the East. This time around, that won't be the case. So, snowfall amounts will likely be lighter in Baltimore and Washington than they were back in 1994. At present, taking into consideration the latest guidance and the forecast 500 mb pattern with some modifications, likely snowfall amounts for the January 7-8 system for the Middle Atlantic region include: Atlantic City: 1" or less Baltimore: 1"-2" Harrisburg: 1" or less Islip: 0.5" or less New York City: 0.5" or less Newark: 0.5" or less Philadelphia: 1" or less Sterling: 1"-3" Washington, DC: 1"-2" Wilmington, DE: 1"-2"

A weak disturbance coated parts of the region with snow earlier today. Snowfall amounts included: Basking Ridge, NJ: 0.8"; Bridgeport: Trace; Islip: Trace; New York City: 0.2"; and, Newark: 0.9". Following the light snowfall, temperatures rose into the middle 40s. It is now all but certain that New York City will have a mean temperature of 40° or above during the first week of the month. Since 1869, there were 23 cases when the first week of January had a mean temperature of 40° or above in New York City. In 17 (74%), January wound up warmer than normal and in 12 (52%), January had a mean temperature of 35° or above. The average monthly temperature for January for all 23 cases was 36.0° (median temperature: 35.6°). A short-duration fairly sharp cold shot is possible Wednesday and Thursday. Ahead of the cold shot, a system will likely bring precipitation to the region from tomorrow into Wednesday. Parts of the area could pick up a light snowfall, though most of the region will likely see little or no accumulation. A greater chance for 2" or more snow exists for parts of Virginia, Maryland, Delaware, and southern New Jersey. The light snowfall scenario is consistent with historic experience during very strong AO+ patterns during the first half of January. 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). Following the brief cold shot, ridging with warmer than normal temperatures will develop and persist through at least mid-month. Beyond that, there is the potential that the closing part of the month could see a colder pattern develop. The progression of the MJO and state of the teleconnections will determine the pattern evolution for the second half of the month. Despite continuing 500 mb differences in the extended range, there remains strong consensus between the EPS and GEFS that the PNA will remain negative to strongly negative past mid-month. Such a scenario would lead to a continuation of a generally mild pattern beyond mid-month. Transient cold shots would be possible. A PNA- typically translates in warm anomalies in the Middle Atlantic region. For the January 16-31, 1981-2019 period, the mean temperature for New York City and Philadelphia was 32.2° and 32.1° respectively. When the PNA was negative, those values were 34.2° and 34.1° respectively. The coldest mean temperatures for PNA- periods occurred when the EPO and AO were both negative (New York City: 29.1° and Philadelphia: 28.9°). The warmest occurred when the EPO and AO were both positive (New York City: 37.9° and Philadelphia: 37.5°). The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around January 1. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°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 +18.61 today. That is the highest SOI figure since August 10, 2019 when the SOI was +20.15. Today, the preliminary Arctic Oscillation (AO) figure was +3.126. No significant stratospheric warming event appears likely through January 14, several short periods of warming appear likely to develop in the upper stratosphere and then to approach or reach 5 mb over the next 10 days before fading. Wave 2 activity will remain relatively muted following the first week of the month except in the upper stratosphere where it will trigger the warming principally above 5 mb. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 5, the MJO was in Phase 3 at an amplitude of 0.904 (RMM). The January 4-adjusted amplitude was 0.405. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 81% probability of a warmer than normal January.

I don't think one will have to wait until February 15, mainly for two reasons: 1. Since 1974, the overwhelming majority (88%) of cases that saw the MJO peak in Phase 4 at an amplitude of 1.500 or above during the January 5-15 period progressed to Phases 7 and 8. Until the MJO plots are within 7 days or so, I believe the base case is just such a progression. 2. The impact of strong AO+/PNA- regimes on the hemispheric pattern can take some time to wind down (majority of such cases). But once they do, a sustained period of troughing in the means often develops for the East (February 1993 is one example). Those that rapidly collapse often see a temporary period of troughing followed by a return to the predominant AO+/PNA-/ridge in the East pattern (February 2000 is one example). So, at least for now, relying on the above, I think the base case is a warmer than normal January 16-31 period, but not as warm relative to normal as the January 1-15 period. Attempts at developing a trough in the East prior to at least January 20 will probably be short-lived. The closing week of January could turn colder. Afterward, the cold could generally prevail for perhaps at least the first half of February.

