2024-2025 La Nina

[bluewave]

1 hour ago, 40/70 Benchmark said:

Should be a decent December....enter Bluewave stressing the need for a disconnect followed by a slew of charts illustrating why it won't happen. 

I haven’t made any official forecasts specifically for December yet. But I will note that the 2 great December La Niña snowfall outcomes for NYC during La Ninas since 15-16 were +PNAs in 2020 and 2017. Before those Decembers we had the more amplified October MJO 4-7 phases with weaker MJO 4-7 December activity. In the multiyear groupings those were the strongest of the La Ninas. So far this La Niña isn’t looking as strong as those like we saw in 2016 coming out of that super El Niño event. But I still want to see how the MJO responds in October before making any early guesses.

When using the term mismatch I am referring to positive +PNA reversing the Aleutian Ridge pattern. I took it from the CPC discussion back during the stronger 20-21 La Niña when the +PNA was strongest on record for such a robust December La Niña. The much less snowy December outcomes were the weaker December La Niñas in 2016, 2021, and 2022 relative to the multiyear groupings.  But my focus is only on NYC and not further north in New England or the Great Lakes which have much more leeway when it comes to snowfall. 

 

December +PNA above average NYC snow

 

 

 

December -PNA below average NYC snow

 

[snowman19]

1 hour ago, 40/70 Benchmark said:

Should be a decent December....enter Bluewave stressing the need for a disconnect followed by a slew of charts illustrating why it won't happen. 

One thing is for sure, the Atlantic is currently dead. If you look back on history, the years that were this quiet in this time frame since August never came back. Would not be the least bit surprised to see a final ACE below 100

[michsnowfreak]

1 hour ago, roardog said:

Wasn’t it Raindance that showed previously how a Modoki Nina is actually correlated to a cold December in the US?

Ninas historically have great Decembers in Michigan. If this December by chance sucks, itll probably be a good February. (One "stand out" month in a Nina is a near given here).

[qg_omega]

On 8/18/2024 at 12:30 PM, qg_omega said:

No reason to not go warmest winter ever, Nina + -PDO = 4+5+6 all winter

no changes

[snowman19]

IMO the dry pattern we entered at the tail end of August is going to have staying power this fall. I’m expecting the next 3 months (SON) to be drier than normal as well as warmer than normal

[raindancewx]

Still waiting on how hurricane season plays out in the Atlantic. But the SST configuration from the Canadian looks a lot like a simple blend of 2013-14 and 2021-22 to me. That gets you to ~90 ACE for the season which looks like a decent guess at the moment.

August was almost identical.

Kind of toying with 2013-14, 2021-22 and then some maybe minor input from 1966, 1970, 2001, 2008, 2020, 2022.

I'm tempted to do something like this but I still need to play with the weighting. I am planning to have my outlook by 10/10.

2013-14 x4

2021-22 x3

2022-23 x2

1966-67 x2

1970-71

2001-02

2008-09

2020-21

[PhiEaglesfan712]

8 hours ago, snowman19 said:

IMO the dry pattern we entered at the tail end of August is going to have staying power this fall. I’m expecting the next 3 months (SON) to be drier than normal as well as warmer than normal
 

I just have to hope for a mudstorm in late October, like 2007, or we're probably going to have a drought in the mid-Atlantic.

[Stormchaserchuck1]

9 hours ago, snowman19 said:

IMO the dry pattern we entered at the tail end of August is going to have staying power this fall. I’m expecting the next 3 months (SON) to be drier than normal as well as warmer than normal

October has been a wet month in the Northeast for the last 20 years

[snowman19]

5 hours ago, Stormchaserchuck1 said:

October has been a wet month in the Northeast for the last 20 years

IMO that changes this year

@bluewave The warmest SSTs on the planet are right in the MJO phase 4-6 regions. Gee, I wonder where the main tropical convective forcing is going to set up shop?

[bluewave]

Strongest WPAC warm pool on record during the summer. 

 

 

[PhiEaglesfan712]

On 9/5/2024 at 8:38 AM, 40/70 Benchmark said:

1971-1972 could be a decent analog...I just don't like how La Nina died so early on in the winter season, which is probably at least partly why February was such a good month....maybe be an okay analog for the first half.

