2024-2025 La Nina

[SnoSki14]

Things could easily revert to a warmer pattern. Getting snow in early December would be really beneficial 

[brooklynwx99]

4 minutes ago, 40/70 Benchmark said:

I appreciate the objectivity in the flavor of your posts.....whereas the knock on some of the guys in here is that they only report data that caters to perceived bias.

going to be honest, I really did think that early Dec would be quite warm with the state of the MJO, but it clearly isn't driving the bus. my guess is the higher AAM is leading to a more extended jet, pushing the ridge near the Aleutians closer to AK and leading to more poleward wave breaking

[40/70 Benchmark]

10 minutes ago, brooklynwx99 said:

going to be honest, I really did think that early Dec would be quite warm with the state of the MJO, but it clearly isn't driving the bus. my guess is the higher AAM is leading to a more extended jet, pushing the ridge near the Aleutians closer to AK and leading to more poleward wave breaking

Yea, that is what Bluewave said.

I expected late November and the onse tof December to perhaps be wintry, but expect it to shift warmer within the first severday days.

Balance of November-December 2024 Outlook

December Analogs: 2022, 2021,1999

The mild pattern currently in place with the approach of mid-November is being driven by phase 2 of the MJO.

 

 

This warmer pattern should remain in place until about Thanksgiving week, when the passage of the MJO into phase 3 may herald in a colder, and more festive pattern.

 

 

Long range guidance is beginning to detect that +PNA/-NAO driven regime towards the holiday, which would result in at least colder weather and potentially even the first snowflakes for some locales.

 

 

The colder pattern looks to be fleeting, as the month of December should turn very mild in short order with the passage of the MJO in phase 4. The mild regime should remain in place until at the very least mid month. 

 

 

The first bonafide stretch of wintry weather looks to hold off until at least mid month for most locales. 

 

 

The polar vortex appears rather unremarkable through the balance of most of November and it would not be surprising for it to even weaken for a time later in the month of December.

 

While the pattern appears variable throughout much of the month of December, the warmth should be much greater in magnitude than the cold and much of the period(s) of polar blocking will be mitigated by an adjoining southeast ridge. Drier than average conditions in conjunction with the anomalous warmth should help to keep snowfall at a premium across much of the region. The appreciable cold periods will be primarily -WPO driven, per the above composite.

Temperatures across the mid Atlantic and New England should range anywhere from 3-5F degrees above average.

 

 

 

[brooklynwx99]

Just now, 40/70 Benchmark said:

Yea, that is what Bluewave said.

I expected late November and the onse tof December to perhaps be wintry, but expect it to shift warmer within the first severday days.

Balance of November-December 2024 Outlook

December Analogs: 2022, 2021,1999

The mild pattern currently in place with the approach of mid-November is being driven by phase 2 of the MJO.

 

 

This warmer pattern should remain in place until about Thanksgiving week, when the passage of the MJO into phase 3 may herald in a colder, and. more festive pattern.

 

 

Long range guidance is beginning to detect that +PNA/-NAO driven regime towards the holiday, which would result in at least colder weather and potentially even the first snowflakes for some locales.

 

 

The colder pattern looks to be fleeting, as the month of December should turn very mild in short order with the passage of the MJO in phase 4. The mild regime should remain in place until at the very least mid month. 

 

 

The first bonafide stretch of wintry weather looks to hold off until at least mid month for most locales. 

 

 

The polar vortex appears rather unremarkable through the balance of most of November and it would not be surprising for it to even weaken for a time later in the month of December.

 

While the pattern appears variable throughout much of the month of December, the warmth should be much greater in magnitude than the cold and much of the period(s) of polar blocking will be mitigated by an adjoining southeast ridge. Drier than average conditions in conjunction with the anomalous warmth should help to keep snowfall at a premium across much of the region. The appreciable cold periods will be primarily -WPO driven, per the above composite.

Temperatures across the mid Atlantic and New England should range anywhere from 3-5F degrees above average.

 

 

 

I guess the "Nino hangover" is a thing after all

that also makes me wonder if Feb is really going to be that crappy... if we don't have a super strong Nina influence, is it wise to assume so? for the record, I still expect a warm Feb, I'm just not as confident in it 

[40/70 Benchmark]

2 minutes ago, brooklynwx99 said:

I guess the "Nino hangover" is a thing after all

that also makes me wonder if Feb is really going to be that crappy... if we don't have a super strong Nina influence, is it wise to assume so? for the record, I still expect a warm Feb, I'm just not as confident in it 

I didn't go that warm in February...+1 to +3 with near normal snowfall.

[mitchnick]

1 hour ago, 40/70 Benchmark said:

I expected a mismatch period, but not one the magnitude of 2017 and 2020, which also encompassed December...I bit on a more tempered version like Jan 2022. 

We'll see. 2020 was one of the elite QBO analogs I selected, so there is that.

95/96 had plenty of warm-ups, so I  expect it.

