donsutherland1

In much of the region, the temperature topped out in the upper 40s and lower 50s. However, from Philadelphia to Washington, DC, temperatures reached the upper 60s and lower 70s. That warm air will push northward tonight into tomorrow. As a result, tomorrow and Friday will likely be the warmest days so far this year. Temperatures in the region will likely rise well into the 60s on both days. Some areas, including Philadelphia and Newark, will likely see temperatures top out in the 70s on one or both days. Afterward, temperatures could begin to cool. However, just as was the case during the historic February arctic outbreak, the core of the cold will likely remain west of the region on account of a fairly expansive western Atlantic ridge. Further, since 1950, nearly 60% of days two weeks after the AO reached +3.000 or above in the March 1-15 period were warmer than when the AO reached +3.000 or above. The mean figure was 2.8°. This suggests that it is more likely than not that the closing week of March could see a return to warmer conditions. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.7°C for the week centered around March 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.43°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely prevail at least through most of March. Afterward, neutral-cool ENSO conditions will likely develop as the spring progresses. The SOI was +4.21 today. The SOI had been negative for 10 consecutive days. That development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages. The preliminary Arctic Oscillation (AO) figure was +3.476 today. Over the next few days, the AO is forecast to continue to rise sharply. The ensembles suggest that the AO could peak at or above +5.000. This would be a rare event in March. Since 1950, only March 7-8, 2015 saw the AO at or above +5.000. The March record is +5.588, which was set on March 8, 2015. On March 9 the MJO was in Phase 1 at an amplitude of 1.092 (RMM). The March 8-adjusted amplitude was 1.010 (RMM). The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow. Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February. Based on sensitivity analysis applied to the latest guidance, there is an implied 50% probability that New York City will have a warmer than normal March. March will likely finish with a mean temperature near 43.0° (0.5° above normal).

There were a mixture of ENSO states involved. The sample size is too small to draw firm conclusions.

Today's preliminary value of the AO was +3.476. On February 11, it was -5.254. The previous highest AO within 30 days of a -5.000 or below figure was +3.351 on April 21, 2013. 30 days earlier on March 22, the AO was -5.240.

Morning thoughts... Today will be fair and somewhat cooler. Temperatures will likely top out mainly in the middle and upper 50s in most of the region. Some parts of the region, especially around Philadelphia and interior New Jersey could see readings reach the 60s. Likely high temperatures around the region include: New York City (Central Park): 56° Newark: 56° Philadelphia: 63° Tomorrow and Friday will likely see the warmest weather since late fall 2020. Cooler weather could develop near or after mid-month. This weekend into Monday, a major snowstorm appears likely in parts of the Rockies, including Casper, Cheyenne, and possibly Denver. To date, Casper has received 41.8” of snow, which is 10.4” below normal. Following the weekend storm, Casper should have above normal snowfall.

The evolution of the La Niña, the persistence of the western Atlantic ridge, especially if it links up to ridging over the Plains States, and precipitation will likely shape the kind of summer that lies ahead. From this vantage point, it looks to be warmer than normal, but a lot can change between now and then.

