bluewave

Warm and super amped up MJO facing off against the strong -AO due to the final or major SSW is a very rainy pattern in the early spring. So a raging Pacific Jet undercutting the -AO block. Another case in recent times of the Pacific overpowering the Atlantic.

The only real heat that summer was the memorable heatwave in mid-July. The summer average was cool compared to our warmer summers since 2010. Those 70s heatwaves lacked the staying power that we get regularly today. The NYC summer monthly departures for todays climate in 1977 were -1.8,+1.5, and -0.4. Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Season Mean 73.4 80.1 77.4 77.0 2023 71.6 80.6 76.7 76.3 2022 74.4 82.6 80.5 79.2 2021 76.2 78.8 80.0 78.3 2020 74.4 80.8 77.7 77.6 2019 72.7 80.6 76.2 76.5 2018 72.1 78.2 79.2 76.5 2017 72.7 77.3 74.0 74.7 2016 72.9 79.9 79.9 77.6 2015 72.0 79.0 78.7 76.6 2014 72.8 77.0 74.5 74.8 2013 73.3 80.9 74.7 76.3 2012 72.4 80.8 77.6 76.9 2011 74.5 82.7 76.9 78.0 2010 76.2 82.3 77.7 78.7 Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Season Mean 71.6 77.0 76.2 74.9 1979 69.3 77.0 76.6 74.3 1978 71.6 75.0 76.6 74.4 1977 70.3 78.1 75.1 74.5 1976 73.6 74.9 74.4 74.3 1975 71.6 76.9 75.0 74.5 1974 70.1 77.1 76.4 74.5 1973 74.6 78.6 79.6 77.6 1972 68.8 77.9 75.9 74.2 1971 74.8 77.7 76.0 76.2

The summer of 1977 was cool by todays standards. People remember the 10 day heatwave in mid-July. But the rest of the summer was cool.

Thanks for creating that chart. NYC would have more top 10 warmest months If they measured the temperatures the same way as before the 1990s. Switching to measurements under the fully leafed out trees during the warmer months since the 90s lowered the rankings of recent years. We can see how during the colder months when the leaves on the trees aren’t an issue, NYC has a similar amount of top 10 warmest months as the surrounding stations. But it has fallen behind during the summer when the deep shade artificially cools the readings since the 1990s. Plus NYC is also losing top 10s after the spring leaf out and before the fall leaf drop. NYC top 10 warmest summers dense ranked by temperature https://www.sqltutorial.org/sql-window-functions/sql-dense_rank/ Summers since 2010 bolded NYC 5 top 10 warmest temperature summers Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2010 77.8 0 2 1966 77.3 0 3 2005 77.1 0 4 2020 76.9 0 - 1993 76.9 0 - 1983 76.9 0 5 1949 76.8 0 6 2022 76.7 0 - 2016 76.7 0 - 1999 76.7 0 7 1988 76.6 0 - 1980 76.6 0 - 1906 76.6 0 8 1995 76.5 0 - 1944 76.5 0 9 2015 76.3 0 - 1991 76.3 0 - 1952 76.3 0 - 1943 76.3 0 - 1908 76.3 0 10 1994 76.2 0 LGA 8 top 10 Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2020 79.5 0 2 2010 79.1 0 3 2016 78.8 0 4 2022 78.1 0 5 2005 78.0 0 6 2018 77.9 0 7 2021 77.5 0 - 1966 77.5 0 8 2006 77.4 0 - 1999 77.4 0 9 2019 77.3 0 - 2012 77.3 0 - 1991 77.3 0 10 1994 77.2 0 Newark 6 top 10 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2022 79.2 0 - 1993 79.2 0 2 2010 78.7 0 3 1994 78.5 0 4 2021 78.3 0 5 2011 78.0 0 6 2005 77.8 0 7 1988 77.7 0 8 2020 77.6 0 - 2016 77.6 0 - 1973 77.6 0 9 1999 77.1 0 10 1995 77.0 0 JFK 7 top 10 warmest Time Series Summary for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2010 77.1 0 2 2016 76.5 0 3 2022 76.1 0 4 2015 76.0 0 5 2011 75.8 0 6 2020 75.7 0 7 1983 75.6 0 8 1984 75.4 0 9 2012 75.3 0 - 1991 75.3 0 10 1971 75.2 0 - 1949 75.2 0 BDR 10 top 10 warmest Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2016 75.4 0 2 2020 75.3 0 3 2010 75.0 0 4 2022 74.4 0 5 2018 74.3 0 6 2021 74.2 0 - 2012 74.2 0 7 2019 74.0 0 - 2011 74.0 0 - 1994 74.0 0 - 1993 74.0 0 8 2005 73.9 0 9 2013 73.8 0 - 1973 73.8 0 10 1949 73.7 0 ISP 10 top 10 warmest Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2010 74.7 0 2 2022 74.6 0 - 2020 74.6 0 3 1999 74.5 0 4 2016 74.4 0 5 2011 73.9 0 6 2019 73.8 0 7 2021 73.7 0 8 2018 73.5 0 - 2005 73.5 0 9 2013 73.4 0 10 2012 73.3 0 - 1991 73.3 0

