donsutherland1

The temperature rose into the upper 60s this afternoon as sunshine followed a mainly cloudy morning. It is currently horseshoe crab mating season. Below is a photo of a female horseshoe crab with a male attached to her taken at Playland Beach (Rye, NY) late this afternoon.

Clouds broke for sunshine this afternoon sending readings well into the 60s. Tomorrow should again feature partly sunny skies. Warmer temperatures appear likely during the closing days of May. However, no excessive heat appears likely for at least the next 10-14 days. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.35°C. ENSO Region anomalies, which cooled slightly during the last week of April, could continue a steady cooling through the remainder of May. The SOI has continued to experience an increased tendency for positive values during May. For the May 1-23 period, the SOI was positive on 16 (70%) days. In April, 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 continue to cool. The SOI was not available today. Today, the preliminary Arctic Oscillation (AO) figure was +1.084. On May 23, the MJO was in Phase 5 at an amplitude of 1.642 (RMM). The May 22-adjusted amplitude was 1.237. Considerable uncertainty exists with regard to June. The May 21 0z EPS weeklies remained consistent with earlier EPS guidance favoring a cooler than normal June. The CFSv2 has been very consistent in showing an area of warm anomalies in the Northeast. However, the CFSv2 is just nearing its skillful range. Based on sensitivity analysis applied to the latest guidance, there is an implied 94% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.4°.

The temperature rose into the middle 60s this afternoon as the sun returned. At Playland Beach in Rye, access to the Boardwalk and beach were limited to Westchester County residents. Residency was verified at a police checkpoint. Visitors were also required to have masks. One elderly couple with New Hampshire license plates was turned away in front of me. The beach was not very crowded. There was a police officer on the beach to enforce social distancing. Messages about social distancing and the wearing of masks whenever one was less than 6 feet from another person were repeatedly broadcast over a sound system. Approximately one-third of the beach was closed. Three photos:

Today, parts of the region experienced periods of rain, some of which was briefly heavy. Through 9 pm rainfall amounts included: Atlantic City: 0.55" Bridgeport: 0.04" Islip: 0.01" New York City: 0.65" Newark: 0.79" Philadelphia: 1.08" Tomorrow and Memorial Day should feature partly sunny skies. Warmer temperatures appear likely during the closing days of May. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.35°C. ENSO Region anomalies, which cooled slightly during the last week of April, could continue a steady cooling through the remainder of May. The SOI has continued to experience an increased tendency for positive values during May. For the May 1-23 period, the SOI was positive on 16 (70%) days. In April, 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 continue to cool. The SOI was -4.42 today. Today, the preliminary Arctic Oscillation (AO) figure was +1.027. On May 22, the MJO was in Phase 5 at an amplitude of 1.232 (RMM). The May 21-adjusted amplitude was 1.158. Considerable uncertainty exists with regard to June. The May 21 0z EPS weeklies remained consistent with earlier EPS guidance favoring a cooler than normal June. The CFSv2 has been very consistent in showing an area of warm anomalies in the Northeast. However, the CFSv2 is just nearing its skillful range. Based on sensitivity analysis applied to the latest guidance, there is an implied 90% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.5°.

Photo from this morning (Temperature: 64°):

Under bright sunshine, the temperature rose into the 70s across the area. High temperatures included: Brigeport: 75° Islip: 76° New York City: 76° Newark: 77° Philadelphia: 71° An area of light rain moved through parts of the New York City region this evening. Tomorrow will feature mainly cloudy skies with periods of rain. Sunday and Memorial Day should feature partly sunny skies. Warmer temperatures appear likely during the closing days of May. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.35°C. ENSO Region anomalies, which cooled slightly during the last week of April, could continue a steady cooling through the remainder of 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 +5.15 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.457. On May 21, the MJO was in Phase 4 at an amplitude of 1.157 (RMM). The May 20-adjusted amplitude was 1.202. Considerable uncertainty exists with regard to June. The May 21 0z EPS weeklies remained consistent with earlier EPS guidance favoring a cooler than normal June. The CFSv2 has been very consistent in showing an area of warm anomalies in the Northeast. However, the CFSv2 is just nearing its skillful range. Based on sensitivity analysis applied to the latest guidance, there is an implied 85% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.5°.

