donsutherland1

February is now concluding. New York City finished with a monthly mean temperature of 36.2°, which was +0.9° above normal. Snowfall was just 2.6", which was 6.6" below normal for the month. Select seasonal snowfall amounts (through 2/28 5 pm) were: Albany: 45.0", 1.9" below normal Allentown: 20.6", 6.4" below normal Baltimore:15.6", 2.6" below normal Binghamton: 72.2", 8.3" above normal Boston: 13.9", 20.2" below normal Bridgeport: 11.1", 10.5" below normal Buffalo: 107.8", 29.0" above normal (26th snowiest winter) Burlington: 87.2", 26.4" above normal (30th snowiest winter) Caribou: 147.0", 64.5" above normal (8th snowiest winter) Chicago: 41.3", 11.8" above normal Detroit: 28.7", 5.2" below normal Harrisburg: 28.7", 3.7" above normal Hartford: 29.8", 2.9" below normal Islip: 8.7", 11.0" below normal New York City: 10.1", 11.2" below normal Newark: 11.9" 12.1", 10.9" below normal Philadelphia: 13.1", 5.9" below normal Portland: 50.9", 4.5" above normal Providence: 17.6", 10.1" below normal Scranton: 25.9", 8.0" below normal Sterling: 24.9", 6.0" above normal Washington, DC: 16.6", 2.5" above normal Worcester: 35.8", 14.1" below normal　 The ENSO Region 1+2 anomaly was +0.20°C and the Region 3.4 anomaly was +0.70°C for the week centered around February 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Similar ENSO conditions will likely persist through much of March with some possible fluctuations to just below weak El Niño levels. Some guidance suggests the potential for further warming of ENSO Region 3.4 in coming weeks. The SOI was -2.88 today. That is its highest figure since February 9 when the SOI was -2.40. Today's preliminary value of the Arctic Oscillation (AO) was +1.707. The preliminary average for meteorological winter was +0.132. In total, 51% days had positive values and 48% days had negative values. The AO will very likely remain predominantly positive through March 1-15. This historic experience has strong support from the latest ensembles. On February 27, the MJO moved into Phase 2 at an amplitude of 1.920(RMM). The amplitude was somewhat lower than the February 26-adjusted figure of 2.053. The MJO will continue to advance toward Phase 3. The SOI is now approaching zero. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, a drier pattern could begin to evolve in both the Southwestern United States (including California) and Southeastern United States over the next 2-3 weeks. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or perhaps significant snowstorm in the New York City area. That the MJO will likely enter March at a high amplitude is consistent with a colder start to the month. Due to shorter wave lengths, the state of the AO has little impact on the probability of such storms. Afterward, sustained warming could limit opportunities for snowfall. The potential for widespread high temperatures in the upper 40s into southern New England and 50s in portions of the Middle Atlantic region near mid-month exists. The odds of such warming would be particularly high should the PDO be negative, as has been the case in both December and January. In terms of snowfall, another system could bring parts of the area, especially south of New York City, some measurable snow very late tonight into tomorrow and again Friday night into Saturday. A bigger system could impact the region Sunday night into Monday. The potential exists for a moderate accumulation of snow in and around New York City and possibly a significant snowfall well inland and in parts of New England, including the Boston area.

Photo from Larchmont, NY (0.3" snow):

DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA -2.0 -1.7 -1.3 -5.2 -1.4 0.0 -3.5 -0.2 -0.1 NYC subforum