[bluewave]

52 minutes ago, GaWx said:

@bluewave Chris, If NYC were to get accumulating snow at the end of Nov like this Euro op run shows, would it count toward the Dec snowfall total as regards your Dec SN indicator for the remainder of winter? I know getting over 3” in Dec is what you were keying on.

Would be an interesting question since the atmospheric 500 mb state now is more El Niño +PDO than La Niña with the high AAM pattern.

[snowman19]

1 hour ago, brooklynwx99 said:

I guess the "Nino hangover" is a thing after all

that also makes me wonder if Feb is really going to be that crappy... if we don't have a super strong Nina influence, is it wise to assume so? for the record, I still expect a warm Feb, I'm just not as confident in it 

I don’t know if what we’re seeing is related to a temporary and transient flux in the longwave pattern due to the sudden, unexpected (and very strong) WWB altering the Rossby wave train and subsequently causing a +AAM spike or the start of something bigger. It’s going to take more than a pattern shift from 10/28 into the 1st week of December to figure that out. We are going to have to wait until we are into December to see what or if anything changes. The wild claims on twitter that the PDO is about to go positive is absurd. The PDO is still extremely negative, just not the record breaking -3 anymore. And the WPAC warm pool is still there. While I’m open to anything at this point, I’m definitely not ready to completely abandon my winter forecast or say that the PAC or Atlantic is having a full scale shift

This is not about to magically flip to a +PDO:

[brooklynwx99]

15 minutes ago, snowman19 said:

I don’t know if what we’re seeing is related to a temporary and transient flux in the longwave pattern due to the sudden, unexpected (and very strong WWB) altering the Rossby wave train and subsequently causing a +AAM spike or the start of something bigger. It’s going to take more than a pattern shift from 10/28 into the 1st week of December to figure that out. We are going to have to wait until we are into December to see what or if anything changes. The wild claims on twitter that the PDO is about to go positive is absurd. The PDO is still extremely negative, just not the record breaking -3 anymore. And the WPAC warm pool is still there. While I’m open to anything at this point, I’m definitely not ready to completely abandon my winter forecast

This is not about to magically flip to a +PDO:

although it won't magically flip, the Japan trough and equatorward jet will promote LP and cooling from Japan to N of HI, and the AK ridge will promote warming in the GoAK

the PDO won't flip this year, but this will almost certainly make a big dent in the magnitude of the negative anomaly

[Terpeast]

1 hour ago, mitchnick said:

95/96 had plenty of warm-ups, so I  expect it.

60s and severe thunderstorms with flooding. Won't be surprised to see it this winter, too. (Not saying I also expect another Jan 1996)

[snowman19]

6 minutes ago, brooklynwx99 said:

although it won't magically flip, the Japan trough and equatorward jet will promote LP and cooling from Japan to N of HI, and the AK ridge will promote warming in the GoAK

the PDO won't flip this year, but this will almost certainly make a big dent in the magnitude of the negative anomaly

That’s true, however, the claims of a full scale regime shift of the PAC and Atlantic that some in the Twitter crowd are making right now are ludicrous. A pattern change projected by the models the last few days of this month into the beginning of December doesn’t = full scale PAC and Atlantic regime shift. Those don’t happen within 2 weeks 

[mitchnick]

32 minutes ago, brooklynwx99 said:

although it won't magically flip, the Japan trough and equatorward jet will promote LP and cooling from Japan to N of HI, and the AK ridge will promote warming in the GoAK

the PDO won't flip this year, but this will almost certainly make a big dent in the magnitude of the negative anomaly

I've been harping on that Japan trough for a while as I believe it's key to maintaining the trough in the east. Modeling seems bent on holding it in. Otoh, I couldn't care less if it disintegrated so long as it stays cold!

[FPizz]

2 hours ago, GaWx said:

@bluewave Chris, If NYC were to get accumulating snow at the end of Nov like this Euro op run shows, would it count toward the Dec snowfall total as regards your Dec SN indicator for the remainder of winter? I know getting over 3” in Dec is what you were keying on.

I've kept my own records since 87/88 and since then Novembers with an inch of snow+ have gone on to have 1 below average, 3 around average and 2 above average winters for my area.  So odds seem to be slightly above average winter snow wise down this way. 

[mitchnick]

On 11/15/2024 at 3:24 PM, snowman19 said:

The CPC has just spoken: 

I would guess they want a redo in that map.

P.s. I know it's for a longer period, but they clearly were not thinking temps shown on the new map for that period.

[snowman19]

27 minutes ago, mitchnick said:

I would guess they want a redo in that map.

P.s. I know it's for a longer period, but they clearly were not thinking temps shown on the new map for that period.

Obviously 

[bluewave]

1 hour ago, snowman19 said:

That’s true, however, the claims of a full scale regime shift of the PAC and Atlantic that some in the Twitter crowd are making right now are ludicrous. A pattern change projected by the models the last few days of this month into the beginning of December doesn’t = full scale PAC and Atlantic regime shift. Those don’t happen within 2 weeks 

It’s possible that we are seeing the early stages of some type of 500 mb regime shift in the North Pacific. The ridge today in the Bering Sea has exceeded a +500 meter anomaly which is one of the strongest on record for this time of year. SST indices like the PDO are usually lagging indicators after the 500mb pattern gets stuck in place for a long enough period of time. For the 2020s so far the North Pacific Ridge has been anchored to the south of the Aleutians. So if the pattern can persist past the first week of December it’s possible that something significant shifted with this +AAM rise and WWB which caused the Nino 1+2s to warm off of South America. 

