donsutherland1

Yes, March 1992 was snowy (9.4” in NYC).

Below are the 500 mb maps (GEFS forecast and February 1-10, 1992): During February 1-10, 1992 the MJO was in Phase 1 (low amplitude by February 4). By February 12, it moved into Phase 4, quickly attaining an amplitude of 1.000 or above. For much of the rest of the month, it was locked between Phases 4 and 5. The February 1-15 mean temperature in New York City was 30.9° and in Philadelphia it was 32.5°. The February 16-29 mean temperature in New York City was 42.2° and in Philadelphia it was 42.9°. For now, this outcome should be seen as a potential alternative scenario should a colder pattern fail to take hold. The evolution of the teleconnections and progression of the MJO will provide insight.

Gusty winds ushered a colder air mass into the region. As the colder air arrived, parts of the region saw some rain and snow showers. Tomorrow will be much colder than today. The temperature could even fall into the teens in New York City on Saturday morning. Afterward, even as moderation should follow for a time, the cold will likely return during the closing week of the month. At that point, the cold could become sustained and it could continue into at least the first week of February. On Saturday a system could bring New York City and Newark its first measurable snowfall since January 6. Philadelphia could receive its first measurable snowfall since December 11. Snowfall estimates for select locations are: Albany: 3"-6" Binghamton: 3"-6" Boston: 2"-4" Bridgeport: 1"-3" Islip: 2" or less New York City: 1"-3" Newark: 1"-3" Philadelphia: 2" or less Poughkeepsie: 3"-6" Scranton: 3"-6" With a mean temperature of 42.7° during January 1-15, 2020 ranked as the 6th warmest such period on record in New York City. Since 1869, just 2/13 (15%) cases (2000 and 2005) that saw the temperature average 40.0° or above during January 1-15 went on to have a colder than normal January. The mean monthly temperature for those 13 cases was 37.2°. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.5°C for the week centered around January 8. 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 +0.50°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -13.00 today. Today, the preliminary Arctic Oscillation (AO) figure was +2.445. No significant stratospheric warming event appears likely through January 24. Wave 2 activity will remain relatively suppressed. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 15, the MJO was in Phase 6 at an amplitude of 3.048 (RMM). The January 14-adjusted amplitude was 3.240. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were three January cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period as a whole would be colder than normal overall. However, uncertainty about the extended range has recently increased. The mean 500 mb pattern forecast for the closing 5 days of January on the January 16, 2020 12z and 18z GEFS has some similarities to the February 1-10, 1992 pattern in the Northern Hemisphere. February 1-10, 1992 was colder than normal in the East, but the remainder of February was warmer to much warmer than normal across much of the CONUS. Although such an outcome is not yet the most likely one, the probability of such a scenario could increase should ENSO Region 1+2 warm during the closing half of January. In addition, an MJO in Phase 7 at an amplitude of 2.000 or above typically sees measurable snowfall consistent with overall January 16-31 climatology. That would imply approximately 2 measurable snow events for Philadelphia to New York City and 2-3 such events for Boston during the closing two weeks of January. The first such event should occur this coming weekend. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 89% probability of a warmer than normal January. The monthly mean temperature could finish near 36.0° in New York City.

By now, the above normal height anomalies shown on the closing days of the operational ECMWF have likely gained notice. Those height anomalies and the accompanying temperature rebound are well-supported. The 12z GEFS is in good agreement with the 12z operational ECMWF at 240 hours. However, by the end of the GEFS run, the area of above normal height anomalies retrogrades toward western Canada and a trough takes shape in the East. My thinking has been and, at least for now, remains as noted in my nearly daily discussions of the longer-term pattern evolution: During the coming weekend, colder temperatures are likely. The temperature could even fall into the teens in New York City on Saturday morning. Afterward, even as moderation should follow for a time, the cold will likely return during the closing week of the month. At that point, the cold could become sustained and it could continue into at least the first week of February. Obviously, the situation bears watching. At least for me, I will need to see more evidence that the change is not a temporary period of moderation (highlighted above) during a transition toward a more sustained period of cold. The evolution of the teleconnections and progression of the MJO will provide insight over the next week. If people want something gloomy to consider, January 1-15, 1998 had a mean temperature of 43.3° (2020 was 42.7°) in New York City. February 1998 went on to have a mean temperature of 40.6°. If people want something more appealing to consider, January 1-15, 1907 had a mean temperature of 43.5°. February 1907 had a mean temperature of 25.9° and monthly snowfall of 21.8".

