PhiEaglesfan712

We really only got one cold and snowy month at PHL that winter, and that was February 2021. Those closer to the coast, like ACY, escaped the snow that year for the most part. So, pretty much an inverse of 2017-18.

For me, 2007-08 is the best match and 1998-99 is the second best.

The blocking in 2020 didn't come until after the winter was over. We did get a cold spell in April and early May, but that was way too late for any snow.

Yeah, which is why 2007-08 is the best analog. If we were getting an ENSO neutral, I'd probably use 1993-94 over 2001-02. That 01-02 is coming off a triple la nina (with no el nino buffer) and has a warm subsurface. 93-94 is a much better subsurface match. 1993: 2001:

What about 2007? Did we also have the strong Maritime Continent that year? That year was less active in the Atlantic outside of Dean and Felix, and the Pacific had a very quiet year. Pretty similar to what we have so far this year.

Any la nina in the 1950s makes the list. The subsurface was warm throughout the decade, even through a double la nina early in the decade and a triple la nina in the middle. 1949-50 1950-51 1954-55 1955-56 (believe it or not, this was a strong la nina - this probably would be #1 on the list) 1956-57

Based on the link, it looks like the subsurface stayed warm throughout the entire triple la nina, and expanded in the year leading into the strong el nino. 1955 (year leading into the strong la nina - amazing how this could form at the same time with such a warm subsurface): 1956 (leading into the final year of the triple la nina, a weak la nina year): 1957 (the year leading into the strong la nina - many years of warm subsurface finally bubbling up to the surface):

Looks like a very hot first week of August on tap: PHL hasn't had a 100-degree day in over 12 years (since July 2012), and in the month of August since 2001. That could be changing very soon.

Maybe some activity in the Atlantic:

I was not expecting the subsurface to look like that, especially after 3 years of mostly el nino. I would have thought there would be a strong cold layer below it. Amazing to think that a strong la nina could develop with this subsurface.

The 1954 one may have been a weak la nina the first year, but it eventually peaked as a strong la nina in the second (1955-56). That transition was years in the making. The preceding el nino technically peaked as a moderate in 1951-52, before becoming disjointed in 1952-54. I wonder what the subsurface looked like in summer 1954, and if it had that cool pool that is present in both 2007 and this summer.

Moderate el ninos (+1 to +1.4C) seem to be the sweet spot for cold/snow. 76-77, 77-78, and 02-03 are very good examples. The only one that really didn't work out was 94-95, and even then, we got one decent month of cold/snow in February out of it. I got to think we're well overdue for a moderate el nino. We haven't had one since 02-03.

I mean, if you looked at the subsurface, it was pretty obvious that a full-fledged la nina was developing. We're going to reach the strong la nina threshold at some point between the fall/winter 2024-25 and fall/winter 2025-26. I'll be absolutely shocked if 2024-25 and 2025-26 aren't both la ninas.

2020-21 was more a one-month winter (February), and even then it was hit or miss. If you really think about it, it was a reversal of 2017-18 (which had that outlier warm February). Those north and west of Philly really got hammered, but it was a non-existent winter south and east, especially in places like ACY. In fact, ACY got hammered worse in 2021-22 (another one-month winter, January) than in 2020-21.

And it really wasn't a true ENSO neutral season. One could argue it was a weak el nino, since we were at 0.5 for more than 3 trimonthlies. 2018-20 was more of a disjointed el nino like 1952-54. (Oddly enough, both were followed by a triple la nina [1954-57 and 2020-23] then a strong el nino [1957-58 and 2023-24].) FWIW, 1958-59 was a weak el nino, but I don't think we're getting that in 2024-25. The last true ENSO neutral season was 2013-14, which was a blockbuster winter. However, ENSO neutrals are hit or miss. For every cold/snowy winter (2003-04 and 2013-14), there's a warm winter (2001-02 and 2012-13) that balances it out. That said, the chances of an ENSO neutral season the next 2 years are very low. The subsurface is screaming la nina in 2024-25 and 2025-26. Maybe we'll get an ENSO neutral season in 2026-27. Moderate el ninos (76-77, 77-78, and 02-03, for example) seem to be more favorable for snow than ENSO neutrals. We haven't had one since 02-03, which is now over 20 years ago, so we're overdue.