This evening a light rain arrived, moistening the ground, and leaving a thick smell of humidity hanging in the air.

This morning, temperatures fell to near record lows with a few record lows in the region. Low temperatures included: Allentown: 34° Bridgeport: 41° Islip: 39° (tied record set in 2009) New York City-JFK: 42° (old record: 43°, 2002) New York City-LGA: 48° New York City-NYC: 46° Newark: 47° Poughkeepsie: 36° Westhampton: 32° White Plains: 38° Readings continue to remain below normal and that should be the case into the closing days of May. Conditions will also remain generally dry. The final days of the month could end on a warmer note. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.35°C. ENSO Region anomalies, which cooled slightly during the last week of April, could continue a steady cooling through the remainder of 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 +10.97 today. Today, the preliminary Arctic Oscillation (AO) figure was +0.001. On May 20, the MJO was in Phase 3 at an amplitude of 1.203 (RMM). The May 19-adjusted amplitude was 1.331. Since 1950, there were two cases where the April AO averaged +0.500 or above while the May AO averaged -0.500 or below: 1952 and 1954. Both cases featured a warmer than normal June. The flip to a warm June was particularly notable in 1954. Such an outcome suggests that the prevailing pattern could change toward one that would favor a warm June and perhaps warm summer. Moreover, just as the warm pattern that set in during late December and then the cool pattern that set in after the first week of April was prolonged, the warmth could be prolonged once it develops. Based on sensitivity analysis applied to the latest guidance, there is an implied 82% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.5°.

66 degrees yesterday.

Readings continue to remain below normal and that should be the case into the closing days of May. Conditions will also remain generally dry. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around May 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.35°C. ENSO Region anomalies, which cooled slightly during the last week of April, could continue a steady cooling through the remainder of 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 -6.57 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.344. On May 19, the MJO was in Phase 3 at an amplitude of 1.332 (RMM). The May 18-adjusted amplitude was 1.695. Since 1950, there were two cases where the April AO averaged +0.500 or above while the May AO averaged -0.500 or below: 1952 and 1954. Both cases featured a warmer than normal June. The flip to a warm June was particularly notable in 1954. Such an outcome suggests that the prevailing pattern could change toward one that would favor a warm June and perhaps warm summer. Moreover, just as the warm pattern that set in during late December and then the cool pattern that set in after the first week of April was prolonged, the warmth could be prolonged once it develops. At the same time, the latest EPS weeklies show the potential for a continuation of the cool pattern well into June. Based on sensitivity analysis applied to the latest guidance, there is an implied 84% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.3°.

Another May day, another day with cooler than normal readings. That has been the story through much of this month. That will remain the story for the foreseeable future. Readings continue to remain below normal and that should be the case into the closing days of May. Conditions will also remain generally dry. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 -8.71 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.444. On May 18, the MJO was in Phase 2 at an amplitude of 1.692 (RMM). The May 17-adjusted amplitude was 1.746. Since 1950, there were two cases where the April AO averaged +0.500 or above while the May AO averaged -0.500 or below: 1952 and 1954. Both cases featured a warmer than normal June. The flip to a warm June was particularly notable in 1954. Such an outcome suggests that the prevailing pattern could change toward one that would favor a warm June and perhaps warm summer. Moreover, just as the warm pattern that set in during late December and then the cool pattern that set in after the first week of April was prolonged, the warmth could be prolonged once it develops. Based on sensitivity analysis applied to the latest guidance, there is an implied 83% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.3°.

Readings continue to remain below normal and that should be the case through at least Friday. Conditions will also remain generally dry. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +0.17 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.696. On May 17, the MJO was in Phase 2 at an amplitude of 1.743 (RMM). The May 16-adjusted amplitude was 1.464. Since 1950, there were two cases where the April AO averaged +0.500 or above while the May AO averaged -0.500 or below: 1952 and 1954. Both cases featured a warmer than normal June. The flip to a warm June was particularly notable in 1954. Such an outcome suggests that the prevailing pattern could change toward one that would favor a warm June and perhaps warm summer. Based on sensitivity analysis applied to the latest guidance, there is an implied 80% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.6°.

