donsutherland1

The 30-year means are updated each decade. There are no ulterior motives involved with this. Clearly, the climate has warmed since the 1981-2010 base period. In the high latitudes, the warming has been even more pronounced. For example, in Utqiagvik (formerly Barrow), the 1981-2010 base mean for October is 17.2°. The most recent 30-year period (1989-2018) has a mean temperature of 20.5°. After this October, which will very likely be the second or third warmest October on record, that figure could be 20.9°. So, should the reference point be increased more frequently, maybe every 5 years? The drawback with a frequently changing reference point is that it tends to make such an exercise relatively futile. In other words, there is no relatively stable "normal" value for temperatures. Perhaps things will get there on a "business as usual" path. Things may already be there in the Arctic due to related feedbacks that are amplifying the warming.

Following a frontal passage with some showers and periods of rain overnight, sunshine will return tomorrow. During the next 5-8 days, temperatures will likely average warmer than normal. October could end with a cool shot. The cool conditions will then likely persist through the first week of November as the Arctic Oscillation goes negative for at least a time. Nevertheless, the cool shot should prove transient. 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 October 16. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.82°C and the ENSO Region 3.4 anomaly has averaged +0.28°C. A neutral ENSO is currently the base case for Winter 2019-20. Since 1981, approximately one out of every seven December cases involved a neutral ENSO. In general, a neutral ENSO in which Region 1+2 had a cold anomaly and Region 3.4 had a warm anomaly (as has been the case in the 6 week moving average) saw a warmer than normal December. Such neutral ENSO cases accounted for about 27% of all neutral ENSO December cases during the 1981-2018 period. This data does not consider blocking, as it is too soon to be confident about that factor in December. However, the greatest warmth coincided with a negative PDO while the coldest outcome coincided with a strongly positive PDO (+1.00 or above for December). Therefore, the first part of winter could start off milder than normal in the Middle Atlantic and southern New England regions. The SOI was +2.90 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.148. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. There remains a potential for autumn 2019 to rank among the 30 warmest cases on record. For New York City, that would translate into a September-November mean temperature of at least 58.8°. In August, the AO averaged -0.722 and in September the AO rose to +0.306. The possible transition to predominantly positive values from September into October has been a relatively uncommon occurrence. Since 1950, only 1963 and 2011 saw a transition of an August value of -0.500 or below to positive values in September and a positive average in October. Both cases featured a warmer than normal November in the Middle Atlantic and southern New England areas. Despite what might be a somewhat cooler than normal start to November, a warmer than normal outcome for the month as a whole remains likely. On October 21, the MJO was in Phase 2 at an amplitude of 1.885 (RMM). The October 20-adjusted amplitude was 1.914. In the two prior cases when the MJO moved into Phase 1 in late September or early October and then remained in Phase 1 for 12 or more consecutive days as occurred this year, the average decline in the 14-day average temperature for the 2-3 weeks that followed the MJO's moving out of Phase 1 was gradual. The current long-duration Phase 1 episode suggests that the second half of October could be warmer than normal. For New York City, an October mean temperature of 58.5°-59.5° (1.6° to 2.6° above normal) would be implied by those earlier long-duration Phase 1 cases. Based on the sensitivity analysis, the estimated October mean temperature is currently near 59.0°. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 84%. Finally, the C3S (Europe's seasonal forecasting ensemble system) hints that the predominant state of the NAO and possibly AO could be positive during the upcoming winter. That would tend to translate into warmer anomalies in eastern North America, including the Middle Atlantic and southern New England areas. However, there remains time for conditions to change and the state of blocking typically cannot be forecast reliably at the kind of long timescales involved in the current C3S forecast.

It should be noted that the C3S used by the major European forecasting agencies for seasonal forecasts shows warm anomalies throughout almost all of the Northern Hemisphere, including North America. The CFSv2 isn't alone with such a forecast right now. Of course, this is October, so things can still change.

I have a co-worker who traveled to the Dominican Republic. She had a great experience and some of the places she visited were incredibly scenic. IMO, the recent bad publicity should not skew perceptions of the DR as a travel destination.

