bluewave

The HRRR has some 70° potential today down around Philly.

February 2018 style all-time record warmth but to our west this time.

I noticed that the MJO 5-6 was much stronger in the Octobers ahead of our snowiest La Ninas since 2010. But two of our three snowiest La Niña winters were still warmer than average like the ones with the weaker October MJO 5-6 and less snowy winters. So not sure why this has worked out for us just since 2010. The 10-11 and 11-12 multiyear La Niña was snowier in 10-11. Then the 16-17 and 17-18 event was snowier in 17-18. This was followed by 20-21, 21-22, and 22-23 which was snowiest in 20-21. It was almost like 20-21 was a weaker and warmer reflection of the stronger -AO and snowy 10-11. 16-17 was less snowy and much warmer than 17-18. But still found a way to produce above average snow. February 2018 was the most extreme daily winter warmth record we ever saw when we hit 80° for the first time. Even if the winter into spring was so snowy.

Under 15” seasons in NYC before 1990 were usually the result of drier conditions or hostile storm tracks. These days it’s warmer conditions of 38.0° to 41.5° and hostile storm tracks which result in under 15” seasons. Having those two features working in tandem will eventually produce more frequent under 15” seasons. But we will still have opportunities for snowier seasons from time to time like 20-21. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 DJF Average Temperature 1 2023-04-30 2.3 41.0° 2 1973-04-30 2.8 35.5° 3 2002-04-30 3.5 41.5° 4 1919-04-30 3.8 36.6° 5 2020-04-30 4.8 39.2° 6 1901-04-30 5.1 31.7° 7 1932-04-30 5.3 40.1° 8 1998-04-30 5.5 39.6° 9 2012-04-30 7.4 40.5° 10 2024-04-30 7.5 40.3° 11 1989-04-30 8.1 35.9° - 1878-04-30 8.1 33.2° 12 1951-04-30 9.3 36.1° 13 1997-04-30 10.0 37.8° 14 1942-04-30 11.3 32.9° 15 1955-04-30 11.5 33.9° 16 1931-04-30 11.6 33.7° 17 1995-04-30 11.8 37.1° 18 2008-04-30 11.9 36.4° 19 1872-04-30 12.1 29.5° 20 2007-04-30 12.4 36.5° 21 1992-04-30 12.6 37.2° 22 1999-04-30 12.7 38.6° 23 1980-04-30 12.8 35.4° 24 1986-04-30 13.0 33.4° - 1959-04-30 13.0 30.8° 25 1975-04-30 13.1 37.5° 26 1990-04-30 13.4 35.7° 27 1930-04-30 13.6 35.4° - 1900-04-30 13.6 33.6° 28 1929-04-30 13.8 34.7° 29 1950-04-30 14.0 37.6°

The 95° days have also been increasing at the warm spots like Newark away from the sea breeze. But the days with the heat index of 95° have also been increasing due to the higher humidity. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=161&network=NJ_ASOS&zstation=EWR&var=max_tmpf&dir=aoa&thres=95&month=all&year=2024&_r=t&dpi=100&_fmt=js

On track for another winter with 30 or more days reaching 50° at the warm spots away from the immediate shoreline.

If they measured the temperatures in Central Park the same way they did before the 1990s, then NYC would average closer to 29 days a year reaching 90° than the 19 days since the warmer summer era began in 2010. 1951-1980 average number of 90° days EWR….23 NYC….18 LGA…..15 2010-2023 warmer era EWR….33 NYC…..19…actual ..close to 29 LGA…..26

Taking the Central Park temperatures under the trees since the new ASOS was installed back in the 90s created an artificial cooling of daytime highs during the the warm season. When they measured the temperatures away from the trees prior to the 1990s, NYC had more 90° days than LGA. So the decline in 90° days from 30 years before and after the new ASOS was installed is an artifact of the poor sitting and not a reflection of the actual temperatures in Central Park which used to be warmer than LGA. All our other stations away from the sea breeze have seen a steep increase in 90° days over this period. https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=74&network=NJCLIMATE&station=NJTNBR&season=all&dir=above&var=high&threshold=90&year=1960&_r=t&dpi=100&_fmt=png

We came close back in 2022. But notice all the 40 day years recently reaching 90°. 2011 and 2012 had a much lower number of 90° days. But noteworthy shorter record heatwaves centered in July. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Max Temperature >= 90 Missing Count 1 2010 54 0 2 2022 49 0 - 1993 49 0 3 1988 43 0 4 2021 41 0 - 2002 41 0 - 1991 41 0 5 2016 40 0 - 1983 40 0 - 1959 40 0 6 1994 39 0 - 1944 39 0 7 2005 37 0 - 1987 37 0 8 2018 36 0 - 1949 36 0 9 2015 35 0 10 1961 34 0 11 2012 33 0 - 1999 33 0 - 1995 33 0 - 1966 33 0 12 1955 32 0 - 1953 32 0 - 1943 32 0 13 2020 31 0 - 2011 31 0 - 1973 31 0 - 1952 31 0

2010 is the only summer that the coastal stations stations haven’t been able to beat. The summers after 2011 did have the memorable 105-108° maxes. But the heat peaked during 30 day periods centered around July. Our recent summers have had extended warmth throughout the summer. Places like Newark have already surpassed 2010 in the last few years. The lack of westerly flow in recent years has favored the stations away from the shore for the most extreme heat. 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 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

Yeah, the El Niño releases the excess heat building up in the oceans as the climate warms. So the El Niño itself isn’t causing the warming. If we had a stable climate like in the late 1800s, the global temperatures would quickly drop in few years like after the super El Niño like in 1877-1878. But as the climate continues to warm, each El Niño year sees a new annual jump. So it’s mostly a modulator of which years set new global temperature records between the neutral or La Nina years. I guess we have been lucky that the pace of the summer warming since 2010 hasn’t been as high as the winter warming since 2015.