Tomorrow will be mainly cloudy with readings in the lower and middle 60s. The probability of a wet week has diminished markedly in the region, as Arthur will very likely turn out to sea. Thus, moderate to significant rainfall will likely be confined to the Southeast coast and lower Middle Atlantic region. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +11.51 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.018. On May 16, the MJO was in Phase 2 at an amplitude of 1.465 (RMM). The May 15-adjusted amplitude was 1.055. Since 1950, there were two cases where the April AO averaged +0.500 or above while the May AO averaged -0.500 or below: 1952 and 1954. Both cases featured a warmer than normal June. The flip to a warm June was particularly notable in 1954. Such an outcome suggests that the prevailing pattern could change toward one that would favor a warm June and perhaps warm summer. Based on sensitivity analysis applied to the latest guidance, there is an implied 78% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.6°.

Temperatures rose well into the 60s even as sunshine was dimmed by high clouds and advancing mid-level clouds. In one community, the fun was back… In another, the litter was back…

The increasing greenhouse gas forcing is overwhelming the modest dip in solar irradiance.

Early clouds gave way to abundant sunshine. In response, temperatures rose into the 70s across the region. Tomorrow will likely be cooler with readings mainly in the middle 60s. The potential exists for a very wet week next week though differences exist among the guidance. Much will depend on the track what will likely become Tropical Storm Arthur will take and how it interacts with a system coming out of the Ohio Valley. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +12.66 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.070. On May 15, the MJO was in Phase 2 at an amplitude of 1.052 (RMM). The May 14-adjusted amplitude was 1.076. Based on sensitivity analysis applied to the latest guidance, there is an implied 73% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.8°.

This afternoon, the temperature soared to 84° in New York City. Despite today's warmth, the first 15 days of May saw readings average 4.0° to 6.0° below normal in the northern Middle Atlantic and southern New England regions. In New York City, the temperature was 4.5° below normal. In parts of Greece, Bulgaria, and Serbia & Montenegro, May record high temperatures were set today. The ingredients are coming together for a very wet week next week. The potential exists for tropical moisture to get involved. If that happens, some parts of the region could see excessive amounts of rain. The second half of May could wind up warmer than normal overall. There is some model and ensemble support for at least one bout of much above normal readings. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 -0.90 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.254. On May 14, the MJO was in Phase 2 at an amplitude of 1.073 (RMM). The May 13-adjusted amplitude was 0.959. Based on sensitivity analysis applied to the latest guidance, there is an implied 70% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.8°.

This afternoon and early evening was mostly sunny and very warm. The temperature soared into the 80s. Spring was in full bloom. People came out to the park to enjoy the refreshing sea breeze that had developed during the afternoon.

The exceptional cold pattern that led to parts of the region experiencing a rare May snowfall is now behind us. Moderation is underway. Ahead of an approaching front, temperatures could surge into the upper 70s and even lower 80s across the region. Showers and thunderstorms are likely late in the day. A few could be strong. Despite tomorrow's warmth, the first 15 days of May will see readings average 4.0° to as much as 6.0° below normal in the northern Middle Atlantic and southern New England regions. The second half of May could wind up warmer than normal overall. There is some model and ensemble support for at least one bout of much above normal readings. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +8.90 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.230. On May 13, the MJO was in Phase 2 at an amplitude of 0.959 (RMM). The May 12-adjusted amplitude was 0.927. Based on sensitivity analysis applied to the latest guidance, there is an implied 74% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.8°.

Temperatures again ran below normal today, but slow moderation should commence in coming days. Nevertheless, the first 15 days of May could see readings average 4.0° to as much as 6.0° below normal in the northern Middle Atlantic and southern New England regions. Just before mid-month, the pattern will likely change bringing about warmer weather, including more frequent days where the temperature is above normal. The second half of May could wind up warmer than normal. There is model and ensemble support for at least one bout of much above normal readings. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +15.26 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.546. On May 12, the MJO was in Phase 2 at an amplitude of 0.933 (RMM). The May 11-adjusted amplitude was 0.650. 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 71% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 60.8°.

The wind will diminish tonight. Under mainly clear skies readings will drop into the 30s outside New York City. Some frost is possible in some of the distant suburbs. Afterward, slow moderation should commence. Nevertheless, generally cooler than normal to much cooler than normal conditions will likely predominate until toward mid-month. Overall, the first 15 days of May could see readings average 4.0° to as much as 6.0° below normal in the northern Middle Atlantic and southern New England regions. However, just before mid-month, the pattern will likely change bringing about warmer weather, including more frequent days where the temperature is above normal. The second half of May could wind up warmer than normal. There is growing model and ensemble support for at least one bout of much above normal readings. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +3.62 today. Today, the preliminary Arctic Oscillation (AO) figure was -0.324. On May 11, the MJO was in Phase 1 at an amplitude of 0.653 (RMM). The May 10-adjusted amplitude was 0.675. 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. May will likely finish with a mean temperature near 61.0°.

Another strong cold front moved through the region today, bringing showers, thundershowers, and even some hail to parts of the region. The air mass behind the front was sufficiently cold to bring 0.5" snow to Detroit last night. Tomorrow morning could witness more low temperature records challenged or broken across parts of the region. Daily record low temperatures for May 12 include: Allentown: 34°, 1963 Binghamton: 31°, 1988 and 1996 Bridgeport: 40°, 1990 Harrisburg: 36°, 1907 New York City-JFK: 43°, 1963 and 2019 New York City-LGA: 43°, 1940 New York City-NYC: 40°, 1874 and 1907 Newark: 40°, 1938 Philadelphia: 37°, 1962 White Plains: 38°, 1969 and 1990 There is a chance that New York City's low temperature could drop below 40°. Currently, May 2020, which has had 3 such days, is tied with 1874, 1891, 1923, 1947, and 1963 for the most such days in May. Generally cooler than normal to much cooler than normal conditions will likely predominate until toward mid-month. Overall, the first 15 days of May could see readings average 4.0° to as much as 6.0° below normal in the northern Middle Atlantic and southern New England regions. However, just before mid-month, the pattern will likely change bringing about warmer weather, including more frequent days where the temperature is above normal. The second half of May could wind up warmer than normal. There is growing model and ensemble support for at least one bout of much above normal readings. The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.2°C for the week centered around May 6. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.37°C and the ENSO Region 3.4 anomaly has averaged +0.52°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 +1.70 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.261. On May 10, the MJO was in Phase 1 at an amplitude of 0.683 (RMM). The May 9-adjusted amplitude was 0.523. 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 65% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 61.0°.

Today, the temperature rebounded into the 60s after a brisk start. Nevertheless, the first 10 days of May were much cooler than normal in the Northeast. At New York City, the temperature averaged 4.5° below normal. Another cold front will move across the region tomorrow bringing showers and just a chance of a thundershower. Clouds will likely break during the afternoon. Generally cooler than normal to much cooler than normal conditions will likely predominate until toward mid-month. Overall, the first 15 days of May could see readings average 4.0° to as much as 6.0° below normal in the northern Middle Atlantic and southern New England regions. However, near mid-month, the pattern will likely change bringing about warmer weather, including more frequent days where the temperature is above normal. The second half of May could wind up warmer than normal. 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 +2.55 today. Today, the preliminary Arctic Oscillation (AO) figure was -1.303. On May 9, the MJO was in Phase 8 at an amplitude of 0.517 (RMM). The May 8-adjusted amplitude was 0.406. 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 67% probability that New York City will have a cooler than normal May. May will likely finish with a mean temperature near 61.0°.

The return of sunshine vanquished the early morning chill. As a result, a fairly large number of people came out to the local park. Three photos:

Morning thoughts... 1. The current generally cold pattern will likely conclude near mid-month. Afterward, a warmer regime with more frequent above normal readings will develop. 2. This morning, the low temperature in New York City was 39 degrees. The last time New York City had 3 consecutive low temperatures in the 30s during May was in 1947. 3. Caribou picked up a daily record 5.5" snow yesterday. The old record was 1.4", which was set in 1967. As a result, seasonal snowfall increased to 151.6", which makes winter 2019-2020 Caribou's 6th snowiest winter on record. The two-winter total is 317.0", which exceeds the previous two-winter record of 313.5", which had been set during winters 2007-08 and 2008-09. Caribou has also received 150" or more snow in two consecutive winters for the first time on record.