Isn't it common for last year la ninas to die early on? It happened in 1950-51, 1956-57, and to an extent 2022-23. None of those years were good snow years at PHL (all finished below 8 in of snow). Even with the snowy February, 1971-72 finished with just over 12 in of snow at PHL.

[mitchnick]

6 hours ago, snowman19 said:

IMO that changes this year

@bluewave The warmest SSTs on the planet are right in the MJO phase 4-6 regions. Gee, I wonder where the main tropical convective forcing is going to set up shop?

Be careful hanging your hat on 1 strong factor and disregarding competing, weaker ones. Sometimes the strong ones do prevail, but it's those weaker, competing ones that make long term forecasting so difficult imho.

[mitchnick]

Today’s Cfs2 says Raindance is onto something. 

Surface:

https://www.cpc.ncep.noaa.gov/products/CFSv2/htmls/usT2me3Mon.html

850:

https://www.cpc.ncep.noaa.gov/products/CFSv2/htmls/usT850e3Mon.html

[snowman19]

1 hour ago, mitchnick said:

Be careful hanging your hat on 1 strong factor and disregarding competing, weaker ones. Sometimes the strong ones do prevail, but it's those weaker, competing ones that make long term forecasting so difficult imho.

Not hanging my hat on just that but it’s a very good bet that the atmosphere is going to put the strongest convection over the warmest SSTs, just looking at the laws of physics/thermodynamics. Very likely the MJO favors those phase regions. When you have SSTs that anomalously warm, it alters the global heat budget and subsequently the main forcing

[michsnowfreak]

12 hours ago, raindancewx said:

Still waiting on how hurricane season plays out in the Atlantic. But the SST configuration from the Canadian looks a lot like a simple blend of 2013-14 and 2021-22 to me. That gets you to ~90 ACE for the season which looks like a decent guess at the moment.

August was almost identical.

Kind of toying with 2013-14, 2021-22 and then some maybe minor input from 1966, 1970, 2001, 2008, 2020, 2022.

I'm tempted to do something like this but I still need to play with the weighting. I am planning to have my outlook by 10/10.

2013-14 x4

2021-22 x3

2022-23 x2

1966-67 x2

1970-71

2001-02

2008-09

2020-21

Several FANTASTIC winters in there for the Lakes! In fact, the only undesirable ones are 2022-23 & 2001-02, but even those had multiple nice snowstorms. But sweet Jesus, 2013-14 x 4!?  .

That composite gives Detroit an average snowfall of 58.4". 

[PhiEaglesfan712]

On 9/6/2024 at 11:12 AM, bluewave said:

I haven’t made any official forecasts specifically for December yet. But I will note that the 2 great December La Niña snowfall outcomes for NYC during La Ninas since 15-16 were +PNAs in 2020 and 2017. Before those Decembers we had the more amplified October MJO 4-7 phases with weaker MJO 4-7 December activity. In the multiyear groupings those were the strongest of the La Ninas. So far this La Niña isn’t looking as strong as those like we saw in 2016 coming out of that super El Niño event. But I still want to see how the MJO responds in October before making any early guesses.

When using the term mismatch I am referring to positive +PNA reversing the Aleutian Ridge pattern. I took it from the CPC discussion back during the stronger 20-21 La Niña when the +PNA was strongest on record for such a robust December La Niña. The much less snowy December outcomes were the weaker December La Niñas in 2016, 2021, and 2022 relative to the multiyear groupings.  But my focus is only on NYC and not further north in New England or the Great Lakes which have much more leeway when it comes to snowfall. 

 

December +PNA above average NYC snow

 

 

 

December -PNA below average NYC snow

 

December 2016 was the cool month of the winter here at PHL. Almost reminded me a lot of December 2007.

January and February 2017 were a lot warmer than average.

[bluewave]

1 hour ago, PhiEaglesfan712 said:

December 2016 was the cool month of the winter here at PHL. Almost reminded me a lot of December 2007.

January and February 2017 were a lot warmer than average.

Yeah, 16-17 was the 7th  warmest winter for NYC. We were fortunate to have the lingering +PDO pattern from 13-14 to 15-16  and BM storm track back to 09-10. So we had a great blizzard in February even though there record mid-60s the day before.