The ENSO Region 1+2 anomaly was +0.20°C and the Region 3.4 anomaly was +0.70°C for the week centered around February 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Similar ENSO conditions will likely persist through much of March with some possible fluctuations to just below weak El Niño levels. Some guidance suggests the potential for further warming of ENSO Region 3.4 in coming weeks. The SOI was -10.52 today. The 30-day SOI average is -13.34. Today's preliminary value of the Arctic Oscillation (AO) was +1.656. The preliminary average for meteorological winter is +0.114. It is now all but certain that the AO will finish with a positive value for meteorological winter. Therefore, given the latest ensemble forecast, the AO is all but certain to finish with a positive average for winter 2018-19. Further, consistent with cases where the AO peaked at +3.000 or above during the February 20-28 period, the AO will remain predominantly positive through March 1-15. This historic experience has strong support from the latest ensembles. On February 26, the MJO was in Phase 1 at an amplitude of 2.053 (RMM). The amplitude was somewhat lower than the February 25-adjusted figure of 2.159. Over the next 2 days, the MJO will likely move into Phase 2. Afterward, it could move into Phase 3 near the start of the second week of March. The SOI remains at negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or perhaps significant snowstorm in the New York City area. That the MJO will likely enter March at a high amplitude is consistent with a colder start to the month. Due to shorter wave lengths, the state of the AO has little impact on the probability of such storms. Taking into consideration current ENSO conditions (which are consistent with a reduced frequency of 6" or greater snowstorms during the first half of March in the Middle Atlantic and southern New England areas) and the forecast MJO over through the first week of March, one should wait for good run-to-run continuity and strong model consensus before embracing high-impact snow scenarios for the Philadelphia-Boston region that may appear from time to time on the guidance. Even as a moderate or significant snowfall remains possible, confidence in such an outcome could be fairly low until the event is 48-96 hours away. Afterward, sustained warming could limit opportunities for snowfall. The potential for widespread high temperatures in the upper 40s into southern New England and 50s in portions of the Middle Atlantic region near mid-month exists. The odds of such warming would be particularly high should the PDO be negative, as has been the case in both December and January. Meanwhile, a clipper-type system will likely bring a generally light to moderate snowfall to the northern Middle Atlantic region tonight into tomorrow. A coating is possible in New York City and nearby northern suburbs, while 1"-3" could accumulate well to the north of the City, including such locations as Danbury, Hartford, and Poughkeepsie. The Boston area should pick up 2"-4" snow with some potential for higher amounts should ocean enhancement occur. Another system could bring parts of the area, especially south of New York City, additional precipitation, including snow, very late Friday night into Saturday.

The ENSO Region 1+2 anomaly was +0.20°C and the Region 3.4 anomaly was +0.70°C for the week centered around February 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Basin-wide, neutral-warm/very weak El Niño conditions are not conducive for large snowstorms in northern Mid-Atlantic cities including New York and Philadelphia during February. Conditions can be somewhat more favorable during the first half of March, but based on historic data, the recent warming of ENSO Region 3.4 may not be a positive development for the first half of March. Similar ENSO conditions will likely persist through at least the first half of March with some possible fluctuations to just below weak El Niño levels. Some guidance suggests the potential for further warming of ENSO Region 3.4. The SOI was -15.32 today. The 30-day SOI average is -12.90. Today's preliminary value of the Arctic Oscillation (AO) was +1.997. The preliminary average for meteorological winter is +0.096. Should the AO average -4.192 for the remainder of February, it would finish with a meteorological winter average +0.001. Therefore, given the latest ensemble forecast, the AO is virtually certain to finish with a positive average for winter 2018-19. Further, consistent with cases where the AO peaked at +3.000 or above during the February 20-28 period, the odds of a return to negative AO values is low. Almost half of such cases actually had no AO- readings through March 15. On February 25, the MJO was in Phase 1 at an amplitude of 2.157 (RMM). The amplitude was somewhat higher than the February 24-adjusted figure of 2.126. Over the next 1-3 days, the MJO will likely move into Phase 2. Afterward, it could move into Phase 3 near the start of the second week of March. The SOI remains at negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or significant snowstorm in the New York City area. That the MJO will likely enter March at a high amplitude is consistent with a colder start to the month. Due to shorter wave lengths, the state of the AO has little impact on the probability of such storms. Afterward, pronounced warming could limit opportunities for snowfall. The odds of such warming would be particularly high should the PDO be negative, as has been the case in both December and January. During the March 1-15 period, the frequency of a widespread moderate or significant snowstorm (a storm that brings 4" or more snow to two or more of the following cities--Boston, New York City, and/or Philadelphia) has been limited when the March ENSO Region 3.4 anomaly has been at or above the El Niño threshold. Since 1950, 18/21 (86%) of such snowstorms occurred when the ENSO region 3.4 anomaly was below +0.50°C. The biggest snowstorms when the March Region 3.4 anomaly was at or above +0.50°C were as follows: Boston: 5.8"; New York City: 7.5"; and, Philadelphia: 7.5". In terms of 6" or greater snowstorms during March 1-15, 1950-2018, 0/19 (0%) in Boston, 1/7 (14%) in New York City, and 1/13 (8%) in Philadelphia have occurred when the March ENSO Region 3.4 anomaly was +0.50°C or above. However, March 1958 saw a major snowstorm during the second half of the month during El Niño conditions, so some probability of such a storm would exist even if current ENSO Region 3.4 anomalies persist. March could finish with an ENSO Region 3.4 anomaly above +0.50°C if some of the recent ENSO forecasts are reasonably accurate and earlier today the World Meteorological Organization indicated that there is a 50%-60% chance that a weak El Niño could develop by May. https://public.wmo.int/en/media/press-release/wmo-update-50-60-chance-of-el-ni%C3%B1o-within-next-3-months Therefore, one should wait for good run-to-run continuity and strong model consensus before embracing high-impact snow scenarios for the Philadelphia-Boston region that may appear from time to time on the guidance. Put another way, even as a moderate or significant snowfall remains possible, confidence in such an outcome could be fairly low until the possible event is 48-96 hours away.

