PhiEaglesfan712

Even lower than spring 2002?

March is going to end up solidly above average. We already have a +4 temperature departure for the month so far, and at least the next few weeks looks well above average.

I'm not so sure if it's the jet pattern or the deep -PDO. Even when we had the favorable jet pattern, there were 2 years when we had a deep -PDO (11-12 and 12-13). Those were two of the least snowy winters in the mid-Atlantic.

Assuming no more snow falls this year, PHL could set the record for the least snowy 10-year period next year. The current record is 1922-23 to 1932-33, averaging 13.2 inches. 1923 19.5 1924 21.8 1925 12.1 1926 19.1 1927 11.8 1928 15.5 1929 11.9 1930 8.2 1931 4.1 1932 8 2016-17 to 2024-25 is averaging 13.18 inches. 2017 15 2018 29.8 2019 17.1 2020 0.3 2021 23.9 2022 12.9 2023 0.3 2024 11.2 2025 8.1 2025-26 would need to come in at less than 13.4 inches to break the record.

Still, we've only had 2 summers cooler than average since 2010 (namely 2014 and 2023). And 2023 was due to a historically cold June. Despite that, the JJA 2023 average was a tenth below average. If you use JAS 2023, it's above the historical summer average. 2014 was two-tenths below average. So, we really haven't had a cool summer in the East since 2009.

I think it was December 2015 that was the spring month. December 2014 was a warm month (an outlier to the rest of the winter, but a +3, not +9. December 2013 was close to normal, like this December. Difference is that February 2014 was much colder, whereas this February was another near normal month. I'd say 2014 was definitely more consistent cold than this winter. 2015 has them both beat at the depths of their cold (coldest tri-monthly at PHL was 31.9 Jan-March, while 2014 was 33, and this year 34.9).

March 1998 shows we can go from one extreme to the other in very short order. Just a week later, we were in an early heat wave, and we made a run at 90 on 3/31. 01-02 is one that never really had a winter. Save for the snowstorm on 1/19, that was a torch from late October until the heat wave in mid-April.

That el nino that developed in 86 was a unicorn. That was a 2-year strong el nino, which peaked in the summer of 87. Of course, after the el nino ended, there was a sharp correction to one of the strongest la ninas on record in 88-89. I think if we get an el nino in 25-26, it will be much weaker, like 06-07. If this is the case, I think this year is closer to 12-13 than to 13-14. 12-13, while warmer than this winter, had similar snowfall to this year, in a ENSO neutral, deep -PDO year, which rose throughout the winter.

2014 and 2015 exist. To me, those are the gold standards for winters going forward.

So glad this morning is trash day.

DJF ONI: -0.6 DJF RONI: -1.18

February 2025 PDO is in at -1.4, which is lower than the -1.28 reading in January. I had 2013 as the analog for PDO this year. How Jan/Feb 2025 compares to Jan/Feb 2013: 2025 -1.28 -1.40 2013 -1.10 -1.42

After our first below average temperature winter in 10 years, is a warm March in the cards?

The only time we got those temperatures in March was in 2014 and 2015, and that was early in the month, following historical cold in January and February. Yep, this is not going to happen.

Can you really this year a la nina when Nino 1+2 is at +1.1C, and has been in an el nino state most of the winter?

I'd say 2024-25 is an ENSO neutral, even if it wasn't conventional (like say 2013-14). We basically had a WPAC la nina and a EPAC el nino.

I'd argue the historic benchmark snowfall pattern ended after the January 2016 snowstorm. If not for that snowstorm, then 2014-15 would have been a clear demarcation on when the snowy pattern ended. The pattern started to break down when the super el nino/cyclical +PDO pattern ended in 2016. Though we were still hitting snowfall averages in 16-17, 17-18, and even 18-19, we weren't getting the blockbuster snowstorms (like we were from 3/1/2009 to 1/2016). If not for the late Jan/early Feb 2021 snowstorm, NYC would be working on 9 straight years without a 10-inch snowstorm. PHL hasn't had an 8-inch snowstorm since the January 2016 snowstorm.

The 71/36 rule holds true for the 16th straight year. Average monthly temperature for September and February at PHL since 2009-10: Sep 2009 - 68.0 Feb 2010 - 31.8Sep 2010 - 72.9 Feb 2011 - 37.2Sep 2011 - 71.1 Feb 2012 - 40.9Sep 2012 - 70.3 Feb 2013 - 35.1 Sep 2013 - 67.9 Feb 2014 - 32.1 Sep 2014 - 70.5 Feb 2015 - 25.8Sep 2015 - 74.5 Feb 2016 - 38.6Sep 2016 - 73.5 Feb 2017 - 44.2Sep 2017 - 71.4 Feb 2018 - 41.9Sep 2018 - 72.5 Feb 2019 - 37.1Sep 2019 - 72.5 Feb 2020 - 40.8Sep 2020 - 69.4 Feb 2021 - 34.2Sep 2021 - 71.6 Feb 2022 - 39.7Sep 2022 - 72.1 Feb 2023 - 42.7 Sep 2023 - 71.4 Feb 2024 - 40.1 Sep 2024 - 70.6 Feb 2025 - 35.9

2002-03 was similar to 2009-10, but 02-03 falls short of 1.5 benchmark on most measures, while 09-10 clears the 1.5 benchmark on most (ONI, RONI).

94-95 was a moderate el nino. 14-15 was a borderline warm neutral/weak el nino. If you consider it an el nino, it's just a piggy back of the incoming super el nino of 15-16. (19-20 was another piggy back borderline warm neutral/weak el nino, but the other direction - piggy backing off the previous year's el nino, and led into a la nina the following year.) The only strong/super el ninos in the last 75 years are 1957-58, 1965-66, 1972-73, 1982-83, 1986-88, 1991-92, 1997-98, 2009-10, 2015-16, and 2023-24.

Not really. We had a strong el nino in 1982-83, then the double-year event in 1986-88, and again in 1991-92. That's 3 el nino events in a 10-year span. Then another 6-year gap between the 1991-92 event and 1997-98 (a 4th in just over 15 years). 2009-10 and 2015-16 is another 6-year gap. The common theme with these strong/super el ninos was either a +PDO (like we had for most of the 80s and 90s) or a flip to +PDO (which is what happened in the years leading up to 2015-16). If we can get a flip to +PDO in the next few years, I think a super el nino in 2027-28 can happen.

The 2010 one should definitely debunk the myth. That was a record warm spring, which was followed by a record warm summer. By the way, that was coming off a record snow season (though that one came to an abrupt end, it was done by the end of February, and as early as mid-February in places Baltimore and south).

The ENSO neutral period that started in 2012 was the last real sustained ENSO neutral period. You could even argue that 14-15 was an ENSO neutral season, as the (super) el nino didn't really form until the season was just about over. If 25-26 stays ENSO neutral, I could see a similar sustained ENSO neutral until the inevitable strong/super el nino forms in 27-28.

If we get this, then the Nino 1+2 is going to be somewhere near +3 for 2025-26. We'd get the warmest year on record for 2026, but we'd correct to a strong la nina in 2026-27 (like in 2009-10 -> 2010-11).