donsutherland1

Morning thoughts… Today will be partly sunny and continued cooler than normal. High temperatures will likely reach the lower and middle 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 40° Newark: 44° Philadelphia: 47° Normals: New York City: 30-Year: 49.0°; 15-Year: 49.4° Newark: 30-Year: 49.6°; 15-Year: 50.1° Philadelphia: 30-Year: 50.6°; 15-Year: 51.1° The cool weather will continue through tomorrow.

Dry but cool weather will continue into the middle of the week. A brief push of milder air could occur on Thursday ahead of the next cold front. No Arctic blasts appear likely for the foreseeable future. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9; 2021-22: November 28 Philadelphia: Normal: December 19; 2020-21: December 16 Out West, Denver has yet to see its first measurable snowfall through November 28. The previous record latest first measurable snowfall occurred on November 21, 1934. Phoenix reached 80° for the 24th time this month. That tied the November record, which was set in 1949. That record could be surpassed tomorrow. Atlantic blocking (AO and NAO) will break down during the first week of December. As a result, temperatures will likely turn milder for at least a time. Although the first 10 days of December will likely average somewhat cooler than normal overall from a lag in the pattern response to the breakdown in Atlantic blocking, the first half of the month overall could wind up near normal or somewhat warmer than normal. Afterward, developments related to the EPO and AO could determine the outcome for much of the remainder of the month. For now, there remains uncertainty about the evolution of the teleconnections. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 29 4 pm is 16.41". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -0.7°C for the week centered around November 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.80°C and the ENSO Region 3.4 anomaly has averaged -0.90°C. La Niña conditions will likely persist into at least late winter. The SOI was -1.72 today. The preliminary Arctic Oscillation (AO) figure was -0.829 today. On November 27 the MJO was in Phase 4 at an amplitude of 1.104 (RMM). The November 26-adjusted amplitude was 1.255 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

Morning thoughts… Today will be partly sunny and continued cooler than nor all. High temperatures will likely reach the lower and middle 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 43° Newark: 46° Philadelphia: 46° Normals: New York City: 30-Year: 49.4°; 15-Year: 49.7° Newark: 30-Year: 50.0°; 15-Year: 50.4° Philadelphia: 30-Year: 51.0°; 15-Year: 51.5° The cool weather will continue through the remainder of November.

Light snow and flurries fell across the region today. A few places picked up a coating of snow. Newark received 0.1" of snow.In the wake of the weak system responsible for the snowfall, dry but cool weather will follow into the middle of the week. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9; 2021-22: November 28 Philadelphia: Normal: December 19; 2020-21: December 16 Out West, near record to record warmth prevailed in a number of cities. Records included: Helena: 65° (old record: 56°, 2014) and Portland: 63° (old record: 59°, 1940). The temperature at Helena was the highest on record this late in the season. As the ongoing blocking weakens over the next week, temperatures will likely turn milder for at least a time starting during the first week of December. The probability of a relatively mild EPO+/AO+ pattern through at least the first half of December has increased in recent days. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 28 4 pm is 16.41". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter. The SOI was +6.42 today. The preliminary Arctic Oscillation (AO) figure was -1.184 today. On November 26 the MJO was in Phase 4 at an amplitude of 1.251 (RMM). The November 25-adjusted amplitude was 1.177 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

For one thing, the blocking wasn’t as strong as forecast 5-7 days ago.

From Larchmont, NY:

Light snow.

Nothing reported yet.

Morning thoughts… Today will be variably cloudy and cold. Some snow flurries and snow showers are possible, especially this morning. The areas with the highest chance of measurable snow are to the north and west of Newark, New York City, and Bridgeport. High temperatures will likely reach the lower and middle 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 43° Newark: 46° Philadelphia: 45° Normals: New York City: 30-Year: 49.7°; 15-Year: 50.0° Newark: 30-Year: 50.3°; 15-Year: 50.7° Philadelphia: 30-Year: 51.3°; 15-Year: 51.8° The cool weather will continue through the remainder of November.