The extended range of the 12z GEFS is almost the opposite of what one would want to see if one is looking for sustained cold. More than likely, one is dealing with what will be a slow transition toward sustained cold (probably taking place during the last week of January). I've labeled what one would like to see as opposed to what the GEFS shows.

Based on the latest radar and the most recent guidance, snow showers still appear on track to affect the New York City area tonight into perhaps the first part of tomorrow morning. Numerous areas, especially outside the City, could pick up a coating of snow. Even Central Park could pick up a few tenths of an inch of snow if some of the guidance is accurate. The lack of a significant snowfall fits a strong AO+ pattern in January. Below are the percentages of days on which 2" or more snow fell in New York City during the January 1-31, 1981-2019 period: All dates (n=1209): 4.1% AO < 0 (n=617): 4.7% AO +2.000 or above (n=164): 1.8% AO +3.000 or above (n=81): 0.0% The January 5 AO was +3.302.

Seasonal snowfall forecast, season-to-date snowfall and anomalies (through 1/5) for select cities: Albany: Forecast: 60"-70"; 30.2" (10.6" above normal) Baltimore: Forecast: 10"-20"; 0.3" (3.8" below normal) Binghamton: Forecast: 80"-90"; 28.9" (0.9" above normal) Boston: Forecast: 30"-40"; 11.5" (0.9" below normal) Burlington: Forecast: 80"-90"; 27.9" (1.2" above normal) Chicago: Forecast: 25"-35"; 10.8" (0.4" below normal) Detroit: Forecast: 30"-40"; 12.9" (0.3" below normal) New York City: Forecast: 20"-30"; 2.5" (3.6" below normal) Newark: Forecast: 20"-30"; 4.2" (2.8" below normal) Philadelphia: Forecast: 10"-20"; 0.1" (4.4" below normal) Providence: Forecast: 25"-35"; 8.0" (3.6" below normal) Washington, DC: Forecast: 7"-17"; 0.4" (3.0" below normal)

In the wake of a frontal passage, today saw readings top out in the lower 40s, along with a gusty wind. Overnight a weak disturbance could touch off some snow showers. A coating of snow is possible in some areas, especially outside New York City. New York City will very likely have a mean temperature of 40° or above during the first week of the month. Since 1869, there were 23 cases when the first week of January had a mean temperature of 40° or above in New York City. In 17 (74%), January wound up warmer than normal and in 12 (52%), January had a mean temperature of 35° or above. The average monthly temperature for January for all 23 cases was 36.0° (median temperature: 35.6°). A short-duration fairly sharp cold shot is possible during mid-week. Ahead of the cold shot, a system will likely bring precipitation to the region from Tuesday into Wednesday. Parts of the area could pick up a light snowfall, though most of the region will likely see little or no accumulation. A greater chance for somewhat higher accumulations of snow exists for eastern New England, especially Cape Cod, and perhaps southeast New Jersey. The light snowfall scenario is consistent with historic experience during very strong AO+ patterns during the first half of January. 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). Following the brief cold shot, ridging with warmer than normal temperatures will develop and persist through at least mid-month. Beyond that, the progression of the MJO and state of the teleconnections will determine the pattern evolution for the second half of the month. Despite 500 mb differences in the extended range, there remains strong consensus between the EPS and GEFS that the PNA will remain negative to strongly negative past mid-month. Such a scenario would lead to a continuation of a generally mild pattern beyond mid-month. Transient cold shots would be possible. A PNA- typically translates in warm anomalies in the Middle Atlantic region. For the January 16-31, 1981-2019 period, the mean temperature for New York City and Philadelphia was 32.2° and 32.1° respectively. When the PNA was negative, those values were 34.2° and 34.1° respectively. The coldest mean temperatures for PNA- periods occurred when the EPO and AO were both negative (New York City: 29.1° and Philadelphia: 28.9°). The warmest occurred when the EPO and AO were both positive (New York City: 37.9° and Philadelphia: 37.5°). 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 +18.52 today. That is the highest SOI figure since August 10, 2019 when the SOI was +20.15. Today, the preliminary Arctic Oscillation (AO) figure was +3.302. No significant stratospheric warming event appears likely through January 13, several short periods of warming appear likely to develop in the upper stratosphere and then to approach or reach 5 mb over the next 10 days. Wave 2 activity will remain relatively muted following the first week of the month except in the upper stratosphere where it will trigger the warming principally above 5 mb. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 4, the MJO was in Phase 3 at an amplitude of 0.407 (RMM). The January 3-adjusted amplitude was 0.322. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 79% probability of a warmer than normal January.

Ahead of a strong cold shot, a system will likely bring precipitation to the region from Tuesday into Wednesday. Parts of the area could pick up a light snowfall (likely less than 2" for much of the region). A greater chance for a moderate accumulation of snow (4" or more) exists for eastern New England, southeastern New Jersey, and eastern Long Island on account of the storm's beginning to intensify as it moves offshore toward the New England coastal waters. A light snowfall scenario for the Philadelphia, Newark, and New York City areas is consistent with historic experience during very strong AO+ patterns during the first half of January. The 6z NAM was an outlier with both its 0z run and the other guidance. The 12z NAM corrected back toward the consensus.

Overnight, the EPS and GEFS moved farther apart in the extended range with their 500 mb forecasts. For the GEFS, it is "Groundhog Day." Nothing more needs to be said about its forecast. The EPS begins to elongate the Aleutian High, until it reaches the Pacific Northwest. As a result, the trough over the west gets pushed eastward and the ridge in the East gets pushed eastward, as well. For now, I continue to suspect that the pattern change will be more gradual than what is shown on the 0z EPS, especially as the EPS continues to forecast a negative PNA (perhaps a measure of some discontinuity with its 500 mb maps). The last week of January could turn colder. The progression of the MJO and state of the teleconnections will be important. Twin "nightmare" scenarios for consideration: 1. The GEFS scores a "win." Efforts to knock down the ridge are quickly followed by a recovery of the ridge and the ridge remains resilient through the remainder of the month. 2. The pattern abruptly changes as the above normal height anomalies are rapidly elongated. However. the pattern change is short-lived as a fast Pacific jet leads to the above normal height anomalies eventually stretching across the CONUS leaving the below normal height anomalies over Canada and perhaps northern New England. The underlying assumption is the continued strength of the polar vortex with a persistent AO+. Interestingly enough, at 500 mb, both the EPS and GEFS remain in agreement over the fate of Europe. There, the unwelcome above-to-much above normal height anomalies will persist through the end of their forecast.

Parts of the region, especially north and west of NYC, could see some snow showers and flurries overnight.

Temperatures rose into the lower 50s across the New York Metro Area and nearby suburbs today. New York City will very likely have a mean temperature of 40° or above during the first week of the month. Since 1869, there were 23 cases when the first week of January had a mean temperature of 40° or above in New York City. In 17 (74%), January wound up warmer than normal and in 12 (52%), January had a mean temperature of 35° or above. The average monthly temperature for January for all 23 cases was 36.0° (median temperature: 35.6°). A short-duration cold shot is possible after the first week of January. A small window of opportunity for at least some snowfall in the region and especially across central/upstate New York and New England could exist until around January 10. 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 prior to January 10. 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. Afterward, the progression of the MJO and state of the teleconnections will determine the pattern evolution for the second half of the month. Right now, there is strong consensus between the EPS and GEFS that the PNA will remain negative to strongly negative past mid-month. That typically translates in warm anomalies in the Middle Atlantic region. For the January 16-31, 1981-2019 period, the mean temperature for New York City and Philadelphia was 32.2° and 32.1° respectively. When the PNA was negative, those values were 34.2° and 34.1° respectively. The coldest mean temperatures for PNA- periods occurred when the EPO and AO were both negative. The warmest occurred when the EPO and AO were both positive. 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 +11.50 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.040. No significant stratospheric warming event appears likely through January 12, several periods of warming appear likely to develop in the upper stratosphere and approach or reach 5 mb over the next 10 days. Wave 2 activity will remain relatively muted following the first week of the month except in the upper stratosphere where it will trigger the warming principally above 5 mb. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 3, the MJO was in Phase 1 at an amplitude of 0.331 (RMM). The January 2-adjusted amplitude was 0.512. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 79% probability of a warmer than normal January.