Under brilliant sunshine, the temperature soared into the 60s across much of the region. High temperatures included: Allentown: 61° (warmest since December 25) Boston: 61° (warmest since December 1) Bridgeport: 64° (old record: 63°, 2020; warmest since November 30) Islip: 63° (warmest since December 13) New York City: 64° (warmest since November 26) Newark: 66° (warmest since November 26) Philadelphia: 69° (warmest since November 11) Poughkeepsie: 61° (warmest since December 25) Tomorrow will likely be a few degrees cooler and then the warmest air of the season will arrive for Thursday and Friday. Afterward, temperatures could begin to cool. However, just as was the case during the historic February arctic outbreak, the core of the cold will likely remain west of the region on account of a fairly expansive western Atlantic ridge. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.7°C for the week centered around March 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.43°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely prevail at least through most of March. Afterward, neutral-cool ENSO conditions will likely develop as the spring progresses. The SOI was -8.09 today. The SOI has now been negative for 10 consecutive days. The last time that occurred was March 16-31, 2020 when the SOI was negative for 16 consecutive days. This development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages. The preliminary Arctic Oscillation (AO) figure was +2.094 today. Over the next few days, the AO is forecast to continue to rise sharply. The ensembles suggest that the AO could peak at or above +5.000. This would be a rare event in March. Since 1950, only March 7-8, 2015 saw the AO at or above +5.000. The March record is +5.588, which was set on March 8, 2015. On March 8 the MJO was in Phase 8 at an amplitude of 1.022 (RMM). The March 7-adjusted amplitude was 0.758 (RMM). The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow. Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February. Based on sensitivity analysis applied to the latest guidance, there is an implied 53% probability that New York City will have a warmer than normal March. March will likely finish with a mean temperature near 43.0° (0.5° above normal).

There has been a statistically significant rise in early season storms. As the roots of the cause (warmer SSTs) is likely to endure (persistent energy imbalance with the oceans taking up most of the extra heat), one is likely dealing with a long-term change, not a periodic anomaly related to early-season tropical cyclone formation.

Statistically, a case can probably be made for lengthening the hurricane season given the rise in oceanic heat content that has translated into warmer oceans than in the past.

Morning thoughts... At 7:50 am, an area of clouds stretched from central Maryland east-northeastward across southeastern Pennsylvania and southern New Jersey. Those clouds will yield to sunshine later this morning. Overall, today will be noticeably warmer than yesterday. Temperatures will likely top out mainly in the upper 50s and lower 60s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 61° Newark: 62° Philadelphia: 63° Tomorrow will be somewhat cooler. Thursday and Friday will likely see the warmest weather since late fall 2020. Cooler weather could develop near or after mid-month.

No. This air mass is cold but nothing like the February one relative to normal (standard deviations from normal).

The temperature rose into the 40s across much of the region today. Not too far south in Baltimore and Washington, the temperature rose into the 50s. Tomorrow, that warmth will surge northward with much of the region seeing the temperature top out in the 50s with some 60s possible. Wednesday could be a few degrees cooler and then the warmest air of the season will arrive for Thursday and Friday. The 60° isotherm will likely extend into southern and perhaps even central New England during the height of the warmth. Central Park will very likely see its first 60° reading since December 25 and likely its highest temperatures since late November. Toward the latter part of the week, near or just after mid-month, temperatures could begin to cool as the AO falls sharply from its forecast peak. However, just as was the case during the historic February arctic outbreak, the core of the cold will likely remain west of the region on account of a fairly expansive western Atlantic ridge. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.7°C for the week centered around March 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.43°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely prevail at least through most of March. Afterward, neutral-cool ENSO conditions will likely develop as the spring progresses. The SOI was -4.12 today. The SOI has now been negative for nine consecutive days. The last time that occurred was March 16-31, 2020 when the SOI was negative for 16 consecutive days. This development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages. The preliminary Arctic Oscillation (AO) figure was +1.206 today. Over the next few days, the AO is forecast to rise sharply. The ensembles suggest that the AO could peak at or above +5.000. This would be a rare event in March. Since 1950, only March 7-8, 2015 saw the AO at or above +5.000. The March record is +5.588, which was set on March 8, 2015. On March 7 the MJO was in Phase 8 at an amplitude of 0.764 (RMM). The March 6-adjusted amplitude was 0.713 (RMM). The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow. Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February. Based on sensitivity analysis applied to the latest guidance, there is an implied 52% probability that New York City will have a warmer than normal March. March will likely finish with a mean temperature near 43.0° (0.5° above normal).

This could be kind of a replay of February where the core of the cold never reaches the East.

April snows can be very picturesque. One photo from the April 2, 2018 snowstorm:

That’s possible. It may take a little longer before a stormier pattern develops.

22°. No radiational cooling.

