2024-2025 La Nina

[ice1972]

the toaster lol

[ice1972]

Hamsterdam y'all.........lol

[snowman19]

^New February CANSIPS

Expected tropical forcing:

 

 

 

 

 

[bluewave]

10 hours ago, 40/70 Benchmark said:

Maybe that is the reason for the unexpected -AO/NAO....interesting.

This was the lowest anomaly we have ever seen this time of year. The EPS weeklies missed this January pattern from back on December 11th. It had lower heights near Hudson Bay and Greenland and not the very strong blocking we have now. Almost looks like the original runs were defaulting to a coupled look with the strong SPV over Canada. Also notice the long range EPS continuing to show too strong a -EPO with lower heights near Alaska than originally forecast. Also a stronger Pacific Jet lowering heights near that region.

https://nsidc.org/sea-ice-today/analyses/sluggish-freeze-warming-north

https://sites.google.com/view/arctic-sea-ice/home/nsidc-arctic

New forecast

EPS forecast from December 11th

 

 

[SnoSki14]

1 hour ago, snowman19 said:

^New February CANSIPS

Expected tropical forcing:

 

 

 

 

 

If models are underestimating the Atlantic blocking like they've been doing then that may not play out. Could end up shunting SE ridge further south setting up a potential gradient pattern. 

[40/70 Benchmark]

5 hours ago, snowman19 said:

^New February CANSIPS

Expected tropical forcing:

 

 

 

 

 

That could work for New England

[Maxim]

Models def backing off on the cold in the extended, unsurprisingly.

[PhiEaglesfan712]

10 minutes ago, Maxim said:

Models def backing off on the cold in the extended, unsurprisingly.

I'm not surprised. I see January 17-31 being warmer than average and February 1-14 colder.

[bluewave]

The warmer December than forecast allowed Lander, Wyoming to go +11.3° for December.

The extreme winter warmth across parts of the CONUS regions has been unprecedented since 15-16. Before this period, having near to above a +10 monthly departure for a U.S. climate station would be a rare to uncommon event. We can remember the double digit departure months occurring much less frequently in the past. January 2006 in the Upper Midwest and March 2012 come to mind. Now these very high monthly winter departures have been happening yearly with multiple months in the same winter recording such departures. We have had a remarkable 12 winter months across varying ENSO states since December 2015 meeting this criteria for one or more climate stations. It’s even more impressive to see these monthly temperature departures occurring in the warmest climate normals period.

 

Dec…2015….NYC….+13.3

JAN…2017….BTV…..+11.0

FEB….2017….ORD….+10.3

FEB…..2018…ATL….+10.6

FEB….2019…MGM….+10.5

JAN….2020…YAM….+9.8

DEC….2021….DFW….+13.2

JAN….2023….DXR….+12.3

FEB….2023…..SSI…..+9.8

DEC….2023….INL…..+15.8

FEB…..2024….FAR…..+17.5

DEC….2024…..LND…..+11.3

 

 

 

 

 

[roardog]

3 hours ago, Maxim said:

Models def backing off on the cold in the extended, unsurprisingly.

I see nothing on the ensembles that show anything but cold for the part of the country and time frame that’s been discussed forever now. You’re either trying to get people fired up or you’re basing your claims off of individual operational runs which everyone has been told for the last 25 years on various boards to never use an operational run in the medium range. 

[roardog]

3 hours ago, PhiEaglesfan712 said:

I'm not surprised. I see January 17-31 being warmer than average and February 1-14 colder.

At this point, your January torch in the east forecast is in trouble regardless of how the end of the month plays out. 

[GaWx]

20 minutes ago, roardog said:

I see nothing on the ensembles that show anything but cold for the part of the country and time frame that’s been discussed forever now. You’re either trying to get people fired up or you’re basing your claims off of individual operational runs which everyone has been told for the last 25 years on various boards to never use an operational run in the medium range. 

Per the avg of the last 12 runs of the 4 member CFS ens, part of the E US is forecasted to be near 10 F BN for the two week period Jan 8-21 and is forecasted to be the coldest area anomalywise on the entire globe through that period! These runs suggest these areas of the E US will be ~7 BN for Jan as a whole.

[michsnowfreak]

33 minutes ago, roardog said:

I see nothing on the ensembles that show anything but cold for the part of the country and time frame that’s been discussed forever now. You’re either trying to get people fired up or you’re basing your claims off of individual operational runs which everyone has been told for the last 25 years on various boards to never use an operational run in the medium range. 

His posting style/agenda is clear. Some think he's our old pal from saukville.

[roardog]

35 minutes ago, michsnowfreak said:

His posting style/agenda is clear. Some think he's our old pal from saukville.

Most likely. lol

[Maxim]

3 hours ago, roardog said:

I see nothing on the ensembles that show anything but cold for the part of the country and time frame that’s been discussed forever now. You’re either trying to get people fired up or you’re basing your claims off of individual operational runs which everyone has been told for the last 25 years on various boards to never use an operational run in the medium range. 

