donsutherland1

Last weekend's brief bout of warmth is now a memory. Colder air is now drilling into the region. Generally cooler than normal to much cooler than normal conditions will now likely predominate until toward mid-month. Overall, the first 10 days of May could see readings average 2.5° to as much as 5.0° below normal in the northern Middle Atlantic and southern New England regions. During the cold, New York City could see among its lowest May readings since 2000. Since 2000, there were 25 days on which the temperature fell to 45° or below in May; 15 days on which the temperature fell to 44° or below; 4 days on which the temperature fell to 43° or below; and, 3 days on which the temperature fell to 42° or below. The last time the temperature fell below given thresholds in May were as follows: Below 45°: 44°, May 15, 2019 Below 44°: 42°, May 13, 2019 Below 42°: 41°, May 10, 2010 Below 41°: 40°, May 6, 1992 Below 40°: 38°, May 1, 1978 Moderation may commence near mid-month. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.4°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.46°C and the ENSO Region 3.4 anomaly has averaged +0.56°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies, which cooled slightly during the last week of April, could continue a steady cooling during May. The SOI had an increased tendency for positive values during April. During this month, the SOI was positive on 17 (57%) days. During the February-March period, the SOI was positive on 38% days. This shift in tendencies may further reinforce or reflect the idea that ENSO region anomalies could begin to cool. The SOI was +5.00 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.631. On May 3, the MJO was in Phase 4 at an amplitude of 1.391 (RMM). The May 2-adjusted amplitude was 1.475. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer.

Today was another warm day with temperatures again rising into the 70s and even 80s across the region. At Central Park, the temperature peaked at 80°. The last time the temperature reached 80° in New York City was October 2, 2019 when the temperature hit a daily record of 93°. High temperatures included: Bridgeport: 72°; Hartford: 81°; Islip: 73°; New York City: 80°; Newark: 80°; and, Philadelphia: 79°. This weekend's brief bout of warmth will become a memory in coming days. Generally cooler than normal to much cooler than normal conditions will now likely predominate until toward mid-month. Overall, the first 10 days of May could see readings average 2.5° to as much as 5.0° below normal in the northern Middle Atlantic and southern New England regions. During the cold, New York City could see among its lowest May readings since 2000. Since 2000, there were 25 days on which the temperature fell to 45° or below in May; 15 days on which the temperature fell to 44° or below; 4 days on which the temperature fell to 43° or below; and, 3 days on which the temperature fell to 42° or below. The last time the temperature fell below given thresholds in May were as follows: Below 45°: 44°, May 15, 2019 Below 44°: 42°, May 13, 2019 Below 42°: 41°, May 10, 2010 Below 41°: 40°, May 6, 1992 Below 40°: 38°, May 1, 1978 Moderation may commence near mid-month. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during May. The SOI had an increased tendency for positive values during April. During this month, the SOI was positive on 17 (57%) days. During the February-March period, the SOI was positive on 38% days. This shift in tendencies may further reinforce or reflect the idea that ENSO region anomalies could begin to cool. The SOI was +7.22 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.438. On May 2, the MJO was in Phase 4 at an amplitude of 1.361 (RMM). The May 1-adjusted amplitude was 1.414. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer.

A notably warmer weekend is underway. Today, the temperature reached 70° in Central Park hit 70° for the first time since March 20 when the thermometer reached 77°. High temperatures included: Allentown: 73°; Bridgeport: 74°; Harrisburg: 72°; Islip: 72°; New York City: 73°; Newark: 74°; and, Philadelphia: 73°. Some parts of the region could experience similar or even warmer high temperatures tomorrow. Nevertheless, the milder conditions will likely be short-lived. Overall, the first 10 days of May could see readings average 2.5° to as much as 5.0° below normal in the northern Middle Atlantic and southern New England regions. During the cold, New York City could see among its lowest May readings since 2000. Since 2000, there were 25 days on which the temperature fell to 45° or below in May; 15 days on which the temperature fell to 44° or below; 4 days on which the temperature fell to 43° or below; and, 3 days on which the temperature fell to 42° or below. The last time the temperature fell below given thresholds in May were as follows: Below 45°: 44°, May 15, 2019 Below 44°: 42°, May 13, 2019 Below 42°: 41°, May 10, 2010 Below 41°: 40°, May 6, 1992 Below 40°: 38°, May 1, 1978 Moderation may commence near mid-month. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during May. The SOI has seen an increased tendency for positive values during April. During this month, the SOI was positive on 17 (57%) days. During the February-March period, the SOI was positive on 38% days. This shift in tendencies may further reinforce or reflect the idea that ENSO region anomalies could begin to cool. The SOI was +3.77 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.487. On May 1, the MJO was in Phase 4 at an amplitude of 1.412 (RMM). The April 30-adjusted amplitude was 1.611. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. Based on sensitivity analysis applied to the latest guidance, there is an implied 66% probability that New York City will have a cooler than normal May.

