2024-2025 La Nina

[michsnowfreak]

The Euro used to be called king. For several years that has not been the case. I do not at all expect models to ever be perfect. But how can models get worse at technology advances?

[BuffaloWeather]

57 minutes ago, snowman19 said:

The op Euro/EPS has gotten as bad as the op GFS. There’s no difference between them anymore they equally suck. I don’t trust them as far as I can throw them

Euro is still the king based on recent data.

Operational runs

Ensembles

 

[michsnowfreak]

27 minutes ago, BuffaloWeather said:

Euro is still the king based on recent data.

Operational runs

Ensembles

 

I'd be interested to see stats on its performance the past 5-8 years or so. Seems it's definitely less accurate than it used to be, even if it still is the best model of the group.

[roardog]

1 hour ago, michsnowfreak said:

The Euro used to be called king. For several years that has not been the case. I do not at all expect models to ever be perfect. But how can models get worse at technology advances?

Maybe the American models have just improved over the years. 

[GaWx]

2 hours ago, Terpeast said:

162 for atlantic

Being 160+ barely makes it officially hyperactive. Plus this might be raised in the post-season analyses.

[GaWx]

1 hour ago, BuffaloWeather said:

Euro is still the king based on recent data.

Operational runs

Ensembles

 

Of the operationals over the last month, it looks like Euro 1st and UKMET 2nd at H5 (day 5). But look what’s in 3rd: CMC, which isn’t much behind UKMET! That tells me that if this month is representative of the longer term, the CMC may be the most improved op at H5 (at least at 120 hrs) over the last 10 years or so. In 4th is GFS. Bringing up the rear: the very unreliable CFS.

[so_whats_happening]

2 hours ago, Stormchaserchuck1 said:

Now the 1st week of December looks cold. -WPO develops tonight, and holds through the next 15 days on 18z GFS ensembles.. -WPO patterns don't look that cold in the H5 means, but on the surface they are solidly below average.  If we are going to have a decent -WPO, I would actually watch for a snowstorm threat when the -NAO is coming up to near 0. A lot of research has been done correlating the rising-out-of-strong-negative NAO state with East Coast snowstorms, and if the Pacific pattern is favorable, there could really be a snowstorm threat, at least north of DC. Watch for around Thanksgiving, or a few days after. 

Agreed there seems to be a strong signal showing up around that time. Still over a week out so we will have to wait a few more days for better details. Luckily it seems like the energy off the West/ Pac NW is the culprit so maybe we can get a reconnaissance in there to help clear things up over the weekend before it impacts much of the country during Thanksgiving week. 

[GaWx]

0Z GFS has FIVE Canadian highs bring cold air down into the E US! That’s a relative rarity even for the GFS.

 NYC gets not just one but two measurable snowfalls fwiw.

[BuffaloWeather]

The pattern coming up looks incredible, so many wintry chances. The lakes are going to be firing the first week of December.

[GaWx]

0Z GEFS and EPS at least appear to be the coldest runs yet for the E US! NG is once again at new highs (up 3%), highest since Jan.

[snowman19]

4 hours ago, GaWx said:

0Z GEFS and EPS at least appear to be the coldest runs yet for the E US! NG is once again at new highs (up 3%), highest since Jan.

It’s becoming clear that the massive WWB no one expected, which turned ENSO region 1+2 into an El Niño had huge effects on the Rossby wave train, spiked the AAM positive and completely altered the long wave synoptic pattern. It changed the entire 500mb in the North Pacific (-WPO, -EPO, +PNA). The retrograding -NAO was happening regardless, totally different forcing mechanism with that. Now the million dollar question is did this start the beginning of a legit long term big shift North Pacific pattern for this winter or is this a temporary flux? No one is going to have the answer until we are into December. The models still show a big trade wind burst in region 3.4 in December, but will it actually matter at that point? Once the -NAO block dissipates, it’s going to be a purely PAC driven cold pattern, i.e. 13-14….does it continue??

[bluewave]

It’s been a long time since we saw a 15 day swing in this direction for an early December forecast. But I will give the models credit for seeing the Aleutian Ridge shift north of the Aleutians. If the forecasts are still showing this type of shift from the recent years in early December, then the December 5th Euro seasonal update should look different from what it had on November 5th. 
 

New run

Old run

Dominant 500 mb pattern in December since 2015 with ridge south of Aleutians rather than north

 

 

[PhiEaglesfan712]

The MEI has been updated. AS was -0.6 and SO was -0.5

I certainly wasn't expecting that, but the la nina is cooked. (Although we got an offical weak la nina on the MEI.)

[bluewave]

23 minutes ago, snowman19 said:

It’s becoming clear that the massive WWB no one expected, which turned ENSO region 1+2 into an El Niño had huge effects on the Rossby wave train, spiked the AAM positive and completely altered the long wave synoptic pattern. It changed the entire 500mb in the North Pacific (-WPO, -EPO, +PNA). The retrograding -NAO was happening regardless, totally different forcing mechanism with that. Now the million dollar question is did this start the beginning of a legit long term big shift North Pacific pattern for this winter or is this a temporary flux? No one is going to have the answer until we are into December. The models still show a big trade wind burst in region 3.4 in December, but will it actually matter at that point? Once the -NAO block dissipates, it’s going to be a purely PAC driven cold pattern, i.e. 13-14….does it continue??

The even bigger question is are we a least starting to see a small shift in the PCC? Remember how the El Niño last year began with the record 1+2 warming so early on with that record late winter 2023 WWB which was so east based. This most recent WWB was shifted over to the EPAC also. Maybe this means that at least for shorter intervals the EPAC can have more influence at times than the WPAC warm pool and MJO 4-7 has had since December 2015. It’s also possible that the big jump in global temperatures since 2023 is related to changes in the EPAC near South America. But it’s probably too early to speculate on that until we get more data.

 

https://www.nature.com/articles/s41467-024-52731-6

The eastern tropical Pacific has defied the global warming trend. There has been a debate about whether this observed trend is forced or natural (i.e., the Interdecadal Pacific Oscillation; IPO) and this study shows that there are two patterns, one that oscillates along with the IPO, and one that is emerging since the mid-1950s, herein called the Pacific Climate Change (PCC) pattern. 

 

As the tropical Pacific is known to be a climatic pacemaker, for (at least) the near-future this would mitigate global warming via ocean heat uptake and low-level cloud feedbacks. Instead, if the cyclic IPO dominates the recent cooling, we may expect a strong warming when it reverses.

 

[mitchnick]

48 minutes ago, bluewave said:

It’s been a long time since we saw a 15 day swing in this direction for an early December forecast. But I will give the models credit for seeing the Aleutian Ridge shift north of the Aleutians. If the forecasts are still showing this type of shift from the recent years in early December, then the December 5th Euro seasonal update should look different from what it had on November 5th. 
 

New run

Old run

Dominant 500 mb pattern in December since 2015 with ridge south of Aleutians rather than north

 

 

Interesting. Maybe the next question, assuming we see the same look in early December, is whether we should bother caring what the seasonal models say. Idk. Both the Euro and Cfs2 weeklies just caught on to the cold pattern yesterday.