donsutherland1

Showers and perhaps thundershowers are possible tonight into tomorrow morning. A general 0.50"-1.00" of rain is likely with some locally higher amounts. Afterward, the sun will return and it will remain mild for one more day. A sustained cool period will develop just after the weekend and continue into the opening days of May. The opening days of May could also see the first period of much above normal warmth develop in the Pacific Northwest. A cool period in the East is supported by the MJO's having moved into Phase 8, along with the development of strong Atlantic blocking. That blocking is forecast to fade during the first week of May leading to the possible development of a return of warmer conditions during the second week of the month. Given the timeframe involved, there remains considerable uncertainty beyond the first week of May. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. The potential exists for some locations to challenge their warmest April on record. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was +0.1°C for the week centered around April 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.03°C and the ENSO Region 3.4 anomaly has averaged +0.02°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -26.39 today. The preliminary Arctic Oscillation (AO) was -3.255 today. On April 20 the MJO was in Phase 8 at an amplitude of 1.615 (RMM). The April 19-adjusted amplitude was 1.635 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 58.0° (4.3° above normal). That would rank April 2023 as the warmest April on record.

Some photos from Earth Day at the New York Botanical Garden. It was mostly cloudy with a few intervals of sunshine. Temperatures were in the middle 60s.

Tomorrow will be variably cloudy. There could be some fog and drizzle in coastal areas. Showers and perhaps thundershowers are possible tomorrow night into Sunday morning. A sustained cool period will develop just after the weekend and continue into the opening days of May. The opening days of May could also see the first period of much above normal warmth develop in the Pacific Northwest. A cool period in the East is supported by the MJO's having moved into Phase 8, along with the development of strong Atlantic blocking. That blocking is forecast to fade during the first week of May leading to the possible development of a return of warmer conditions during the second week of the month. Given the timeframe involved, there remains considerable uncertainty beyond the first week of May. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. The potential exists for some locations to challenge their warmest April on record. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was +0.1°C for the week centered around April 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.03°C and the ENSO Region 3.4 anomaly has averaged +0.02°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -19.97 today. The preliminary Arctic Oscillation (AO) was -3.455 today. On April 19 the MJO was in Phase 8 at an amplitude of 1.635 (RMM). The April 18-adjusted amplitude was 1.766 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 58.0° (4.3° above normal). That would rank April 2023 as the warmest April on record.

Tomorrow will be a warm day except along the immediate coastal plain. The temperature could reach the upper 70s and perhaps lower 80s tomorrow in southern New Jersey and Philadelphia and lower 70s in New York City. A more sustained cool period could develop during or just after the weekend and continue into the opening days of May. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. The potential exists for some locations to challenge their warmest April on record. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was +0.1°C for the week centered around April 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.03°C and the ENSO Region 3.4 anomaly has averaged +0.02°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was +2.88 today. The preliminary Arctic Oscillation (AO) was -2.955 today. On April 18 the MJO was in Phase 7 at an amplitude of 1.764 (RMM). The April 17-adjusted amplitude was 1.697 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 58.0° (4.3° above normal). That would rank April 2023 as the warmest April on record.

Through mid-spring, most of the Northern Hemisphere has seen a warmer than normal spring. Cold has remained largely confined to western North America while the East has been exceptionally warm.

Milder air will continue to overspread the region tomorrow. The temperature could reach the upper 70s and perhaps lower 80s on Friday in southern New Jersey and Philadelphia and lower 70s in New York City. A more sustained cool period could develop during or just after the weekend and continue into the opening days of May. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. The potential exists for some locations to challenge their warmest April on record. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was +0.1°C for the week centered around April 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.03°C and the ENSO Region 3.4 anomaly has averaged +0.02°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was +4.47 today. The preliminary Arctic Oscillation (AO) was -2.459 today. On April 17 the MJO was in Phase 7 at an amplitude of 1.697 (RMM). The April 16-adjusted amplitude was 1.631 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 58.0° (4.3° above normal). That would rank April 2023 as the warmest April on record.