 

[Maxim]

3 hours ago, michsnowfreak said:

His posting style/agenda is clear. Some think he's our old pal from saukville.

Nah, just pointing out obvious trends. I don't have an agenda. I'm not sure why that's triggering to some on here, but it's not normal behavior imo.

[snowman19]

The ensembles are starting to hint at a late month retrogression and pattern change

[roardog]

9 minutes ago, snowman19 said:

The ensembles are starting to hint at a late month retrogression and pattern change
 

There are some subtle changes at the end of the ensembles like a weaker Aleutian trough and lower heights/reduced high latitude blocking but they still have a +PNA continuing right to the end. That tweet is showing the weeklies.

[PhiEaglesfan712]

14 minutes ago, snowman19 said:

The ensembles are starting to hint at a late month retrogression and pattern change
 

Better to have the regression during the 2nd half of January than in February. Because if the pattern changes in February, many times it never really comes back. 1977, 2010, and 2011 are all good examples.

[snowman19]

17 minutes ago, PhiEaglesfan712 said:

Better to have the regression during the 2nd half of January than in February. Because if the pattern changes in February, many times it never really comes back. 1977, 2010, and 2011 are all good examples.

When you consider that the models are likely rushing it some, that actual change is probably during the last week of this month

[MJO812]

43 minutes ago, roardog said:

There are some subtle changes at the end of the ensembles like a weaker Aleutian trough and lower heights/reduced high latitude blocking but they still have a +PNA continuing right to the end. That tweet is showing the weeklies.

I don't see a pattern change at all on the ensembles.

[snowman19]

I don't see a pattern change at all on the ensembles.

There are signs at the end of the month

[snowman19]

Definite signal on the EURO for a -PNA late month
 

[GaWx]

16 minutes ago, snowman19 said:

Definite signal on the EURO for a -PNA late month
 

Indeed, here’s yesterday’s Euro Weekly map for 1/20-6 with a -PNA forming:

Accompanying 2 meter temps: coldest shifts W/NW from E US to N Plains/Rockies/Midwest/Ohio Valley; note also that E US still mainly BN:

 After that week, the run has the subsequent 2 weeks NN in E US/no warmth.
 

[PhiEaglesfan712]

Much has been made about the 9 straight above average winters, but the last real cold summer was in 2009. I know 2014 and 2023 were technically below average, but even those were by a few tenths of a degree. Not to mention, 2023 only finished below average because of the coldest June since 1985. Replace June with September, and JAS 2023 finishes above the JJA average. So, 2014 is the only year in the last 14 that didn't have a 3-month period that finished above the summer average, and that was by 0.2 degree.

[donsutherland1]

On 12/5/2024 at 10:12 PM, donsutherland1 said:

This is an example of the hype that I was criticizing earlier:

Now, let's take a look at the BAMWX extreme forecast and historic data for four cities shown in the more extreme parts of the map: Chicago, Great Falls, Indianapolis, and Madison. In three cases, the cold would be unprecedented for the period in question.

While it could be colder than normal, the probability of the kind of cold shown on the map is extremely low. Moreover, one is dealing with a timeframe more than five weeks into the future where model skill is far less than climatology.

Considering the timeframe, the historic data, and the smaller pool of Northern Hemisphere deep cold in the contemporary area, the kind of widespread extreme weekly anomalies shown on the map are exceptionally unlikely. Posting such a map is reckless. Moreover, even as BAMWX focuses on Indiana, the map is disconnected from Indianapolis' historic climate data.

I suspect that the BAMWX forecast will be off by an average of 10° or more for these four cities and can't rule out a miss by more than 20°. I also expect that BAMWX will never verify its extreme idea.

This outlook will be verified here and on X.

 

Brief update:

Now that the forecast period is within the range of the EPS and GEFS, it is possible to get a reasonable idea of whether the extreme forecast is in line for possible verification. In fact, BAM's forecast appears headed for a spectacular bust (>20°F in all four highlighted cities). Some will argue that I shouldn't treat it as BAM's forecast, but when one posts deterministic output to the general public with no clarifications or caveats, that's exactly what one is doing.

Again, what the social media site ignored or did not understand is that:

1. Amount of deep cold in the Northern Hemisphere matters (it was limited then and it remains limited now)

2. Historic climate provides useful benchmarks for assessing the credibility of model output. One can't blindly take model output verbatim stripped of historic context, especially when one is dealing with potentially extreme events.

3. Model skill at the timeframe involved (> 5 weeks!) is essentially non-existent. Thus, one should typically focus on patterns and probabilities, not details and values

4. Basing one's forecasts on cherry-picked model runs is especially risky. To date, no other single model run has come close to the cherry-picked one featured by BAM.

