2024-2025 La Nina

[GaWx]

32 minutes ago, mitchnick said:

Thanks Larry.

I  got thinking that the EPS didn't do so hot with last winter's forecast. Although I  couldn't find a site that had the 1/24 EPS 5H forecast from July 2023, I  did find one from September 2023 for 1/24-3/24. so keep a stiff upper lip! Lol

 I remember many of us salivating about this and other H5 maps for 23-4. (By the way, I’m hoping we’ll see maps like this posted in the 25-6 thread.) I mean it had El Niño, Aleutian low, strong +PNA, -NAO, and -AO. It had the pentafecta of wx indices for great E US winter potential! I was even thinking I’d have a decent chance for a wintry precip event way down here, which would have been the 1st in 6 years.
 Well, El Niño was correct and we had a modest +PNA. But the Aleutian low and -NAO were miserable fails. And the AO averaged neutral, which was a moderate fail. The SE still averaged only slightly warmer than normal. So, I can’t complain too much.

  This Euro 24-5 map has La Niña, Aleutian high, -PNA, +NAO, and +AO. Exact opposites. All the things that most E US cold/snowy winter lovers don’t want.

 

[raindancewx]

Atlantic ACE got to about 36 with Beryl. Nothing on the horizon for a little while.

SE ridge?

[Stormchaserchuck1]

Climate models have a heavy ENSO bias.. they didn't estimate that the subsurface would cool so much going into the Winter last year.  

I agree with what they are showing now.. -PNA/+NAO. There is going to be a 601-602dm ridge in the N. Atlantic in the coming days over the area that has a pretty big summertime SST correlation to Wintertime NAO.. warm water there favors +NAO. It seems like recent seasonal model runs have been going more +NAO. It may also be that they just weigh heavily on trends.. as this will be our 5th solid +NAO burst since the start of the year (negative H5 over Greenland and Davis Strait), which was more than the last few years combined.  It also seems like the Sun spikes in May really led some good +NAO.. 

[Stormchaserchuck1]

3 hours ago, raindancewx said:

Atlantic ACE got to about 36 with Beryl. Nothing on the horizon for a little while.

SE ridge?

July is going to be a very warm month for the CONUS. This is going to make Dec-July one of the warmest on record, if not the warmest for the lower 48. 

Roll forward of 30 top analogs going back to 1948 (which is 40% of the dataset) shows a ridiculous strong signal for the following September through March: 

 

+3-4F anomalies over a 7-month period, covering 40% of the dataset is pretty ridiculous signal. Law of averages says it should be ~+1F (since I am using + and - years, somewhat muting the overall warming trend). I guess here locally continuum trumps. 

I've been waiting for the June map to update, once it does ill post comparison to what we have seen vs analogs used above. 

[mitchnick]

41 minutes ago, raindancewx said:

Atlantic ACE got to about 36 with Beryl. Nothing on the horizon for a little while.

SE ridge?

Coincidentally, I  just noticed this product from the Euro today. Basically says the chances of Atlantic tropical activity at or below normal thru the first week of August. 

https://charts.ecmwf.int/products/mofc_multi_tcyc_family_frequency?base_time=202407080000&parameter=Accumulated cyclone energy&valid_time=202407150000

[snowman19]

10 hours ago, Stormchaserchuck1 said:

Climate models have a heavy ENSO bias.. they didn't estimate that the subsurface would cool so much going into the Winter last year.  

I agree with what they are showing now.. -PNA/+NAO. There is going to be a 601-602dm ridge in the N. Atlantic in the coming days over the area that has a pretty big summertime SST correlation to Wintertime NAO.. warm water there favors +NAO. It seems like recent seasonal model runs have been going more +NAO. It may also be that they just weigh heavily on trends.. as this will be our 5th solid +NAO burst since the start of the year (negative H5 over Greenland and Davis Strait), which was more than the last few years combined.  It also seems like the Sun spikes in May really led some good +NAO.. 

Correct me if I’m wrong but I believe that the New Foundland warm pool is a very strong signal for +NAO

[40/70 Benchmark]

13 hours ago, GaWx said:

Forecasted Jan 2025 H5 height anomalies from July Euro: most of US 2.4-3.5 dm above climo

Euro tempts me to quit weather.

[bluewave]

That Euro run would make it an historic 10th warmer to record warm winters in a row for places like NYC and the Northeast region in general.

