2025-2026 ENSO

[bluewave]

13 hours ago, GaWx said:

Good points. But if there were a clearly identified long time model bias,  adjusting for that would obviously make sense.

Models have a situational bias based on the specific weather regime.

Long range models tend to underestimate the warmth in warmer patterns. None of the long range models saw the warmth in December 2015 from November forecasts.  Same for the too numerous to count warmer periods since then.

They also underestimate the cold from long range forecasts at times in the fewer colder patterns we get. As the recent November forecasts missed the first half of December cold. This was also the case before the transition to colder in 2014-2015.

It’s just that the climate has become so skewed toward warmth, as Guy shows below,  that there is much more opportunity to underestimate warmth than cold since it occurs so much more frequently. 
 

 

[snowman19]

@40/70 Benchmark What is the RONI out of curiosity? I’m assuming the Niña is about to peak soon (within the next couple of weeks?)….OISST has started cooling again, it’s around -0.7C right now 

[40/70 Benchmark]

16 minutes ago, snowman19 said:

@40/70 Benchmark What is the RONI out of curiosity? I’m assuming the Niña is about to peak soon (within the next couple of weeks?)….OISST has started cooling again, it’s around -0.7C right now 

SON is -.85

[PhiEaglesfan712]

51 minutes ago, snowman19 said:

If you are correct about a 1989-90 turnaround, that would be astounding. 89-90 saw the biggest, most dramatic pattern flip in the last 50 years. We went from an ice cold arctic tundra in November and December to palm trees sprouting in January and February….

Pretty much all the metrics are screaming at me "warm January and February". I mean, we got a deep -IOD. The last 2 times we had that, January and February literally torched.

89-90 is once in a lifetime, though. We had the coldest December, than turned into spring in January, and winter never really returned.

PHL temperatures (Dec 1989-Mar 1990):

Dec 89: 25.5

Jan 90: 40.3

Feb 90: 41.2

Mar 90: 46.1

A 15-degree increase in between December and January is absurd. That's something you see in between spring months (and sometimes, you don't even get a monthly swing that big).

The Decembers in 95, 00, 05, and 10 all ended up in the 31-34.5 range (and this December may end up not even being that cold), so the turnaround won't be as dramatic.

[MJO812]

24 minutes ago, PhiEaglesfan712 said:

Pretty much all the metrics are screaming at me "warm January and February". I mean, we got a deep -IOD. The last 2 times we had that, January and February literally torched.

89-90 is once in a lifetime, though. We had the coldest December, than turned into spring in January, and winter never really returned.

PHL temperatures (Dec 1989-Mar 1990):

Dec 89: 25.5

Jan 90: 40.3

Feb 90: 41.2

Mar 90: 46.1

A 15-degree increase in between December and January is absurd. That's something you see in between spring months (and sometimes, you don't even get a monthly swing that big).

The Decembers in 95, 00, 05, and 10 all ended up in the 31-34.5 range (and this December may end up not even being that cold), so the turnaround won't be as dramatic.

Way too early to say since long range has been awful.  Typical la Nina's do have a warm February and March but this isnt a typical one. Its dying. 

[snowman19]

5 minutes ago, MJO812 said:

Way too early to say since long range has been awful.  Typical la Nina's do have a warm February and March but this isnt a typical one. Its dying. 

It is absolutely a typical Niña. They all usually peak in December and then start weakening. It’s cooling right now and is at -0.7C. It probably peaks within the next couple of weeks then starts weakening toward cold-neutral. That would fit climo perfectly for a normal La Niña event

[MJO812]

8 minutes ago, snowman19 said:

It is absolutely a typical Niña. They all usually peak in December and then start weakening. It’s cooling right now and is at -0.7C. It probably peaks within the next couple of weeks then starts weakening toward cold-neutral. That would fit climo perfectly for a normal La Niña event

So these very cold temps and snow as far south as the southern mid atlantic is typical ? Not at all.

[EasternLI]

51 minutes ago, 40/70 Benchmark said:

I still think we see a strong +NAO stretch in January, which will lead into a period of +TNH later in the month.

I think I see where you're coming from with that. I could buy that. Fits in with the natural progression of similar past events well I think. Still really interested to see how this year ultimately handles matters. 

[snowman19]

4 minutes ago, MJO812 said:

So these very cold temps and snow as far south as the southern mid atlantic is typical ? Not at all.

They have seen cold all the way into Florida in many past La Niña Decembers lol