2024-2025 La Nina

[LibertyBell]

18 minutes ago, PhiEaglesfan712 said:

We do have precedent for that, and not too long ago. In 2022, we had a la nina that peaked in between seasons.

2021-22 RONI:

JAS  2021 -0.71
ASO  2021 -0.92
SON  2021 -1.06
OND  2021 -1.23
NDJ  2021 -1.24
DJF  2022 -1.21
JFM  2022 -1.21
FMA  2022 -1.28
MAM  2022 -1.34
AMJ  2022 -1.22
MJJ  2022 -0.98
JJA  2022 -0.90

Thanks, so this really isn't that unusual.  We also had a nice snowstorm that season near the end of January.

[Maxim]

1 hour ago, brooklynwx99 said:

so predictable. this is like the third time this has happened this winter

The Midwest is currently experiencing record breaking warmth. Chicago may even tag 60 tomorrow. Don’t think any of the long-range ensembles saw that coming.

[brooklynwx99]

2 minutes ago, Maxim said:

The Midwest is currently experiencing record breaking warmth. Chicago may even tag 60 tomorrow. Don’t think any of the long-range ensembles saw that coming.

i don't think any of the long range ensembles had much of the central and eastern CONUS with far BN temps thus far this winter, especially not the Southeast

[Stormchaserchuck1]

8 minutes ago, Maxim said:

The Midwest is currently experiencing record breaking warmth. Chicago may even tag 60 tomorrow. Don’t think any of the long-range ensembles saw that coming.

I mean, models were showing -PNA/+EPO/+NAO for a long time.. You would think with that upper latitude pattern, Chicago would hit 60, but the downstream projected pattern didn't show that. It makes you think.. is index forecasting a better way to go? In the last few years on here I have made model error bias calls, particularly with -PNA leading to less/no snow in the Mid-Atlantic, and it has been working out. Surprisingly, the downstream effect of index-patterns isn't completely factored in the models in the medium/long range.. 

[GaWx]

3 hours ago, brooklynwx99 said:

i don't think any of the long range ensembles had much of the central and eastern CONUS with far BN temps thus far this winter, especially not the Southeast

 Both the CFS and the Euro Weeklies this winter have had the E (including the SE) with far BN temps several weeks in advance (and the coldest anomalies on the globe) and they remained consistent with the cold thereafter. These are just 3 examples of the many times they did with strong signals for cold in the E US:

Issued 12/28/24 for 1/13-19:

CFS 48 forecast mean (4 members, 12 runs 12/25-28) for 1/11-17:

 

CFS 48 forecast mean (4 members, 12 runs 12/29-1/1) for 1/15-22):

 

 In contrast, today’s significantly colder Euro map vs yesterday for 2/17-23 is at least as of yet nowhere near as cold:

 

Latest CFS 48 forecast mean for 2/20-7: still mild in E US

 

[so_whats_happening]

Looks like on the horizon (to about hr 240) we have yet another solid warming event taking shape in the stratosphere. We can not seem to link up both the Atlantic and Pacific ridging patterns so gotta take what we can get. This may on the level of what we saw about a month ago placement is a little off compared to the last go about but have to see how it eventually translates to the surface. Usually this time of year these connections start to become quicker in the overall affect to the 500mb pattern, I believe Stormchaserchuck may have mentioned it once or twice before.

You know something is up when surface temps on the Euro in all high latitude locations start to show +20 to +30 anomalies. It looks as though the Euro may actually be trying to do a bottom up split of the SPV one caveat here is it may not fully translate to about 10mb splitting which is fine because it can still disrupt the pattern at 500mb if such a response occurs.

Lets see how it translates over the next week. This would lead to a second half of February into early March not being as canonical. Everything seems to be going according to plan though where we have averageish temps to finish out the last week of January and the first week of February average to above average. Depending on storm track some areas do look to have a 1 day spike in temps to well above average but to pinpoint when and where at this time is a tough call.

 

[michsnowfreak]

2 hours ago, brooklynwx99 said:

i don't think any of the long range ensembles had much of the central and eastern CONUS with far BN temps thus far this winter, especially not the Southeast

Nope. Some on here were calling for a warm Jan, yet the conus is experiencing its coldest January since 1988.

 

And fwiw, ensembles did show well above avg 850s for the upper/western midwest tmrw going back over a week. Here in Detroit yesterday was our first 40 of the month. Jan has had a light snowcover nearly all month, frequent but light dry snowfalls, and precip has been well below avg. Also there's been little roller coaster in temps (just mostly cold). That's literally as un-nina-like as you can get lol.

[so_whats_happening]

4 minutes ago, so_whats_happening said:

Looks like on the horizon (to about hr 240) we have yet another solid warming event taking shape in the stratosphere. We can not seem to link up both the Atlantic and Pacific ridging patterns so gotta take what we can get. This may on the level of what we saw about a month ago placement is a little off compared to the last go about but have to see how it eventually translates to the surface. Usually this time of year these connections start to become quicker in the overall affect to the 500mb pattern, I believe Stormchaserchuck may have mentioned it once or twice before.

You know something is up when surface temps on the Euro in all high latitude locations start to show +20 to +30 anomalies. It looks as though the Euro may actually be trying to do a bottom up split of the SPV one caveat here is it may not fully translate to about 10mb splitting which is fine because it can still disrupt the pattern at 500mb if such a response occurs.

Lets see how it translates over the next week. This would lead to a second half of February into early March not being as canonical. Everything seems to be going according to plan though where we have averageish temps to finish out the last week of January and the first week of February average to above average. Depending on storm track some areas do look to have a 1 day spike in temps to well above average but to pinpoint when and where at this time is a tough call.

 

I do like that we saw a large spike in the MJO phase 3 this is usually a precursor to these type of events to unfold. From the looks of it we have a weakening MJO wave as it pushes into 4/5/6 and eventually 7 by about mid February. The key will be how quickly all this moves through the phases, I have a feeling we may start to halt MJO progression as we get to phase 6 and eventually 7 but how quickly we move through 4/5 will how warm the east gets. The active storm track that looks to set up may create quite the boundary across the country with the SE to Texas rather warm and mid atlantic ohio valley battling it out.

Lets see what happens, one more bout of winter could bring us awfully close to seasonal average (maybe above depending on quite a few factors).

 

[GaWx]

1 hour ago, so_whats_happening said:

Looks like on the horizon (to about hr 240) we have yet another solid warming event taking shape in the stratosphere. We can not seem to link up both the Atlantic and Pacific ridging patterns so gotta take what we can get. This may on the level of what we saw about a month ago placement is a little off compared to the last go about but have to see how it eventually translates to the surface. Usually this time of year these connections start to become quicker in the overall affect to the 500mb pattern, I believe Stormchaserchuck may have mentioned it once or twice before.

You know something is up when surface temps on the Euro in all high latitude locations start to show +20 to +30 anomalies. It looks as though the Euro may actually be trying to do a bottom up split of the SPV one caveat here is it may not fully translate to about 10mb splitting which is fine because it can still disrupt the pattern at 500mb if such a response occurs.

Lets see how it translates over the next week. This would lead to a second half of February into early March not being as canonical. Everything seems to be going according to plan though where we have averageish temps to finish out the last week of January and the first week of February average to above average. Depending on storm track some areas do look to have a 1 day spike in temps to well above average but to pinpoint when and where at this time is a tough call.

 

 However, the latest Euro Weeklies and extended GEFS still show no strong signal for a major SSW in Feb like they did for the several that occurred in 2023 and 2024. But Joe D’Aleo did find a connection with high solar and +QBO that says to be on guard for that possibility:

EPS (1/29): shows 60N 10 mb zonal winds dropping 2/6-15, but mean drops only to a little above climo with most members at 15-40:

 

GEFS (1/28): mean drops to 40 on Feb 11th, but that’s still well above 20 climo (**edited for correction):

*Edited for correction

[so_whats_happening]

1 minute ago, GaWx said:

 However, the latest Euro Weeklies and extended GEFS still show no strong signal for a major SSW in Feb like they did for the several that occurred in 2023 and 2024. But Joe D’Aleo did find a connection with high solar and +QBO that says to be on guard for that possibility:

EPS: shows 60N 10 mb zonal winds dropping 2/6-15, but only to near climo with most members at 15-40:

 

GEFS: mean drops to 40 on Feb 11th, but that’s still near climo:

I think we need to stop expecting every single warming event to be a major SSW I don't know why everyone seems to think that a warming event must be a reversal for us to get a winter like pattern. These reversals happen on average 2-3 times a decade based on averages, sometimes more sometimes less. A weakening of the SPV was enough to bring us some impressive cold conditions without a reversal. 

A reversal just extends the amount of time one of these events lock the pattern but it doesn't need to reverse in order to cause a changeup.

[GaWx]

16 minutes ago, so_whats_happening said:

I think we need to stop expecting every single warming event to be a major SSW I don't know why everyone seems to think that a warming event must be a reversal for us to get a winter like pattern. These reversals happen on average 2-3 times a decade based on averages, sometimes more sometimes less. A weakening of the SPV was enough to bring us some impressive cold conditions without a reversal. 

A reversal just extends the amount of time one of these events lock the pattern but it doesn't need to reverse in order to cause a changeup.

 Even a weak SPV isn’t anywhere close to being a reliable indicator for a cold E US. Consider that the SPV mean wind was actually peaking near a record high upper 50s on the days that the Deep South had an historic snow/sleetstorm (1/21-2)!

[so_whats_happening]

6 minutes ago, GaWx said:

 Even a weak SPV isn’t anywhere close to being a reliable indicator for a cold E US. Consider that the SPV mean wind was actually peaking near a record high upper 50s on the days that the Deep South had an historic snow/sleetstorm (1/21-2)!

I really don't have the time to get into a back forth about something that can be read through many journals. You realize it takes time for it to translate vertically right? This was not an instantaneous event nor was it ever advertised to be. Yes there is always a possibility that the east doesn't get significantly colder never mentioned once in my post that it would get significantly colder because of the warming event, maybe you inferred it differently because I said winter-like pattern?

[GaWx]

18 minutes ago, so_whats_happening said:

I really don't have the time to get into a back forth about something that can be read through many journals. You realize it takes time for it to translate vertically right? This was not an instantaneous event nor was it ever advertised to be. Yes there is always a possibility that the east doesn't get significantly colder never mentioned once in my post that it would get significantly colder because of the warming event, maybe you inferred it differently because I said winter-like pattern?

Yeah, I fully realize that it takes on average a couple of weeks to translate vertically. But about all of Jan has been much stronger than average with high 50s to 60 also 1/7-14 (see image below) and it was pretty high before that. Yes, I realize you didn’t say significantly colder.

 

[Typhoon Tip]

Needs to propagate downward or the correlation goes to very low skill 

[so_whats_happening]

33 minutes ago, GaWx said:

Yeah, I fully realize that it takes on average a couple of weeks to translate vertically. But about all of Jan has been much stronger than average with high 50s to 60 1/7-14:

 

These have all been tropospheric driven events meaning the troposphere reacted first most likely due to tropical forcings that took place. The SPV reacted as such with a weakening the issue is the SPV is strong for this time year so it could not weaken significantly so the pattern was not able to lock in like one would typically hope so we had our cold spell and reverted quickly back. The warming and weakening of the SPV is a reaction to what is going on down below now if the events taking place below are quite strong the better it translates to the SPV weakening and creating potentially a longer lasting effect into the 500mb pattern. We can connect but it doesn't always mean it will last especially with how strong the SPV is right now.

This event coming up will probably be no different where initially the pattern will be driven from what takes place at 500mb the subsequent warming will ensue in the lower to upper stratosphere and maybe this could significantly disrupt the SPV going forward considering in about a month we start to talks of final warmings. Now will this make the pattern last probably not but as of now there seems to be quite a shakeup showing up that should start around mid February and provide the last little bit of winter like pattern for many areas. 

Edit: Forecast right now for this eddy heat flux is rather impressive so something may actually try to come of this.

vtn_50_2024_merra2.pdf

[so_whats_happening]

20 minutes ago, Typhoon Tip said:

Needs to propagate downward or the correlation goes to very low skill 

We have been able to propagate down here and there so far this year but with the SPV being so above average it would take a rather significant event to help with downward propagation and be meaningful other than another probably 1-2 week winter like pattern that evolves.

[so_whats_happening]

9 minutes ago, so_whats_happening said:

These have all been tropospheric driven events meaning the troposphere reacted first most likely due to tropical forcings that took place. The SPV reacted as such with a weakening the issue is the SPV is strong for this time year so it could not weaken significantly so the pattern was not able to lock in like one would typically hope so we had our cold spell and reverted quickly back. The warming and weakening of the SPV is a reaction to what is going on down below now if the events taking place below are quite strong the better it translates to the SPV weakening and creating potentially a longer lasting effect into the 500mb pattern. We can connect but it doesn't always mean it will last especially with how strong the SPV is right now.

This event coming up will probably be no different where initially the pattern will be driven from what takes place at 500mb the subsequent warming will ensue in the lower to upper stratosphere and maybe this could significantly disrupt the SPV going forward considering in about a month we start to talks of final warmings. Now will this make the pattern last probably not but as of now there seems to be quite a shakeup showing up that should start around mid February and provide the last little bit of winter like pattern for many areas. 

Edit: Forecast right now for this eddy heat flux is rather impressive so something may actually try to come of this.

vtn_50_2024_merra2.pdf 22.8 kB · 1 download

The last thing I will add the only 500mb tropospheric pattern that has seemingly locked so far this year has been the Pacific pattern. The European side has been extremely transient, unfortunately, so repeated attacks have been few and far between but luckily for us the EPO has managed to help us out quite a bit even with a non consistent +PNA pattern. We do not know yet whether the European side will help aid in this event yet or if it will once again be transient. 

[Maxim]

5 hours ago, Stormchaserchuck1 said:

I mean, models were showing -PNA/+EPO/+NAO for a long time.. You would think with that upper latitude pattern, Chicago would hit 60, but the downstream projected pattern didn't show that. It makes you think.. is index forecasting a better way to go? In the last few years on here I have made model error bias calls, particularly with -PNA leading to less/no snow in the Mid-Atlantic, and it has been working out. Surprisingly, the downstream effect of index-patterns isn't completely factored in the models in the medium/long range.. 

The -EPO really needs to go. Been screwing up the entire pattern this month. Seeing signs of it returning again, but not sure how long it'll last.

[MJO812]

8 hours ago, Maxim said:

The -EPO really needs to go. Been screwing up the entire pattern this month. Seeing signs of it returning again, but not sure how long it'll last.

A negative epo is essential for cold in the east. A positive PNA and a negative NAO are the most important imo for NYC.

[MJO812]

@snowman19

 

[snowman19]

19 minutes ago, MJO812 said:

@snowman19

 

So a -EPO, ridge wayyy west of the west coast. Zero Atlantic and arctic blocking. Raging positive NAO, no 50/50 low, +AO, negative PNA and the SE ridge flexing. Cutter and inside runner city. Enjoy the rain in NYC

[GaWx]

23 minutes ago, MJO812 said:

@snowman19

 

Even in a mild (cold) month, a short period or two of cold (mild) isn’t uncommon. 0Z/6Z ens means are suggesting a 2-3 day long cold period is quite possible in the E US starting ~Feb 9th-10th but otherwise they’re mainly on the mild side NYC south and restrengthen the SE ridge immediately afterward. So, the means for the first half of Feb would still easily be AN NYC south. Will keep watching ens mean trends for Feb 9th+ to see how they trend going forward.

 Phases 6-7, especially 6, lean toward the AN temp side in Feb fwiw. Phases that are BN in Feb on avg are 8, 1, 2, and 3, especially if amplitude isn’t strong.

[MJO812]

10 minutes ago, snowman19 said:

So a -EPO, ridge wayyy west of the west coast. Zero Atlantic and arctic blocking. Raging positive NAO, no 50/50 low, +AO, negative PNA and the SE ridge flexing. Cutter and inside runner city. Enjoy the rain in NYC

You love being wrong. Keep it up.

[snowman19]

2 minutes ago, MJO812 said:

You love being wrong. Keep it up.

All and I mean all of your snow hype since the end of November has been an epic, monumental bust. Miserable fail after fail. Talk about the pot calling the kettle black. 

[MJO812]

43 minutes ago, snowman19 said:

All and I mean all of your snow hype since the end of November has been an epic, monumental bust. Miserable fail after fail. Talk about the pot calling the kettle black. 

Keep backtracking.  You are looking like a fool. I never called for alot of snow. Just cold and we did get it.

Anyway some good news after the 1st week of February . Winter looks like it will return in the east. The length is in question. 

[LibertyBell]

1 hour ago, GaWx said:

Even in a mild (cold) month, a short period or two of cold (mild) isn’t uncommon. 0Z/6Z ens means are suggesting a 2-3 day long cold period is quite possible in the E US starting ~Feb 9th-10th but otherwise they’re mainly on the mild side NYC south and restrengthen the SE ridge immediately afterward. So, the means for the first half of Feb would still easily be AN NYC south. Will keep watching ens mean trends for Feb 9th+ to see how they trend going forward.

 Phases 6-7, especially 6, lean toward the AN temp side in Feb fwiw. Phases that are BN in Feb on avg are 8, 1, 2, and 3, especially if amplitude isn’t strong.

You don't need it to be very cold for in February for it to snow in NYC (see February 2018).  This is MUCH better than the crap we had in January.  Those 2-3 days are plenty to get a snow storm and it can be in the 60s both before and after the storm.

[LibertyBell]

39 minutes ago, MJO812 said:

Keep backtracking.  You are looking like a fool. 

 

Anyway some good news after the 1st week of February . Winter looks like it will return in the east. The length is in question. 

Some people think we live on the Gulf Coast and we need it to be extremely cold for it to snow here LOL.  There are numerous examples that show otherwise.

The January pattern was trash, good riddance to it being gone.

We can even have an HECS with a monthly average temperature around 40.  Chris has said that storm track matters more for us than temperatures.

 

[LibertyBell]

1 hour ago, GaWx said:

Even in a mild (cold) month, a short period or two of cold (mild) isn’t uncommon. 0Z/6Z ens means are suggesting a 2-3 day long cold period is quite possible in the E US starting ~Feb 9th-10th but otherwise they’re mainly on the mild side NYC south and restrengthen the SE ridge immediately afterward. So, the means for the first half of Feb would still easily be AN NYC south. Will keep watching ens mean trends for Feb 9th+ to see how they trend going forward.

 Phases 6-7, especially 6, lean toward the AN temp side in Feb fwiw. Phases that are BN in Feb on avg are 8, 1, 2, and 3, especially if amplitude isn’t strong.

Most people around here care about snow not cold.  It's perfectly fine for all of February to be in the 60s except for the one or two days on which it snows, that happens a lot around here and with climate change increasing going forward that's how we get our snowstorms, not with monthlong cold and suppressed patterns that deliver snow in places that never get snow.

 

[GaWx]

49 minutes ago, LibertyBell said:

Most people around here care about snow not cold.  It's perfectly fine for all of February to be in the 60s except for the one or two days on which it snows, that happens a lot around here and with climate change increasing going forward that's how we get our snowstorms, not with monthlong cold and suppressed patterns that deliver snow in places that never get snow.

 

 I don’t disagree for the most part. But I was responding to CWG’s tweet saying this:

“MJO approach to phase 7 could flip pattern back to cold side for U.S. by 2nd week of February, similar to super-warm late December
to cold early January flip from this winter.”

 So, the tweet was referring explicitly to temperatures and said nothing about snow. Thus, my response was referring to just temperatures based on what 0Z/6Z model consensus was showing. I wasn’t at all addressing snow, which is much more unpredictable, especially 11+ days out, since it is so dependent on precise storm track and actually having a storm at the right time.

 Also, some do care about temps on their own.

[michsnowfreak]

1 hour ago, LibertyBell said:

Most people around here care about snow not cold.  It's perfectly fine for all of February to be in the 60s except for the one or two days on which it snows, that happens a lot around here and with climate change increasing going forward that's how we get our snowstorms, not with monthlong cold and suppressed patterns that deliver snow in places that never get snow.

 

Obviously the Great Lakes are a different climate than the east coast, but im noticing the cold vs snow thing, especially this year since its been such a cold January with very little snow (in the north) outside the lakes. Weve done ok in SE MI- snow has been below avg and precip well below avg, but we have had some snow on the ground nearly all month. But west of the lakes (Chicago, Minneapolis, Green Bay, etc) its been frozen dry ground. I have no problem with people liking what they like, but im definitely finding some weenies contradicting themselves locally. All the complaining about recent mild winters...but really, in the post 2007-15 record snow era, snowfall has been largely around avg here before last winter. So I have to say to them, if all you care about is snow thats fine, but then you need to give those mild winters more credit and less bitching lol. (again im talking about the masses...I personally love snow AND cold).