Implementation of the FV3 has been delayed due to two primary issues: -The snow depth and the water equivalent of snow depth at the surface have unrealistically large values when precipitation occurs in environments with low-level temperature profiles close to freezing. Techniques that use either of these variables for deriving snowfall will exhibit excessive snowfall values. -The model forecasts exhibit a cold bias in the lower atmosphere that became more prominent after late September 2018. https://www.weather.gov/media/notification/scn19-12gfsv15.pdf

The two primary issues that delayed the FV3's implementation: -The snow depth and the water equivalent of snow depth at the surface have unrealistically large values when precipitation occurs in environments with low-level temperature profiles close to freezing. Techniques that use either of these variables for deriving snowfall will exhibit excessive snowfall values. -The model forecasts exhibit a cold bias in the lower atmosphere that became more prominent after late September 2018. https://www.weather.gov/media/notification/scn19-12gfsv15.pdf

Weak El Niño conditions have redeveloped. The ENSO Region 1+2 anomaly was +0.20°C and the Region 3.4 anomaly was +0.70°C for the week centered around February 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Basin-wide, neutral-warm/very weak El Niño conditions are not conducive for large snowstorms in northern Mid-Atlantic cities including New York and Philadelphia during February. Conditions can be somewhat more favorable during the first half of March. Such ENSO conditions will likely persist into at least the first half of March with some possible fluctuations to levels consistent with weak El Niño events. The warm SSTAs will likely remain basin-wide. The SOI was -9.99 today. The 30-day SOI average is -12.50. Today's preliminary value of the Arctic Oscillation (AO) was +1.620. The preliminary average for meteorological winter is +0.074. Should the AO average -2.129 for the remainder of February, it would finish with a meteorological winter average +0.001. Therefore, given the latest ensemble forecast, the AO will very likely finish with a positive average for winter 2018-19. Further, consistent with cases where the AO peaked at +3.000 or above during the February 20-28 period, the odds of a return to negative AO values is low. Almost half of such cases actually had no AO- readings through March 15. On February 24, the MJO was in Phase 1 at an amplitude of 2.125 (RMM). The amplitude was somewhat lower than the February 23-adjusted figure of 2.172. The SOI remains at negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or significant snowstorm in the New York City area. That the MJO will likely enter March at a high amplitude is consistent with a colder start to the month. Due to shorter wave lengths, the state of the AO has little impact on the probability of such storms. Afterward, pronounced warming could limit opportunities for snowfall. The odds of such warming would be particularly high should the PDO be negative, as has been the case in both December and January. The 12z ECMWF was most aggressive with the idea of a Middle Atlantic and New England snowstorm during the first week in March. Both the latest CFSv2 and EPS weekly forecasts favor a warm-up near mid-month. Cold could linger in the Central and Northern Plains through much of March.

The mean Central Park temperature through 2/24 is 37.0°, which is approximately 2.1° above normal.