The new EC-AIFS looks like a better defined version of the EPS without the smoothing longer range. It would be great if it can correct some of the long range biases of the Euro and EPS. So it will be interesting to see going forward. https://openmeteo.substack.com/p/artificial-intelligence-weather-model The open-data weather forecasting landscape is experiencing a breath of fresh air with an exciting development the European Centre for Medium-Range Weather Forecasts (ECMWF). ECMWF Opens the Doors to AIFS: In a significant move towards open-data, ECMWF has made data from its cutting-edge artificial intelligence weather model (AIFS) publicly available. Unlike traditional numerical models, AIFS leverages Graph Neural Networks (GNNs), similar to those used in AI image generation, but with significantly more data. This shift, made possible by recent advancements in computing power, allows AIFS to learn complex weather patterns with high accuracy. In recent years, several AI weather models have emerged, with Google's GraphCast gaining attention for surpassing even the world-renowned IFS model. However, AIFS now takes the crown, demonstrating superior accuracy as shown in the provided forecast performance chart below. While all models perform well in the short term (first few days), AI models like AIFS excel in longer-range forecasts, exceeding 5 days. This development is a significant step forward for AI in weather forecasting, paving the way for more accurate and accessible weather information for everyone.

Some stations in the Northeast are over 50 to 1 top 10 warmest to coldest months since 2010.

It didn’t even take 10 years to surpass the CONUS warm record set in 15-16.

Historic pattern of winter warmth since the +13.3 December 2015 continues. This makes it a first 9 warmer to record warm winters in a row. It included 21 out of the last 27 winter months finishing warmer than average. NYC Feb 24…+4.2 Jan 24..+3.3 Dec 23..+5.5 …………..+4.3 Feb 23…+5.2 Jan 23…+9.8 Dec 22…-0.6 …………..+4.8 Feb 22….+1.4 Jan 22….-3.2 Dec 21….+4.7 ……………..+1.0 Feb 21….-1.7 Jan 21….+1.1 Dec 20…+1.7 …………..+0.4 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 …………….+4.0 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 …………….+1.1 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 …………….+1.1 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 …………….+4.2 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3 …………….+5.9

Arctic outbreaks are getting much shorter and covering a smaller geographic region than they used to. We can still get stronger Arctic outbreaks from time to time but they don’ have the lasting power, geographic coverage, and intensity like they did up through around 1994. One of the more interesting events was the Valentines Day Arctic outbreak of 2016. This was the first time an Arctic outbreak below 0° in NYC occurred during a 40° winter. We couldn’t even pull off below 0° during February 2015. So these days we have Arctic outbreaks surrounded by 60° days which was much rarer in the old days when we had much more extended cold. We can remember the brief single digits Arctic shot last winter and the 60° days surrounding. So we can still get very cold days from time to time. But it’s been very difficult since 14-15 to get extended cold. A great example of this was the impressive cold from after Christmas in 2017 into early January. If this had occurred 30 years earlier in a colder climate, then the whole winter would have finished with below normal temperatures. Instead the temperatures rebounded to all-time winter warmth of 80° which was much more impressive vs the long term records that the cold around Christmas was. So the average in February close to 40° resulted in a warmer than average winter.

While it’s always possible to eventually have a colder winter or series of winters again, the coldest winters have been steadily warming over time. None of our colder winters since the late 1970s can come close to a winter like 76-77 for the magnitude and duration of that cold. Our coldest recent winter in 14-15 had 60s on Christmas and NYC averaged 40.5° in December. The last top 10 coldest month in February 2015 was answered by over 30 top 10 warmest months around the region throughout the year since then.

31-32 was a warm outlier for that much colder era. Now we get 40° winter months or 40° average winters nearly every year around NYC. There is much more than background warming occurring when we have seen an historic 9 warmer to record winters in row. The area is more than +3° above any previous 30 year winter average temperature over nearly the last decade. Why is it so hard to believe that CO2 causes the planet to warm up? The first studies were done in the 1800s on this topic. NYC hasn’t had a winter average temperature below 30° since the 1970s. So the much warmer climate makes this an unlikely occurrence barring some major volcanic eruption. As winters have been steadily warming over time, our area has had more all or nothing type snowfall winters since the 1990s. Either above average or below average snowfall with almost no median seasons for places like Long Island. Those more average snowfall seasons were much more common before the 1990s. The risk with the all or nothing track we have been on since the 1990s is that the nothing will become a more common outcome with continued warming. But like we saw in 21-22, we can still score some more above average snowfall seasons along the way. Nearly every snowfall season on Long Island since the 90s has been under 15” or over 30”. The 20s season common before the 90s is almost non-existent at places like Islip.

