donsutherland1

The latest ensemble guidance continues to suggest that the Arctic Oscillation (AO) will reach extreme positive values (probably +5.000 or above for the first time since March 8, 2015): Extreme AO+ situations typically lead to much above normal temperatures on the U.S. East Coast and in Europe. In large part, the consistent guidance suggesting the potential for an extreme AO+ event allowed for a high degree of confidence that the Middle Atlantic and southern New England regions would likely see a warmer to perhaps much warmer than normal February and that Europe would see a much warmer than normal February (with the warmest anomalies occurring in eastern Europe and western Russia). The cooler air that moves into Europe later this week will again yield to much warmer than normal conditions early next week. The GEFS Day 8-12 average 500 mb height anomalies forecast shows ridging on the East Coast and over much of Europe. The 8-12 day temperature average is warmer than normal in both areas. Finally, should the AO remain strongly positive through mid-month, the probability of significant snowfall in the Middle Atlantic region will be low during that period. Not surprisingly, the ECMWF, which had been showing a potentially major snowstorm during the second week of February has now backed off from that idea.

Afternoon thoughts... 1. The light rain that had been affecting parts of the region continues to move eastward, with most of the showers south of Long Island's South Shore. 2. New York City is solidly on track for a 40° or higher mean temperature for the first week of February. The most likely range is 42.0° (7th warmest) to 43.7° (3rd warmest). 3. A series of waves Wednesday night into Thursday and Thursday night into Friday will bring mainly rain to such cities as Baltimore, New York City, Newark, Philadelphia, and Washington, DC. Appreciable snow will be confined well north and west of the cities, particularly in an area running from central/upstate New York to northern New England. 4. Another system will move rapidly eastward off the Middle Atlantic coast and out to sea this weekend. Historic experience with the teleconnections and the emerging model consensus suggest that there is the potential for a light accumulation of snow in the above-mentioned cities. The risk of a significant (6" or greater snowfall) during the weekend is low.

Longer stretches are possible. For example, the 1949-50 through 1954-55 winters saw 6 consecutive winters where NYC received less than 20" snow. The average seasonal snowfall was just 14.6".

I hope we can get at least a moderate, if not significant snowfall, before winter concludes. It has been a painful winter so far.

Today saw widespread readings in the 50s and 60s in the Middle Atlantic region. High temperatures included: Atlantic City: 64°; Baltimore: 67° (old record: 66°, 1932); Bridgeport: 53°; Clarksburg, WV: 67° (old record: 66°, 1989); Islip: 53°; New York City: 57°; Newark: 58°; Philadelphia: 60°; Sterling: 67° (old record: 66°, 1991); Washington, DC: 63°; and, Wilmington, DE: 64° (tied record set in 1991). Across the Atlantic where winter has been largely absent, even greater warmth prevailed. Locations in France and Italy saw record daily highs and, in cases, February record high temperatures. Europe remains on track for a much warmer than normal February with the greatest warmth likely occurring in eastern Europe and western Russia. Tomorrow will be another unseasonably mild day. Overall, the first week of February will be much warmer than normal in the Middle Atlantic and southern New England areas. The February 1-7 mean temperature will likely average 40.0° or higher in New York City. Since 1869, New York City has had 10 prior cases where the temperature averaged 40.0° or above during the February 1-7 period. All 10 cases saw a warmer than normal February. The mean monthly temperature was 38.2°. Eight of those cases occurred during 1990 or later. Somewhat colder air could return late in the first week of February or just afterward. However, Arctic air is unlikely. In addition, no significant snowfalls (6" or above) are likely through at least the first week of February for Washington, DC to New York City and the surrounding region. Consistent with the pattern and supported by most of the guidance, a pair of storms will likely snowfall to parts of northern Pennsylvania, central and upstate New York, and northern New England Wednesday night and Thursday and Thursday night into Friday. The second storm will likely be the larger of the two. The major cities from Washington to New York City will likely see no more than a light accumulation from that storm. Another system could follow during the weekend. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.8°C for the week centered around January 29. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.07°C and the ENSO Region 3.4 anomaly has averaged +0.52°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -8.79 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.279. The guidance suggests that the AO could spend an extended period at or above +3.000 beginning during the second week of the month. Since 1950, none of the 36 days during which the AO was +3.000 or above saw daily snowfall of 1" or more in New York City or Philadelphia. During the overall February 5-20, 1950-2019 period, daily snowfall of 1" or more occurred on 8% days in New York City and 7% of days in Philadelphia. The biggest snowstorm during that timeframe when the AO was +3.000 or above was February 9-10, 1982. Boston picked up 4.0" snow; New York City received 0.3" snow; and, Philadelphia saw 0.6" snow. No significant stratospheric warming is likely through February 11. Wave 2 activity will dissipate following the first week of February. Overall, most of the stratosphere is forecast to remain cold on the EPS through into the second week of February. On February 2, the MJO was in Phase 5 at an amplitude of 0.593 (RMM). The February 1-adjusted amplitude was 0.623.