This afternoon the temperature topped out at 73° in New York City. Some scenes:

Thanks. Stay healthy, too.

Thanks. I hope thing change soon.

May began with a continuation of the cooler than normal weather that prevailed in April. However, as the system responsible for the recent rain and clouds departed, temperatures spurted into the middle 60s late in the day. Unlike the system earlier in the week, the most recent storm largely delivered the 0.50"-1.50" rainfall with locally higher amounts as had been modeled. Two-day rainfall amounts included: Albany: 0.67"; Allentown: 1.02"; Binghamton: 1.63"; Bridgeport: 1.09"; Harrisburg: 1.55"; Islip: 0.91"; New York City: 0.91"; Newark: 0.59"; Philadelphia: 0.34"; Poughkeepsie: 1.09"; and, Scranton: 1.06". A notably warmer weekend is in store. Readings could soar into the 70s in New York City and even southern New England, especially on Sunday. The last time Central Park hit 70° or above was on March 20 when the thermometer reached 77°. Nevertheless, the milder conditions will likely be short-lived. Overall, the first 10 days of May could see readings average 2.5° to as much as 5.0° below normal in the northern Middle Atlantic and southern New England regions. Moderation may commence near mid-month. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during May. The SOI has seen an increased tendency for positive values during April. During this month, the SOI was positive on 17 (57%) days. During the February-March period, the SOI was positive on 38% days. This shift in tendencies may further reinforce or reflect the idea that ENSO region anomalies could begin to cool. The SOI was +0.02 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.685. On April 30, the MJO was in Phase 4 at an amplitude of 1.605 (RMM). The April 29-adjusted amplitude was 1.751. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer.

Clouds broke this afternoon. As a result, temperatures rose quickly into the middle 60s. This weekend could see readings in the 70s across much of the region. Two photos from this evening:

Morning thoughts... This weekend, the temperature could reach or exceed 70 degrees in New York City for the first time since March 20 when the thermometer topped out at 77 degrees. April’s monthly maximum temperature was just 68 degrees. That was the coldest April maximum temperature and the first one in the 60s since April 1940 when the monthly high temperature was 67 degrees. However beyond the coming weekend, the generally cool pattern that predominated in April will likely reassert itself. Generally cooler than normal conditions will likely prevail through at least the first half of May, which should set the stage for a cooler than normal May in the region.

A cooler than normal April is now concluding. New York City had a mean temperature of 50.4°, which was 2.6° below normal. Periods of heavy rain were moving from south to north along a slow-moving front this evening. Additional rain is likely tomorrow. Two-day rainfall amounts will likely range from 0.50"-1.50" with some locally higher amounts in excess of 2.00" The highest amounts will likely be north and west of New York City and Newark. In the wake of the system, warmer conditions will return this weekend. However, the milder conditions will likely be short-lived. Overall, the first 10 days of May could see readings average 1.5° to 3.5° below normal in the northern Middle Atlantic and southern New England regions. Moderation could occur near mid-month. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during May. The SOI has seen an increased tendency for positive values during April. During this month, the SOI was positive on 17 (57%) days. During the February-March period, the SOI was positive on 38% days. This shift in tendencies may further reinforce or reflect the idea that ENSO region anomalies could begin to cool. The SOI was +0.43 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.766. On April 29, the MJO was in Phase 3 at an amplitude of 1.747 (RMM). The April 28-adjusted amplitude was 1.916. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Such a summer is now likely in much or all of the East. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. May will likely be cooler than normal in the northern Middle Atlantic and southern New England region with anomalies of 1°-2° below normal in much of the region.

Four photos from early this evening ahead of the front and possible squall line:

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA -0.4 -1.0 -1.2 -1.0 0.5 0.9 1.1 2.8 1.0

Clouds and somewhat cooler than normal conditions prevailed today. Meanwhile, in the Southwest near record and record heat prevailed. High temperatures included: Flagstaff: 79 (old record: 78, 1992); Las Vegas: 99 (tied record set in 2013); Phoenix: 104; and, Tucson: 101. Another storm will impact the region tomorrow and Friday. The potential exists for 0.50"-1.50" rain with some locally higher amounts in excess of 2.00". The highest amounts will likely be north and west of Newark and New York City. In the wake of the system, warmer conditions will return this weekend. However, the milder conditions will likely be short-lived. Overall, the first 10 days of May could see readings average 1° to 3° below normal in the northern Middle Atlantic and southern New England regions. Some of the guidance is even colder. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was +6.56 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.160. On April 28, the MJO was in Phase 3 at an amplitude of 1.912 (RMM). The April 27-adjusted amplitude was 1.917. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Such a summer is now likely in much or all of the East. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. 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 April. April will likely finish with a mean temperature near 50.4°. Overall, May will likely be cooler than normal in the northern Middle Atlantic and southern New England region.

Today saw partly sunny skies and somewhat milder conditions. Temperatures topped out in the lower and middle 60s across the region. However, another storm will impact the region Thursday and Friday. In the wake of the system, warmer conditions will likely return this weekend. However, the milder conditions will likely be short-lived. Overall, the first 10 days of May could see readings average 1° to 3° below normal in the northern Middle Atlantic and southern New England regions. Some of the guidance is even colder. The probability of a cooler than normal May has continued to increase in recent days. The cooler scenario is supported by the latest EPS weekly guidance. The CFSv2 has been evolving toward a cooler scenario. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was +3.39 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.575. On April 27, the MJO was in Phase 3 at an amplitude of 1.915 (RMM). The April 26-adjusted amplitude was 1.941. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Such a summer is now likely in much or all of the East. 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 April. April will likely finish with a mean temperature near 50.4°.

This morning, the temperature fell to 39° at New York City's Central Park. That was only the third time since 2000 that the temperature fell into the 30s on or after April 27. The other times since 2000 were: April 27, 2000: 37° and April 28, 2012: 38°. Across parts of New York State, snow fell overnight into this morning. Snowfall amounts included: Binghamton: 0.9"; Cherry Valley: 14.0"; East Springfield: 6.5"; Jefferson: 8.0"; and, Springfield: 6.0". Tomorrow will likely feature partly sunny skies and somewhat milder conditions. However, clouds will increase later tomorrow as another storm impacts the region late in the week. Temperatures will likely average generally below normal across the Middle Atlantic and southern New England regions through the remainder of the month. Warmer conditions will likely return during the first week of May, but the milder conditions will likely be short-lived. Overall, the first 10 days of May could see readings average 1° to 3° below normal in the northern Middle Atlantic and southern New England regions. The probability of a cooler than normal May has increased since mid-April. The cooler scenario is supported by the latest EPS weekly guidance. The CFSv2 has been evolving toward a cooler scenario. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.6°C for the week centered around April 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.53°C and the ENSO Region 3.4 anomaly has averaged +0.63°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was +0.94 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.283. On April 26, the MJO was in Phase 3 at an amplitude of 1.942 (RMM). The April 25-adjusted amplitude was 2.115. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Such a summer is now likely in much or all of the East. 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 April. April will likely finish with a mean temperature near 50.3°.

A stretch with highs near 60 and lows well into the 40s.

At 7 am, the temperature was 39 degrees at New York City. The last time the temperature fell into the 30s this late in the season was April 28, 2012 when the temperature fell to 38 degrees.

Rain will continue overnight into tomorrow morning before yielding to mainly overcast skies. Tuesday could see partly sunny skies. However, another storm will likely impact the region late in the week. Temperatures will likely average generally below normal across the Middle Atlantic and southern New England regions through the remainder of the month. Warmer conditions will likely return during the first week of May, but the milder conditions will likely we short-lived. Overall, the first 10 days of May could see readings average 1° to 3° below normal in the northern Middle Atlantic and southern New England regions. The probability of a cooler than normal May has increased since mid-April. The cooler scenario is supported by the latest EPS weekly guidance and the CFSv2 has been evolving toward that scenario. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around April 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.55°C and the ENSO Region 3.4 anomaly has averaged +0.62°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was -7.43 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.113. On April 25, the MJO was in Phase 3 at an amplitude of 2.116 (RMM). The April 24-adjusted amplitude was 2.151. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Such a summer is now likely in much or all of the East. 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 April. April will likely finish with a mean temperature near 50.5°.

That is Manor Park in Larchmont, NY.

Under partly to mostly sunny skies, temperatures rose into the springlike 60s across much of the region. However, the dry respite will quickly come to an end. Another storm will bring a general 0.50"-1.50" rain to much of the region later tomorrow into Monday. Temperatures will likely average generally below normal across the Middle Atlantic and southern New England regions through the remainder of the month. Warmer conditions will likely return during the first week of May. Past cases that saw the NAO average -0.750 or below during April 1-5 with warmth in the East, as occurred this month, saw the development of a trough in the East after April 10. That trough typically persisted in the means for 1-2 weeks. Looking ahead to May, 73% of cases that saw one or more days where the NAO fell to -1.000 or below during April 1-10, 1950-2019, as was the case this April, wound up with a warmer than normal May. However, uncertainty about the May outcome has increased. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around April 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.55°C and the ENSO Region 3.4 anomaly has averaged +0.62°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was -3.53 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.610. On April 24, the MJO was in Phase 2 at an amplitude of 2.155 (RMM). The April 23-adjusted amplitude was 2.049. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Based on recent MJO data, the probability of a warmer than normal summer has increased. Such a summer is now likely in much or all of the East. 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 April. April will likely finish with a mean temperature near 50.5°.