December 2015 would have tied 1999 as the 9th warmest November on record.

oday again saw temperatures run above normal. In the Southeast, near record and record warmth prevailed. However, the prevalent pattern that saw New York City record a mean temperature of 42.7° during January 1-15 (6th warmest on record going back to 1869) is coming to a close. Winter has not been canceled. During the coming weekend, colder temperatures are likely. The temperature could even fall into the teens in New York City on Saturday morning. Afterward, even as moderation should follow for a time, the cold will likely return during the closing week of the month. At that point, the cold could become sustained and it could continue into at least the first week of February. In addition, on Friday night and Saturday a system could bring New York City and Newark its first measurable snowfall since January 6. Philadelphia could receive its first measurable snowfall since December 11. Initial snowfall estimates are: Albany: 3"-6" Binghamton: 3"-6" Boston: 2"-4" Bridgeport: 1"-3" Islip: 2" or less New York City: 1"-3" Newark: 1"-3" Philadelphia: 1"-3" Poughkeepsie: 3"-6" Scranton: 3"-6" The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.5°C for the week centered around January 8. 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 +0.50°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -11.63 today. Today, the preliminary Arctic Oscillation (AO) figure was +3.622. The AO had a preliminary average of +3.560 during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000. No significant stratospheric warming event appears likely through January 23. Wave 2 activity will remain relatively suppressed. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 14, the MJO was in Phase 5 at an amplitude of 3.258 (RMM). The January 13-adjusted amplitude was 3.554. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into at least the start of February. Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were three January cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period would be colder than normal overall. In addition, an MJO in Phase 7 at an amplitude of 2.000 or above typically sees measurable snowfall consistent with overall January 16-31 climatology. That would imply approximately 2 measurable snow events for Philadelphia to New York City and 2-3 such events for Boston during the closing two weeks of January. The first such event should occur this coming weekend. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 84% probability of a warmer than normal January. The monthly mean temperature could finish near 36.0° in New York City. Finally, the latest C3S multi-system forecast suggests that the February-April temperature will likely be somewhat warmer than normal for the region (despite what could be a colder than normal February) and warmer to perhaps much warmer than normal in Europe where winter has been largely absent.

On GISS, 2019 was easily the second warmest year on record with an annual temperature anomaly of +0.98 degrees C. December was also the second warmest December with a monthly temperature anomaly of +1.11 degrees C.

January 1-15, 2020 will very likely finish with a mean temperature of 42.8°. That would rank as the 6th warmest start to January in New York City (Central Park). The five warmer years were: 2007: 46.4° 1932: 44.0° 1950: 43.6° 1907: 43.5° 1998: 43.3°

The February 24-25, 1989 event was very localized. Atlantic City picked up 12.3". Islip received only 1.1". New York City had no snow.

The preliminary AO value today was +3.622. The January 1-15, AO average was +3.560. That is the second highest such figure on record since daily AO values were recorded beginning in 1950. It is only the fourth case on record where the AO averaged +3.000 or above during the January 1-15 period. The three prior cases were: 1989 +3.480 1993 +3.886 2007 +3.342 In two of the three prior cases, the AO averaged > 0 during February. In all three cases, the AO averaged > 0 in March. More importantly, all three prior cases saw a colder than normal February in the Middle Atlantic and southern New England regions. For the December 1-January 15 period, the AO has averaged +1.429. The AO has been positive on 70% days and negative on 30% days. It has also been at +3.000 or above on 33% days. Mean seasonal snowfall in New York City for the 11 cases where the December 1-January 15 AO average was +1.000 or above was 18.5". When the 3 cases with an AO average of +2.000 are excluded, the mean seasonal snowfall figure was 18.9".