Groundhog Day was milder than normal across the region. However, even warmer temperatures prevailed in an area running from the Plains States to the Great Lakes region where numerous record high temperatures were toppled. Daily records included: Chicago: 52° (old record: 51°, 1992); Colorado Springs: 73° (old record: 66°, 1934); Denver: 74° (tied record set in 1934); Goodland, KS: 79° (old record: 72°, 1934); Indianapolis: 63° (old record: 61°, 2016); Madison: 51° (old record: 47°, 1987); Milwaukee: 56° (old record: 49°, 1992); Peoria: 61° (old record: 54°, 1920); St. Louis: 70° (old record: 66°, 2016); and, Wichita: 76° (old record: 73°, 1924). Kansas City had a high temperature of 65°, which missed the daily record of 69°, which was set in 1924 and tied in 1992. However, Kansas City was able to settle for a victory in Super Bowl LIV. Even milder air will push into the region tomorrow. Temperatures could peak well into the 50s during the first half of the work week in the Middle Atlantic and southern New England regions. As a result, the first week of February will be much warmer than normal in the Middle Atlantic and southern New England areas. The February 1-7 mean temperature will likely average 40.0° or higher in New York City. Since 1869, New York City has had 10 prior cases where the temperature averaged 40.0° or above during the February 1-7 period. All 10 cases saw a warmer than normal February. The mean monthly temperature was 38.2°. Eight of those cases occurred during 1990 or later. Somewhat colder air could return late in the first week of February or just afterward. However, Arctic air is unlikely. In addition, no significant snowfalls (6" or above) are likely through at least the first week of February for Washington, DC to New York City and the surrounding region. Consistent with the pattern and supported by most of the guidance, a storm will likely bring a moderate or significant snowfall to parts of northern Pennsylvania, central and upstate New York, and northern New England late this week. The major cities from Washington to New York City will likely see no more than a light accumulation from that storm. Another system could follow during the weekend. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was +0.3°C for the week centered around January 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°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 -13.59 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.857. The guidance suggests that the AO could spend an extended period at or above +3.000 beginning during the second week of the month. Since 1950, none of the 36 days during which the AO was +3.000 or above saw daily snowfall of 1" or more in New York City or Philadelphia. During the overall February 5-20, 1950-2019 period, daily snowfall of 1" or more occurred on 8% days in New York City and 7% of days in Philadelphia. The biggest snowstorm during that timeframe when the AO was +3.000 or above was February 9-10, 1982. Boston picked up 4.0" snow; New York City received 0.3" snow; and, Philadelphia saw 0.6" snow. No significant stratospheric warming is likely through February 10. Wave 2 activity will dissipate following the first week of February. Overall, most of the stratosphere is forecast to remain cold on the EPS through into the second week of February. On February 1, the MJO was in Phase 6 at an amplitude of 0.609 (RMM). The January 31-adjusted amplitude was 0.818.

I agree with your concerns, as well as thoughts for I-84 and northward. Over the next week or so, I think there remain opportunities for at least some snowfall, generally well north and west of PHL-EWR-NYC-BDR. I'm not confident in the EPS's idea that the AO will exceed +6.000 for multiple days. +3.000 and +4.000 seem likely. Have a great rest of the weekend.