We could have used these dewpoints in the single digits ahead of some our winter storms. East Hampton MOSUNNY 33 3

Looks like plenty of clouds and rain to go along with the warmer temperatures. We have a strong blocking signal getting met by an overpowering warm Pacific MJO signal. So flooding could eventually become a concern again like we saw before we dried out in February. Could also be more beach erosion with so much high pressure east of New England with easterly flow and lows undercutting. It’s very hard to do warm and dry in a transition month like March with so much volatility. That 80° warmth with dry conditions in early March 2016 after that super El Niño was a real rarity. Our warmest days this March through the first 10 days will probably be 50s and 60s. Maybe someone in the interior away from the marine influence can make a run on 70°. Data for March 10, 2016 through March 11, 2016 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ CANOE BROOK COOP 82 NJ NEWARK LIBERTY INTL AP WBAN 81 NJ TETERBORO AIRPORT WBAN 81 NJ TETERBORO AIRPORT COOP 81 NJ HARRISON COOP 80 NY SHRUB OAK COOP 80 NY YORKTOWN HEIGHTS 1W COOP 80 NY PORT JERVIS COOP 79 NY NY CITY CENTRAL PARK WBAN 79 NJ CALDWELL ESSEX COUNTY AP WBAN 79 NJ CHARLOTTEBURG RESERVOIR COOP 79 NY WEST POINT COOP 79 NY MOUNT SINAI COOP 79 NY LAGUARDIA AIRPORT WBAN 78 CT SAUGATUCK RESERVOIR COOP 78 CT STAMFORD 5 N COOP 77 NY WESTCHESTER CO AP WBAN 77 NY BAITING HOLLOW COOP 77 NY CENTERPORT COOP 76 NY CARMEL 4N COOP 76 NY SETAUKET STRONG COOP 76 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 75 CT PUTNAM LAKE COOP 75 CT NORWICH PUBLIC UTILITY PLANT COOP 75 NY RIVERHEAD RESEARCH FARM COOP 75 NY UPTON COOP - NWSFO NEW YORK COOP 75

High pressure will dominate east of New England in early March so plenty of easterly flow with clouds and rain potential. It looks like the kind of pattern where the warmer days are into the 50s to lower 60s around EWR and NYC but clouds and onshore flow limit the 70°+ potential for a while near the metro.

Looks like a warm and wet pattern going into March as this is another example of these south based blocks linking up with the Southeast ridge. March 4-11

No problem. I think the reference to 72-73 came up in discussion about this being a rare case of a -PDO with such a strong El Niño. Not that the actual 500 mb and temperature pattern would be a carbon copy. We are even seeing changes with the -PDO due to so much warming in the entire Western Pacific Basin. In addition to the record tropical marine heatwaves in the warmer WPAC MJO phases for us, the ongoing marine heatwave near Japan has been a compounding warm factor also. I saw a great post recently on twitter on how this is a different flavor of -PDO than we used to see before.

I didn’t say 72-73 was a good match for this winter since that was a much colder winter than this one was across North America. We are in such a different global climate state now, that winter analogs before the 15-16 super El Niño are too different. I mostly focused on the record WPAC warm pool for such a strong El Niño presenting warmer risks to the winter computer model forecasts.

One of the strongest leap day cold fronts on record with 50+ mph gusts and heavy convection to possible snow squalls. Temps will quickly fall from the 60s to 20s.

This winter is a great example of the limitations of long range computer model forecasts beyond the 360 hr EPS and other models. All the EPS forecasts beyond 15 days defaulted to its seasonal forecast of -EPO -AO. My guess is this was based solely on the models simple structure of being able to detect the El Niño and not the long range MJO. Notice how the closer in we got to the late February into March period the more amplified the forcing became from the IO into WPAC. This has been the pattern all winter. Longer range models tried to weaken the convection in these areas only to see the stronger convection once within 2 weeks. I was discussing the record marine heatwave potential since last summer that I believed would occur once the -IOD rapidly reversed in December. This is why I had the warmer risks to the forecasts as the primary issue that I saw for the long range this winter. The EPS even had a cold bias for its first two weeks.