Under bright sunshine, readings soared well into the 60s across the New York City area. High temperatures included 67° at Central Park and 69° at Newark. During the next 6-9 days, temperatures will likely average warmer than normal. However, October could end with a cool shot. The cool conditions will likely to persist through the first week of November as the Arctic Oscillation goes negative for at least a time. Nevertheless, the cool shot should prove transient. 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 October 16. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.82°C and the ENSO Region 3.4 anomaly has averaged +0.28°C. A neutral ENSO is currently the base case for Winter 2019-20. Since 1981, approximately one out of every seven December cases involved a neutral ENSO. In general, a neutral ENSO in which Region 1+2 had a cold anomaly and Region 3.4 had a warm anomaly (as has been the case in the 6 week moving average) saw a warmer than normal December. Such neutral ENSO cases accounted for about 27% of all neutral ENSO December cases during the 1981-2018 period. This data does not consider blocking, as it is too soon to be confident about that factor in December. However, the greatest warmth coincided with a negative PDO while the coldest outcome coincided with a strongly positive PDO (+1.00 or above for December). Therefore, the first part of winter could start off milder than normal in the Middle Atlantic and southern New England regions. The SOI was +7.41 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.637. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. There remains a potential for autumn 2019 to rank among the 30 warmest cases on record. For New York City, that would translate into a September-November mean temperature of at least 58.8°. In August, the AO averaged -0.722 and in September the AO rose to +0.306. The possible transition to predominantly positive values from September into October has been a relatively uncommon occurrence. Since 1950, only 1963 and 2011 saw a transition of an August value of -0.500 or below to positive values in September and a positive average in October. Both cases featured a warmer than normal November in the Middle Atlantic and southern New England areas. Despite what might be a somewhat cooler than normal start to November, a warmer than normal outcome for the month as a whole remains likely. On October 20, the MJO was in Phase 2 at an amplitude of 1.912 (RMM). The October 19-adjusted amplitude was 1.662. In the two prior cases when the MJO moved into Phase 1 in late September or early October and then remained in Phase 1 for 12 or more consecutive days as occurred this year, the average decline in the 14-day average temperature for the 2-3 weeks that followed the MJO's moving out of Phase 1 was gradual. The current long-duration Phase 1 episode suggests that the second half of October could be warmer than normal. For New York City, an October mean temperature of 58.5°-59.5° (1.6° to 2.6° above normal) would be implied by those earlier long-duration Phase 1 cases. Based on the sensitivity analysis, the estimated October mean temperature is currently near 59.0°. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 83%.

IMO, it's too early to be certain of the winter outlook (good or bad). Some critical pieces are beginning to fall into place. Others remain to be resolved.

On October 20, Arctic sea ice extent on JAXA was 5,625,765 square kilometers. That is both the lowest on record for the date and the latest figure below 6 million square kilometers in record . The previous daily record low was 6,136,029 square kilometers from last year.