Morning thoughts... 1. Much of the region saw little or no snow during the past 36 hours. The seasonal snow drought continues. 2. The AO remains forecast to rise to extreme positive levels after the first week of the month (> +5.000 on the EPS). 3. The day 10-15 mean 500 mb height anomalies on the EPS depict a ridge that extends over the southeast and below normal height anomalies over a broad expanse of below normal height anomalies that stretch from the Pacific Northwest, across much of Canada, and into northern Europe. 4. A cluster of February AO +4.000 or above cases had a similar hemispheric pattern, though the composite mean didn't stretch quite as far east into Scandinavia as is currently shown on the EPS. The 500 mb height anomalies and surface temperature anomalies for that subset are below: 5. Parts of the Northeast were shown as somewhat colder than normal with the Lower Mid-Atlantic and Southeast being warmer than normal. Most of Europe was warmer than normal. 6. Within a week, the cool anomalies in the Northeast, where they existed, yielded to warmer anomalies. Europe remained warm. 7. Overall, the ideas of a warmer to much warmer than normal February in the Middle Atlantic and southern New England regions and much warmer than normal (especially in eastern Europe and western Russia) would remain solidly on track if the forecast teleconnections and depicted pattern on the EPS verify.

With good agreement among the EPS and GEFS that the Arctic Oscillation (AO) will likely have an extended duration where it is at +3.000 or above, below are the Northern Hemisphere composite 500 mb and surface temperature anomalies for all February dates when the AO was +3.000 or above. February 1950-2019 cases with the AO of +3.000 or above (n=81 days): Warmth in the eastern United States and in much of Europe, an outcome that appears likely for February 2020, was associated with those dates. At the same time, only 1 of New York City's 6" or greater February snowstorms (1950-2019) occurred when the AO was at or above +3.000. Neither Philadelphia nor Washington, DC had any such storms with such a strongly positive AO.

The ongoing sea level rise may not seem apparent, as the sea level has been rising by millimeters per year. But over time, the rise is already playing out in an increased incidence of tidal flooding events. A useful paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5291542/pdf/pone.0170949.pdf

February began on a mild note as winter 2019-2020 remained remarkably moderate. In parts of the northern Rockies, temperatures soared to records. At Lewistown, MT, the temperature topped out at a springlike 70°, which tied that city's February record of 70°, which occurred on February 27, 1932. Even warmer weather lies ahead for the Middle Atlantic and southern New England regions in coming days. As a result, the first week of the month will be much warmer than normal in the Middle Atlantic and southern New England areas. The February 1-7 mean temperature will likely average 40.0° or higher in New York City. Since 1869, New York City has had 10 prior cases where the temperature averaged 40.0° or above during the February 1-7 period. All 10 cases saw a warmer than normal February. The mean monthly temperature was 38.2°. Eight of those cases occurred during 1990 or later. Somewhat colder air could return late in the first week of February or just afterward. However, Arctic air is unlikely. In addition, no significant snowfalls (6" or above) are likely through at least the first week of February for Washington, DC to New York City and the surrounding region. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was +0.3°C for the week centered around January 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°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 -15.27 today. Today, the preliminary Arctic Oscillation (AO) figure was +2.022. The guidance suggests that the AO could spend an extended period at or above +3.000 beginning during the second week of the month. Since 1950, none of the 36 days during which the AO was +3.000 or above saw daily snowfall of 1" or more in New York City or Philadelphia. During the overall February 5-20, 1950-2019 period, daily snowfall of 1" or more occurred on 8% days in New York City and 7% of days in Philadelphia. The biggest snowstorm during that timeframe when the AO was +3.000 or above was February 9-10, 1982. Boston picked up 4.0" snow; New York City received 0.3" snow; and, Philadelphia saw 0.6" snow. No significant stratospheric warming is likely through February 9. Upper stratospheric warming will peak just after the first week of February before slowly fading. Strong Wave 2 activity will occur during the first week of February driving the warming of the upper stratosphere, but then diminish. Overall, most of the stratosphere is forecast to remain cold on the EPS through into the second week of February. On January 31, the MJO was in Phase 5 at an amplitude of 0.809 (RMM). The January 30-adjusted amplitude was 1.133.

Stunning.

New York City's 9th warmest January on record concluded with another warmer than normal day and a monthly mean temperature of 39.1° (6.5° above normal). In addition, Boston (38.0°) had its 3rd warmest January; Newark (38.7°) had its 9th warmest January; and, Philadelphia (38.9°) had its 14th warmest January. January's notable warmth will be followed by a warmer to much warmer than normal February in the region. Exceptional February warmth has occurred in 3 of the last 10 winters in New York City: 2012: 40.9° mean temperature (3rd warmest) 2017: 41.6° mean temperature (2nd warmest) 2018: 42.0° mean temperature (1st warmest) February will start mild with the first week of the month winding up much warmer than normal in the Middle Atlantic and southern New England areas. The February 1-7 mean temperature could average 40.0° or higher, much as it did during the January 1-7 period. Somewhat colder air could return late in the first week of February or just afterward. However, Arctic air is unlikely. In addition, no significant snowfalls (6" or above) are likely through at least the first week of February for Washington, DC to New York City and the surrounding region. Tomorrow, a storm moving offshore will likely intensify rapidly as it moves into and through the waters off New England. However, little or no snow is likely for the New York City area. There remains some possibility that a light accumulation could occur over parts of Cape Cod. Based on the latest guidance, the likely seasonal snowfall distribution through January 31, will be < 20" at Boston; < 6" at New York City; < 3" at Philadelphia; and, < 2" at Washington, DC. There were 5 prior cases that met the above criteria for seasonal snowfall through January 31: 1895-96, 1918-19, 1931-32, 1949-50, and 1972-73. The single case with a colder than normal January (1895-96) saw 43.0" snow in the February-April period in New York City. All of the remaining four cases, all of which had a warmer than normal January, had less than 12.0" (mean: 4.6"; median 2.8"). Should blocking largely fail to develop in February, the risk of the very low snowfall for the remainder of winter 2019-20 would increase. For historical perspective, 6% of winters since winter 1869-70 had less than 10" seasonal snowfall in New York City. For winters that concluded February with less than 10" seasonal snowfall to date, one-third went on to see less than 10" seasonal snowfall. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was +0.3°C for the week centered around January 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°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. For February 1981-2019, the following monthly temperature averages were recorded for cases when the ENSO Region 3.4 anomaly averaged 0.00°C to +0.75°C: ENSO R1+2 Anomaly < 0: AO+: NYC: 36.9°; Philadelphia: 37.6° (n=101 dates); EPO+ subset: NYC: 40.5°; Philadelphia: 40.8° (n=57 dates) ENSO R1+2 Anomaly < 0: AO-: NYC: 34.7°; Philadelphia: 34.9° (n=97 dates) ENSO R1+2 Anomaly > 0: AO+: NYC: 35.7°; Philadelphia: 36.6° (n=82 dates); EPO+ subset: NYC: 41.2°; Philadelphia: 42.0° (n=18 dates) ENSO R1+2 Anomaly > 0: AO-: NYC: 30.9°; Philadelphia: 31.6° (n=58 dates) February 1981-2019: NYC: 35.8°; Philadelphia: 36.0° The SOI was -2.82 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.489. Upper stratospheric warming will commence near the beginning of February and continue through February 8. Strong Wave 2 activity will occur during the first week of February driving the warming of the upper stratosphere. Overall, most of the stratosphere is forecast to remain cold on the EPS through at least the first week of February. On January 30, the MJO was in Phase 6 at an amplitude of 1.131 (RMM). The January 29-adjusted amplitude was 1.101. Based on sensitivity analysis applied to the latest guidance, there is an implied 70% probability that February will be warmer than normal in New York City. There is a near 50% probability that February 2020 will rank among the 10 warmest February cases on record.

For those who are interested, the February and all-time AO+ record is +5.911, which was set on February 26, 1990.

In the case of winter 2006-07, February 2007 was much colder than normal in the Middle Atlantic and southern New England areas.

