donsutherland1

Persistence. 2002's high monthly mean temperature was largely the result of a historic April heat wave. Average High: 2002: 64.8; 2019: 63.5 (through 4/22/2019) Average Low: 2002: 47.4; 2019: 47.1 (through 4/22/2019) Mean: 2002: 56.1; 2019: 55.3 (through 4/22/2019) % Lows 50 or above: 2002: 30% days; 2019: 36% days (through 4/22/2019) % Highs 60 or above: 2002: 57% days; 2019: 77% days (through 4/22/2019)

This afternoon, the clouds broke and the sun returned. The temperature soared into the middle 60s across the region. Tomorrow and Tuesday could see even warmer temperatures. The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -12.84 today. Today's preliminary value of the Arctic Oscillation (AO) was +1.721. The closing 10 days of the month will likely be generally warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The implied probability of a warmer than normal April is currently 97%. There is also an implied 77% probability that April 2019 will wind up among the 10 warmest April cases on record and 63% probability that it will wind up among the 5 warmest April cases on record. The mean temperature for May following April cases with a mean temperature of 56.0° or above is 63.0°. It is likely that April 2019 will finish with a mean temperature of 56.0° or above. The dynamic guidance and statistical guidance are in agreement that May will wind up on the warm side of normal in the New York City area. On April 20, the MJO was in Phase 2 at an amplitude of 1.009(RMM). The amplitude was above the April 19-adjusted figure of 0.878. The April 20 amplitude ended the 37-day stretch during which the amplitude was below 1.000. That was the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015.

This afternoon, the clouds broke for sunshine. The temperature soared to 66° in New York City. Some scenes from the New York Botanical Garden from this afternoon:

There’s a shower in Harrison, NY. The streets are wet.

Rainfall totals in the New York City area were generally well within the expected range of 0.50"-1.50". Amounts included: Bridgeport: 0.55"; Islip: 0.61"; New York City: 0.71"; Newark: 0.58"; Poughkeepsie: 0.49"; and, White Plains: 0.88". The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -17.67 today. Today's preliminary value of the Arctic Oscillation (AO) was +1.363. The closing 10 days of the month will likely be generally warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The implied probability of a warmer than normal April is currently 96%. There is also an implied 76% probability that April 2019 will wind up among the 10 warmest April cases on record and 63% probability that it will wind up among the 5 warmest April cases on record. The mean temperature for May following April cases with a mean temperature of 56.0° or above is 63.0°. It is likely that April 2019 will finish with a mean temperature of 56.0° or above. The dynamic guidance and statistical guidance are in agreement that May will wind up on the warm side of normal in the New York City area. On April 19, the MJO was in Phase 2 at an amplitude of 0.875 (RMM). The amplitude was somewhat below the April 18-adjusted figure of 0.928. The MJO has now had an amplitude below 1.000 for 37 consecutive days. That's the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015. Within the next day or so, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2. Historic data with the very long duration periods of low amplitude favors a return to higher amplitude at Phases 8, 1, or 2 (Phase 2 accounts for 6/14 or 43% cases). Typically, additional days at low amplitude then follow during the subsequent 30 days.

There was. 2019 has a real chance to have a higher mean temperature, especially if some of the near record and record heat being experienced in Kansas and Colorado can make it to the region.

Some photos from the New York Botanical Garden from late this morning and early this afternoon. The temperature was 60° and the rain came to an end. Skies remained overcast.

Although the warmth this April has not been as extreme as it was in 2002, it has been more persistent. There is a distinct possibility that the mean temperature for April 2019 could approach or reach that of April 2002.

Earlier today, the temperature soared to 80° in New York City. That was New York City's first 80° temperature since the mercury topped out at 80° on October 10, 2018. Last year, the City had its first 80° reading on April 13. Since 2000, only 2000 and 2014 saw no 80° temperatures in April. Even as the temperature reached the warmest levels so far this year, a storm was bringing severe thunderstorms and heavy rain to the Southeast. Overnight and tomorrow, that storm will likely bring a general 0.50"-1.50" rain to the New York City area. Some locally higher amounts are possible, especially to the west of I-95. Readings should remain above average. Based on sensitivity analysis, there is an implied probability of 64% that New York City will pick up 1.00" or more rain. The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -17.59 today. Today's preliminary value of the Arctic Oscillation (AO) was +0.712. The closing 7-10 days of the month will likely be generally warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The implied probability of a warmer than normal April is currently 91%. There is also an implied 67% probability that April 2019 will wind up among the 10 warmest April cases on record and 54% probability that it will wind up among the 5 warmest April cases on record. On April 17, the MJO was in Phase 2 at an amplitude of 0.927 (RMM). The amplitude was above the April 16-adjusted figure of 0.752. The MJO has now had an amplitude below 1.000 for 36 consecutive days. That's the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015. Within the next day or so, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2. Historic data with the very long duration periods of low amplitude favors a return to higher amplitude at Phases 8, 1, or 2 (Phase 2 accounts for 6/14 or 43% cases). Typically, additional days at low amplitude then follow during the subsequent 30 days.