Under partly to mostly sunny skies, the temperature rose into the middle 60s this afternoon. As a result, people came out to the parks, some wearing masks, others none.

Tomorrow will see abundant sunshine, but the respite from rain will be short-lived. Another storm will bring a general 0.50"-1.50" rain to much of the region later Sunday into Monday. Temperatures will likely average generally below normal across the Middle Atlantic and southern New England regions through most of the remainder of the month. Warmer than normal conditions could return near the end of the month or just afterward. Past cases that saw the NAO average -0.750 or below during April 1-5 with warmth in the East, as occurred this month, saw the development of a trough in the East after April 10. That trough typically persisted in the means for 1-2 weeks. Looking ahead to May, 73% of cases that saw one or more days where the NAO fell to -1.000 or below during April 1-10, 1950-2019, as was the case this April, wound up with a warmer than normal May. However, uncertainty about the May outcome has increased. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around April 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.55°C and the ENSO Region 3.4 anomaly has averaged +0.62°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was +0.07 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.514. On April 23, the MJO was in Phase 2 at an amplitude of 2.051 (RMM). The April 22-adjusted amplitude was 1.790. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Based on recent MJO data, the probability of a warmer than normal summer has increased. Such a summer is now likely in much or all of the East. Based on sensitivity analysis applied to the latest guidance, there is an implied 96% probability that New York City will have a cooler than normal April. April will likely finish with a mean temperature near 51.0°.

There will be some changes to start May, but they don't appear too big right now.

Yesterday, 5.5" snow fall at Caribou. That exceeded the previous daily record of 4.6", which was set in 1989. Seasonal snowfall has now reached 146.0", which is the 9th highest figure on record. In addition, the total snowfall for the last two seasons (2018-19 through 2019-20) is 311.4", which is the second highest such figure on record. Only 2007-08 through 2008-09 with 313.5" had more. A storm coming out of the Ohio Valley will bring showers and periods of rain tonight and tomorrow. Temperatures will likely stay well below normal through tomorrow. Overall, readings will likely average generally below normal to near normal with a few warmer than normal days across the Middle Atlantic and southern New England regions through most of the remainder of the month. Warmer than normal conditions could return near the end of the month or just afterward. Past cases that saw the NAO average -0.750 or below during April 1-5 with warmth in the East, as occurred this month, saw the development of a trough in the East after April 10. That trough typically persisted in the means for 1-2 weeks. Looking ahead to May, 73% of cases that saw one or more days where the NAO fell to -1.000 or below during April 1-10, 1950-2019, as was the case this April, wound up with a warmer than normal May. However, uncertainty about the May outcome has increased. The MJO was recently in Phase 1 at an amplitude in excess of 1.500 for two days. During the 1981-2019 period, the MJO was in Phase 1 at an amplitude of 1.500 or above for two or more years in six cases: 1988, 1990, 1995, 1997, 2005, and 2010. During May, three (50%) were cooler than normal; two (33%) were near normal; and, one (17%) was warmer than normal. Ultimately, two-thirds of those cases went on to have a warmer to much warmer than normal summer. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was +0.7°C for the week centered around April 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.55°C and the ENSO Region 3.4 anomaly has averaged +0.62°C. Neutral and occasionally warm ENSO conditions will likely prevail through mid-May. ENSO Region anomalies could begin a steady cooling during late April or May. The SOI was +1.87 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.217. On April 22, the MJO was in Phase 2 at an amplitude of 1.793 (RMM). The April 21-adjusted amplitude was 1.796. February 2020 saw the ENSO Region 1+2 anomaly increase by more than 0.50°C. Such a development has typically occurred before a warmer than normal summer. In all such cases, a warmer than normal spring was followed by a warmer than normal summer. Based on recent MJO data, the probability of a warmer than normal summer has increased. Such a summer is now likely in much or all of the East. Based on sensitivity analysis applied to the latest guidance, there is an implied 91% probability that New York City will have a cooler than normal April. April will likely finish with a mean temperature near 51.5°.

Some sleet pellets are falling in Larchmont, NY.