 

NYC

Feb 24…+4.2

Jan 24..+3.3

Dec 23..+5.5

…………..+4.3

 

Feb 23…+5.2

Jan 23…+9.8

Dec 22…-0.6

…………..+4.8

 

Feb 22….+1.4

Jan 22….-3.2

Dec 21….+4.7

……………..+1.0

 

Feb 21….-1.7

Jan 21….+1.1

Dec 20…+1.7

…………..+0.4

 

Feb 20…+4.8

Jan 20….+6.5

Dec 19….+0.8

…………….+4.0

 

Feb 19….+0.9

Jan 19….-0.1

Dec 18…+2.6

…………….+1.1

 

Feb 18…+6.7

Jan 18….-0.9

Dec 17…..-2.5

…………….+1.1

 

Feb 17…..+6.3

Jan 17….+5.4

Dec 16….+0.8

…………….+4.2

 

Feb 16….+2.4

Jan 16….+1.9

Dec 15….+13.3

…………….+5.9

[snowman19]

22 minutes ago, 40/70 Benchmark said:

Euro tempts me to quit weather.

Verbatim, that’s a warmer version of the 88-89 La Niña disaster 

[George001]

41 minutes ago, snowman19 said:

Verbatim, that’s a warmer version of the 88-89 La Niña disaster 

It’s probably wrong, but that would be a repeat of 2011-2012. 

[PhiEaglesfan712]

If we are still stuck in -PDO, then I expect 2025-26 to be a moderate or strong la nina. I see no possible way 2025-26 being an el nino unless we shift to a +PDO. There's no way we get 2 significant el ninos in 3 years in -PDO.

[bluewave]

1 hour ago, snowman19 said:

Verbatim, that’s a warmer version of the 88-89 La Niña disaster 

It’s a general repeat of its 22-23 La Niña forecast. Did very well with the main ridge axis over the Aleutians and the Eastern US. The trough verified deeper in the West and the AO was more negative than forecast with more Greenland blocking.

Current forecast

 

 November 2023 forecast

 

Winter 22-23 verification

 

[snowman19]

11 minutes ago, bluewave said:

It’s a general repeat of its 22-23 La Niña forecast. Did very well with the main ridge axis over the Aleutians and the Eastern US. The trough verified deeper in the West and the AO was more negative than forecast with more Greenland blocking.

Current forecast

 

 November 2023 forecast

 

Winter 22-23 verification

 

If we assume it’s not deep enough with the RNA/-PNA again (possible given the strong -PDO), it doesn’t get much uglier than that…..flat Aleutian ridge, ++AO/++NAO, SE ridge/WAR on steroids 

[bluewave]

20 minutes ago, snowman19 said:

If we assume it’s not deep enough with the RNA/-PNA again (possible given the strong -PDO), it doesn’t get much uglier than that…..flat Aleutian ridge, ++AO/++NAO, SE ridge/WAR on steroids 

A ridge axis out near the Aleutians is always going to be warmer than average for the Northeast like we have seen in the general 500 mb composite over the last 9 winters. 

We would need some help from the MJO 8 like we got back in January 2022 to at least get one interesting winter month with a break from the dominant MJO 4-7 forcing.

 

 

 

[Terpeast]

3 hours ago, bluewave said:

A ridge axis out near the Aleutians is always going to be warmer than average for the Northeast like we have seen in the general 500 mb composite over the last 9 winters. 

We would need some help from the MJO 8 like we got back in January 2022 to at least get one interesting winter month with a break from the dominant MJO 4-7 forcing.

 

 

 

Another way we could get some help is an -epo block that happened in the middle of Jan. It was short lived so this plot has some noise, but we can see the cold air dumping into the CONUS. One pathway to this happening is the aleutian ridge pushing poleward through AK, which can occasionally happen in La Ninas. 

The biggest irony is that this wasn’t driven by El Nino. This was the only 10 day period when the STJ all but quieted down this winter. If I remember correctly, the MJO was in 3 before this pattern aberration occurred (and went onto 4-6 driving record warmth after the two MA snows).

Your Jan 2022 scenario and this one are just about the best short-term wintery hits that we can hope for south of 40N in this coming winter, imo  

[brooklynwx99]

16 hours ago, raindancewx said:

Atlantic ACE got to about 36 with Beryl. Nothing on the horizon for a little while.

SE ridge?

CSU is now forecasting 230 ACE... this is probably one of the only variables that actually looks good for E US winters. otherwise, slim pickings 

[Stormchaserchuck1]

7 hours ago, snowman19 said:

Correct me if I’m wrong but I believe that the New Foundland warm pool is a very strong signal for +NAO

This region has the highest correlation to Winter NAO

Now we are going to be warming this further in the next few days with a record breaking ridge developing over the eastern part of the box:

We'll be looking at a pretty high index reading by mid-July. 

[PhiEaglesfan712]

All is not lost with the 2022-23 setup. We just need the exact pattern that was in place from March-June 2023 to be there 3 months earlier. I keep thinking what if that rainstorm in late April happened in late January/early February or if that blocking pattern that was in place in June was there in March.