On Saturday, January 5, I noted that the idea of a warmer than normal winter has verified quite well in most areas with some exceptions. The main focus of that message concerned the increased likelihood of reduced snowfall amounts in parts of the East relative to what had been forecast. Now, as January concludes and two-thirds of meteorological winter have concluded, it its useful to look more closely at the details concerning the temperatures. Although the general idea of widespread warmth is on track, the magnitude of the warmth in areas has greatly exceeded the ideas cited. That includes eastern Canada, New England, the Middle Atlantic region, and parts of the Great Lakes region. One key error was the assumption of AO variability. Instead, the AO has been positive on 76% days so far and strongly positive on more than two-thirds of days during meteorological winter to date. Such an outcome in combination with a positive EPO tends to favor excessive warmth in parts of eastern North America, as has occurred. In contrast parts of western Canada and Alaska were colder to much colder than normal despite my thinking of warmth there. In large part, the early tendency for an EPO+ (which I thought would become more likely as the winter progressed) played a key role in that outcome. Below are the North American temperature anomalies for December 1, 2019 through January 29, 2020: Overall, the idea of widespread warmth was a good one. But no meaningful skill was shown when it came to delineating the magnitude of the warmth. Barriers to seasonal forecasting at a level of detail exist, because some of the key variables (particularly select teleconnections) cannot yet be forecast reliably beyond two weeks. Additional variables such as the risk of sudden stratospheric warming (SSW) events (none have occurred so far this winter) that could have a large impact cannot be forecast very well, in part because the dynamics are not well-understood. While a connection between wave-breaking (particularly Wave 2 exists), most such waves neither displace nor split the polar vortex and most don't lead to dramatic warming events that propagate downward. In addition, SSW events can also be driven from bottom-up in response to sustained periods of strong Atlantic blocking. These barriers likely explain part of the reason that the C3S multi-system seasonal forecast also significantly missed the magnitude of the warmth, even as its outlook was warmer than normal across much of North America. The three-month CFSv2 forecast for December-February from November (November 1-10 initial conditions) was more in line with CONUS temperature anomalies, but showed widespread cold in Canada and warmth in western Canada/Alaska. However, the forecast from the November 21-30 initial conditions had significantly trimmed the CONUS warmth.

Morning thoughts... 1. The Arctic Oscillation is now rebounding. Today's preliminary value was +1.489. The ensembles are in strong agreement that the AO will rise above +3.000 by the end of the first week of February. 2. No significant snowfalls (6" or greater) appear likely through at least the first week of February and possibly the first half of the month. Despite model mirages of digital snow that may pop up from time to time in the extended range, the forecast pattern (and patterns associated with strong AO+/PNA- setups) is inconsistent with those associated with significant or major snowstorms in the northern Middle Atlantic region. 3. February is poised to be warmer to possibly much warmer than normal. On the table is the possibility that New York City's 9th warmest January will be followed by a February that also rank among the 10 warmest on record. Prior cases with such an outcome were 1990, 1998, and 2002. 4. February snowfall amounts for those three cases were 1.8", 0.0", and Trace respectively. That would represent a reasonable worst-case idea. Nevertheless, it is likely that the month will feature below to perhaps much below normal snowfall for the snow-starved Middle Atlantic region. 5. Things could be worse. In Europe, where winter has been largely absent, January was concluding with another round of record warmth. Daily records included: Bonn: 59° (old record: 55°); Dresden: 54° (old record: 48°); Lyon: 63° (old record: 57°); Tenerife, Spain: 79° (old record: 71°); and, Zurich: 57° (old record: 55°). February will very likely be much warmer than normal in Europe, particularly in eastern Europe and western Russia.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 3.5 3.2 2.7 1.5 1.6 0.7 0.2 0.3 -1.0

There's a big difference between pointing out that the impacts of greenhouse gas forcing are influencing the hemispheric circulation (as noted in a growing body of literature), along with other aspects of internal variability, and making the claim that the ultimate outcome will be the disappearance of the NAO- (no literature that I am aware of supports such a claim, though there is some literature suggesting a somewhat greater frequency of the NAO+ state due, in part, to ocean-cryosphere-atmosphere changes).