On a side note, in late December, the site cherry-picked another extreme model run to invoke "historic cold." Day's later, the local NBC affiliate called it out. In addition, NWS Atlanta called out the posting of extreme snowfall maps on social media.

In the end, the failure to consider or understand (or both) the four points raised above are bad practices. Indeed, if one is tempted to even consider a model at the timeframe involved, one should ask, "Is the output reasonable?" One then needs to look at whether such events have occurred before (rarity) and what was involved. As the kind of cold shown was extremely rare or unprecedented for the climate record, one should wait for strong evidence before embracing the outlier guidance. Of course, the outlier guidance did not survive to the following model cycle, but that wasn't mentioned.

Hype does not serve the public interest.  Social Media today, which is now relied upon by the public almost as much as conventional sources for news/weather/information, provides a powerful platform for hype. Not surprisingly, the general public is confused about the skill of meteorologists, because hype is psychologically more memorable and the busts that occur skew their perceptions of the profession.

The next update will be the verification here and on X.

[Maxim]

Was honestly really disappointed seeing my sub promote those clowns. Bamwx is and always has been awful, and that will likely never change.

[snowman19]

4 hours ago, donsutherland1 said:

Brief update:

Now that the forecast period is within the range of the EPS and GEFS, it is possible to get a reasonable idea of whether the extreme forecast is in line for possible verification. In fact, BAM's forecast appears headed for a spectacular bust (>20°F in all four highlighted cities). Some will argue that I shouldn't treat it as BAM's forecast, but when one posts deterministic output to the general public with no clarifications or caveats, that's exactly what one is doing.

Again, what the social media site ignored or did not understand is that:

1. Amount of deep cold in the Northern Hemisphere matters (it was limited then and it remains limited now)

2. Historic climate provides useful benchmarks for assessing the credibility of model output. One can't blindly take model output verbatim stripped of historic context, especially when one is dealing with potentially extreme events.

3. Model skill at the timeframe involved (> 5 weeks!) is essentially non-existent. Thus, one should typically focus on patterns and probabilities, not details and values

4. Basing one's forecasts on cherry-picked model runs is especially risky. To date, no other single model run has come close to the cherry-picked one featured by BAM.

On a side note, in late December, the site cherry-picked another extreme model run to invoke "historic cold." Day's later, the local NBC affiliate called it out. In addition, NWS Atlanta called out the posting of extreme snowfall maps on social media.

In the end, the failure to consider or understand (or both) the four points raised above are bad practices. Indeed, if one is tempted to even consider a model at the timeframe involved, one should ask, "Is the output reasonable?" One then needs to look at whether such events have occurred before (rarity) and what was involved. As the kind of cold shown was extremely rare or unprecedented for the climate record, one should wait for strong evidence before embracing the outlier guidance. Of course, the outlier guidance did not survive to the following model cycle, but that wasn't mentioned.

Hype does not serve the public interest.  Social Media today, which is now relied upon by the public almost as much as conventional sources for news/weather/information, provides a powerful platform for hype. Not surprisingly, the general public is confused about the skill of meteorologists, because hype is psychologically more memorable and the busts that occur skew their perceptions of the profession.

The next update will be the verification here and on X.

The people who were hyping a historic, record east coast snowstorm (KU) pattern for 1/1 - 1/15, even mentioning blizzards, repeated tweets of “buckle up!” and invoking January, 1996 as a very good analog, look to be in the exact same boat as the historic arctic cold crowd 

[donsutherland1]

5 minutes ago, snowman19 said:

The people who were hyping a historic, record east coast snowstorm (KU) pattern for 1/1 - 1/15, even mentioning blizzards, repeated tweets of “buckle up!” and invoking January, 1996 as a very good analog, look to be in the exact same boat as the historic arctic cold crowd 

Yes, that's correct. It's not surprising, either, as the pattern was not forecast to become a classic KU snowstorm-type pattern.

[donsutherland1]

Even as much of the CONUS is in the early stages of what should be a multiweek period of generally sustained cold, albeit with only limited severe cold, if that, there are distant hints of a dramatic pattern shift for late January or the start of February. The 46-day ECMWF ensemble forecast now shows the development of a strong EPO+/AO+ pattern. At the same time, the AAM will likely have been negative for approximately two weeks.

The January 2, 2025 ECMWF weekly forecast showed a break from the cold to start February. The January 3 cycle reaffirmed that change with an even more expansive warm signal.

January 3 run of the ECMWF Weeklies:

Strong EPO+/AO+ Patterns (February 1-10, 1980-2024):

It should be noted that the maps are currently used to illustrate a scenario now showing up on the long-range guidance. Skill scores at the timeframe involved are low. What is important is that one has now seen multiple runs suggesting that a milder/warmer regime could set in for the start of February. That's the only point that should be taken from the post at this time. In short, if the early shift in the long-range guidance is correct, winter could relax to end January/start February.