The Mineola COOP was active from 1938 to 2010. The guy who maintained the observations for all those years was the president of the Long Island Weather Observers. 2010 was the only year with over 50 days due to the unusual amount of heat combined with westerly flow. Time Series Summary for MINEOLA, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 90 Mar 1 to Sep 30 Missing Count 1 2010-09-30 52 0 2 1988-09-30 34 0 3 2002-09-30 33 0 4 2005-09-30 32 1 5 1999-09-30 27 6 - 1991-09-30 27 0 https://www.nytimes.com/1990/01/07/nyregion/cold-snap-tests-service-agencies.html The average temperature on the Island in December was 25.9 degrees, 10.3 degrees below normal and the third coldest on record, according to Steve Thomas, a National Weather Service meteorologist for the New York region. The coldest December on record occurred in 1876, when temperatures averaged 24.9 degrees; the most recent record was 1976, when temperatures averaged 29.9 degrees. In Mineola, temperatures hit a low of 6 degrees on Dec. 23, according to Ed Lynt, president of the Long Island Weather Observers, a volunteer organization that provides data for the New York Regional Office of the National Weather Service and to local radio and television stations.

Mineola had 52 days reach 90° in 2010. Data for January 1, 2010 through December 31, 2010 Click column heading to sort ascending, click again to sort descending. State Name Station Type Number of Days Max Temperature >= 90 NJ CANOE BROOK COOP 59 NJ NEWARK LIBERTY INTL AP WBAN 54 NY MINEOLA COOP 52 NJ RINGWOOD COOP 51 NJ HARRISON COOP 50 NY LAGUARDIA AIRPORT WBAN 48 NJ CRANFORD COOP 46 NY BRONX COOP 45 NJ TETERBORO AIRPORT COOP 41 NJ TETERBORO AIRPORT WBAN 40 NY NY CITY CENTRAL PARK WBAN 37 CT DANBURY COOP 37 NY WANTAGH CEDAR CREEK COOP 35 NY DOBBS FERRY-ARDSLEY COOP 34 NY WEST POINT COOP 33 NY JFK INTERNATIONAL AIRPORT WBAN 32 NJ CALDWELL ESSEX COUNTY AP WBAN 31

I believe the old Mineola COOP holds the record for Long Island with 6 days reaching 100° in 2010. That’s a great spot for compressional heating along the sea breeze front. We would probably need a severe drought from the Midwest to East Coast to see 10 days reaching 100 around the region. NJ would probably have the best chance. As it’s been tough to sustain offshore flow near the coast with the big highs parking to the east of New England instead of to our SW. Plus extended droughts have been tough to come by in the much wetter recent era. for January 1, 2010 through December 31, 2010 Click column heading to sort ascending, click again to sort descending. State Name Station Type Number of Days Max Temperature >= 100 NY MINEOLA COOP 6 NJ NEWARK LIBERTY INTL AP WBAN 4 NJ HARRISON COOP 4 NY WANTAGH CEDAR CREEK COOP 4 NJ CANOE BROOK COOP 3 NJ RINGWOOD COOP 3 NY JFK INTERNATIONAL AIRPORT WBAN 3 CT DANBURY COOP 3 Data for January 1, 2010 through December 31, 2010 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NY MINEOLA COOP 108 NJ CANOE BROOK COOP 107 NY WANTAGH CEDAR CREEK COOP 107 NJ HARRISON COOP 106 NJ RINGWOOD COOP 106

The summer of 2022 came close in NJ. Data for January 1, 2022 through December 31, 2022 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 100 Newark Area ThreadEx 6 NEWARK LIBERTY INTL AP WBAN 6 FREEHOLD-MARLBORO COOP 5 SOMERSET AIRPORT WBAN 5 CANOE BROOK COOP 4 HARRISON COOP 4

Guidance is confirming that the warmer and less snowy March pattern which began in 2020 will continue. March used to be a colder and snowier more winter-like month from 2013 to 2019. So March is much more like a an early spring month during the 2020s. Monthly Mean Avg Temperature for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 42.8 42.8 2023 41.8 41.8 2022 42.4 42.4 2021 42.4 42.4 2020 44.8 44.8 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 0.8 0.8 2023 1.6 1.6 2022 1.6 1.6 2021 T T 2020 T T Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 11.3 11.3 2019 4.1 4.1 2018 31.9 31.9 2017 7.4 7.4 2016 3.2 3.2 2015 19.7 19.7 2014 5.4 5.4 2013 7.4 7.4 Monthly Mean Avg Temperature for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 38.4 38.4 2019 38.7 38.7 2018 38.0 38.0 2017 37.1 37.1 2016 45.5 45.5 2015 35.2 35.2 2014 35.8 35.8 2013 38.3 38.3

Very unusual. Many comments on the rare location of the dryline to our West. We could actually see dewpoints in the single digits on Thursday behind the front.