Light rain and drizzle gave way to fog as temperatures rose into the lower 50s this afternoon. Two photos:

I've always favored political reforms aimed at full disclosure that eliminates "dark money." All donors and amounts should be transparent so that the electorate can make an informed judgment. Hopefully, that issue will be addressed in the not-too-distant future. Lobbying is a trickier issue. At present, it is protected under the First Amendment. Individuals can come together in various ways to engage in the political process. Enforcement issues could also arise, as what would stop a Senator, for example, from meeting with CEOs of various companies doing business in his/her State. Barring participation of those who have potential conflicts of interest from serving on regulatory agencies would be an easier and almost certainly constitutional fix. The regulatory process allows input from all parties, so all parties have a fair chance to make their case.

There are several suboptimal reactions that have occurred (based largely on policy changes, Social Media activity of those within or aligned with the current Administration): 1. A small number increasingly accept the evidence for climate change, but they have little clout. 2. Some choose to impose the artificial constraint of "helplessness." From there standpoint, there's nothing that can be done. Thus, they find comfort in maintaining a business as usual course. 3. Others continue to reject scientific understanding of climate change. Part of this group rejects the scientific basis outright. Others take a more sophisticated approach in their denialism by consistently downplaying its impacts, amplifying uncertainties far beyond the narrow areas in which they exist, and pointing to forcings to be discovered/determined later that are natural. Some disguise their denialism with caveats, essentially stating/writing: "Anthropogenic climate change is real but..." What follows the conjunction is a defense of the status quo, doing nothing, discrediting climate scientists, etc.

As the world's largest ocean, most of the world's oceanic heat content is there. That's why what happens in the Pacific region can have global consequences. Extreme developments in the Atlantic can also have a global impact, at times, but the Atlantic's overall influence is notably less than that of the Pacific.

The GEFS has continued to shift toward a higher amplitude passage through the Maritime Continent. I suspect that's part of the reason the 6z GEFS showed a fleeting flattening of the ridge and then its rebound in the extended range.

I don't disagree that some societal-level changes will be needed/will occur if society makes a credible move toward a carbon neutral status. However, that should not mean that living standards must automatically deteriorate in a material fashion. If that becomes the cost, society will almost certainly choose adaptation. Ultimately, though, fossil fuels are not renewable, so a post-fossil fuel era will arrive. Hopefully, the changes will be made in a timely fashion to mitigate the worst of the anthropogenic warming, but so far with a few small exceptions e.g., New Zealand, the world remains largely on autopilot, even in countries that have devoted bold rhetoric to the issue of climate change. Policy changes matter far more than words.

There remains broad agreement among the ECMWF, GEFS, and bias-corrected GEFS that the MJO will be progressing to Phase 4 at an amplitude in excess of +1.500. Afterward, it should progress into Phase 5. The result will be a pattern that favors ridging in the means from January 10-17 and perhaps somewhat longer. Afterward, if past cases of such high amplitude MJO passages through Phase 4 during the January 5-20 period are representative, it should move toward and likely into Phases 7 and 8, if only for a short time. In a majority of cases, the 500 mb pattern changes dramatically to one that favors a ridge in the West and trough in the East. However, in a not insignificant cluster of cases, the pattern adjusts somewhat, but ridging continues to predominate in the East. 15-day Mean 500 mb Anomalies for the period beginning 10 days after the MJO Peaks in Phase 4 at an amplitude of +1.500 or above during the January 5-20 period: One teleconnection appears to offer insight into how the pattern will evolve. All of the cases that went into the cluster that saw ridging persist in the East had a PNA that remained persistently and predominantly negative.

