2024-2025 La Nina

[LibertyBell]

12 minutes ago, michsnowfreak said:

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).

Yes one of my favorite and most memorable snowstorms happened during a mild winter overall, 2015-16, over 30 inches of snow in one snowstorm and -1 on Valentines Day!  One of my favorite winters for those two reasons alone (we also had some other moderate snowstorms that winter.)

We had over 40 inches of snow that season with a seasonal average temperature over 40 degrees.

[LibertyBell]

57 minutes ago, GaWx said:

 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.

Yes-- and we're more focused on snow instead of cold also because cold has become more rare as the years go by (regardless of enso state, warmer winters are canonical now....)

 

 

[PhiEaglesfan712]

Early look for mid-March: 

[LibertyBell]

31 minutes ago, PhiEaglesfan712 said:

Early look for mid-March: 

lol any reason why you're looking at Mid March? Winter will likely be over before then.

[purduewx80]

7 hours ago, MJO812 said:

@snowman19

 

7 is still warm in Feb. 

[MJO812]

4 minutes ago, purduewx80 said:

7 is still warm in Feb. 

Depends on the enso

[GaWx]

On 1/29/2025 at 7:13 PM, GaWx said:

 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

 

 Unfortunately for cold lovers like myself, today’s Euro Weeklies for 2/17-23 & 2/24-3/2 totally reversed yesterday’s much colder runs for those two weeks and are back to a solid mild signal:

2/17-23:

 All 6 weeks of today’s run are this warm or warmer in the E US. The implied Feb avg is ~4F AN NYC and ~5-6F DC south. Would be very close to March normals in SE. Many places in the area DC south would have a Feb ~13-15 warmer than Jan.

 Be that as it may, there still appears to be a good shot at a 2-3 day long cold period starting Feb 8-9.

[michsnowfreak]

45 minutes ago, GaWx said:

 Unfortunately for cold lovers like myself, today’s Euro Weeklies for 2/17-23 & 2/24-3/2 totally reversed yesterday’s much colder runs for those two weeks and are back to a solid mild signal:

2/17-23:

 All 6 weeks of today’s run are this warm or warmer in the E US. The implied Feb avg is ~4F AN NYC and ~5-6F DC south. Would be very close to March normals in SE. Many places in the area DC south would have a Feb ~13-15 warmer than Jan.

Is there a scale for colors and departures? Also, why do the 2m and surface temp maps differ so much? I always considered them one in the same.

[GaWx]

4 minutes ago, michsnowfreak said:

Is there a scale for colors and departures? Also, why do the 2m and surface temp maps differ so much? I always considered them one and the same.

-I thought 2m and surface were the same.

-Please show me where they’re different.

-Shades of red: anomalies in degrees C

1st: 0 to +1

2nd: +1 to +3

3rd: +3 to +6

4th: +6 to +10

5th: +10+

[michsnowfreak]

9 hours ago, michsnowfreak said:

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).

If you scroll down. You will see 2m first and then surface. They are always different. 

https://charts.ecmwf.int/?facets={"Product type"%3A[]%2C"Parameters"%3A[]%2C"Type"%3A[]%2C"Range"%3A["Extended (42 days)"]}

[GaWx]

22 minutes ago, michsnowfreak said:

If you scroll down. You will see 2m first and then surface. They are always different. 

https://charts.ecmwf.int/?facets={"Product type"%3A[]%2C"Parameters"%3A[]%2C"Type"%3A[]%2C"Range"%3A["Extended (42 days)"]}

I never noticed there was a different Euro Weeklies chart for surface! I always look at 2m. 
 
 For determining frost on ground, I’d think surface would be more important than 2m. On good radiational cooling nights, you may already realize that surface is sometimes couple of degrees colder than 2m due to colder air being heavier. But 2m is official. And thus I’ll continue to use those.

 On nights after a cold front has just come through and the cold winds are advecting colder air, I’d think sfc would tend to be slightly warmer.

 When sun is out, the ground should be warmer than 2m, especially in summer.

[GaWx]

On 1/29/2025 at 10:08 PM, 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 · 3 downloads

 You may be onto something that I wasn’t paying attention to til just now when I saw this on the 0Z GFS 168 for Feb 7: check out the strength of this Scandinavian-Greenland Dipole! Is this what you were looking at yesterday?