Basin-wide neutral-warm ENSO conditions persist. The ENSO Region 1+2 anomaly was +0.60°C and the Region 3.4 anomaly was +0.60°C for the week centered around February 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.58°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Basin-wide, neutral-warm/very weak El Niño conditions are not conducive for large snowstorms in northern Mid-Atlantic cities including New York and Philadelphia during February. Conditions can be somewhat more favorable during the first half of March. Such ENSO conditions will likely persist into at least the first half of March with some possible fluctuations to levels consistent with weak El Niño events. The warm SSTAs will likely remain basin-wide. The SOI was -9.85 today. That ended the stretch of 13 consecutive days during which the SOI was -10.00 or below. The last time the SOI was at or below -10.00 for at least 13 consecutive days was February 13-March 3, 2016 when the SOI was at -10.00 or below for 20 consecutive days. Today's preliminary value of the Arctic Oscillation (AO) was +1.537. The preliminary average for meteorological winter is +0.056. Should the AO average -1.192 for the remainder of February, it would finish with a meteorological winter average +0.001. Therefore, given the latest ensemble forecast, the AO will very likely finish with a positive average for winter 2018-19. Further, consistent with cases where the AO peaked at +3.000 or above during the February 20-28 period, the odds of a return to negative AO values is low. Almost half of such cases actually had no AO- readings through March 15. On February 23, the MJO moved into Phase 1 at an amplitude of 2.173 (RMM). The amplitude was little changed from the February 22-adjusted figure of 2.162. The SOI remains at negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. As a powerful storm moves across southern Canada, winds will likely gust past 50 mph tonight and tomorrow. Some areas could experience gusts in excess of 60 mph. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or significant snowstorm in the New York City area. That the MJO will likely enter March at a high amplitude is consistent with a colder start to the month. Due to shorter wave lengths, the state of the AO has little impact on the probability of such storms. Afterward, pronounced warming could limit opportunities for snowfall. The odds of such warming would be particularly high should the PDO be negative, as has been the case in both December and January.

That’s a window of opportunity. We’ll see whether it is realized.

Historic data for similar basin-wide ENSO conditions shows just such a tendency around mid-March +/- a few days. The warming is even more pronounced when the PDO is negative.

Basin-wide neutral-warm ENSO conditions persist. The ENSO Region 1+2 anomaly was +0.60°C and the Region 3.4 anomaly was +0.60°C for the week centered around February 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.58°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Basin-wide, neutral-warm/very weak El Niño conditions are not conducive for large snowstorms in northern Mid-Atlantic cities including New York and Philadelphia during February. Conditions can be somewhat more favorable during the first half of March. Such ENSO conditions will likely persist into at least the first half of March with some possible fluctuations to levels consistent with weak El Niño events. The warm SSTAs will likely remain basin-wide. The SOI was -15.51 today. That is the 13th consecutive day during which the SOI was -10.00 or below. The last time the SOI was at or below -10.00 for at least 13 consecutive days was February 13-March 3, 2016 when the SOI was at -10.00 or below for 20 consecutive days. Today's preliminary value of the Arctic Oscillation (AO) was +1.840. The preliminary average for meteorological winter is +0.039. Should the AO average -0.646 for the remainder of February, it would finish with a meteorological winter average +0.001. Therefore, given the latest ensemble forecast, the AO will very likely finish with a positive average for winter 2018-19. On February 22, the MJO was in Phase 8 at an amplitude of 2.165 (RMM). The amplitude was slightly lower than the February 21-adjusted figure of 2.097. The MJO is now poised to head into Phase 1 as February concludes. Afterward, the MJO will advance toward and into Phase 2. The SOI remains at very negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. A deepening storm will track across the Great Lakes region and then southern Canada over the next two days. As it does so, it will bring moderate to potentially heavy rainfall to parts of the East later tonight and tomorrow. In its wake, winds will likely gust past 50 mph both tomorrow night and Monday. Some areas could experience gusts in excess of 60 mph. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or significant snowstorm in the New York City area. That the MJO will likely enter March at a high amplitude is consistent with a colder start to the month. Afterward, pronounced warming could limit opportunities for snowfall. The odds of such warming would be particularly high should the PDO be negative, as has been the case in both December and January. Finally, looking back at the major oceanic indices for winter 2018-19, the ENSO Region 3.4 anomaly is all but certain to fall into a neutral-warm/weak El Niño range of 0.01°C to +0.70°C (December-February average), the ENSO Region 1+2 will have finished with a warm anomaly making this a basin-wide event. The December-January PDO figures were negative. Since 1950, a single winter saw reasonably similar ENSO conditions paired with a negative PDO for December and January: winter 1979-80. This time around, the PDO was not as negative as it was back in 1979-80, or it is possible that the snow deficit across much of the East would have extended even farther north into New England, including Vermont and Maine. All said, the large-scale drivers of the pattern proved to be quite hostile for the development of a snowy meteorological winter for the northern Middle Atlantic and southern New England areas. The December SOI+ tendency also proved to be the "barking dog" that warned of the collapse of the El Niño that had been in place going into 2019. For the past six weeks, neutral-warm ENSO conditions have prevailed and on a basin-wide, not central Pacific-centered basis.

Outside, the grounds of the New York Botanical Garden were largely barren. Witch Hazel and Snowdrops were in blossom. There were still some patches of snow on the grounds. Inside the Haupt Conservatory, the 2019 orchid show had opened. Its colors hint at what lies ahead in perhaps just 4-6 weeks as Spring takes hold.

Basin-wide neutral-warm ENSO conditions persist. The ENSO Region 1+2 anomaly was +0.60°C and the Region 3.4 anomaly was +0.60°C for the week centered around February 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.58°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Basin-wide, neutral-warm/very weak El Niño conditions are not conducive for large snowstorms in northern Mid-Atlantic cities including New York and Philadelphia during February. Conditions can be somewhat more favorable during the first half of March. Such ENSO conditions will likely persist into at least the first half of March with some possible fluctuations to levels consistent with weak El Niño events. The SOI was -19.36 today. That is the 12th consecutive day during which the SOI was -10.00 or below. The last time the SOI was at or below -10.00 for at least 12 consecutive days was April 12-23, 2016. Today's preliminary value of the Arctic Oscillation (AO) was +1.869. The preliminary average for meteorological winter is +0.018. Should the AO average -0.232 for the remainder of February, it would finish with a meteorological winter average +0.001. On February 21, the MJO was in Phase 8 at an amplitude of 2.096 (RMM). The amplitude was slightly lower than the February 20-adjusted figure of 2.152. The MJO could spend an extended duration in Phase 8 before moving slowly into Phase 1 during the closing week of February. Late February high amplitude MJO Phase 8 cases have not always led to a snowy March. March 1978 saw 6.8" snow fall in New York City. March 1988 saw no measurable snowfall in New York City. The SOI remains at very negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. The ongoing snowstorm had dumped 40.1" snow at Flagstaff as of 11 am MST. Farther east, a storm could bring moderate to potentially heavy rainfall to parts of the East this weekend. That storm will very likely be followed by strong winds that could gust past 40 mph over a large part of the region. Afterward, the pattern could evolve toward a colder one. Unlike with February when neutral-warm to very weak El Niño conditions are not conducive to significant snows in the Middle Atlantic region, the frequency of such snowfalls during such ENSO conditions increases in March courtesy of shortening wave lengths. Since 1950, 43% of New York City's 6" or greater snowstorms during March 1-15 occurred with an AO+/PNA- pattern and 27% occurred with an AO-/PNA+ pattern. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or significant snowstorm in the New York City area. Afterward, pronounced warming could limit opportunities for snowfall. The odds of such warming would be particularly high should the PDO be negative.

Flagstaff finished with an all-time daily snowfall record of 35.9" yesterday and daily record precipitation of 1.44". Flagstaff's two-day snowfall was 37.4". Phoenix also picked up a daily record precipitation amount of 1.01". There is a strong correlation between precipitation in the Southwest and a negative SOI.

I don't think it will reach or exceed the 54.0" record. It should surpass 40.0".

As of 5 pm MST, Flagstaff had picked up 31.6" snow today. That snowfall set a new daily snowfall record. The previous record was 31.0", which was set on December 30, 1915. So far, Flagstaff has picked up a storm total of 33.1" over two days. The two-day record is 51.0", which was established during December 30-31, 1915. The three-day record is 54.0", which was set during December 29-31, 1915.