Tomorrow will be another unseasonably cool day. There is a small chance that a weak system could bring a period of snow showers or light snow or flurries to parts of the region tomorrow. The areas with the highest probability of seeing measurable snow are those that are to the northwest of Newark, New York City, and Bridgeport. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9 Philadelphia: Normal: December 19; 2020-21: December 16 As the ongoing blocking weakens over the next week, temperatures will likely turn milder for at least a time starting during the first week of December. The probability of a relatively mild EPO+/AO+ pattern through at least the first half of December has increased in recent days. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 26 4 pm is 16.41". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter. The SOI was +20.87 today. The preliminary Arctic Oscillation (AO) figure was -1.336 today. On November 25 the MJO was in Phase 4 at an amplitude of 1.171 (RMM). The November 24-adjusted amplitude was 1.308 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

So far, no such event is showing up on the EPS forecast, which goes out two weeks. At present 1 mb, 10 mb, and 30 mb are all near normal or cooler than normal. Until there is consensus, my confidence in a stratospheric warming event remains low. That the MJO has been stuck in phases 3-5 (currently 4) for almost all of November isn’t helping things either. I agree with you that we need something to trigger a pattern change that would yield more sustained wintry weather.

Morning thoughts… Today will be partly sunny and unseasonably cold. High temperatures will likely reach the lower and middle 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 41° Newark: 44° Philadelphia: 44° Normals: New York City: 30-Year: 50.0°; 15-Year: 50.3° Newark: 30-Year: 50.7°; 15-Year: 51.1° Philadelphia: 30-Year: 51.7°; 15-Year: 52.1° There remains a possibility that parts of the region could see snow showers or even a light snowfall tomorrow. The areas with the highest chance of measurable snow are to the north and west of Newark, New York City, and Bridgeport.

A much colder air mass began moving into the region today. A few locations saw some snow flurries during the late afternoon. An unseasonably cold weekend lies ahead. There is a small chance that a weak system could bring a period of light snow or flurries to parts of the region late Sunday into Monday. The areas with the highest probability of seeing snowfall are those that are northwest of Newark, New York City, and Bridgeport. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9 Philadelphia: Normal: December 19; 2020-21: December 16 As the ongoing blocking weakens over the next week, temperatures will likely turn milder for at least a time starting during the first week of December. The probability of a relatively mild EPO+/AO+ pattern through at least the first half of December has increased in recent days. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 26 4 pm is 16.41". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter. The SOI was +30.98 today. The preliminary Arctic Oscillation (AO) figure was -0.906 today. On November 24 the MJO was in Phase 4 at an amplitude of 1.303 (RMM). The November 23-adjusted amplitude was 0.937 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

A snow flurry:

Morning thoughts… Light rain will move out of the region and the clouds could break late in the day. High temperatures will likely reach the middle and upper 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 46° Newark: 49° Philadelphia: 49° Normals: New York City: 30-Year: 50.4°; 15-Year: 50.6° Newark: 30-Year: 51.0°; 15-Year: 51.4° Philadelphia: 30-Year: 52.0°; 15-Year: 52.4° A cold weekend lies ahead. There remains a possibility that parts of the region could see a light snowfall Sunday night into Monday. The areas with the highest chance of measurable snow are to the north and west of Newark, New York City, and Bridgeport.

After today's brief shot of warmer air, much colder air is again poised to move into the region. Tomorrow will see temperatures hold steady or fall from the 40s during the afternoon and evening hours. An unseasonably cold weekend will follow. There is a small chance that a weak system could bring a period of light snow or flurries to parts of the region late Sunday into Monday. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9 Philadelphia: Normal: December 19; 2020-21: December 16 The temperature anomaly for November 20-30 is on course to average below normal due to the development of AO blocking. The recent guidance has been correcting colder in response to this blocking. The Arctic Oscillation fell below -1.000 on November 23. Such strong blocking typically favors a period of colder than normal weather (November 20-30, 1991-2020 period): Boston: Normal: 42.2°; AO cases: 38.4° New York City: Normal: 45.5°; AO cases: 41.7° Philadelphia: Normal: 45.4°; AO cases: 41.7° The duration of the blocking remains uncertain. Should blocking dissipate, warmer conditions could develop near the start of December. Both the CFSv2 and EPS weeklies favor a return of warmer air at some point during the first week of December. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 25 4 pm is 16.28". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter. The SOI was +24.68 today. The preliminary Arctic Oscillation (AO) figure was -1.222 today. On November 23 the MJO was in Phase 4 at an amplitude of 0.931 (RMM). The November 22-adjusted amplitude was 0.733 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

Morning thoughts… Sunshine will give way to increasing clouds this afternoon. It will be noticeably milder. High temperatures will likely reach the lower and middle 50s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 53° Newark: 56° Philadelphia: 55° Normals: New York City: 30-Year: 50.7°; 15-Year: 50.9° Newark: 30-Year: 51.4°; 15-Year: 51.8° Philadelphia: 30-Year: 52.4°; 15-Year: 52.7° After some overnight showers, it will turn colder again. There remains a possibility that parts of the region could see a light snowfall Sunday night into Monday.