[Stormchaserchuck1]

1 hour ago, PhiEaglesfan712 said:

All is not lost with the 2022-23 setup. We just need the exact pattern that was in place from March-June 2023 to be there 3 months earlier. I keep thinking what if that rainstorm in late April happened in late January/early February or if that blocking pattern that was in place in June was there in March.

Subsurface was turning positive pretty early in 2023:

In the central-ENSO region (west-based) March-June 2023 was greater positive than even most of the El Nino event. We have a colder subsurface this year, although it is starting to warm again in the last few days. 

Look at this -PNA though since the central-subsurface went cold in March this year

This is while we've had +Neutral at the surface. 

[bluewave]

4 hours ago, Terpeast said:

Another way we could get some help is an -epo block that happened in the middle of Jan. It was short lived so this plot has some noise, but we can see the cold air dumping into the CONUS. One pathway to this happening is the aleutian ridge pushing poleward through AK, which can occasionally happen in La Ninas. 

The biggest irony is that this wasn’t driven by El Nino. This was the only 10 day period when the STJ all but quieted down this winter. If I remember correctly, the MJO was in 3 before this pattern aberration occurred (and went onto 4-6 driving record warmth after the two MA snows).

Your Jan 2022 scenario and this one are just about the best short-term wintery hits that we can hope for south of 40N in this coming winter, imo  

Yeah, those were some of the strongest VP anomalies that we have seen in early January in the MJO 2 region. There was a record marine heatwave at the time there. The RMM charts didn’t really do the forcing there justice. Sometimes the RMM captures the signal better and other times the VP anomalies. 

[George001]

4 hours ago, PhiEaglesfan712 said:

All is not lost with the 2022-23 setup. We just need the exact pattern that was in place from March-June 2023 to be there 3 months earlier. I keep thinking what if that rainstorm in late April happened in late January/early February or if that blocking pattern that was in place in June was there in March.

I disagree, the 2022-2023 temp profile is not conducive to snow outside of NNE and elevations. The reason I am more optimistic about this winter is the shift in guidance to a later developing Nina. While later developing Nina doesn’t inherently mean better winter for the east, the way this specific event is developing right now (from east to west), the earlier the Nina develops, I would think the earlier in the winter it would shift west. This gives me hope that the Nina will be east based or at least east tilted throughout the first half of winter. 

[SnoSki14]

11 hours ago, 40/70 Benchmark said:

Euro tempts me to quit weather.

We're in the runaway warming phase now.

It's mostly game over 

At least we had some nice winters to look back on

[Yanksfan]

On 7/8/2024 at 5:47 PM, GaWx said:

Forecasted Jan 2025 H5 height anomalies from July Euro: most of US 2.4-3.5 dm above climo

Euro is off its rocker.

[GaWx]

3 minutes ago, Yanksfan said:

Euro is off its rocker.

Based on what? TIA

[raindancewx]

Here is a look at the Summer MJO composites for precipitation v. observations globally in June. The map is closest to the MJO 5-6 composite. MJO 4 is generally pretty active in the Atlantic but the huge dry spot in the Indian Ocean is very much anti-MJO 4. 

[George001]

2 hours ago, GaWx said:

Based on what? TIA

I think it’s strange that there is a ridge in the east and west. Usually bad Nina patterns have a massive trough out west like 2022-2023. 

[Terpeast]

2 minutes ago, George001 said:

I think it’s strange that there is a ridge in the east and west. Usually bad Nina patterns have a massive trough out west like 2022-2023. 

Climate change.

And no, I'm not being flippant. It's easy to see that if the jet stream runs further north, then everywhere underneath and south of it will be above normal

[George001]

13 minutes ago, Terpeast said:

Climate change.

And no, I'm not being flippant. It's easy to see that if the jet stream runs further north, then everywhere underneath and south of it will be above normal

That makes sense, the jet stream moving north over time is one of many observed long term effects of climate change. That also explains why clippers are so rare now. They still exist, but they don’t dive as far south as they did in the past.

[Terpeast]

49 minutes ago, George001 said:

That makes sense, the jet stream moving north over time is one of many observed long term effects of climate change. That also explains why clippers are so rare now. They still exist, but they don’t dive as far south as they did in the past.

Yeah those clippers have been replaced by GL lows that always seem to interfere with the genesis of cold highs at the most inopportune times. 

It’s almost as if we need a strong PV to squeeze as far south as Ontario just to get those lows far enough south for DC to snow (like it did twice this January)

[Stormchaserchuck1]

+NAO in January also favors country-wide warmth

A lot of these models just take what's happening and initialize it out.. You probably have to pay to get really good products.  5 +NAO periods since January, so now all the seasonal models have +NAO. I would guess their forecasting accuracy for that specific thing is not that high. That's why I like to look at Natural Gas futures primarily. They crushed the Euro last Winter.