Near record 500 MB heights today Bering Sea 

 

2020s mean ridge south of Aleutians

 

[Wow]

It's things like this that make long range/seasonal forecasting so interesting.  There's always something that defies what we thought we expected.  How a simple anomaly can force a butterfly effect on the entire long range forecast.

[Wow]

1 hour ago, Terpeast said:

60s and severe thunderstorms with flooding. Won't be surprised to see it this winter, too. (Not saying I also expect another Jan 1996)

There will never be another Jan 96.  Every KU storm is distinct in its own way.  I mean, was that storm similar to any other previous storm?

[PhiEaglesfan712]

4 hours ago, brooklynwx99 said:

I guess the "Nino hangover" is a thing after all

that also makes me wonder if Feb is really going to be that crappy... if we don't have a super strong Nina influence, is it wise to assume so? for the record, I still expect a warm Feb, I'm just not as confident in it 

The Weather Channel has been very good at predicting crappy (torch) winter months in recent years. They nailed Decembers 2015, 2021, and 2023 in advance. For what it's worth, they have January torching.

I think February is going to be the best month for winter weather.

[George001]

4 hours ago, 40/70 Benchmark said:

I appreciate the objectivity in the flavor of your posts.....whereas the knock on some of the guys in here is that they only report data that caters to perceived bias.

This has my attention because most of Allsnows posts the past 2 years have been favoring warmth to the extent he was accused of having a warm bias. He ended up being right, as the past 2 winters had near record warmth in the east. 

[mitchnick]

1 hour ago, snowman19 said:

Obviously 

That forecast came out on the 15th. Gefs and Geps were showing persistent cold pattern on the 12z runs of the 15th. Eps were showing average temps. Guess they didn't buy the Gefs and Geps. Eps late to the party again. They wrecked that model.

[mitchnick]

37 minutes ago, PhiEaglesfan712 said:

The Weather Channel has been very good at predicting crappy (torch) winter months in recent years. They nailed Decembers 2015, 2021, and 2023 in advance. For what it's worth, they have January torching.

I think February is going to be the best month for winter weather.

Turn off TWC before you go blind. Lol

[George001]

2 hours ago, snowman19 said:

I don’t know if what we’re seeing is related to a temporary and transient flux in the longwave pattern due to the sudden, unexpected (and very strong) WWB altering the Rossby wave train and subsequently causing a +AAM spike or the start of something bigger. It’s going to take more than a pattern shift from 10/28 into the 1st week of December to figure that out. We are going to have to wait until we are into December to see what or if anything changes. The wild claims on twitter that the PDO is about to go positive is absurd. The PDO is still extremely negative, just not the record breaking -3 anymore. And the WPAC warm pool is still there. While I’m open to anything at this point, I’m definitely not ready to completely abandon my winter forecast or say that the PAC or Atlantic is having a full scale shift

This is not about to magically flip to a +PDO:

I agree that the PDO isn’t going positive. The question is can we get an extended stretch of cold and possibly snow even with a -2 PDO? It has happened in the past, this year I’m not sure about yet. I don’t expect a 10-11 repeats where the cold and snowy pattern locks in for 2 months, if the cold pattern does set in I want to see how long it lasts before the shift back warm. Once that happens it isn’t over, then we need to see how long the warm period is before shifting back cold. Only when that happens will we have an idea of which camp this winter is headed. If the warm pattern lasts longer than the cold one, that’s an indicator we are headed towards the warm camp (01-02, 16-17, 21-22 top analogs). If the cold pattern lasts longer than the warm one that’s an indicator we are headed towards the cold camp (13-14, 08-09, 17-18 top analogs). I decided to remove 10-11 as a possible analog because it’s now both a terrible ENSO (strong Nina vs ENSO neutral) and solar match. I’m going to make my forecast by the end of the week, well before this winter shows its hand. 

[bluewave]

1 hour ago, snowman19 said:

Obviously 

This will probably be the first time in the last few years that a week 2 forecast trended colder instead of warmer.

New run

 

Old run

 

 

 

[mitchnick]

Anybody know where the ACE ended, or soon to end? Seems like it made a last ditch save into something respectable. Thanks.

[Terpeast]

3 minutes ago, mitchnick said:

Anybody know where the ACE ended, or soon to end? Seems like it made a last ditch save into something respectable. Thanks.

162 for atlantic

[Stormchaserchuck1]

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. 

[snowman19]

45 minutes ago, mitchnick said:

That forecast came out on the 15th. Gefs and Geps were showing persistent cold pattern on the 12z runs of the 15th. Eps were showing average temps. Guess they didn't buy the Gefs and Geps. Eps late to the party again. They wrecked that model.

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

[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