donsutherland1

Early clouds yielded to abundant sunshine in parts of the region sending temperatures soaring for another day. Parts of the northern Middle Atlantic and southern New England areas saw record high temperatures. High temperatures included: Allentown: 65° Boston: 65° Bridgeport: 67° (old record: 65°, 2012) Islip: 67° (old record: 65°, 1973 and 2012) New Haven: 66° (old record: 63°, 1973) New York City-JFK: 70° (old record: 68°, 1973) New York City-LGA: 69° (tied record set in 2012) New York City-NYC: 68° Newark: 71° Philadelphia: 71° Providence: 65° Poughkeepsie: 63° Trenton: 69° Westhampton: 67° (old record: 60°, 2012) The early episode of spring is now concluding. Cooler weather will return this weekend. Since 1990, 73% of cases that saw a high temperature of 70° or above during March 1-15 were followed by a low temperature of 32° or below during the following two weeks. 54% of such cases saw a low temperature below 30° during the following two weeks and 27% saw the temperature fall below 25°. The mean lowest temperature during the following two weeks was 29°. In sum, the fairly strong cold shot for early next week is consistent with recent historical experience. 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. Nevertheless, the March 16-19 period could offer a period of opportunity for a light snow event in parts of the region. 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 increase 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. This warmth is now showing up on the CFSv2's week 3 maps. Out west, a major to perhaps historic snowstorm will develop in the Rockies late tonight and continue into late Sunday or early Monday. Denver, Cheyenne, and possibly Casper, as well as the Nebraska Panhandle, will likely see heavy snowfall. Denver will likely pick up 8"-16" of snow, though there is greater uncertainty. Cheyenne will likely see 20"-30" of snow. That would set a new March record and could challenge that Cheyenne's all-time record snowstorm amount. Cheyenne's March Snowfall Records: Daily: 15.9”, March 18, 2003; 2-Day: 17.2”, March 17-18, 2003; 3-Day: 18.9”, March 5-7, 1990 Cheyenne's All-Time Snowfall Records: Daily: 19.8”, November 20, 1979; 2-Day: 25.2”, November 20-21, 1979; 3-Day: 25.6”, November 19-21, 1979 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 -6.51 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 +5.656 today. That exceeds the March record of +5.588, which was set on March 8, 2015. On March 11 the MJO was in Phase 1 at an amplitude of 1.290 (RMM). The March 10-adjusted amplitude was 1.099 (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 42.9° (0.4° above normal).

January 6, 2007: 71 degrees

JFK: 69 degrees at 3 pm (old daily record: 68 degrees, 2012)

The AO played a prominent role. For February, the AO averaged +3.440. For March, it averaged +2.990. February closed with a very strong AO+ regime (+5.911 on February 26) and the AO remained strongly positive through March 30. A strong PNA- pattern developed after the first week of March and this could have been the trigger for the sequence of events that culminated in the exceptional warmth that occurred near mid-March. Overall, the exceptional heat occurred within an enduring pattern that favored above to much above normal temperatures with only short breaks of colder weather (2/25-3/9 cool period but a smaller number of days with much below normal temperatures). Select NYC Data: February 1-24: Mean Temperature: 42.2°; Days 50° or above: 15; Days 60° or above: 4

Today’s preliminary AO value is +5.656. That would surpass the March record of +5.588, which was set on March 8, 2015. The AO is forecast to fall sharply in coming days.

Morning thoughts... On this date in 1888, a ferocious blizzard was raging across much of the northern Mid-Atlantic region into central and western New England. The temperature had fallen into the single digits. Blinding snow was being blown by near hurricane-force wind gusts into towering drifts, blocking streets and making outdoor activity all but impossible. Today will be a far more tranquil day. Under partly sunny skies, another day of unseasonable warmth will prevail. Temperatures will likely top out mainly in the middle and upper 60s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 65° Newark: 67° Philadelphia: 70° Cooler weather will return for the weekend. The March 16-19 period could offer a period of opportunity for at least some snow in parts of the region. Out west, a major to perhaps historic snowstorm is likely in parts of the Rockies, including Casper, Cheyenne, and possibly Denver from late Friday into Monday. Cheyenne will likely challenge some of its March snowfall records. There is a chance that Cheyenne’s all-time snowfall record could be challenged. At present, Cheyenne looks to be on track to pick up 20”-30” of snow. March Snowfall Records: Daily: 15.9”, March 18, 2003; 2-Day: 17.2”, March 17-18, 2003; 3-Day: 18.9”, March 5-7, 1990 All-Time Snowfall Records: Daily: 19.8”, November 20, 1979; 2-Day: 25.2”, November 20-21, 1979; 3-Day: 25.6”, November 19-21, 1979