I got to think the cold pocket eventually has to bubble up to the surface. Like in 2007-08. I'm almost certain 2024-25 and 2025-26 are going to be la nina seasons, with at least one being a strong la nina. After that, it's too early to tell what will come next. All options are open for 2026-27 (3rd year la nina, ENSO neutral, el nino).

Yeah, I got to think that pocket of cold in the subsurface has to bubble up to the surface at some point, whether it be 2024-25 or 2025-26. We might even have the anti-86/87 scenario, where a strong la nina peaks in the summer/early fall 2025. (Though, I don't expect a quick flip to super el nino right after, like the 88-89 la nina followed the 86-88 el nino.)

At some point, it's time to let go of the hyperactive hurricane season forecast. If there was truly going to be one, like in 2005 or 2020, we wouldn't be stuck in this extended lull, and outside of Beryl, we've been quiet for much of the season. 2005 got the late start like this year, but it was active for 4-5 months straight.

Probably not going to happen, but anti-86/87 would be a really fun next 3 years. We'd be getting a strong la nina that peaks in the summer/early fall 2025, followed by super el nino in 2026-27 (the anti-88/89). That would be unprecedented, so I expect the anti-86/87 analog to fall apart within 3 years. Or if the super el nino still forms, there would be an ENSO neutral season or two first (following the 2024-26 la nina). The anti-76/77 analog does better in the long run. We'd be getting record warm winters and cooler springs here at PHL the next 3 years. 77-78 is pretty much the same setup as 76-77 (which we would be getting in 2024-25 and 2025-26), and anti-78/79 is pretty much 2019-20 (which we would be getting in 2026-27), before a weak la nina in 2027-28.

By the way, here's the mid-July IRI plot:

2007-08 is a really good analog at this point. Just look at the subsurface.

Yeah, if there was a winter that was cooked in November, it was 2011-12. We got the famous storm in October, and the pattern just suddenly flipped after that. The warmth continued well after the 'winter', with extreme above average temperatures especially in March, May, and July.

We've had colder days than Valentine's Day 2016 (20/8) at PHL. There was the prolonged arctic outbreak of late Dec 2017/first week of Jan 2018 (16/7 on the 6th and 19/4 on the 7th), as well as 1/31/2019 (18/5). Even the flash event of Christmas Eve 2022 (18/7) was colder than Valentine's Day 2016.

Come to think of it, the closest thing to 18-19 and 19-20 was the disjointed el nino of 52-53/53-54. In fact, the last 6 years closely resemble 52-53 through 57-58. You got the disjointed el nino (52-54, 18-20) followed by a triple la nina (54-57, 20-23), and a strong el nino (57-58, 23-24). I just realized that 64-65 was the only la nina of the 1960s. If not for that, we would have 13 years between la ninas (from the dissipation of the triple la nina in 57 until the 70-71 la nina). Despite the lack of la ninas, PHL had stretch of cold and snowy winters during this time. The only other time we followed a triple la nina with an el nino was in 76. Like after 57, there was a stretch of a lack of la ninas. The next one would be in 83-84 (which would continue into 84-85), after a failed la nina in summer 78. Like with the 60s, 76-77 through 82-83 produced some historically cold and snowy winters at PHL. Heck, even the la nina winters (Jan 84 and Jan 85) produced historical cold, something we've only seen one time since (1/19/94).

Common theme with those cold winters were a lot of ENSO neutral (78-79, 03-04, 13-14), weak el ninos (04-05, 14-15), and moderate el ninos (76-77, 77-78, 02-03). Also interesting to note that each one of those la nina blocks had a strong (09-10) or super el nino (72-73 and 97-98) in between.