 

 This paper was written by Dr. Simon Lee and others about the 2/12/2018 major SSW that was not forecasted beyond 12 days:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JD030940

 He talks about a S-G Dipole pattern (strong high over Scand/low over Greenland) often being predictive of major SSWs before models actually do so (they’re still not). This dipole peaked ~2/6/2018, or only one day prior to the forecasted peak of ~2/7/25! Aside: the major SSW of 2/16/23 was also preceded by a similar early Feb S-G Dipole!

Dr. Lee’s latest tweets:

 

 Despite the models still not showing even a hint of a major SSW, I’ve been wary about it based on Joe D’Aleo’s study showing a heightened chance during high solar/+QBO. I took his idea and looked at the actual #s. I considered high solar for DJF to be 135+. DJ will be ~145. If Feb ends up 115+, it would qualify. Check this out:

 

Solar DJF 135+/west QBO:

57-8: SSW 1/31/58

59-60: SSW 1/17/60

69-70: SSW 1/2/70

78-9: SSW 2/22/79

80-1: SSW 2/6/81

90-1: no SSW

99-00: SSW 3/20/00

01-02: SSW  12/31/01, 2/18/02

 So, a whopping 7 of these 8 winters had at least one major SSW! Just food for thought. The progged strong Feb 7th S-G Dipole is consistent with a potential major SSW on or near Feb 13th if it were to actually occur with similar timing to 2018. If so, look for hints on the EPS/GEFS starting this weekend. IF there were to be one ~Feb 13th, look out for the potential of a colder E US pattern starting ~Feb 27th and lasting through at least ~Mar 15th and quite possibly the entire month or further. Anything to keep the bugs quiet would be a winning pattern for me!

 

[GaWx]

Further to the above fwiw, the 0Z 1/29 GFS (latest available) brought the mean wind down to 19 m/s on Feb 13th and 13 m/s on Feb 14th:

 In comparison, the prior run (0Z 1/28) had it bottoming out way up at 28 m/s on Feb 13th:

 So, the GFS had a significant drop on 1/29. I’ll be watching the GFS closely because it was ahead of the ensembles in advance of 2 major SSWs since 2023.

[PhiEaglesfan712]

15 hours ago, LibertyBell said:

lol any reason why you're looking at Mid March? Winter will likely be over before then.

It's never to early to prepare for life post-Eagles Super Bowl victory/parade. Looks like we're getting an early jump on spring, as the first half of March looks very warm.

[mitchnick]

4 hours ago, GaWx said:

Further to the above fwiw, the 0Z 1/29 GFS (latest available) brought the mean wind down to 19 m/s on Feb 13th and 13 m/s on Feb 14th:

 In comparison, the prior run (0Z 1/28) had it bottoming out way up at 28 m/s on Feb 13th:

 So, the GFS had a significant drop on 1/29. I’ll be watching the GFS closely because it was ahead of the ensembles in advance of 2 major SSWs since 2023.

I haven't been following the SSW threat, but I  did see that the Euro is indicating a strong heat flux by day 10. Honestly, I'm sure if it means much toward a SSW, but thought it interesting after reading your post.

Here's the link to the Euro strat stuff. They used to provide free all info at the link but not anymore unfortunately. 

https://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

[donsutherland1]

6 hours ago, GaWx said:

 You may be onto something that I wasn’t paying attention to til just now when I saw this on the 0Z GFS 168 for Feb 7: check out the strength of this Scandinavian-Greenland Dipole! Is this what you were looking at yesterday?

 

 This paper was written by Dr. Simon Lee and others about the 2/12/2018 major SSW that was not forecasted beyond 12 days:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JD030940

 He talks about a S-G Dipole pattern (strong high over Scand/low over Greenland) often being predictive of major SSWs before models actually do so (they’re still not). This dipole peaked ~2/6/2018, or only one day prior to the forecasted peak of ~2/7/25! Aside: the major SSW of 2/16/23 was also preceded by a similar early Feb S-G Dipole!