Today saw a continuation of warmer than normal weather. The generally warmer than normal conditions will likely persist through Friday. However, a more winter-like pattern lies ahead in the medium-term. During the coming weekend, colder air will likely return for a period. There is potential for the temperature to fall into the teens even in New York City. Afterward, even as moderation should follow for a time, the cold will likely return during the closing week of the month. At that point, the cold could become sustained and continue into at least the start of February. On Friday night and Saturday there is potential for a system to bring New York City and Newark its first measurable snowfall since January 6. Philadelphia could receive its first measurable snowfall since December 11. At present, this continues to appear to be the kind of storm that could bring 1"-3"/2"-4" to Philadelphia to New York City, more to the north and west, including New England, and less to the south and east. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.5°C for the week centered around January 8. 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 +0.50°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -10.64 today. Today, the preliminary Arctic Oscillation (AO) figure was +4.368. The AO will average above +3.000 during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000. No significant stratospheric warming event appears likely through January 22. Wave 2 activity will remain relatively suppressed just past mid-January. Toward January 20, a short-lived moderate amplitude Wave 2 could impact the upper stratosphere. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 13, the MJO was in Phase 5 at an amplitude of 3.555 (RMM). The January 12-adjusted amplitude was 3.530. The January 13 amplitude is the highest January figure on record during Phase 5 of the MJO. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into at least the start of February. Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were January three cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period would be colder than normal overall. In addition, an MJO in Phase 7 at an amplitude of 2.000 or above typically sees measurable snowfall consistent with overall January 16-31 climatology. That would imply approximately 2 measurable snow events for Philadelphia to New York City and 2-3 such events for Boston during the closing two weeks of January. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 77% probability of a warmer than normal January. 　 　

Morning thoughts... The GEFS and GEFS bias-corrected MJO forecasts have retreated somewhat from a scenario where the MJO moves into Phase 8 in the extended range. However, the extended range of the MJO forecasts does not exhibit high skill, though a trend away from Phase 8 would need to be watched should it develop. The historical evidence from the MJO's reaching Phase 4 and Phase 5 at amplitudes of 1.500 or above during January 5-20 strongly argues that the MJO will move into Phases 7 and 8. That remains the base case. Newly published research showed that oceanic heat content continued to increase. https://link.springer.com/content/pdf/10.1007%2Fs00376-020-9283-7.pdf Interestingly enough, the long-term mean amplitude of the MJO has also increased. The 1980-99 average amplitude was 1.238. The 2000-19 preliminary average was 1.284. During the last 5 years, the preliminary average was 1.326. However, on scales of a decade or less, there can be fluctuations in MJO amplitude due to internal variability e.g., ENSO. Finally, the upcoming system that will impact the region this weekend continues to look like the kind that has delivered 1"-3"/2"-4" to such cities as Philadelphia, Newark, and New York City in the past. Higher amounts, generally 3"-6" (with some locally higher figures) had occurred to the north and west of those cities and in parts of New England (cities such as Scranton, Binghamton, Albany, and Boston). Lesser amounts occurred to the south and east (cities such as Atlantic City and Islip). The multi-model mean is reasonably consistent with the historic data (1950-2019). A 1"-3" snowfall would represent a nice increase in seasonal snowfall for Philadelphia (0.1" season-to-date), Newark (5.1" season-to-date), and New York City (2.7" season-to-date).