Today, the temperature reached 80° in Central Park for the first time this year. Last year, the temperature hit 82° on April 13. Today's high temperature was the warmest reading in New York City since October 10, 2018 when the temperature also hit 80°.

79 at Central Park at 3 pm.

As of 12:30 pm, EDT, Atlanta had picked up 3.31" rain today (storm total: 3.40"). That smashed the previous daily record of 1.45", which was set in 1940. As the day goes on, the rain should spread northward and eastward into the New York City region. Farther south, severe thunderstorms are very likely in parts of Florida, Georgia, South Carolina, and Virginia. Some of those locations could experience tornadoes. In New York City (Central Park) and adjacent suburbs, it still appears that 0.50"-1.50" rain will fall. Western New Jersey and parts of southeastern New York State could pick up locally higher amounts. Across Upstate New York, northern Vermont, northern Maine, and parts of Quebec, including Montreal and Quebec City, widespread amounts of 1.50"-2.50" with locally higher figures are likely. Parts of that region will likely experience flooding on account of the much above normal snowfall that had occurred this winter. Through yesterday, Caribou, which had received 164.7" snow this winter (3rd highest on record) had a 6" snowcover. Annual precipitation to date was 12.36", which was 3.33" above normal.

Through 7:45 pm CDT, Baton Rouge had picked up 4.82" rain. That smashed the daily record of 2.40" that was set way back in 1901. The storm responsible for this heavy rain will affect the region later tomorrow into Saturday. That storm will likely bring a general 0.50"-1.50" rain to the New York City area. Some locally higher amounts are possible. Readings should remain above average. Based on sensitivity analysis, there is an implied probability of 64% that New York City will pick up 1.00" or more rain. To date, New York City has received 12.93" precipitation, which is 0.98" below normal. The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -8.15 today. Today's preliminary value of the Arctic Oscillation (AO) was -0.107. The closing 7-10 days of the month will likely be generally warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The implied probability of a warmer than normal April is currently 90%. There is also an implied 68% probability that April 2019 will wind up among the 10 warmest April cases on record and 57% probability that it will wind up among the 5 warmest April cases on record. On April 17, the MJO was in Phase 2 at an amplitude of 0.753 (RMM). The amplitude was above the April 16-adjusted figure of 0.671. The MJO has now had an amplitude below 1.000 for 35 consecutive days. That's the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015. Within the next 3 days, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2. Historic data with the very long duration periods of low amplitude favors a return to higher amplitude at Phases 8, 1, or 2 (Phase 2 accounts for 6/14 or 43% cases). Typically, additional days at low amplitude then follow during the subsequent 30 days. Finally, according to the GISS dataset, March 2019 was the 3rd warmest March on record (global land and sea temperatures) with an anomaly of +1.11°C. Only 2016 and 2017 were warmer. Meanwhile, on April 17, Arctic sea ice extent was 12,756,658 square kilometers. That broke the daily record low figure of 12,985,833 square kilometers, which was set just last year. However, Arctic temperatures have recently moved closer to normal, so the melt rate could slow in coming days.

A strong storm will likely bring 1.00" or more rain across parts of the Gulf Region tomorrow into Saturday. The heaviest amounts could be focused on northern Mississippi, northern Alabama, Tennessee, Kentucky, and parts of North Carolina. That region could also see severe thunderstorms. Excessive rainfall figures of 2.00" or more are likely along the Appalachians. Afterward, a general 0.50"-1.50" rain is likely in the New York City area. The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -11.03 today. Today's preliminary value of the Arctic Oscillation (AO) was -0.700. The closing 7-10 days of the month will likely be generally warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 59.1° for that period this year. The implied probability of a warmer than normal April is currently 88%. On April 16, the MJO was in Phase 2 at an amplitude of 0.666 (RMM). The amplitude was above the April 15-adjusted figure of 0.540. The MJO has now had an amplitude below 1.000 for 34 consecutive days. That's the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015. Within the next 4 days, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2. Historic data with the very long duration periods of low amplitude favors a return to higher amplitude at Phases 8, 1, or 2 (Phase 2 accounts for 6/14 or 43% cases). Typically, additional days at low amplitude then follow during the subsequent 30 days.