Time Series Summary for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

1	2001-2002	41.5	0
2	2022-2023	41.0	0
-	2015-2016	41.0	0
3	2023-2024	40.6	0
4	2011-2012	40.5	0
5	1931-1932	40.1	0
6	1997-1998	39.6	0
7	2016-2017	39.3	0
8	2019-2020	39.2	0
9	1990-1991	39.1	0
10	1998-1999	38.6	0

 

 

[snowman19]

The -PDO is strengthening and a healthy -PMM is also starting to emerge with the cooling off Baja. And it looks like a GOA cold pool is poised to develop as the strong cooling in the Bering Sea results in downstream cooling of the GOA:
 

 

 

 

 

 

 

[snowman19]

This solar max is now on par with the solar cycle 23 max (01-02), in terms of sunspots, radio flux (a whopping 246 radio flux) and geomag activity
 

 

 

 

At this point, it doesn’t appear that any of the main variables (central based -ENSO, strong -PDO, weak -IOD, -PMM, +QBO, high solar flux/sunspots, high geomag, low arctic sea ice, +AMO/New Foundland warm pool, record warm SSTs in MJO phases 4-6) are going to change as we go into met winter. The only unknown is if the cumulative VEI 5 Ruang volcanic eruptions end up having any stratospheric effects, though likely to be minimal

 

 

[bluewave]

9 hours ago, snowman19 said:

The -PDO is strengthening and a healthy -PMM is also starting to emerge with the cooling off Baja. And it looks like a GOA cold pool is poised to develop as the strong cooling in the Bering Sea results in downstream cooling of the GOA:
 

 

 

 

 

 

 

The Pacific Jet was the strongest on record for the summer near the SW portions of the Bering Sea.

 

[snowman19]

The new NMME is out FWIW:

[40/70 Benchmark]

3 hours ago, snowman19 said:

The new NMME is out FWIW:
 

That looks decent for me. Seeing a theme among seasonal guidance of the heat being focused around the Texarkana with relative cooler values the deeper once goes into New England. Real 2007-2008 vibe...

[GaWx]

27 minutes ago, 40/70 Benchmark said:

That looks decent for me. Seeing a theme among seasonal guidance of the heat being focused around the Texarkana with relative cooler values the deeper once goes into New England. Real 2007-2008 vibe...

 Indeed, taken at face value (yes I realize that’s a huge risk due to major unreliability and a tendency of recent years’ progs to be cold biased from what I can recall), this would mean a significantly colder NE than last winter. For example, it has NYC at only +2 vs +5 last winter, a large difference.

 For the SE, this map has a major +5+ torch, which would be much warmer than last year’s mainly NN to +3. Ouch but I’ve been expecting a warm winter here. That’s why I keep thinking about 2025-6 so much lol.

 It also has the SE mainly drier than normal. That’s common for especially the deep SE in a Niña. Totally expecting that but not worried about drought here right now.

*Corrected for typo….cold not warm biased

 

[snowman19]

1 hour ago, 40/70 Benchmark said:

That looks decent for me. Seeing a theme among seasonal guidance of the heat being focused around the Texarkana with relative cooler values the deeper once goes into New England. Real 2007-2008 vibe...

07-08 was an unmitigated, epic disaster south of New England.
 

For NYC: November: no snow that month, 2nd warmest Thanksgiving Day on record. December: 12/2 - 1.4 inches of snow, washed away by rain. 12/16 - sleet and rain, 1 inch of frozen (sleet). January: 1/31 - Trace of snow, which was the total for the month. February: 2/12 - 2.8 inches of snow followed by sleet/freezing rain, then a huge torch and very heavy rain into 2/13. 2/22 - 6 inches of wet, slushy snow, biggest storm of the entire winter. 2/29 - 0.2 of snow and the last time it snowed that winter. March: nothing. April: nothing.

Sources: https://thestarryeye.typepad.com/weather/2012/02/new-york-weather-highlights-2007.html%20

https://thestarryeye.typepad.com/weather/2012/02/new-york-weather-highlights-2008-.html%20

[40/70 Benchmark]

54 minutes ago, snowman19 said:

07-08 was an unmitigated, epic disaster south of New England.
 

For NYC: November: no snow that month, 2nd warmest Thanksgiving Day on record. December: 12/2 - 1.4 inches of snow, washed away by rain. 12/16 - sleet and rain, 1 inch of frozen (sleet). January: 1/31 - Trace of snow, which was the total for the month. February: 2/12 - 2.8 inches of snow followed by sleet/freezing rain, then a huge torch and very heavy rain into 2/13. 2/22 - 6 inches of wet, slushy snow, biggest storm of the entire winter. 2/29 - 0.2 of snow and the last time it snowed that winter. March: nothing. April: nothing.