Post-Tropical Storm Nestor took a track closer to the coast bringing steady rain to the New York City area. Rather than turning sharply out to sea from eastern North Carolina or southeast Virginia, Nestor came northward and moved across the southern portion of the Delmarva Peninsula. Although this subtle northwestward shift in the storm track was most noticeable with today's precipitation, it could also hint that the western Atlantic ridge may be somewhat stronger and more expansive than had previously been modeled. Rainfall amounts today through 8 pm included: Baltimore: 1.34" Islip: 0.41" New York City: 0.51" Newark: 0.58" Norfolk: 1.85" Philadelphia: 0.48" Poughkeepsie: 0.21" Richmond: 1.59" Sterling, VA: 1.43" (old daily record: 1.27", 1976) Washington, DC: 1.60" During the next 7-10 days, temperatures will average warmer than normal. However, October could end with a cool shot. The cool conditions will likely to persist through the first week of November as the Arctic Oscillation goes negative for at least a time. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was +0.4°C for the week centered around October 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.88°C and the ENSO Region 3.4 anomaly has averaged +0.12°C. A neutral ENSO is currently the base case for Winter 2019-20. Since 1981, approximately one out of every seven December cases involved a neutral ENSO. In general, a neutral ENSO in which Region 1+2 had a cold anomaly and Region 3.4 had a warm anomaly (as has been the case in the 6 week moving average) saw a warmer than normal December. Such neutral ENSO cases accounted for about 27% of all neutral ENSO December cases during the 1981-2018 period. This data does not consider blocking, as it is too soon to be confident about that factor in December. However, the greatest warmth coincide with a negative PDO while the coldest outcome coincided with a strongly positive PDO (+1.00 or above for December). Therefore, the first part of winter could start off milder than normal in the Middle Atlantic and southern New England regions. The SOI was +11.21 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.870. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. There remains a potential for autumn 2019 to rank among the 30 warmest cases on record. For New York City, that would translate into a September-November mean temperature of at least 58.8°. In August, the AO averaged -0.722 and in September the AO rose to +0.306. The possible transition to predominantly positive values from September into October has been a relatively uncommon occurrence. Since 1950, only 1963 and 2011 saw a transition of an August value of -0.500 or below to positive values in September and a positive average in October. Both cases featured a warmer than normal November in the Middle Atlantic and southern New England areas. Despite what might be a somewhat cooler than normal start to November, a warmer than normal outcome for the month as a whole remains likely. On October 19, the MJO was in Phase 2 at an amplitude of 1.664 (RMM). The October 18-adjusted amplitude was 1.361. In the two prior cases when the MJO moved into Phase 1 in late September or early October and then remained in Phase 1 for 12 or more consecutive days as occurred this year, the average decline in the 14-day average temperature for the 2-3 weeks that followed the MJO's moving out of Phase 1 was gradual. The current long-duration Phase 1 episode suggests that the second half of October could be warmer than normal. For New York City, an October mean temperature of 58.5°-59.5° (1.6° to 2.6° above normal) would be implied by those earlier long-duration Phase 1 cases. Based on the sensitivity analysis, the estimated October mean temperature is currently near 58.5°. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 75%. With today's rainfall, there is an implied 61% probability (1971-2018 data) that New York City will reach at least 50.00" annual precipitation this year.

Yes. Many models missed how far north the rain came, even as the steadiest and heaviest rain was confined to such cities as Baltimore, Richmond, and Washington.

Yesterday was Utqiagvik's (formerly Barrow) 9th October minimum temperature of 30° or above. That is the second highest figure on record. Only October 2016 with 15 had more. The frequency of such elevated minimum temperatures in October has increased dramatically in recent years. 2015-2019 has accounted for 4 of the nine cases in which Utqiagvik recorded more than 3 days with minimum temperatures of 30° or above in October. The 1981-2010 base mean was 1.1 days. The latest 30-year period (1990-2019) has an average of 2.2. The average for the past 10 years is 4.2. Put another way, the average for the past 10 years would rank as the 8th highest such figure on record. Records go back to 1920. The increase in such October warmth has coincided with a dramatic decline in October Arctic sea ice extent. During the 1990-99 period, Arctic sea ice extent averaged 8.497 million square kilometers. During the 2009-18 period, it has averaged 6.466 million square kilometers, a 23.9% decline. During the October 1-18 period, which includes 2019 data, Arctic sea ice extent averaged 7.962 million square kilometers. During the 2009-18 period, it has averaged 5.737 million square kilometers, a 27.9% decline from the 1990s. For 2010-19, the average has been 5.603 million square kilometers (which includes the record low 4.776 million square kilometers from this year, which broke the old mark of 5.046 million square kilometers from 2007). The most-recent 10-year average is 29.6% lower than that during the 1990s. Finally, the following is the breakdown of record-breaking or record-tying warm minimum temperatures during October at Utqiagvik: 2000 or later: 20 days 2010 or later: 17 days 2015 or later: 8 days 2019: 4 days: October 10: 34° (old record: 33°, 1926) October 11: 32° (tied record set in 2016) October 16: 33° (old record: 31°, 1993) October 17: 32° (old record: 28°, 1951 and 2011)