A strong storm will likely bring 1.00" or more rain across parts of the Gulf Region Thursday into Saturday. The heaviest amounts could be focused on northern Mississippi, northern Alabama, Tennessee, Kentucky, and parts of North Carolina. That region could also see severe thunderstorms. Excessive rainfall figures of 2.00" or more are likely along the Appalachians. Afterward, a general 0.50"-1.00" rain is likely in the New York City area. The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -7.14 today. Today's preliminary value of the Arctic Oscillation (AO) was -0.655. Over the next 3-4 days, variable temperatures can be expected. Several days of generally cooler than normal readings are possible, along with several warmer days. The closing 7-10 days of the month could be warmer than normal with perhaps a turn toward normal as the month comes to a close. There remains uncertainty concerning the risk of a possible turn to near normal readings near the end of the month. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 58.2° for that period this year. The implied probability of a warmer than normal April is currently 82%. On April 15, the MJO moved into Phase 2 at an amplitude of 0.553 (RMM). The amplitude was above the April 14-adjusted figure of 0.444. The MJO has now had an amplitude below 1.000 for 33 consecutive days. That's the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015. Within 1-5 days, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2. Historic data with the very long duration periods of low amplitude favors a return to higher amplitude at Phases 8, 1, or 2 (Phase 2 accounts for 6/14 or 43% cases). Typically, additional days at low amplitude then follow during the subsequent 30 days.

I still think it is more likely than not that the temperature will reach 80° in Central Park this month. The most likely timing could be early next week. Since 2000, only April 2000 and 2014 had no 80° days.

The final snowfall in Chicago on Sunday was 5.4". That tied the record set on April 16, 1961 for the greatest daily snowfall after April 10. The ENSO Region 1+2 anomaly was 0.1°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.20°C and the ENSO Region 3.4 anomaly has averaged +0.98°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -4.04 today. Today's preliminary value of the Arctic Oscillation (AO) was -0.066. Over the next 4-5 days, variable temperatures can be expected. Several days of generally cooler than normal readings are possible, along with several warmer days. The closing 7-10 days of the month could be warmer than normal with perhaps a turn toward normal as the month comes to a close. There remains uncertainty concerning the risk of a possible turn to near normal readings near the end of the month. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 57.6° for that period this year. The implied probability of a warmer than normal April is currently 78%. On April 14, the MJO was in Phase 1 at an amplitude of 0.444 (RMM). The amplitude was above the April 13-adjusted figure of 0.377. The MJO has now had an amplitude below 1.000 for 32 consecutive days. That's the longest such stretch since the MJO was at a low amplitude for 39 consecutive days from April 21, 2015 through May 29, 2015. Within 2-6 days, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2.

Through 4 pm, Chicago had picked up 4.8" snow. That set a new daily record snowfall amount for April 14. The previous record was 2.2", which was set back in 1980. This was only Chicago's second daily snowfall of 4" or above after April 10. The only other such daily snowfall occurred on April 16, 1961 when 5.4" accumulated (6.7" was the storm total from April 15-17, 1961). To date, Chicago has received 46.4" snow for the 2018-19 snowfall season, which ranks the current season as Chicago's 34th snowiest on record. Tonight into tomorrow morning, a cold front associated with the storm responsible for Chicago's snowfall will bring periods of rain and thunderstorms. That system will likely bring a general 0.25"-0.75" rain to the New York City area with some locally higher amounts (especially to the north and west of New York City and Newark). The potential for strong to severe thunderstorms is somewhat elevated across southeastern New York State and more so south and westward. Across central and Upstate New York, a widespread 1.00"-2.00" rainfall is likely with some locally higher amounts. As a result, flooding is possible in parts of that area, especially Upstate where above normal seasonal snowfall has occurred. As the storm pulls away, the clouds will break. However, the wind could gust past 40 mph. The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 3. 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 +1.02°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -15.14 today. Today's preliminary value of the Arctic Oscillation (AO) was +0.488. That ends the stretch of 10 consecutive days during which the AO was negative. Over the next 5-6 days, variable temperatures can be expected. Several days of generally cooler than normal readings are possible, along with several warmer days. The closing 7-10 days of the month could be warmer than normal with perhaps a turn toward normal as the month comes to a close. There remains uncertainty concerning the risk of a possible turn to near normal readings near the end of the month. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 58.0° for that period this year. The implied probability of a warmer than normal April has increased to 78%. At this point in time, the EPS hints at a cooler than normal May. However, the CFSv2 favors warm anomalies in the region. Model skill from this point in time is generally poor, but current ENSO conditions suggest warm anomalies may be somewhat more likely than not. On April 13, the MJO moved into Phase 1 after having spent 3 days at Phase 2. The MJO's amplitude was 0.375 (RMM). The amplitude was above the April 12-adjusted figure of 0.162. Within 3-7 days, the MJO could emerge into an amplitude of 1.000 or above, likely in Phase 2.