Time will tell whether Gupta's hypothesis has merit. The younger generations are far more engaged and, quite frankly more knowledgeable about climate change, than many of their parents' and grandparents' generation. They understand the implications of a status quo approach. Polling outcomes and engagement on the issue provide evidence toward that end. They have become the leading advocates for addressing climate change. It's premature to speculate much about their impact once they gain policy making influence, but my hypothesis is that they will move more aggressively than today's leaders. Moreover, they will make some decisive choices that impinge on the policy preferences of those who back the status quo.

New Research: AMO, PDO Appear not to Exist... The Atlantic Multidecadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO) do not appear to exist, according to a team of meteorologists who believe this has implications for both the validity of previous studies attributing past trends to these hypothetical natural oscillations and for the prospects of decade-scale climate predictability. Using both observational data and climate model simulations, the researchers showed that there was no consistent evidence for decadal or longer-term internal oscillatory signals that could be differentiated from climatic noise—random year to year variation. The only verifiable oscillation is the well-known El Niño/Southern Oscillation (ENSO). "A distinct—40 to 50 year timescale—spectral peak that appears in global surface temperature observations appears to reflect the response of the climate system to a combination of anthropogenic and natural forcing rather than any intrinsic internal oscillation," the researchers report today (Jan. 3) in Nature Communications. https://phys.org/news/2020-01-atlantic-pacific-oscillations-lost-noise.html The paper can be found at: https://www.nature.com/articles/s41467-019-13823-w

Temperatures continued to run above normal in the region. In the Southeast, record high temperatures were tied and toppled. Select records there included: Jacksonville: 85° (tied January record set on January 30, 2013); Pensacola: 79°; Savannah: 80°; and, Wilmington, NC: 77° (tied daily record). Some of this warmth will push northward for a day tomorrow. Readings could soar into the middle and even upper 60s in such cities as Baltimore and Washington and into the middle 50s into southern New England. The first week of the month remains on track to average 5° or more above normal across much of the region. New York City will likely have a mean temperature of 40° or above. Since 1869, there were 23 cases when the first week of January had a mean temperature of 40° or above in New York City. In 17 (74%), January wound up warmer than normal and in 12 (52%), January had a mean temperature of 35° or above. The average monthly temperature for January for all 23 cases was 36.0° (median temperature: 35.6°). A short-duration cold shot is possible after the first week of January. A small window of opportunity for at least some snowfall in the region and especially across central/upstate New York and New England could exist until around January 10. 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. Afterward, the progression of the MJO and state of the teleconnections will determine the pattern evolution for the second half of the month. Right now, there is strong consensus between the EPS and GEFS that the PNA will remain negative to strongly negative past mid-month. That typically translates in warm anomalies in the Middle Atlantic region. For the January 16-31, 1981-2019 period, the mean temperature for New York City and Philadelphia was 32.2° and 32.1° respectively. When the PNA was negative, those values were 34.2° and 34.1° respectively. The coldest mean temperatures for PNA- periods occurred when the EPO and AO were both negative. The warmest occurred when the EPO and AO were both positive. 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 -7.34 today. Today, the preliminary Arctic Oscillation (AO) figure was +2.949. No significant stratospheric warming event appears likely through January 12, several periods of warming appear likely to develop in the upper stratosphere and approach or reach 5 mb over the next 10 days. 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 2, the MJO was in Phase 8 at an amplitude of 0.516 (RMM). The January 1-adjusted amplitude was 0.558.

I agree. While most cases where the MJO reached Phase 4 at very high amplitude during January 5-20 progressed to Phases 7 and 8, there were a cluster of such cases where ridging on the East Coast persisted in the means in the period 10-25 days after the MJO peaked in Phase 4. January 1990 is one such example. The cluster is sufficiently large relative to the whole sample that the scenario cannot be dismissed just yet. If it plays out, then the second half of January would wind up warmer than normal overall, even if colder air arrives late in the month.