Sources: https://thestarryeye.typepad.com/weather/2012/02/new-york-weather-highlights-2007.html%20

https://thestarryeye.typepad.com/weather/2012/02/new-york-weather-highlights-2008-.html%20

That was my snowiest month of December on record. 

[snowman19]

25 minutes ago, 40/70 Benchmark said:

That was my snowiest month of December on record. 

The thing I remember most about 07-08 besides it barely snowing that winter, was the massive Thanksgiving Day torch. It was like 70 degrees and my cousins and I were outside in shorts and short sleeves playing football that afternoon 

[bluewave]

3 hours ago, GaWx said:

 Indeed, taken at face value (yes I realize that’s a huge risk due to major unreliability and a tendency of recent years’ progs to be cold biased from what I can recall), this would mean a significantly colder NE than last winter. For example, it has NYC at only +2 vs +5 last winter, a large difference.

 For the SE, this map has a major +5+ torch, which would be much warmer than last year’s mainly NN to +3. Ouch but I’ve been expecting a warm winter here. That’s why I keep thinking about 2025-6 so much lol.

 It also has the SE mainly drier than normal. That’s common for especially the deep SE in a Niña. Totally expecting that but not worried about drought here right now.

*Corrected for typo….cold not warm biased

 

If a place like Atlanta does indeed go +5.0 or higher next winter, then historically NYC has finished DJF warmer than +2.0. I was able to find 5 La Niña winters when Atlanta averaged +5.0 or greater. The 5 winters all had NYC above +4.0. 
 

+5.0 or warmer Atlanta La Niña winters and NYC departures

22-23….ATL….+5.2……NYC……+4.8

16-17……ATL…..+7.1…….NYC…..+4.2

11-12……ATL……+5.0…..NYC….+5.4

98-99….ATL……+5.8…..NYC…..+4.8

49-50….ATL……+6.6…..NYC…..+4.5

[so_whats_happening]

I feel like I have seen now a few times 2013-14 get thrown around. Quite interesting to say the least so far it is fairly close in matching this August/September 500mb pattern. Hurricane season ended up 14/2/0, we already had 1 major hurricane so there is that at least. Already had a pretty well established westerly QBO. -PDO was around, we are on a different magnitude of PDO right now but we shall see how it continues. Entering a solar max time period. A bit off on the subsurface look as this year has a bit more of negative subsurface. 

Again just pointing out some similarities no real drive to make this a forecast. If models are right in signaling and we do indeed actually start to see more troughing occur onto the Pac NW this may be a year to throw into the consensus.

[so_whats_happening]

Just now, so_whats_happening said:

I feel like I have seen now a few times 2013-14 get thrown around. Quite interesting to say the least so far it is fairly close in matching this August/September 500mb pattern. Hurricane season ended up 14/2/0, we already had 1 major hurricane so there is that at least. Already had a pretty well established westerly QBO. -PDO was around, we are on a different magnitude of PDO right now but we shall see how it continues. Entering a solar max time period. A bit off on the subsurface look as this year has a bit more of negative subsurface. 

Again just pointing out some similarities no real drive to make this a forecast. If models are right in signaling and we do indeed actually start to see more troughing occur onto the Pac NW this may be a year to throw into the consensus.

2007 is a bit off to me but here is the 500mb pattern for August/September. That year we had a late developing WQBO pattern, rather low solar year, the PDO was rather neutral except a random spike negative around October, subsurface was an ok match, the hurricane season put on quite the show. So it has some similarities maybe an anti 2007 would be better?

[so_whats_happening]

Also besides the tropical system near the Bay of Campeche, which may become a hurricane if it can spend enough time over waters, we should see at least one more tropical system form in the Atlantic within the next week given the relaxation in the positive VP that has plagued us this year. Honestly it probably is a good thing, most folks do not want to deal with intense tropical activity especially since insurance is through the roof in many locations along the Gulf coast. 

Current forecast and looking at past relaxations of +VP over the Atlantic they match up pretty well to a system being able to get going. Next potential if forecast holds up would be into the end of the month.