Dr. Lee’s latest tweets:

 

 Despite the models still not showing even a hint of a major SSW, I’ve been wary about it based on Joe D’Aleo’s study showing a heightened chance during high solar/+QBO. I took his idea and looked at the actual #s. I considered high solar for DJF to be 135+. DJ will be ~145. If Feb ends up 115+, it would qualify. Check this out:

 

Solar DJF 135+/west QBO:

57-8: SSW 1/31/58

59-60: SSW 1/17/60

69-70: SSW 1/2/70

78-9: SSW 2/22/79

80-1: SSW 2/6/81

90-1: no SSW

99-00: SSW 3/20/00

01-02: SSW  12/31/01, 2/18/02

 So, a whopping 7 of these 8 winters had at least one major SSW! Just food for thought. The progged strong Feb 7th S-G Dipole is consistent with a potential major SSW on or near Feb 13th if it were to actually occur with similar timing to 2018. If so, look for hints on the EPS/GEFS starting this weekend. IF there were to be one ~Feb 13th, look out for the potential of a colder E US pattern starting ~Feb 27th and lasting through at least ~Mar 15th and quite possibly the entire month or further. Anything to keep the bugs quiet would be a winning pattern for me!

 

Simon Lee's findings are interesting. The reality is that stratospheric warming events remain relatively poorly understood even today, making modeling challenging. Heat fluxes from wave 1 and wave 2 have an impact. However, which specific wave will trigger a stratospheric warming event--especially a major one--remains elusive. Is something else involved e.g., preconditioning?

At present, one finds many "false alarms" and also some "misses" (the type Simon Lee has identified). Hopefully, machine learning will lead to improvement when it comes to the development of such events and, probably just as importantly, their propagation and impact on the polar vortex (displacement, stretch, split).

[mitchnick]

https://x.com/burgwx/status/1885138563982917803

[snowman19]

Although twitterland has locked in/wishcasted an exact replica of the highly anomalous, historic February 2018 SSWE, in reality, what exactly happens is very, very far from being decided. For starters, we have a completely different, night and day QBO evolution, not even close, the current MJO progression and this La Niña event in no way, shape or form resembles 2018. Good luck getting an exact redux of an extremely rare, record-breaking SSWE within 7 years apart
 

 

 

 

 

 

 

 

 

[LibertyBell]

3 hours ago, PhiEaglesfan712 said:

It's never to early to prepare for life post-Eagles Super Bowl victory/parade. Looks like we're getting an early jump on spring, as the first half of March looks very warm.

Yes please do beat KC, I want their streak of luck to end.

[LibertyBell]

2 hours ago, donsutherland1 said:

Simon Lee's findings are interesting. The reality is that stratospheric warming events remain relatively poorly understood even today, making modeling challenging. Heat fluxes from wave 1 and wave 2 have an impact. However, which specific wave will trigger a stratospheric warming event--especially a major one--remains elusive. Is something else involved e.g., preconditioning?

At present, one finds many "false alarms" and also some "misses" (the type Simon Lee has identified). Hopefully, machine learning will lead to improvement when it comes to the development of such events and, probably just as importantly, their propagation and impact on the polar vortex (displacement, stretch, split).

I think we also need quantum computing.

Our conventional computers just won't cut it.

[donsutherland1]

55 minutes ago, LibertyBell said:

I think we also need quantum computing.

Our conventional computers just won't cut it.

The massive increase in capability from quantum computing should, in theory, unleash numerous breakthroughs. Hopefully, quantum computing will advance to a stage where such work is possible this decade.

[GaWx]

2 hours ago, snowman19 said:

Although twitterland has locked in/wishcasted an exact replica of the highly anomalous, historic February 2018 SSWE, in reality, what exactly happens is very, very far from being decided. For starters, we have a completely different, night and day QBO evolution, not even close, the current MJO progression and this La Niña event in no way, shape or form resembles 2018. Good luck getting an exact redux of an extremely rare, record-breaking SSWE within 7 years apart
 

 

 

 

 

 

 

 

 Regarding the bolded: the current +QBO is, indeed, the exact opposite of 2/12/2018’s -QBO. However, it is the same as 2/16/2023’s +QBO. Also, Joe D’Aleo found (and I confirmed) a strong correlation between high Solar/+QBO and major SSWs. So, it now being +QBO shouldn’t on its own reduce the SSW chance but if anything should raise the chance. Furthermore, 2/12/2018 was during very low solar. We now have the opposite, which per Joe enhances the chance a whole lot. 2/16/2023 was during pretty active solar as I assume you know.