Morning thoughts... After a cold start, today will be mostly sunny and somewhat milder than yesterday. Temperatures will likely top out mainly in the lower and middle 40s most of the region. Likely high temperatures around the region include: New York City (Central Park): 43° Newark: 44° Philadelphia: 47° Tomorrow will be fair dramatically warmer. Thursday and Friday will likely see the warmest weather since late fall 2020. Cooler weather could develop near or after mid-month.

Under bright sunshine, the temperature soared 40° or above in many parts of the region. Nevertheless, March 2021 became the 11th case since 1990 during which March 1-7 had a mean temperature below 35° in Central Park. The 10 prior cases were: 1990, 1996, 2001, 2003, 2006, 2007, 2009, 2014, 2015, and 2019. In seven (70%) of those cases, New York City saw measurable snow on or after March 15. Four of those cases saw 4" or more (1996, 2003, 2007, and 2015). After a similar to perhaps somewhat milder day tomorrow, a strong warming trend will commence on Tuesday. Many parts of the region will likely see their warmest temperatures so far this year later this week. The 60° isotherm will likely extend into southern and perhaps even central New England during the height of the warmth. Central Park will very likely see its first 60° reading since December 25 and perhaps its highest temperatures since late November. Toward the latter part of the week, near or just after mid-month, temperatures could begin to cool as the AO falls sharply from its forecast peak. The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -1.2°C for the week centered around February 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.60°C and the ENSO Region 3.4 anomaly has averaged -0.80°C. La Niña conditions will likely prevail at least through most of March. The SOI was -3.40 today. The SOI has now been negative for eight consecutive days. The last time that occurred was June 14-21, 2020 when the SOI was negative for eight consecutive days. This development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages. The preliminary Arctic Oscillation (AO) figure was +1.038 today. On March 6 the MJO was in Phase 8 at an amplitude of 0.715 (RMM). The March 5-adjusted amplitude was 0.784 (RMM). The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow. Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February. Based on sensitivity analysis applied to the latest guidance, there is an implied 52% probability that New York City will have a warmer than normal March. March will likely finish with a mean temperature near 43.0° (0.5° above normal).

Some early indications of spring at the New York Botanical Garden (someone forgot to inform nature of the 18z GFS’s crystal ball):

There is no remotely close case. The highest AO reading 30 days or less following a -5.000 AO reading occurred during 2013. The top 3 figures: 1. March 22, 2013: -5.240; Highest within 30 days: +3.351, April 21 2. March 21, 2013: -5.399; Highest within 30 days: +3.270, April 20 3. March 20, 2013: -5.688; Highest within 30 days: +3.160, April 19 There were no other cases where the AO reached +3.000 within 30 days after the AO had fallen to -5.000 or below.

Morning thoughts... The long-modeled sharp rise in the Arctic Oscillation (AO) is now underway. This development will pave the way for the warmest weather so far this year later this week. Today will be partly sunny and somewhat milder than yesterday. Temperatures will likely top out mainly in the upper 30s and lower 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 38° Newark: 40° Philadelphia: 42° Tomorrow will be fair and a little milder. Tuesday will be dramatically warmer and the latter part of the week will likely see the warmest weather since late fall 2020. Cooler weather could develop near or after mid-month.

Tomorrow will be another cool day, capping a first week of March with temperature anomalies of 4°-6° below normal across the northern Middle Atlantic and southern New England areas. Early next week, a strong warming trend should commence. Parts of the region will likely see their warmest temperatures so far this year. The 60° isotherm will likely extend into southern and perhaps even central New England during the height of the warmth. Central Park will very likely see its first 60° reading since December 25 and perhaps its highest temperatures since late November. Toward the latter part of the week, near or just after mid-month, temperatures could begin to cool as the AO falls sharply from its forecast peak. The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -1.2°C for the week centered around February 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.60°C and the ENSO Region 3.4 anomaly has averaged -0.80°C. La Niña conditions will likely prevail at least through most of March. The SOI was -2.73 today. The SOI has now been negative for seven consecutive days. The last time that occurred was October 14-20, 2020 when the SOI was negative for seven consecutive days. This development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages. The preliminary Arctic Oscillation (AO) figure was +0.243 today. On March 5 the MJO was in Phase 8 at an amplitude of 0.781 (RMM). The March 4-adjusted amplitude was 0.892 (RMM). The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow. Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February.