71 in the Park.

In the wake of last night's and this morning's rainfall, a brief period of dry weather lies ahead. Under bright afternoon sunshine, readings climbed well into the 70s across the region. High temperatures included: Albany: 74°; Allentown: 77°; Baltimore: 77°; Boston: 75°; Burlington: 72°; Concord: 75°; Harrisburg: 77°; Hartford: 77°; Islip: 66°; New York City: 77°; Newark: 78°; Philadelphia: 76°; Portland: 73°; Providence: 70°; Scranton: 72°; and, Washington, DC: 77°. However, by late tomorrow and tomorrow night, another storm will be moving into the region. That system will likely bring a general 0.50"-1.00" rain to the New York City area with some locally higher amounts (especially to the north and west of New York City and Newark). Across central and Upstate New York, a widespread 1.00"-2.00" rainfall is likely with some locally higher amounts. As a result, flooding is possible in parts of that area, especially Upstate where above normal seasonal snowfall has occurred. However, both the 12z ECMWF and 18z NAM suggested much less precipitation, especially in the vicinity of New York City. The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 3. 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 +1.02°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was -23.80 on April 12. No figure was posted for today due to technical difficulties. The possibility exists for a continued interruption in SOI figures for coming days. Today's preliminary value of the Arctic Oscillation (AO) was -0.017. Looking back, the April 1-10 mean temperature was 50.8°. That was close to the figure that had been suggested based on historical experience following the development of a negative AO in during the first 10 days of April after a strongly positive AO near the end of March. The mean temperature for those prior cases was 51.6° (standard deviation 1.8°). Over the next week, variable temperatures can be expected. Several days of generally cooler than normal readings are possible, along with several warmer days. The closing 7-10 days of the month could be warmer than normal with perhaps a turn toward normal as the month comes to a close. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 57.2° for that period this year. Overall, the implied probability of a warmer than normal April has increased to 72%. On April 12, the MJO was in Phase 2 at an amplitude of 0.161 (RMM). The amplitude was slightly below the April 11-adjusted figure of 0.202. Within 4-8 days, the MJO could emerge into an amplitude of 1.000 or above in Phase 2. Finally, based on the guidance coupled with the historical data, it now appears that Atlanta will complete its first snowless winter on record. The old record least snowfall had been a trace of snow, which occurred in 24 winters since 1928-29. This will be the last mention of Atlanta's seasonal snowfall for winter 2018-19.

76° and mostly sunny at 3 pm. 2 photos from the New York Botanical Garden this afternoon:

Yesterday, Caribou picked up 4.2" snow. That brought Caribou's seasonal snowfall to 162.7", making winter 2018-19 Caribou's 3rd snowiest winter on record. The ENSO Region 1+2 anomaly was 0.0°C and the Region 3.4 anomaly was +0.9°C for the week centered around April 3. 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 +1.02°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was +17.01 today. Today's preliminary value of the Arctic Oscillation (AO) was -2.159. As previously noted, since 1950 there have been four prior cases when the AO reached +2.500 or above during the last 10 days of March and then had four or more days with negative values during the first week of April. The mean temperature for the 4/1-10 period in New York City was 51.6° (standard deviation 1.8°). That is about 2 1/2 degrees warmer than climatology for the April 1-10 period (1950-2018). Consequently, based both on that historical data and the latest guidance, it is very likely that the April 1-10 period will wind up warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 56.5° for that period this year. Beyond April 10, 7-10 days of generally cooler than normal to near normal readings are possible. However, the closing 7-10 days of the month could wind up warmer than normal. Overall, based on sensitivity analysis applied to the latest guidance, the implied probability of a warmer than normal April has increased to 63%. On April 8, the MJO was in Phase 7 at an amplitude of 0.063 (RMM). The amplitude was below the April 7-adjusted figure of 0.122. That was the lowest amplitude since the MJO had an amplitude of 0.045 on March 31, 2017. For now, the MJO is essentially irrelevant. However, within 10-14 days, the MJO could emerge into an amplitude of 1.000 or above in Phase 2. There remains considerable uncertainty whether the MJO would then progress to Phase 3 or continue to regress toward Phase 1. During the April 20-30 period, Phase 1 was approximately 1.2° warmer than Phase 3.

Today, the temperature soared to 78° in Central Park. That was New York City's warmest temperature since October 10, 2018 when the thermometer hit 80°. Meanwhile, late this afternoon snow moved into Caribou. The snowstorm will likely deliver 4"-8" snow there. The temperature there was 25° as of 9 pm. The ENSO Region 1+2 anomaly was -0.20°C and the Region 3.4 anomaly was +1.00°C for the week centered around March 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°C and the ENSO Region 3.4 anomaly has averaged +0.96°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was +24.37 today. That is the highest figure since the SOI was +27.20 on October 14, 2018. Today's preliminary value of the Arctic Oscillation (AO) was -2.497. As previously noted, since 1950 there have been four prior cases when the AO reached +2.500 or above during the last 10 days of March and then had four or more days with negative values during the first week of April. The mean temperature for the 4/1-10 period in New York City was 51.6° (standard deviation 1.8°). That is about 2 1/2 degrees warmer than climatology for the April 1-10 period (1950-2018). Consequently, based both on that historical data and the latest guidance, it is very likely that the April 1-10 period will wind up warmer than normal. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period, as happened on April 7. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 56.2° for that period this year. Beyond April 10, 7-10 days of generally cooler than normal to near normal readings are possible. However, the closing 7-10 days of the month could wind up warmer than normal. Overall, based on sensitivity analysis applied to the latest guidance, the implied probability of a warmer than normal April remains approximately 60%. On April 7, the MJO was in Phase 7 at an amplitude of 0.126 (RMM). The amplitude was below the April 6-adjusted figure of 0.311. That was the lowest amplitude since the MJO had an amplitude of 0.095 on September 21, 2018.

That's correct.

Tomorrow and Tuesday will likely see much above normal readings across the northern Middle Atlantic region despite some rain to start the work week. A backdoor cold front could trim the readings on Long Island, coastal Connecticut, and perhaps even New York City. Areas just to the west of New York City in New Jersey could see high temperatures reach the lower or middle 70s both tomorrow and Tuesday. Some temperatures around 80° are possible farther south, especially in parts of Virginia, Maryland, and perhaps even southeastern Pennsylvania. However, despite this unseasonable warmth, an area extending across northern New York State, northern Vermont, northern New Hampshire, and much of Maine could still experience accumulating snow. Caribou will likely pick up 4"-8" snow tomorrow into Tuesday, making winter 2018-19 that city's 3rd snowiest winter on record. The ENSO Region 1+2 anomaly was -0.20°C and the Region 3.4 anomaly was +1.00°C for the week centered around March 27. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.30°C and the ENSO Region 3.4 anomaly has averaged +0.96°C. Conditions consistent with El Niño should persist through April in Region 3.4. The SOI was +11.53 today. Today's preliminary value of the Arctic Oscillation (AO) was -2.511. That preliminary reading is the lowest April AO value since April 27, 2016 when the AO was -3.291. Since 1950, there have been 6 cases where the AO dropped to -2.500 or below during the April 1-10 period. The mean April 16-30 temperature was 56.3° with a standard deviation of 2.3°. The latest guidance shows an estimated mean temperature of 56.2° for that period this year. Also, since 1950 there have been four prior cases when the AO reached +2.500 or above during the last 10 days of March and then had four or more days with negative values during the first week of April. The mean temperature for the 4/1-10 period in New York City was 51.6° (standard deviation 1.8°). That is about 2 1/2 degrees warmer than climatology for the April 1-10 period (1950-2018). Consequently, based both on that historical data and the latest guidance, it is very likely that the April 1-10 period will wind up warmer than normal. The latest guidance suggests a range from 51.0° to 52.8°. Beyond that, 7-10 days of generally cooler than normal to near normal readings are possible. However, the closing 7-10 days of the month could wind up warmer than normal. Overall, based on sensitivity analysis applied to the latest guidance, the implied probability of a warmer than normal April is approximately 60%. On April 6, the MJO moved back into Phase 7 at an amplitude of 0.309 (RMM). The amplitude was a little higher than the April 5-adjusted figure of 0.256. Over the past 5 days, the MJO has been drifting between Phases 7 and 8 at a low amplitude. Based on historical climatology, observed ongoing warming, and the latest ensemble guidance, it is very likely that the 32° temperature on March 18 will wind up becoming New York City's (Central Park) last freeze of the season. Given the latest data, this will be the last mention of New York City's final freeze of the winter 2018-19 season. Atlanta remains on track to receive no snowfall for the first time on record. Such an outcome is now very likely. The existing record is a trace of snow, which occurred during 24 winters. Snowfall records go back to winter 1928-29.