  In the meantime let’s first see if there’s even going to be one. It’s fun to see how these evolve!

[GaWx]

 The last 3 0Z GFS runs have consistently progged a 60N zonal wind min of +13 on Feb 13th, which would be ~one week after the progged S-G Dipole max. We’ll see whether or not these progs actually progress to a major SSW on/near Feb 12th-13th.

 Regarding the progged 60-90N 10 mb temperature rise, today’s 0Z is the most impressive yet with a whopping 31K rise to +238K on Feb 14-5! Yesterday’s rose only to +231K and Jan 28-29 runs rose only to +227-228K:

[PhiEaglesfan712]

January 2025 is the coldest January at PHL since 2014, holding off 2015 by a half-degree. It is also the coldest month since February 2015.

[LibertyBell]

1 hour ago, PhiEaglesfan712 said:

January 2025 is the coldest January at PHL since 2014, holding off 2015 by a half-degree. It is also the coldest month since February 2015.

how much below normal and also actual mean temperature, was it below 30.0 there?

[donsutherland1]

Some updates on last week’s thoughts:

1. Southern California saw badly-needed rain, mainly from Sunday through Monday. Los Angeles (LAX) received 0.94” of rain. Blythe’s record 300-day streak without measurable rainfall ended on Monday when 0.01” fell. Phoenix’s 159-day stretch without measurable rainfall ended on Wednesday with 0.01” of rain. However, Las Vegas saw no rainfall, so its second longest streak without measurable rainfall continues.

2. Heavy rain affected parts of Texas on Wednesday and Thursday. The area of heavy rainfall was smaller than expected. Two-day rainfall at Dallas came to 4.13” (with 2.80” on January 29, which broke the old record of 0.93” from 1999 and 1.33” on January 30, which broke the old record of 1.24” from 1982). The daily value of 2.80” was the 6^th highest daily value for all of January. January records go back to 1899.  However, Houston saw only 0.23”.

3. The idea of little or no rainfall through the end of January in New York City and Philadelphia was incorrect.  January 31 rainfall totals came to: New York City: 0.61” and Philadelphia: 0.93”. As a result, New York City and Philadelphia did not set a record for its driest January on record. Newark wound up tying its monthly record and White Plains set a new monthly record.

4. There was no significant snowfall in the Great Lakes and Middle Atlantic regions. In fact, record warmth affected parts of the Great Lakes and Upper Midwest regions. La Cross, WI set a January monthly high temperature record of 58° on January 30. Green Bay and Madison approached their monthly records.

Three Thoughts Going Forward:

1. Northern California will see above to much above normal precipitation next week. Redding could pick up 3”-6” of rain for the week. Normal rainfall is 1.41”.

2. No significant (6” or above) snowfalls are likely from Washington, DC to New York City or Chicago and Detroit through the first week of February. The February 3-6 timeframe could see accumulating snow in such cities as Billings, Great Falls, and Rapid City.

3. It will turn unseasonably warm in parts of the West early next week. Denver could challenge its record of 70° from 1890 and 1954 on February 3. Oklahoma City could challenge its record high of 78° from 1934 and 1962 on February 3. Phoenix could challenge its record high of 85° on February 4 (1925 and 1963).  The abnormal warmth will then spread eastward. As a result, Little Rock could challenge its record high of 75° from 2008 on February 5 and Nashville will challenge its record high of 73° from 2019 on the same day. One or more of those cities will likely tie or break their daily records during the peak of the heat.

Longer-Range:

It will turn wetter in the Great Lakes Region and parts of the eastern U.S. However, with the AO likely to be predominantly positive through the first 10 days of February and the NAO positive to strongly positive through mid-month, the probability of a significant (6” or above) snowstorm in the New York City and Philadelphia areas will be limited for at least the first 10 days of February. Smaller snowfalls would be possible.