According to the GISS data set, September 2019 was the second warmest September on record globally with a monthly temperature anomaly of +0.90°C. That was near September 2016's record +0.91°C anomaly. To date, 2019 has an annual temperature anomaly of +0.95°C. That is the second warmest January-September period on record. 2019 could finish as the second warmest year on record. To conclude as the second warmest year on record, the average temperature anomaly for the October-December period would need to be just above +0.82°C. The last time the three-month average anomaly was +0.82°C or below was July-September 2018 with an average anomaly of +0.80°C. It is very likely that 2019 will finish as at least the 3rd warmest year on record. To finish below third, 2019 would need an average 3-month temperature anomaly of just under +0.74°C. The last time that happened was June-August 2014 with an average anomaly of +0.69°C.

Milder conditions will gradually return in coming days. Post-Tropical Storm Nestor will likely track rapidly to the east northeast off the Middle Atlantic coast and out to sea. Its rain should pass south of the New York City Metro area later tomorrow and tomorrow night. There is a small chance that a few showers could reach the area. Parts of the Middle Atlantic region including Washington and Baltimore could see a period of rain from Nestor. The last week of October will likely start mild but end with a cool shot. The cool conditions increasingly appear likely to persist through the first week of November as the Arctic Oscillation goes negative for at least a time. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was +0.4°C for the week centered around October 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.88°C and the ENSO Region 3.4 anomaly has averaged +0.12°C. A neutral ENSO is currently the base case for Winter 2019-20. Since 1981, approximately one out of every seven December cases involved a neutral ENSO. In general, a neutral ENSO in which Region 1+2 had a cold anomaly and Region 3.4 had a warm anomaly (as has been the case in the 6 week moving average) saw a warmer than normal December. Such neutral ENSO cases accounted for about 27% of all neutral ENSO December cases during the 1981-2018 period. This data does not consider blocking, as it is too soon to be confident about that factor in December. However, the greatest warmth coincide with a negative PDO while the coldest outcome coincided with a strongly positive PDO (+1.00 or above for December). Therefore, the first part of winter could start off milder than normal in the Middle Atlantic and southern New England regions. The SOI was +10.63 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.989. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September through November in New York City was 58.9° (59.6° adjusted). All cases featured a warmer than normal fall. There remains a potential for autumn 2019 to rank among the 30 warmest cases on record. For New York City, that would translate into a September-November mean temperature of at least 58.8°. In August, the AO averaged -0.722 and in September the AO rose to +0.306. The possible transition to predominantly positive values from September into October has been a relatively uncommon occurrence. Since 1950, only 1963 and 2011 saw a transition of an August value of -0.500 or below to positive values in September and a positive average in October. Both cases featured a warmer than normal November in the Middle Atlantic and southern New England areas. Despite what might be a somewhat cooler than normal start to November, a warmer than normal outcome for the month as a whole remains likely. On October 18, the MJO was in Phase 2 at an amplitude of 1.362 (RMM). The October 17-adjusted amplitude was 1.117. In the two prior cases when the MJO moved into Phase 1 in late September or early October and then remained in Phase 1 for 12 or more consecutive days as occurred this year, the average decline in the 14-day average temperature for the 2-3 weeks that followed the MJO's moving out of Phase 1 was gradual. The current long-duration Phase 1 episode suggests that the second half of October could be warmer than normal. For New York City, an October mean temperature of 58.5°-59.5° (1.6° to 2.6° above normal) would be implied by those earlier long-duration Phase 1 cases. Based on the sensitivity analysis, the estimated October mean temperature is currently near 59.0°. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal October is approximately 78%.

Yes. I think we will get some shots at snow in December even if the month is warm overall.

The kind of sustained blocking necessary to lock in a prolonged cold pattern is lacking. Transient blocks won’t cut it, unfortunately. November still appears likely to be warmer than normal. December could be, as well.

I agree. The forecast upper air pattern is not conducive to its coming north. It will likely make a sharp turn to the right. Whether that happens from eastern North Carolina or extreme southeast Virginia is still somewhat uncertain. The former is probably the more likely outcome.