Abstract: uman-emitted greenhouse gases (GHGs) have resulted in a long-term and unequivocal warming of the planet (IPCC, 2019). More than 90% of the excess heat is stored within the world’s oceans, where it accumulates and causes increases in ocean temperature (Rhein et al., 2013; Abram et al., 2019). Because the oceans are the main repository of the Earth’s energy imbalance, measuring ocean heat content (OHC) is one of the best way to quantify the rate of global warming (Trenberth et al., 2016; Von Schuckmann et al., 2016; Cheng et al., 2018). Following reports released in the previous two years (Cheng and Zhu, 2018; Cheng et al., 2019c), this article presents new OHC data for the year 2019. These data reveal that the world’s oceans (especially at upper 2000 m) in 2019 were the warmest in recorded human history. Specifically, the ocean heat anomaly (0−2000 m) in 2019 was 228 Zetta Joules (ZJ, 1 ZJ=1021 Joules) above the 1981−2010 average and 25 ZJ above 2018 (Table 1). The OHC values (for the upper 2000 m) were obtained from the Institute of Atmospheric Physics (IAP) ocean analysis (see "Data and methods" section, below), which uses a relatively new method to treat data sparseness and updates in the instruments that have been used to measure ocean temperature (Cheng et al., 2017). The evolution of OHC (Fig. 1) shows that the upper 2000 m OHC in 2019 was 228 ± 9 ZJ above the 1981–2010 average. The record-setting ocean warmth is also found in National Oceanic and Atmospheric Administration/National Center for Environmental Information (NOAA/NCEI) data, showing 217± 4 ZJ in 2019 above 1981−2010 average (21 ZJ above 2018) (Table 1) (updated from Levitus et al. 2012). With these newly available IAP data, a ranking of the warmest years since 1950s is now possible (Table 1). The past five years are the top five warmest years in the ocean historically with modern instruments, and the past ten years are also the top ten years on record. The same ranking also applies to NOAA/NCEI data (Table 1). The full paper can be viewed here: https://link.springer.com/content/pdf/10.1007%2Fs00376-020-9283-7.pdf

Temperatures topped out in the 40s across much of the region. Nevertheless, readings remained above normal for the time of year. Generally warmer than normal conditions will likely persist through Friday. Readings could continue to average 5°-10° above normal over the next several days. However, a more winter-like pattern lies ahead in the medium-term. During next weekend, colder air will likely return for a period. At the same time, there is potential for a system to bring New York City and Newark its first measurable snowfall since January 6. Philadelphia could receive its first measurable snowfall since December 11. At present, this appears to be the kind of storm that could bring 1"-3"/2"-4" to Philadelphia to New York City, more to the north and west, including New England, and less to the south and east. Afterward, the cold could become sustained, possibly with some Arctic air. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.5°C for the week centered around January 8. 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 +0.50°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions. The SOI was -2.68 today. Today, the preliminary Arctic Oscillation (AO) figure was +4.698. That was the highest AO figure since December 21, 2016 when the AO was +4.742. That is also the highest January AO figure since January 5, 2005 when the AO was +4.703. Sixteen days later, a blizzard moved into the region dumping more than a foot of snow from Philadelphia to New England. The AO will likely average +2.000 or above during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000. No significant stratospheric warming event appears likely through January 21. Wave 2 activity will remain relatively suppressed just past mid-January. Toward January 20, a moderate amplitude Wave 2 could impact the upper stratosphere. Overall, most of the stratosphere is forecast to remain cold on the EPS. On January 12, the MJO was in Phase 5 at an amplitude of 3.530 (RMM). The January 11-adjusted amplitude was 3.433. The January 12 amplitude was the highest amplitude on record for the MJO's being in Phase 5 during January. Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into at least the start of February. Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were January three cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period would be colder than normal overall. In addition, an MJO in Phase 7 at an amplitude of 2.000 or above typically sees measurable snowfall consistent with overall January 16-31 climatology. That would imply approximately 2 measurable snow events for Philadelphia to New York City and 2-3 such events for Boston during the closing two weeks of January. Based on sensitivity analysis applied to the latest guidance, New York City has an implied 78% probability of a warmer than normal January.

Late afternoon thoughts... 1. Yesterday, the MJO reached Phase 5 at amplitude of 2.430 (a January record for Phase 5). 2. Historically, the MJO progressed into Phases 7 and 8 at amplitude of 1.000 or above following its being in Phase 5 at an amplitude of 1.500 or above. 3. The idea of a pattern change featuring a trough in the means in the East remains on track. 15-day Mean 500 mb Height Anomalies for the period beginning 10 days after the MJO peaks in Phase 5 at an amplitude of 1.500 or above during the January 5-20 period: 4. The 12z EPS, 12z GEFS, and 12z CFSv2 weekly guidance all favor the trough in the means in the East idea for the closing 10 days of January.