bluewave

This is the first time on record that ISP hasn’t dropped below 17° by February 17th. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Lowest Min Temperature Oct 1 to Feb 17 Missing Count 1 2024-02-17 17 1 2 2002-02-17 15 0 - 1998-02-17 15 0 3 2021-02-17 13 0 - 2020-02-17 13 0 4 2010-02-17 12 0 - 2006-02-17 12 0 5 2012-02-17 10 0 - 2008-02-17 10 0

The 0z SPC HREF snowfall max did a nice job with the 8-10” snowfall forecast around Staten Island . But the actual falloff in snowfall to the north was more extreme. This may be the first chance we have had to use this model for a mesoscale snow event. It has done very well in recent years with the numerous flash flood events around the area.

It’s really great to see your area score a top 10 snowiest day for the month of February. Maximum 1-Day Total Snowfall for New Brunswick Area, NJ (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date 1 19.8 2006-02-12 2 19.0 1961-02-04 3 17.9 1983-02-12 4 13.2 1978-02-07 5 13.0 2003-02-17 - 13.0 1967-02-07 - 13.0 1902-02-17 6 11.5 2010-02-11 7 11.0 2024-02-17 - 11.0 1926-02-10 8 10.5 1995-02-04 9 10.1 1987-02-23 10 10.0 1907-02-04 - 10.0 1899-02-13

This may be the first time when New Brunswick was 10”+ and both Philly and NYC stayed under 4”.

A sting jet is in the lower atmosphere right behind a very deep surface low. This is the upper jet. The front left sector gets some great lift.

Nice assist from 200KT+ jet max.

Should be an active hurricane season so the exact tracks will be important with so much SST rocket fuel heading into the season and a developing La Niña.

The SPC HREF max had the right idea with the 8-10” forecast even though the cutoff north of Staten Island to the South Shore was sharper.

One of the better spots for this storm. 0655 AM Snow Coney Island 40.59N 73.99W 02/17/2024 M9.9 inch Kings NY Trained Spotter

Yeah, it was a combination of the El Niño forcing interacting with the MJO forcing from the IO to WPAC. This combination resulted in a much stronger El Niño ridge than usual in Canada. Plus we didn’t get the deeper trough in the Southeast and Mid-Atlantic typical for El Niños. The tendency for the Nino ridge to build into the Northeast continues the pattern of higher 500 mb winter heights in the Northeast since 15-16. This has resulted in the first 9 consecutive warmer to record warm winters in a row around the Northeast. I think the record Atlantic SSTs are probably also factoring into the ridging and record warmth into the Northeast.

Sure. The models did a good job identifying the period leading up to and just after Presidents’ Day for frozen precip potential.

Long range modeling has been running too cold . So if it shows marginal temps near the coast than you have to take note of that. The last event was initially modeled too cold a week out by several models. We ended up losing half the total precipitation to melting and low ratios from around NYC out along the coast. But the areas just inland from the coast have much more leeway being closer to the cold.

Warm temperatures could be a big issue near the coast.

The long range guidance has been running too cold. Probably related to the models underestimating the forcing in the warmer tropical marine zones for us. That’s why I have been pointing out the warmer risks to the long range forecasts. All that record +30°C SST warmth from the IO to west of the Dateline keeps winning out. Convection flares up in a warm MJO phase followed by a big jet extension and warmer temperatures for us. This has been the main temperature theme for us during the winter since the December 2015 +13 departure. It happens whether we are in El Niño, La Niña, or ENSO neutral. So this has been the first time we had 9 warmer to record warm winters a row.

Ridiculous warmth in Canada for the first half of February.

Historic low for Great Lakes ice in mid-February.

Yes, NYC picked up 1” in December 2014.

That was a very unusual event for May. This one was also a rarity for Providence to get a record daily snowfall over 6.2” and Boston only 0.1”.

Just looked at the February days going back to 2000. I know May 77 was another occasion. But it seems pretty rare in general for Providence to get a 6”+ calendar day and Boston to get only 0.1”.

