PhiEaglesfan712

Not really. Here are the high end el ninos (+1.5) since 1949-50 (bold are the very strong ones +2): 1957-58 (temperature jump: no) 1965-66 (temperature jump: no) 1972-73 (temperature jump: maybe) 1982-83 (temperature jump: yes) 1986-88 (temperature jump: yes) 1991-92 (temperature jump: no, but due to Mt. Pinatubo) 1997-98 (temperature jump: yes) 2009-10 (temperature jump: no, but 2010 was the warmest year on record at that point) 2015-16 (temperature jump: yes) 2023-24 (temperature jump: yes) The gap between strong el ninos seem uniform (although there was a higher frequency in the 80s and 90s, due to the +PDO period), and the gap between super el ninos is actually increasing (10 between 72-73 and 82-83, 15 between 82-83 and 97-98, and 18 between 97-98 and 15-16. We are currently at 9 and counting since 15-16.)

That type of winter would almost certainly be a blowtorch winter in the Eastern US in today's warming climate. All you have to do is look at 2016-17, which was a similar-type winter to 98-99, and that torched in January and February. If not for March, this would have been a low-snow season in Philly and NYC. In places south of Philly, 16-17 was a Top 10 least snowy winter in Baltimore and DC.

Timing of the volcano has an impact as well. The effects of it usually have a lag, and Pinatubo happend in June 1991, so the summer of 1992 would have been one year after. Also, the effects may have lingered into the following the winter, with the major snowstorm in March 1993.

Our last major volcanic eruption was Mt. Pinatubo (in 1991), but we didn't really get the full effects of the cooling due to a strong el nino. Just the fact that it was able to cause any type of cooling, despite the strong el nino, should tell you how strong that volcanic eruption was. If Pinatubo happens ahead of strong la nina, like in the summer of 2007, there's no doubt in my mind we would have had a longer lasting temporary cooling period.

June 2023 was helped by the smoke and very low humidity. That wasn't even the coldest average temperature days of the month. We had highs in the 60s, and thus degree heating days, later in the month (during the solstice, on the 21st and 22nd). June 4 was only 5-6 degrees below average. June 21-22 was 12-13 degrees below average. That's a temperature departure you see in winter, not during the summer solstice.

I mean, we had two Nor'easters this year - one on April 11-12, and the other on May 21-22. Why can't that happen during the winter?

The 13-14 analog wasn't even a good match for this past winter. The 12-13 analog was a much better match, as that was a deep -PDO that peaked in the fall. This past winter was colder than 12-13, and had comparable snow totals in most areas, in the Eastern US. Those predicting a 13-14 analog for 24-25 were just grasping on straws. In 13-14, you still had a -PDO, but it was generally trending towards 0, which was what we have this year. (And of course, the WPAC jet cooperated, unlike in most of 11-12 and 12-13.) If we can have a similar WPAC jet to 13-14, I think a cold and snowy winter in 25-26 is pretty much locked in.

We got this cold in June just 2 years ago, right around the summer solstice.

About 2-3 weeks from now, we'll have the earliest sunrise, and we stay constant daylight for about a few weeks before starting the downward trajectory in late June. As we roll further into July, it becomes more noticeable.

It was a strong el nino, so you really can't prevent the warm-ups in between. Although, we did get consistent cold and snowstorms in February. (But the winter ended abruptly, as the snow stopped in Baltimore and DC in mid-February, and north of Baltimore by the beginning of March.) However, 2009-10 is the absolute best case for a strong el nino. It's like the modern day 1957-58 (that one also had warm-ups in between storms). Everyone got a good winter, with the exception of the PNW (the Vancouver Olympics were affected by record warmth and a lack of snow) and maybe the Midwest (ask @michsnowfreak, strong el ninos are never good there).

I keep finding it odd that 2009-10, as a strong el nino, ended up as the coldest CONUS winter of this era. Pretty much every other strong el nino since 1972-73 (with the exception of 1991-92, which was affected by Pinatubo) produced a baseline jump in temperature. Even 1982-83, which had El Chichon. So what caused 2009-10 to be such a cold winter CONUS? There had to be some underlying reason here (like was there a volcano in late 2008/2009?) Otherwise, it should have been a warm CONUS winter at the very least, and possibly produced a baseline jump like the other strong el ninos.

What's impressive about the 2014 and 2015 cold outbreaks is that they didn't really get going until after the new year, and they went on for 2-3 months, not really letting up until the end of March.

11-20 November 2019 (T15 coldest with 3 other years) 21-30 April 2018 (29th coldest) November 2018 (25th coldest famous for the mid-month snow event) June 2023 just missed out at T31 coldest

The fact that we're having a 2nd nor'easter since April 11 makes me more confident that the WPAC jet is changing and that a 2013-14 winter is coming in 2025-26. We have all the other pieces in place. If the WPAC jet cooperates, a cold and snowy winter is almost certain in the Eastern US. [Imagine if the April 11-12 and this event had happened in January/February.]

2018-19 was a nearly identical winter to 2016-17. Both were C to C- winters, with a lot of nickel-and-dimers, but no real snowstorm. Both are notable for having their most notable storm outside of the DJF period (18-19 in mid-November, and 16-17 in mid-March). 18-19 did have its moments of cold (November and March were well below average, and DJF was only about +1, +2 above average), while 16-17 was a blowtorch pretty much all winter (with the exception of March).

Most recent event by ENSO state Strong el nino: 2023-24 (super el nino: 2015-16) Moderate el nino: 2002-03 Weak el nino: 2018-19 (possibly continued into 2019-20?) ENSO neutral: 2024-25 (event currently in progress) Weak la nina: 2016-18 Moderate la nina: 2020-23 Strong la nina: 2010-11

In a warming climate, I think a 2009-10 type year in the future is going to be near impossible. We're never going to get a strong el nino produce such a cold winter in the CONUS. Just look at 2015-16 and 2023-24, which were record breaking warm winters in the CONUS. If we are to get a cold winter in the CONUS in the future, it will almost certainly be a la nina year, and most likely a strong one (like 2007-08 or 2010-11).

I'm not really surprised about 2013-14, as that was a very warm winter out west (same with 2014-15). 2010-11 was the one that surprised me. I thought it would make it, especially as a strong la nina year, and not really having the extreme warmth out west of a 13-14 or 14-15. 2009-10 making the list is more impressive to me, considering that was a strong el nino. Usually, strong el ninos are warm CONUS, as you can see with 2015-16 and 2023-24 taking the #1 and #2 spots. Regarding 1981-82, the bulk of the snow and cold were in January and that April event. February and March were rather quiet.

1976-77 was dry, but one that turned very warm during the spring. 1978-79 was a very wet winter, but that followed a very dry fall. 1979-80 and 1980-81 were very dry winters. 79-80, I think, is the least snowy winter in Boston.

We had that event with Pinatubo, but its effect was minimized by a strong el nino in 1991-92. If we had a strong la nina that year, like 2007-08, we would have had a -0.7, -0.8 cooling event.

Now, here is the cold winters of the 1970s (1976-77, 1977-78, and 1978-79). Notice that, unlike 2013-14 and 2014-15, we don't have a warm west coast:

A reminder, as cold as the winter of 2013-14 and 2014-15 was in the Eastern US, some areas in the West Coast, particularly California, recorded its two warmest winters during that time:

Not really, it was warm through most of the country. Only the Pacific coast saw below average temperatures, and it wasn't by much:

The thing about the -10, -15 temperature departures in the Eastern US in February 2015 is that it was balanced out by similar positive temperature departures in the Western US: