2024-2025 La Nina

[snowman19]

6 hours ago, raindancewx said:

Also, the MJO now looks like a coherent phase 4/5 blend on the global DJF precipitation map from the Canadian.

Shocker….another winter of MJO 4-5-6 and -PDO

[snowman19]

@Gawx @40/70 Benchmark
 

[40/70 Benchmark]

10 hours ago, George001 said:

As someone who was on the strong Niña train, the latest obs have not been impressive at all. The subsurface has actually warmed, and it is still ENSO neutral (if anything it’s warm neutral in the ENSO 3.4 region). Thats something worth watching.

This La Nina never looked strong per ONI, but that doesn't mean the attendant Walker Cell won't be because I think that it will.

[snowman19]

50 minutes ago, 40/70 Benchmark said:

This La Nina never looked strong per ONI, but that doesn't mean the attendant Walker Cell won't be because I think that it will.

^This. You’re right, even if this Niña turns out weak per ONI (I still think it goes moderate), but regardless, it’s clearly not going to behave like a weak La Niña with this background state. It’s VERY likely to behave like a moderate-strong La Niña 

[so_whats_happening]

9 hours ago, snowman19 said:

@Gawx @40/70 Benchmark
 

Huh never took the chance to graph it like this but it is interesting to see that before 1994 RONI was typically warmer than ONI itself.

[GaWx]

1 hour ago, so_whats_happening said:

Huh never took the chance to graph it like this but it is interesting to see that before 1994 RONI was typically warmer than ONI itself.

 Indeed. Interestingly, it appears that the record high RONI minus ONI was +0.53 set in DJF of 1975-6.

[so_whats_happening]

Always fun to see what happened a year ago to now.

This will change day to day unfortunately because we are locked with how much we can upload a hard copy. 140kb lol

[GaWx]

25 minutes ago, so_whats_happening said:

Always fun to see what happened a year ago to now.

This will change day to day unfortunately because we are locked with how much we can upload a hard copy. 140kb lol

Thanks for posting this (6/26-30 avg for 2N to 2S). I see that the the upper 50-75m E of 140W  and the upper 100-125m W of there is still surprisingly warm for a supposed oncoming La Nina even knowing it isn’t a “relative” map. See the top map below to see how it compares to 6 days earlier.

[so_whats_happening]

3 minutes ago, GaWx said:

Thanks for posting this (6/26-30 avg for 2N to 2S). I see that the the upper 50-75m E of 140W  and the upper 100-125m W of there is still surprisingly warm for a supposed oncoming La Nina even knowing it isn’t a “relative” map. See the top map below to see how it compares to 6 days earlier.

The stronger trades are starting to have an impact on the warming that did occur into the second half of June. This has allowed the thermocline to also rise, but the biggest problem I am seeing is where the extra juice in the tank will come from as we head through summer and into fall for the developing La Nina.

It does seem as though things are taking time to establish. We slowly are pushing VP further west to the maritime continent and eroding what little remnants of Nino were left. Just don't know if there will be enough to forcibly put us solidly, even RONI levels, into moderate/ strong like I have been reading. I would like to see some real positive changes to make me think it is reasonable we can attain anywhere near those levels. We saw that this happened earnest last year with the El Nino around end of July into August after months of rather low confidence in the potential. This is also in the wake of me making that prediction of us attaining moderate status via ONI (thinking maybe -1 to -1.2 area at best).

Still have plenty of time and would like to see how things react to the upcoming MJO wave movement, which has been extremely stagnant for a La Nina thus far.

[mitchnick]

I don't know if anyone took a look at the Cansips temps for Dec-Mar, but it's pretty darn cold up north. Caveats are that it's quite a change from last month's run and the 500mb anomalies are suggestive of something warmer.

[40/70 Benchmark]

1 hour ago, mitchnick said:

I don't know if anyone took a look at the Cansips temps for Dec-Mar, but it's pretty darn cold up north. Caveats are that it's quite a change from last month's run and the 500mb anomalies are suggestive of something warmer.

 

1 hour ago, mitchnick said:

I don't know if anyone took a look at the Cansips temps for Dec-Mar, but it's pretty darn cold up north. Caveats are that it's quite a change from last month's run and the 500mb anomalies are suggestive of something warmer.

I'm not saying it's right, but that is not a very warm 500mb pattern to me, at least for the NE....ostensibly it is.....but if you really look at it, that is a sneaky cold pattern because southern Canada is cold and the PV is elongated. This is what I have been saying is the avenue to a decent winter. May gain more credence if its consistent and the ACE ends up into orbit.

[mitchnick]

12 hours ago, 40/70 Benchmark said:

 

I'm not saying it's right, but that is not a very warm 500mb pattern to me, at least for the NE....ostensibly it is.....but if you really look at it, that is a sneaky cold pattern because southern Canada is cold and the PV is elongated. This is what I have been saying is the avenue to a decent winter. May gain more credence if its consistent and the ACE ends up into orbit.

Agree. I am not yet convinced this winter north of 40N is shot. Further south gets tougher with every mile you go. But all Niñas have periods cold enough to snow, and the backing off of the Niña's strength by Cansips and the Cfs2 have come with colder temps.

Still too early to say anything is a lock, but that's not to say a decent winter won't be a struggle.

[snowman19]

1 hour ago, 40/70 Benchmark said:

 

I'm not saying it's right, but that is not a very warm 500mb pattern to me, at least for the NE....ostensibly it is.....but if you really look at it, that is a sneaky cold pattern because southern Canada is cold and the PV is elongated. This is what I have been saying is the avenue to a decent winter. May gain more credence if its consistent and the ACE ends up into orbit.

After the utter debacle, epic fail of this past winter I don’t trust what any of these climate models show for 500mb patterns or temps. And again, as far as whether the Niña is weak or not on the ONI, it’s not going to make a difference on how its actual real long wave pattern effects are with such a very strong La Niña background state

[raindancewx]

La Ninas / El Nino function as an evaporation v. precipitation constant locally. We seem well on our way to an exceptionally wet Summer that is only somewhat warm (+1 or +2). When we get 'too much rain' in the Summer in La Nina, a very dry winter almost always follows.

Given the hurricane season, the trend toward an east-based La Nina instead of a Modoki, the -PDO, and the potential for the -WPO to flip, I'm actually getting a lot more bullish on winter for the East. If we finish with a wet Summer and an active hurricane season, I'd bet at least on an exceptionally dry winter here, even if it isn't blazing hot.

At 180+ ACE or more I'd be pretty tempted to put a +7F over the entire western half of North America with cold draining into the East. At 120-180 ACE it's more of a tough call. Beryl alone could jack up ACE to 30-40 before it dissipates, 1/4-1/3 of a normal season, and it is only July. But we could also do the 2007 thing where we have two huge systems, and a bunch of weak ones that hit Central America. Too early to know.

 

[snowman19]

5 hours ago, so_whats_happening said:

The stronger trades are starting to have an impact on the warming that did occur into the second half of June. This has allowed the thermocline to also rise, but the biggest problem I am seeing is where the extra juice in the tank will come from as we head through summer and into fall for the developing La Nina.

It does seem as though things are taking time to establish. We slowly are pushing VP further west to the maritime continent and eroding what little remnants of Nino were left. Just don't know if there will be enough to forcibly put us solidly, even RONI levels, into moderate/ strong like I have been reading. I would like to see some real positive changes to make me think it is reasonable we can attain anywhere near those levels. We saw that this happened earnest last year with the El Nino around end of July into August after months of rather low confidence in the potential. This is also in the wake of me making that prediction of us attaining moderate status via ONI (thinking maybe -1 to -1.2 area at best).

Still have plenty of time and would like to see how things react to the upcoming MJO wave movement, which has been extremely stagnant for a La Nina thus far.

The theme since last year has been a late developing ENSO event. Given what we are seeing right now, I still expect a rather big uptick in La Niña development this month. Like you said, last year’s El Niño didn’t really “take off” until late July and especially August-September. We have seen later developing Nina’s in the past, so such a scenario definitely has precedence. With such pronounced AGW the last several years, I think the RONI is really the metric we need to use as the adjustment to gauge this event as opposed to the ONI

[GaWx]

48 minutes ago, snowman19 said:

The theme since last year has been a late developing ENSO event. Given what we are seeing right now, I still expect a rather big uptick in La Niña development this month. Like you said, last year’s El Niño didn’t really “take off” until late July and especially August-September. We have seen later developing Nina’s in the past, so such a scenario definitely has precedence. With such pronounced AGW the last several years, I think the RONI is really the metric we need to use as the adjustment to gauge this event as opposed to the ONI

 CANSIPS H5 for DJF: Aleutian high, moderate -PNA, strong -PDO, SE ridge (especially considering it’s been underdone during La Niña/neutral ENSO for years), +AO, +NAO. And that’s not even assuming the common E US cold bias this and most climate models have been exhibiting for years. Also, it is dry. So, what’s to like?

 Translation: looks like a crappy winter for the bulk of the E US. I’m not mad as it is what it is. Besides, winter is always my favorite season no matter what!

[Stormchaserchuck1]

CPC is predicting a widespread drought starting late Summer everywhere but tropical Florida

After I think the warmest Dec-Jun on record for the CONUS, look at this current July forecast:

https://ibb.co/Hxqg6yx

https://ibb.co/YZX9q97

https://ibb.co/qWS9LZV

[George001]

On 5/13/2024 at 12:11 AM, George001 said:

Another thing to watch that could throw a wrench into things is how early/late does this Niña peak? The Niña is expected to transition from an east based event to a modoki, if the Niña peaks early like the latest guidance has that would be bad news. However, if the guidance is jumping the gun a bit and that transition to a modoki event is delayed a couple of months, that could make a big difference for the first half of winter. Despite the latest guidance being a bit weaker with the Niña I’m not sold on that just yet, especially given how the subsurface looks. I still think it’s going to be a strong event with the more aggressive guidance ultimately being correct.

This is what I posted in mid May… a later developing Nina may not be such a bad thing for winter prospects in the east especially New England. 

[George001]

Considering that we are currently warm neutral at the surface in early July, we actually NEED to see a significant uptick in Nina development soon to actually get the ONI to Nina levels. As of the latest IRI update, the ONI crosses the weak threshold by late fall and peaks at -0.653 in NDJ, which is a later peak. Considering that the latest update also still has an 85% chance of La Niña developing, a late developing weak nina is now the favored outcome. Of course there are other variables that could lead to a stronger Nina response than expected from such a weak ONI event, but I am skeptical that a Nina with an ONI that weak will act like a strong Nina. If the ONI gets down to -1.2 or something, different story. 

[snowman19]

5 hours ago, Stormchaserchuck1 said:

CPC is predicting a widespread drought starting late Summer everywhere but tropical Florida

After I think the warmest Dec-Jun on record for the CONUS, look at this current July forecast:

https://ibb.co/Hxqg6yx

https://ibb.co/YZX9q97

https://ibb.co/qWS9LZV

It’s a miracle that we haven’t had a major, full fledged mid-Atlantic to northeast drought since 2002. The fact that it’s been over 22 years since the last one is pretty astounding in itself. I guess you can say “we’re due”

[PhiEaglesfan712]

1 hour ago, George001 said:

Considering that we are currently warm neutral at the surface in early July, we actually NEED to see a significant uptick in Nina development soon to actually get the ONI to Nina levels. As of the latest IRI update, the ONI crosses the weak threshold by late fall and peaks at -0.653 in NDJ, which is a later peak. Considering that the latest update also still has an 85% chance of La Niña developing, a late developing weak nina is now the favored outcome. Of course there are other variables that could lead to a stronger Nina response than expected from such a weak ONI event, but I am skeptical that a Nina with an ONI that weak will act like a strong Nina. If the ONI gets down to -1.2 or something, different story. 

I have been saying that the later the la nina peaks, the stronger it will be. I still think it's possible that we get something similar to 2007-08, which peaked in DJF at around -1.7 on the ONI.

[40/70 Benchmark]

15 hours ago, snowman19 said:

After the utter debacle, epic fail of this past winter I don’t trust what any of these climate models show for 500mb patterns or temps. And again, as far as whether the Niña is weak or not on the ONI, it’s not going to make a difference on how its actual real long wave pattern effects are with such a very strong La Niña background state

I don't disagree with any of this. Just discussing the run, but I do think keeping an open mind is a vital part of seasonal forecasting. 

[40/70 Benchmark]

8 hours ago, raindancewx said:

La Ninas / El Nino function as an evaporation v. precipitation constant locally. We seem well on our way to an exceptionally wet Summer that is only somewhat warm (+1 or +2). When we get 'too much rain' in the Summer in La Nina, a very dry winter almost always follows.

Given the hurricane season, the trend toward an east-based La Nina instead of a Modoki, the -PDO, and the potential for the -WPO to flip, I'm actually getting a lot more bullish on winter for the East. If we finish with a wet Summer and an active hurricane season, I'd bet at least on an exceptionally dry winter here, even if it isn't blazing hot.

At 180+ ACE or more I'd be pretty tempted to put a +7F over the entire western half of North America with cold draining into the East. At 120-180 ACE it's more of a tough call. Beryl alone could jack up ACE to 30-40 before it dissipates, 1/4-1/3 of a normal season, and it is only July. But we could also do the 2007 thing where we have two huge systems, and a bunch of weak ones that hit Central America. Too early to know.

 

@snowman19Must love this....

[Terpeast]

8 hours ago, GaWx said:

 CANSIPS H5 for DJF: Aleutian high, moderate -PNA, strong -PDO, SE ridge (especially considering it’s been underdone during La Niña/neutral ENSO for years), +AO, +NAO. And that’s not even assuming the common E US cold bias this and most climate models have been exhibiting for years. Also, it is dry. So, what’s to like?

 Translation: looks like a crappy winter for the bulk of the E US. I’m not mad as it is what it is. Besides, winter is always my favorite season no matter what!

The only way this could possibly work is for the aleutian high to amplify NEward into -epo like it did in the middle of last January. Which ironically wasn’t driven by the el nino because there was no STJ for those 10 days

[CAPE]

9 hours ago, GaWx said:

 CANSIPS H5 for DJF: Aleutian high, moderate -PNA, strong -PDO, SE ridge (especially considering it’s been underdone during La Niña/neutral ENSO for years), +AO, +NAO. And that’s not even assuming the common E US cold bias this and most climate models have been exhibiting for years. Also, it is dry. So, what’s to like?

 Translation: looks like a crappy winter for the bulk of the E US. I’m not mad as it is what it is. Besides, winter is always my favorite season no matter what!

It's a smoothed snapshot on a seasonal model at super long range. The overall look may be unappealing, but within that general longwave pattern you can see the potential for a period or 2 of cross Polar flow with a -EPO and the TPV stretched and in that position. As we have seen in some recent Ninas, a couple relatively short lived cold periods(and a little luck with timing) within an overall mild winter pattern can produce a few good snow events along the east coast.

[GaWx]

3 hours ago, Terpeast said:

The only way this could possibly work is for the aleutian high to amplify NEward into -epo like it did in the middle of last January. Which ironically wasn’t driven by the el nino because there was no STJ for those 10 days

 As is the case with most mild winters, there likely would still be several favorable periods for the NE US even if a mild winter verifies.

 Regardless, it is the subsequent winter that I’m much more excited about for potential.

[GaWx]

2 hours ago, CAPE said:

It's a smoothed snapshot on a seasonal model at super long range. The overall look may be unappealing, but within that general longwave pattern you can see the potential for a period or 2 of cross Polar flow with a -EPO and the TPV stretched and in that position. As we have seen in some recent Ninas, a couple relatively short lived cold periods(and a little luck with timing) within an overall mild winter pattern can produce a few good snow events along the east coast.

 Even if an overall mild winter verifies, which I’m currently expecting, especially the further S one goes (vs normals), I agree with you about good potential for short-lived cold periods, especially in your area and further N.

 Regardless, 2025-6 is the one I’m much more excited about for potential.

[snowman19]

@bluewave Out of curiosity, what was the time frame for the last major Mid-Atlantic/Northeast drought period? I know it ended in the spring of 2002, but when did it start?

[so_whats_happening]

12 hours ago, snowman19 said:

The theme since last year has been a late developing ENSO event. Given what we are seeing right now, I still expect a rather big uptick in La Niña development this month. Like you said, last year’s El Niño didn’t really “take off” until late July and especially August-September. We have seen later developing Nina’s in the past, so such a scenario definitely has precedence. With such pronounced AGW the last several years, I think the RONI is really the metric we need to use as the adjustment to gauge this event as opposed to the ONI

I get what you are saying but im personally not a fan of picking and choosing years for different metrics how we can go from last year using ONI and saying that was the true metric, to this year and saying RONI is the true metric is not befitting. There needs to be consistency.

[snowman19]

8 minutes ago, so_whats_happening said:

I get what you are saying but im personally not a fan of picking and choosing years for different metrics how we can go from last year using ONI and saying that was the true metric, to this year and saying RONI is the true metric is not befitting. There needs to be consistency.

I was skeptical of the RONI last year, but once I researched it more and looked at the atmospheric response to last winter’s Nino, I’m a believer. Something obviously changed big time (AGW/warm oceans) and we need to change our metrics with it. @40/70 Benchmark ended up being correct about that part of it

 

@GaWx