2015-2016 was the real outlier. All the rest of the Decembers with under 1” of snow since 1950 had below average seasonal snow in NYC. This season is continuing that pattern. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Apr Season 2011-2012 0.0 0.0 4.3 0.2 0.0 0.0 4.5 2006-2007 0.0 0.0 2.6 3.8 6.0 T 12.4 2023-2024 T T 2.3 3.2 M M 5.5 2022-2023 0.0 T T 2.2 0.1 0.0 2.3 2018-2019 6.4 T 1.1 2.6 10.4 0.0 20.5 2015-2016 0.0 T 27.9 4.0 0.9 T 32.8 2001-2002 0.0 T 3.5 T T T 3.5 1999-2000 0.0 T 9.5 5.2 0.4 1.2 16.3 1997-1998 T T 0.5 0.0 5.0 0.0 5.5 1996-1997 0.1 T 4.4 3.8 1.7 T 10.0 1994-1995 T T 0.2 11.6 T T 11.8 1972-1973 T T 1.8 0.8 0.2 T 2.8 1971-1972 T T 2.8 17.8 2.3 T 22.9 1965-1966 0.0 T 11.6 9.8 T 0.0 21.4 1953-1954 2.2 T 12.7 0.5 0.1 0.3 15.8

This was the first February calendar day with 6”+in Providence and under 1” in Boston since at least 2000. Maximum 1-Day Total Snowfall for Providence Area, RI (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date 1 14.7 2003-02-17 2 11.9 2017-02-09 3 10.6 2013-02-08 4 9.4 2006-02-12 5 7.9 2015-02-02 6 7.4 2013-02-09 7 7.2 2003-02-07 8 7.0 2021-02-07 9 6.2 2024-02-13 Maximum 1-Day Total Snowfall for Boston Area, MA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date 1 23.6 2003-02-17 2 17.5 2006-02-12 3 16.2 2015-02-02 4 14.8 2015-02-09 - 14.8 2013-02-09 6 13.0 2015-02-15 7 11.0 2003-02-07 8 10.9 2017-02-09 9 10.7 2014-02-05 10 10.1 2013-02-08 11 8.9 2008-02-22 12 8.5 2022-02-25 13 7.4 2015-02-08 14 6.8 2016-02-05 - 6.8 2011-02-01 16 6.5 2000-02-18 17 6.4 2016-02-08 18 5.5 2005-02-24 - 5.5 2005-02-21 20 5.3 2021-02-07 Maximum 1-Day Total Snowfall for Boston Area, MA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date 1 0.1 2024-02-13

I am guessing the rapid shifts are related to all the extra oceanic heat. So the forcing moves to areas with the warmest SSTs at any given time. Models bring the forcing back to north of Australia next few weeks accompanied by another big jet extension. So we get an early start to spring warmth near the end of February. The big -PNA trough and Southeast ridge has been our default pattern in recent years.

You can quote my whole post from above if you like. But I don’t want to get misquoted in one of our other regional forums.

It’s not about setting anyone straight. Not sure why I keep getting quoted multiple times when I am not in that thread. But I have looked at the responses and statements and have some replies. First, we have never had 9 consecutive winters this warm in the Northeast before. One of the dominant themes is that the rapid expansion of the WPAC warm pool has lead to more forcing from MJO 4-7 which had been written up in numerous studies. Forcing in this region is warm for the Northeast. So it makes perfect sense that it has been this warm in our region over the last 9 winters. I never said that we couldn’t eventually see another colder than average winter in the Northeast. Just that as long as this WPAC warm pool remains so prominent, it will probably load the dice for more warmer than colder winters over time. I am not sure what could shift this but would be open to a change if some new region of tropical forcing can emerge. The reduction in the snowfall has occurred a little later beginning with the 18-19 season. It has resulted in 5 out of the last 6 winters with below normal snowfall in NYC. It seems to be a combo of warmer than normal winters and the more hostile Pacific patterns. The epic 2010-2018 snowfall period carried over into the beginning of the warm winter period that started in December 15 with the historic +13.3 departure. My guess is that the 2010s will stand as our snowiest recent decade. When the 2020s are complete , we are on track for a significantly lower snowfall period vs the 2010s even if snowfall can improve next several seasons. But this doesn’t mean that we can’t have some great snowfall seasons in the mix like 20-21 along the way. Snowfall has been more variable while winters have been steadily warming over the years. Second, the warm blob in the NEPAC from 13-14 to 14-15 was the result of tropical forcing and not the direct cause of the pattern. This pattern quickly shifted after 2 years during the winters but became prominent in the warm season. It was a direct result of the tropical driven Rossby wave pattern. The record PAC NW heatwave a few summers ago and numerous Western drought seasons with the powerful Western Ridge were part of this pattern. An interesting question for study is why the seasonal shift occurred after the 13-14 and 14-15 winters? Feel free to quote this post if you like.

Our main issue for lack of March snowfall after the 2013 to 2019 epic run is how warm the month has become.