There is considerable uncertainty about the second half of February. Heading into the second half, there is a large difference between the GEFS and EPS. However, the the ECMWF weeklies have grown warmer in recent runs for the eastern half of the United States. The CFSv2 remains very warm.

 

[snowman19]

37 minutes ago, donsutherland1 said:

Some updates on last week’s thoughts:

1. Southern California saw badly-needed rain, mainly from Sunday through Monday. Los Angeles (LAX) received 0.94” of rain. Blythe’s record 300-day streak without measurable rainfall ended on Monday when 0.01” fell. Phoenix’s 159-day stretch without measurable rainfall ended on Wednesday with 0.01” of rain. However, Las Vegas saw no rainfall, so its second longest streak without measurable rainfall continues.

2. Heavy rain affected parts of Texas on Wednesday and Thursday. The area of heavy rainfall was smaller than expected. Two-day rainfall at Dallas came to 4.13” (with 2.80” on January 29, which broke the old record of 0.93” from 1999 and 1.33” on January 30, which broke the old record of 1.24” from 1982). The daily value of 2.80” was the 6^th highest daily value for all of January. January records go back to 1899.  However, Houston saw only 0.23”.

3. The idea of little or no rainfall through the end of January in New York City and Philadelphia was incorrect.  January 31 rainfall totals came to: New York City: 0.61” and Philadelphia: 0.93”. As a result, New York City and Philadelphia did not set a record for its driest January on record. Newark wound up tying its monthly record and White Plains set a new monthly record.

4. There was no significant snowfall in the Great Lakes and Middle Atlantic regions. In fact, record warmth affected parts of the Great Lakes and Upper Midwest regions. La Cross, WI set a January monthly high temperature record of 58° on January 30. Green Bay and Madison approached their monthly records.

Three Thoughts Going Forward:

1. Northern California will see above to much above normal precipitation next week. Redding could pick up 3”-6” of rain for the week. Normal rainfall is 1.41”.

2. No significant (6” or above) snowfalls are likely from Washington, DC to New York City or Chicago and Detroit through the first week of February. The February 3-6 timeframe could see accumulating snow in such cities as Billings, Great Falls, and Rapid City.

3. It will turn unseasonably warm in parts of the West early next week. Denver could challenge its record of 70° from 1890 and 1954 on February 3. Oklahoma City could challenge its record high of 78° from 1934 and 1962 on February 3. Phoenix could challenge its record high of 85° on February 4 (1925 and 1963).  The abnormal warmth will then spread eastward. As a result, Little Rock could challenge its record high of 75° from 2008 on February 5 and Nashville will challenge its record high of 73° from 2019 on the same day. One or more of those cities will likely tie or break their daily records during the peak of the heat.

Longer-Range:

It will turn wetter in the Great Lakes Region and parts of the eastern U.S. However, with the AO likely to be predominantly positive through the first 10 days of February and the NAO positive to strongly positive through mid-month, the probability of a significant (6” or above) snowstorm in the New York City and Philadelphia areas will be limited for at least the first 10 days of February. Smaller snowfalls would be possible.

There is considerable uncertainty about the second half of February. Heading into the second half, there is a large difference between the GEFS and EPS. However, the the ECMWF weeklies have grown warmer in recent runs for the eastern half of the United States. The CFSv2 remains very warm.


 

@bluewave The GEFS and EPS are world’s apart with the MJO. One of them is going to be dead wrong. And the new CANSIPS, CFS, NMME and GEFS EXT show this for February:

 

 

 

 

[snowman19]

@donsutherland1 Despite what twitter is telling us/selling us, an SPV split and major SSW is very far from certain:
 

 

 

 

 

 

 

 

 

 

 

 

 

[so_whats_happening]

My god im sorry I even posted that there would be warming event in the strat. The twitter campaign out in full force cant even have a sensible discussion anymore.

[brooklynwx99]

1 hour ago, so_whats_happening said:

My god im sorry I even posted that there would be warming event in the strat. The twitter campaign out in full force cant even have a sensible discussion anymore.

i mean, you’re correct, there’s likely going to be a significant disruption at 50mb that would bolster any blocking from the retrograding Scandi ridge