Despite a slightly colder than normal to near normal day across the region, what will very likely become the 9th warmest January on record in New York City is now concluding. February will start mild with the first week of the month winding up warmer to perhaps much warmer than normal in the Middle Atlantic and southern New England areas. In a taste of deja vu, the February 1-7 mean temperature could average 40.0° or higher, much as it did during the January 1-7 period. In addition, little or no snow is likely in New York City, Newark, Philadelphia, and Washington, DC into at least the middle of the first week of February. Much of the Middle Atlantic and southern New England regions have seen below or much below normal seasonal snowfall to date. Seasonal snowfall totals to date include: Albany: 35.3" (1.1" above normal) Baltimore: 1.8" (8.1" below normal) Boston: 14.6" (7.8" below normal) Bridgeport: 10.1" (3.1" below normal) Hartford: 25.3" (4.4" above normal) Islip: 6.8" (5.6" below normal) New York City: 4.8" (7.0" below normal) Newark: 6.9" (6.5" below normal) Philadelphia: 0.3" (9.6" below normal) Providence: 11.6" (7.0" below normal) Washington, DC: 0.6" (7.6" below normal) Somewhat colder air could return late in the first week of February or just afterward. However, Arctic air is unlikely. During the coming weekend, a storm moving offshore will likely intensify rapidly as it moves into the waters off New England. However, little or no snow is likely for the New York City area. There remains some possibility that a light accumulation could occur over parts of Cape Cod. Based on the latest guidance, the likely seasonal snowfall distribution through January 31, will be < 20" at Boston; < 6" at New York City; < 3" at Philadelphia; and, < 2" at Washington, DC. There were 5 prior cases that met the above criteria for seasonal snowfall through January 31: 1895-96, 1918-19, 1931-32, 1949-50, and 1972-73. The single case with a colder than normal January (1895-96) saw 43.0" snow in the February-April period in New York City. All of the remaining four cases, all of which had a warmer than normal January, had less than 12.0" (mean: 4.6"; median 2.8"). Should blocking largely fail to develop in February, the risk of the very low snowfall for the remainder of winter 2019-20 would increase. The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was +0.3°C for the week centered around January 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.10°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. For February 1981-2019, the following monthly temperature averages were recorded for cases when the ENSO Region 3.4 anomaly averaged 0.00°C to +0.75°C: ENSO R1+2 Anomaly < 0: AO+: NYC: 36.9°; Philadelphia: 37.6° (n=101 dates); EPO+ subset: NYC: 40.5°; Philadelphia: 40.8° (n=57 dates) ENSO R1+2 Anomaly < 0: AO-: NYC: 34.7°; Philadelphia: 34.9° (n=97 dates) ENSO R1+2 Anomaly > 0: AO+: NYC: 35.7°; Philadelphia: 36.6° (n=82 dates); EPO+ subset: NYC: 41.2°; Philadelphia: 42.0° (n=18 dates) ENSO R1+2 Anomaly > 0: AO-: NYC: 30.9°; Philadelphia: 31.6° (n=58 dates) February 1981-2019: NYC: 35.8°; Philadelphia: 36.0° The SOI was +7.78 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.489. Upper stratospheric warming will commence near the beginning of February and continue through February 7. Strong Wave 2 activity will occur during the first week of February driving the warming of the upper stratosphere. Overall, most of the stratosphere is forecast to remain cold on the EPS through at least the first week of February. On January 29, the MJO was in Phase 6 at an amplitude of 1.090 (RMM). The January 28-adjusted amplitude was 0.807. Based on sensitivity analysis applied to the latest guidance, New York City has an implied near 100% probability of a warmer than normal January. The monthly mean temperature could finish near 39.1° in New York City. That would surpass the 38.6° monthly temperature from 1949 to make 2020 the 9th warmest January on record. The evolution of ENSO in combination with an AO+/EPO+ base state suggests that February will wind up warmer than normal in the Middle Atlantic region. Below normal snowfall is increasingly likely during February.

I'm not sure what impact the fires had, but will be looking to read papers that may be published on the topic. On the latter point, there is literature that suggests that the MJO is starting to spend increasing time in Phases 4-6 in response to changing oceanic heat content and SSTAs. I suspect that we will see such outcomes grow more frequent as the underlying factors driving that situation are persisting, namely continuing greenhouse gas emission increases.

The impact of greenhouse gas forcing on internal variability is becoming an increasingly researched area. One example from recent research: https://ui.adsabs.harvard.edu/abs/2017AGUFMGC41A1002M/abstract

November 15, 2018: 6.4"

Internal variability is occurring within the context of increased greenhouse gas forcing and its consequences. Almost certainly this interaction is leading to changes in patterns, pattern tendencies, and pattern evolution.

Great find. IMO, those who assume a static climate put themselves at greater risk of error in extended range and subseasonal forecasting where the risk of error is already high. The paper to which you posted a link referencing a longer residence of the MJO in the Maritime Continent phases is but one example. Bamwx deserves a lot of credit for being open to what the evidence is suggesting, even if it means changing forecasting approaches and questioning the premises deployed in making forecasts.