Basin-wide neutral-warm ENSO conditions persist. The ENSO Region 1+2 anomaly was +0.60°C and the Region 3.4 anomaly was +0.60°C for the week centered around February 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.58°C and the ENSO Region 3.4 anomaly has averaged +0.48°C. Basin-wide, neutral-warm/very weak El Niño conditions are not conducive for large snowstorms in northern Mid-Atlantic cities including New York and Philadelphia during February. There have been just 3 snowstorms of 4" or more in Boston during February when the ENSO 1+2 anomaly was > 0.00°C and the ENSO 3.4 anomaly ranged from 0.00°C to 0.69°C since 1950. In New York City, there was just one such storm and in Philadelphia there were two. The biggest snowstorms during such ENSO conditions were as follows: Boston: 9.7"; New York City: 4.3"; and, Philadelphia: 4.7". Those three figures might represent the upper bound of what's possible in terms of accumulations in the current pattern unless there is strong modeling consensus for a larger snowfall. During the most recent storm, all three cities had accumulations that fell short of 4.0". Such ENSO conditions will likely persist through February with some possible fluctuations to levels consistent with weak El Niño events. Under such a scenario, the probability of a significant snowfall (6" or more) will be well below climatology for the northern Mid-Atlantic region. The SOI was -27.27 today. That is the 11th consecutive day during which the SOI was -10.00 or below. The last time the SOI was at or below -10.00 for at least 11 consecutive days was April 12-23, 2016. Today's preliminary value of the Arctic Oscillation (AO) was +2.486. The preliminary average for meteorological winter is -0.005. Should the AO average +0.068 for the remainder of February, it would finish with a meteorological winter average +0.001. On February 20, the MJO was in Phase 8 at an amplitude of 2.156 (RMM). The amplitude rose from the February 19-adjusted figure of 1.833. The MJO could spend an extended duration in Phase 8 before moving slowly into Phase 1 during the closing week of February. Late February high amplitude MJO Phase 8 cases have not always led to a snowy March. March 1978 saw 6.8" snow fall in New York City. March 1988 saw no measurable snowfall in New York City. The SOI remains at very negative levels. The SOI has a correlation to precipitation in the southern tier of the United States. As a result, precipitation will likely be above to much above normal in both the Southwestern United States (including California) and Southeastern United States. Another storm could bring moderate to potentially heavy rainfall to parts of the East this weekend. Afterward, the pattern could evolve toward a colder one. Unlike with February when neutral-warm to very weak El Niño conditions are not conducive to significant snows in the Middle Atlantic region, the frequency of such snowfalls during such ENSO conditions increases in March courtesy of shortening wave lengths. Since 1950, 43% of New York City's 6" or greater snowstorms during March 1-15 occurred with an AO+/PNA- pattern and 27% occurred with an AO-/PNA+ pattern. Based on historic data following similar ENSO conditions to those of February 2019, March 1-15 could provide perhaps the final window of opportunity for a moderate or significant snowstorm in the New York City area. Afterward, pronounced warming could limit opportunities for snowfall.

I wouldn't be too surprised of Flagstaff reports a storm total and possibly daily total of 30" when the daily climate report is posted around 6 pm MST (8 pm EST). That would bring today's snowfall close to the all-time record. That record will likely be challenged, if not broken. Overall, the snow-liquid ratio has been about 25:1 during the event. Flagstaff's greatest daily snowfall (24" or above): 1. 31.0", December 30, 1915 2. 26.8", December 13, 1967 3. 26.0", March 1, 1970 4. 24.0", February 2, 1901

Some crocuses are already in bloom in the region.

FYI: 23.8" snow at Flagstaff. Snow continues to fall. https://www.weather.gov/source/crh/snowmap.html?sid=fgz

There's still a window of opportunity. Overall, it has been a really disappointing winter.

Ice accretion from the recent storm: New Rochelle, New York

While February 2019 is nowhere near as warm as the record-warm February of last year in Central Park, it is poised to finish 2° or more above normal. Sensitivity analysis applied to the latest guidance provides the following implied probabilities: Warmer than normal: 92% 2° or more above normal: 58% 3° or more above normal: 34%