After a cool night, it will begin to turn milder tomorrow. Noticeably warmer air will then return starting Thursday. The temperature could reach the upper 70s and perhaps lower 80s on Friday. A more sustained cool period could develop during or just after the next weekend and continue into the opening days of May. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. The potential exists for some locations to challenge their warmest April on record. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was +0.1°C for the week centered around April 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +2.03°C and the ENSO Region 3.4 anomaly has averaged +0.02°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -1.01 today. The preliminary Arctic Oscillation (AO) was -1.478 today. On April 16 the MJO was in Phase 7 at an amplitude of 1.519 (RMM). The April 15-adjusted amplitude was 1.722 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 58.0° (4.3° above normal). That would rank April 2023 as the warmest April on record.

A brief shot of much cooler air will move through the region tomorrow and Wednesday. Tomorrow will likely see the temperature stay in the 50s in New York City and struggle to reach the lower 60s in Philadelphia. Noticeably warmer air will then return after midweek. The temperature could reach the upper 70s and perhaps lower 80s on Friday. A more sustained cool period could develop during or just after the next weekend and continue into the opening days of May. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was 0.0°C for the week centered around April 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.77°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -7.43 today. The preliminary Arctic Oscillation (AO) was -0.955 today. On April 15 the MJO was in Phase 7 at an amplitude of 1.750 (RMM). The April 14-adjusted amplitude was 1.661 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 97% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 57.8° (4.1° above normal). That would rank as the second warmest April on record.

Unfortunately, I am not aware of such data.

Following four consecutive 80° or above days, Madison is about to see 2"-5" of snow overnight into tomorrow. Should measurable snowfall be recorded today, that would be the first time Madison has ever seen measurable snowfall one day after an 80° or above reading. Madison has had 3 measurable snowfalls two days after such a temperature: April 2, 1978: 0.5", October 23, 1979: 0.2", and April 9, 1991: 0.5". No such wintry weather is likely anytime soon in the northern Mid-Atlantic region. However, it will turn briefly cooler this week. Tomorrow will be another mild day, but a brief shot of much cooler air will follow. Tuesday may see the temperature stay in the 50s in New York City and struggle to reach the lower 60s in Philadelphia. Milder air will then follow, but a more sustained cool period could develop next weekend. April 2023 remains on a trajectory that will likely rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. A cool end to the month won't be sufficient to avoid top 10 warmth. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was 0.0°C for the week centered around April 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.77°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -12.40 today. The preliminary Arctic Oscillation (AO) was -0.848 today. On April 14 the MJO was in Phase 7 at an amplitude of 1.657 (RMM). The April 13-adjusted amplitude was 1.854 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 57.6° (3.9° above normal). That would rank as the second warmest April on record.

Fog briefly rolls in:

Today was a variably cloudy and cooler day. Parts of the region saw some rain and even thunderstorms. Temperatures reached the lower and middle 70s in contrast to yesterday's upper 80s and lower 90s. Nevertheless, record heat persisted for another day across parts of Upstate New York, Vermont, and southern Canada. Numerous high temperature records were toppled in Ontario. Burlington reached 85°, which broke the daily mark of 82° from 2003. Tomorrow will be variably cloudy with some showers. Readings will top out mainly in the upper 60s and lower 70s. Next week could even see a day where readings struggle to get out of the 50s. Overall, warmth appears likely to define April in much of the East. If the long-range guidance is accurate the first three weeks of the month could put April 2023 on a trajectory that could rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. Afterward, the latest EPS weeklies suggest that the month could finish with near normal readings. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was 0.0°C for the week centered around April 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.77°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -9.74 today. The preliminary Arctic Oscillation (AO) was -0.558 today. On April 13 the MJO was in Phase 7 at an amplitude of 1.863 (RMM). The April 12-adjusted amplitude was 2.005 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 57.6° (3.9° above normal). That would rank as the second warmest April on record.

April will likely end cool. The GEFS appears to be too warm.

The progression of NYC's earliest 70° temperature record:

NYC recorded its earliest 70F minimum temperature on record yesterday. The prior earliest such low temperature occurred on April 17, 2002. It is only the 4th such reading on record in April. Records go back to 1869.

Good charts. It's mostly climate change. I've added Climate Central's instant attribution maps to my above comment.