Each new El Niño boosts the temperatures to a higher baseline. The 09-10 El Niño marked the beginning of a much warmer summer pattern which continues to this day. The 15-16 El Niño coincided with a shift to much warmer winters. The winter warming shift was of a higher magnitude than we have seen relative to the previous means than the summers. Now the global temperature jump with the 23-24 El Niño was even higher than the 15-16 super El Niño even though it wasn’t as strong. So it will be interesting to see what happens to our temperatures and weather patterns in coming years at this even higher temperature baseline.

It was good to see how much we were able to dry out this month. Monthly Total Precipitation for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Feb Season 2023-2024 6.71 5.28 1.35 13.34

Very amplified -PNA Southeast ridge pattern coming up. The amount of rain will depend on whether something tries to cutoff underneath. If we can escape the cutoffs, then just the typical cuttters with showers and maybe some thunderstorms from time to time.

You know how it goes. Low 60s if there are showers and clouds. But any breaks of sun mid 60s or possibly higher for the warm spots away from the shore. Hopefully the Euro is correct and we get more sun with a slower frontal passage.

Early start to spring this week.

That’s for sure. Another case of the warm minimums driving the departures. Pretty wild to see Upstate NY with low temperature departures for the whole winter in the +7 +11 range above the much warmer 91-20 climate normals.

No surprise all the guidance has gone warm when we see a 6 sigma jet max over the North Pacific.

Continuation of the all or nothing snowfall theme at Islip since 1994. Nearly all the seasons have been under 15” or over 30”. Before 1994 we had numerous seasons in the over 15” and under 30 range So the winter warming has introduced a higher degree of volatility into the snowfall patterns. Eventually the under 15” seasons will begin to dominate as it continues to warm. But hopefully we can get more of the over 30” seasons before it just becomes to warm for above average snowfall seasons. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 2024-04-30 10.9 67 2023-04-30 5.0 0 2022-04-30 37.0 0 2021-04-30 33.5 0 2020-04-30 6.8 0 2019-04-30 12.8 0 2018-04-30 65.9 0 2017-04-30 39.3 0 2016-04-30 41.4 0 2015-04-30 63.7 0 2014-04-30 63.7 0 2013-04-30 46.9 0 2012-04-30 4.7 0 2011-04-30 55.3 0 2010-04-30 53.8 0 2009-04-30 36.2 0 2008-04-30 10.7 0 2007-04-30 9.0 0 2006-04-30 36.0 0 2005-04-30 58.8 0 2004-04-30 41.4 0 2003-04-30 54.6 0 2002-04-30 3.7 1 2001-04-30 38.9 1 2000-04-30 9.0 0 1999-04-30 19.4 0 1998-04-30 2.6 0 1997-04-30 12.4 1 1996-04-30 77.1 0 1995-04-30 5.1 0 1994-04-30 37.1 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1993-04-30 28.6 0 1992-04-30 13.4 0 1991-04-30 13.8 0 1990-04-30 19.0 0 1989-04-30 19.0 0 1988-04-30 19.5 0 1987-04-30 22.5 0 1986-04-30 15.2 0 1985-04-30 26.9 0 1984-04-30 27.5 0 1983-04-30 31.9 0 1982-04-30 35.4 0 1981-04-30 20.8 0 1980-04-30 9.0 0 1979-04-30 28.1 0 1978-04-30 68.0 0 1977-04-30 28.0 0 1976-04-30 30.2 0 1975-04-30 14.5 0 1974-04-30 34.0 0 1973-04-30 4.5 0 1972-04-30 15.6 0 1971-04-30 18.9 0 1970-04-30 27.0 0 1969-04-30 33.5 0 1968-04-30 22.6 0 1967-04-30 50.8 0 1966-04-30 15.7 0 1965-04-30 39.5 0 1964-04-30 39.7 6

Officially the lowest 2 year average snowfall at only 7” for LGA.

Yeah, we had an neutral to slightly -EPO in Jan 22. But it wasn’t the wall to wall stronger -EPO for much of the winter like in 13-14 and 14-15. It’s been very tough to get extended winter -EPOs beyond a few weeks to a month since then. The EPS has had issues showing too much -EPO beyond 10 to 15 days only to correct weaker the closer in we get. The coming week was originally forecast to be a strong -EPO -NAO pattern. The model has been doing this all winter in the 3rd and 4th weeks.

Yeah, 13-14 and 14-15 were the last time we had a strong -EPO pattern during the winter.

We had a great -EPO pattern in mid-March 1998.

The 97-98 season was one of the few times that March had a colder daily departure in NYC than during DJF. The -16 on the 12th was the coldest of the entire season. So we needed that colder period in mid-March to prime the pattern for snow on the 22nd. NYC had two days with highs not getting above freezing after March 10th which is rare by todays standards.