Morning thoughts... After a few widely scattered snow flurries, today will be partly sunny and unseasonably cold. Temperatures will likely top out mainly in the middle and upper 30s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 36° Newark: 37° Philadelphia: 38° Tomorrow will be fair and a bit milder. Next week will likely see the arrival of the warmest weather so far this season. Cooler weather could develop near or after mid-month.

Tomorrow will be fair and continued cold. Sunday will be somewhat warmer and still dry. Overall, the first week of March will see variable temperatures, even as the week will very likely average cooler than normal. Another short but sharp cold shot is possible Friday through the weekend. Afterward, a strong warming trend should commence. Parts of the region will likely see their warmest temperatures so far during the second week of March. The 60° isotherm could extend into southern and perhaps even central New England during the height of the warmth. Central Park will very likely see its first 60° reading since December 25 and perhaps its highest temperatures since late November. Toward the latter part of the second week of the month or just after mid-month, temperatures could begin to cool as the AO falls sharply from its forecast peak. The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -1.2°C for the week centered around February 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.60°C and the ENSO Region 3.4 anomaly has averaged -0.80°C. La Niña conditions will likely prevail at least through most of March. The SOI was -6.94 today. The SOI has now been negative for six consecutive days. The last time that occurred was October 14-20, 2020 when the SOI was negative for seven consecutive days. This development could be an early indication that what has been a fairly stable La Niña regime throughout the winter could be moving closer to its end stages. The preliminary Arctic Oscillation (AO) figure was -0.805 today. On March 4 the MJO was in Phase 7 at an amplitude of 0.892 (RMM). The March 3-adjusted amplitude was 0.719 (RMM). The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Since January 1, New York City has picked up 28.1" snow. Winters that saw December receive 10" or more snow, less than 10" in January, and then 10" or more in February in New York City, saw measurable snowfall in March or April in 83% of cases. Winter 2009-2010 was the exception where only a trace of snow was recorded. This group of winters saw 6" or more snow during the March-April period in 50% of the cases. All said, it is more likely than not that there will be measurable snowfall after February.

With the Arctic Oscillation (AO) poised to rise sharply, the latest EPS ensembles continue to suggest a short period in the medium-range where the 500 mb height anomalies are reasonably similar to those that prevailed in the means during the March 9-15, 2020 period. AO: March 9-15, 2020: Average: +3.366 High: +3.993 Low: +2.728 That was a very warm period. Select temperature data: Boston: Average High: 56.9° Average Low: 37.3° Mean: 47.0° Highest: 72° New York City: Average High: 60.7° Average Low: 45.0° Mean: 52.9° Highest: 72° Philadelphia: Average High: 63.6° Average Low: 43.1° Mean: 53.4° Highest: 74° The March 11-13 period could see the highest maximum and minimum temperatures. Some daily record high minimum and maximum temperature records could be challenged if the warmer guidance prevails. There remains a distinct possibility that the second half of March could see additional measurable snow.

Morning thoughts... Today will be mostly sunny and unseasonably cold. Temperatures will likely top out mainly in the middle and upper 30s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 36° Newark: 37° Philadelphia: 38° A dry but cool weekend lies ahead. Next week will likely see the arrival of the warmest weather so far this season. Cooler weather could develop near or after mid-month. Snow statistics for the March 16-31, 1991-2020 base period: New York City: Average: 1.7”; 53% cases with measurable snow; 23% cases with 4” or more; most snow: 9.4”, 1992 Philadelphia: Average: 1.2”; 43% cases with measurable snow; 10% cases with 4” or more; most snow: 7.6”, 2018