In the big cities, UHI and climate change amplify the warmth. But in cities like New York that have a mature urban footprint, climate change is responsible for most of the recent warming. Today’s heat was made 1.5-4 times more likely due to climate change based on Climate Central’s instant attribution algorithm. Globally, there’s little doubt that climate change is responsible for most of the observed warming.

Today was a historic day for early heat in New England. Hartford tied its April record high and established New England's earliest 95° or above reading on record. Records included: Albany: 89° (old record: 83°, 1938 and 1968) Allentown: 88° (old record: 87°, 2018) Bangor: 76° (old record: 74°, 1949) Binghamton: 85° (old record: 79°, 1968) Boston: 83° (old record: 81°, 1945) Bridgeport: 87° (old record: 73°, 1949) ***Hottest temperature so early in the season*** Concord: 90° (old record: 84°, 1870) Hartford: 96° (old record: 82°, 1941) ***Tied monthly city and state record; Earliest 95° temperature in New England*** Islip: 84° (old record: 73°, 1977, 2002, and 2022) Manchester, NH: 91° (old record: 79°, 2014) Mount Pocono, PA: 84° (old record: 82°, 1941) New York City-Central Park: 91° (old record: 85°, 1941) ***Earliest 2 consecutive 90° days*** New York City-JFK Airport: 82° (old record: 78°, 1949) New York City-LaGuardia Airport: 89° (old record: 84°, 1941) Newark: 93° (old record: 88°, 1941 and 2022) ***Earliest 93° or above reading on record*** Portland: 79° (old record: 77°, 1941) Poughkeepsie: 91° (old record: 88°, 1941) Providence: 87° (old record: 83°, 1945) Scranton: 91° (old record: 84°, 1968) ***Earliest 90° reading on record*** Syracuse: 86° (old record: 83°, 1968) Worcester: 90° (old record: 79°, 1938) ***Earliest 90° reading on record*** Cooler weather will follow. Tomorrow will be variably cloudy with some showers. Readings will top out in the middle and perhaps upper 60s. Next week could even see a day where readings struggle to get out of the 50s. Overall, warmth appears likely to define April in much of the East. If the long-range guidance is accurate the first three weeks of the month could put April 2023 on a trajectory that could rank it among the 10 warmest Aprils on record in the northern Middle Atlantic region. Afterward, the latest EPS weeklies suggest that the month could finish with near normal readings. The most recent April case to rank among the 10 warmest was: Boston: 51.7°, 2019 (5th warmest) Bridgeport: 54.0°, 2017 (1st warmest) Islip: 51.9°, 2019 (6th warmest) New Haven: 50.8°, 2022 (6th warmest) New York City-Central Park: 57.2°, 2017 (2nd warmest) New York City-JFK Airport: 55.1°, 2017 (2nd warmest) New York City-LaGuardia Airport: 57.6°, 2017 (2nd warmest) Newark: 57.2°, 2017 (4th warmest) Philadelphia: 59.0°, 2019 (3rd warmest) Poughkeepsie: 53.0°, 2017 (3rd warmest) White Plains: 53.9°, 2017 (2nd warmest) The ENSO Region 1+2 anomaly was +2.7°C and the Region 3.4 anomaly was 0.0°C for the week centered around April 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.77°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely prevail through at least mid-spring. El Niño conditions will likely develop during the summer. The SOI was -9.52 today. The preliminary Arctic Oscillation (AO) was -0.047 today. On April 12 the MJO was in Phase 6 at an amplitude of 2.004 (RMM). The April 11-adjusted amplitude was 2.033 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 94% probability that New York City will have a warmer than normal April (1991-2020 normal). April will likely finish with a mean temperature near 57.5° (3.8° above normal). That would rank as the second warmest April on record.

April 12, 1977. The highest temperature in 1976 was 89.

They did. That tied the April monthly record from April 19, 1976.

Yes, the 2002 heatwave was the earliest on record.

Yes. It’s also New England’s earliest 95-degree reading on record.

It peaked at 91.

Hartford recorded its earliest 95° reading on record: New York City also recorded its earliest two consecutive 90° days. The old record was set during April 16-17, 2002.