Parts of Long Island and the Connecticut shore were locked in temperatures that rose no higher than the upper 50s. Elsewhere in the region, sunshine boosted temperatures to near record and record highs from Philadelphia to New York City. High temperatures included: Allentown: 73° (old record: 71°, 1977) Baltimore 79° (old record: 75°, 1967) New York City: 71° Newark: 75° (old record: 71°, 1977) Philadelphia: 74° (old record: 72°, 1977) Poughkeepsie: 71° Reading: 77° (old record: 74°, 1986) Sterling: 79° (old record: 77°, 1990) Trenton: 73° (old record: 72°, 1977) Washington, DC: 79° (old record: 78°, 1967) Wilmington, DE: 74° (old record: 73°, 1967) Tomorrow will be another very warm day. Temperatures in the region will likely rise well into the 60s. Some areas could again see the temperature reach or exceed 70°. Afterward, temperatures will cool. Since 1990, 73% of cases that saw a high temperature of 70° or above during March 1-15 were followed by a low temperature of 32° or below during the following two weeks. 54% of such cases saw a low temperature below 30° during the following two weeks. The mean lowest temperature during the following two weeks was 29°. In sum, historic experience is consistent with the guidance that shows a fairly strong cold shot for early next week. 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. Nevertheless, the March 16-19 period could offer a period of opportunity for at least some snowfall in parts of the region. The ensembles generally favor the first half of that period. 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 increase 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 +7.71 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 +5.135 today. This is a rare event. Since 1950, only March 7-8, 2015 saw the AO at or above +5.000 during March. The March record is +5.588, which was set on March 8, 2015. On March 10 the MJO was in Phase 1 at an amplitude of 1.090 (RMM). The March 9-adjusted amplitude was 1.087 (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 48% probability that New York City will have a warmer than normal March. March will likely finish with a mean temperature near 42.8° (0.3° above normal).

EWR: 74 at 3 pm.

2 PM: NYC: 71; EWR: 73

797 SXUS71 KOKX 111835 REREWR RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 133 PM EST THU MAR 11 2021 ...RECORD HIGH TEMPERATURE SET AT NEWARK NJ... A RECORD HIGH TEMPERATURE OF 73 DEGREES WAS SET AT NEWARK NJ TODAY. THIS BREAKS THE OLD RECORD OF 71 SET IN 1977. $$

Record AO Declines: 7 days or less: -6.831, January 5-12, 1977 (from +1.029 to -5.802) 6 days or less: -6.522, November 8-14, 1959 (from +1.690 to -4.832) 5 days or less (4-day period): -6.457, January 20-24, 1976 (from +3.195 to -3.262) 3 days or less: -5.142, January 20-23, 1976 (from +3.195 to -1.947) 2 days or less: -3.841, December 13-15, 1972 (from +3.007 to -0.834) 1 day: -2.695, June 30-July 1, 1964 (from +2.988 to +0.293)

Today's preliminary value of the AO was +5.135. 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... On this date in 1888, rain began to fall in New York City. The temperature peaked at 42°, which was cool for the season but not exceptionally cold. Afterward, the temperature gradually descended into the lower 30s as an increasingly cold rain picked up in intensity. Overnight, the temperature declined more rapidly and a heavy rain turned into a howling blizzard that would carve its place into both the weather record books and New York City’s larger history. Today will be the almost complete opposite. Morning fog, mist, and clouds will lift. The afternoon will become partly to mostly sunny. In many parts of the region, the thermometer will soar to its highest levels so far this year. Long Island and the south shore of Connecticut could be exceptions. Temperatures will likely top out mainly in the middle and upper 60s in much of the region. Upper 50s are likely on Long Island and Connecticut’s south shore. Some parts of the region, including Philadelphia, will likely see the temperature push into the lower 70s. Likely high temperatures around the region include: New York City (Central Park): 65° Newark: 68° Philadelphia: 72° Tomorrow will be another unseasonably warm day. Cooler weather will likely return for the weekend. The March 16-19 period could offer a period of opportunity for at least some snow in parts of the region. Out west, a major to perhaps historic snowstorm appears likely in parts of the Rockies, including Casper, Cheyenne, and possibly Denver from late Friday into Monday. Cheyenne could challenge some of its March snowfall records: March Records: Daily: 15.9”, March 18, 2003; 2-Day: 17.2”, March 17-18, 2003; 3-Day: 18.9”, March 5-7, 1990

That’s good to see that Colin was recognized. He has always been enthusiastic about the weather. Quite frankly, hobbyists like him have filled the space left by what are often superficial and almost mechanical TV forecasts in some markets. 15-30 second sound bites are little more than time-fillers. It’s no surprise that the Lehigh Valley Facebook page cited in the article has gained a following. The Lehigh Valley has both widely varying weather and a rich weather record. The Capital Weather Gang has filled a similar need in the Washington, DC area.

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).