Tomorrow will witness the return of a milder air mass, but its stay will be short-lived. Another strong cold front will move across the region tomorrow night. In its wake, an unseasonably cold weekend will follow. There is a small chance that a weak system could bring a period of light snow or flurries to parts of the region late Sunday into Monday. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9 Philadelphia: Normal: December 19; 2020-21: December 16 The temperature anomaly for November 20-30 is on course to average below normal due to the development of AO blocking. The recent guidance has been correcting colder in response to this blocking. The Arctic Oscillation fell below -1.000 on November 23. Such strong blocking typically favors a period of colder than normal weather (November 20-30, 1991-2020 period): Boston: Normal: 42.2°; AO cases: 38.4° New York City: Normal: 45.5°; AO cases: 41.7° Philadelphia: Normal: 45.4°; AO cases: 41.7° The duration of the blocking remains uncertain. Should blocking dissipate, warmer conditions could develop near the start of December. Both the CFSv2 and EPS weeklies favor a return of warmer air at some point during the first week of December. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 23 4 pm is 16.28". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter. The SOI was +11.90 today. The preliminary Arctic Oscillation (AO) figure was -1.749 today. On November 22 the MJO was in Phase 4 at an amplitude of 0.733 (RMM). The November 21-adjusted amplitude was 1.027 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 98% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

Morning thoughts… Today will partly to mostly sunny but still chilly. High temperatures will likely reach the middle and upper 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 45° Newark: 49° Philadelphia: 49° Normals: New York City: 30-Year: 51.1°; 15-Year: 51.3° Newark: 30-Year: 51.8°; 15-Year: 52.1° Philadelphia: 30-Year: 52.8°; 15-Year: 53.1° Tomorrow be milder as clouds increase ahead of the next cold front. There remains a possibility that parts of the region could see a light snowfall Sunday night into Monday.

I agree. It will probably fall to 30.

It reached 32 this morning.

Let’s see how things work out on tonight’s guidance. It would be nice to have at least a light snowfall to before the end of the month.

About 20% of EPS members have 1” or more. The potential exists for a light snowfall.

The coldest air of the season so far covers the region. Tomorrow will be another fair but cold day. Thanksgiving Day will witness the return of a milder air mass, but its duration will be short-lived. Another strong cold front will move across the region Thursday night. In its wake, an unseasonably cold weekend will follow. There is a small chance that a weak system could bring a period of light snow or flurries to parts of the region on Sunday. First measurable snowfall statistics for select cities: Allentown: Normal: December 6; 2020-21: December 9 Bridgeport: Normal: December 3; 2020-21: December 16 Islip: Normal: December 10; 2020-21: December 16 New York City: Normal: December 13; 2020-21: December 16 Newark: Normal: December 9; 2020-21: December 9 Philadelphia: Normal: December 19; 2020-21: December 16 The temperature anomaly for November 20-30 is on course to average below normal due to the development of AO blocking. The recent guidance has been correcting colder in response to this blocking. The Arctic Oscillation fell below -1.000 on November 23. Such strong blocking typically favors a period of colder than normal weather (November 20-30, 1991-2020 period): Boston: Normal: 42.2°; AO cases: 38.4° New York City: Normal: 45.5°; AO cases: 41.7° Philadelphia: Normal: 45.4°; AO cases: 41.7° The duration of the blocking remains uncertain. Should blocking dissipate, warmer conditions could develop near the start of December. Both the CFSv2 and EPS weeklies favor a return of warmer air at some point during the first week of December. Fall 2021 is well on course to being wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27". Fall rainfall through November 23 4 pm is 16.28". Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter. The SOI was +8.40 today. The preliminary Arctic Oscillation (AO) figure was -1.410 today. On November 21 the MJO was in Phase 4 at an amplitude of 1.023 (RMM). The November 20-adjusted amplitude was 1.305 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.4° (1.6° below normal).

A small accumulation also shows up on the National Blend of Models.