2024-2025 La Nina

[brooklynwx99]

how predictable

[Terpeast]

4 minutes ago, brooklynwx99 said:

how predictable

More poleward aleutian/AK ridging, and hints of scandinavian ridging sneaking into the AO domain. If they connect, first half of Feb is gonna be cold

[so_whats_happening]

2 hours ago, Terpeast said:

More poleward aleutian/AK ridging, and hints of scandinavian ridging sneaking into the AO domain. If they connect, first half of Feb is gonna be cold

It does look like we are finally getting poleward movement of the Scandi ridging pattern the one thing we have been missing. This is key in allowing a potential split SPV pattern down the road. Lets see what happens.

[PhiEaglesfan712]

I'm liking this.

[MJO812]

1 hour ago, PhiEaglesfan712 said:

I'm liking this.

Same here

Not staying in the warm phases is a welcome sign.

[brooklynwx99]

lol. just looking more and more like 2013-14

[snowman19]

30 minutes ago, brooklynwx99 said:

lol. just looking more and more like 2013-14

It’s a battle between the EPS and the GEPS/GEFS now. The EPS wants to squash the SE ridge and has a weaker -PNA. The GEPS/GEFS want to really tank the PNA and pump the SE ridge

[brooklynwx99]

even on the GEPS it’s pretty weak with a lot of cold air nearby

[MJO812]

1 hour ago, snowman19 said:

It’s a battle between the EPS and the GEPS/GEFS now. The EPS wants to squash the SE ridge and has a weaker -PNA. The GEPS/GEFS want to really tank the PNA and pump the SE ridge

No warm weather at all on the eps

[BuffaloWeather]

I'm at 114" already this year. The best winter in 10 years. Snowman was so wrong.

[MJO812]

8 minutes ago, BuffaloWeather said:

I'm at 114" already this year. The best winter in 10 years. Snowman was so wrong.

114? Jeez

I'm at 4.7

[Snowstorms]

1 hour ago, MJO812 said:

114? Jeez

I'm at 4.7

Lake effect is nice but incredibly localized. A single squall line could literally be only 15-20 miles long in width meanwhile the people outside that boundary are dry and snowless. 

Made it up to 19.5" here in Toronto thanks to these 1-3" clippers and lake effect. Still running below average though for the ytd. 

[LibertyBell]

On 1/14/2025 at 1:49 PM, snowman19 said:

@brooklynwx99 Would WAR be better than SE ridge then? Also, the models are retrograding the AK ridge out to the Aleutians, is that still a -EPO? 

@MJO812

 

 

 

 

@40/70 Benchmark

Looks like your thoughts on February going canonical La Niña have merit. EPS, GEFS and GEPS all still on board for a big -PNA/SE ridge response in the final days of this month going into February. The EPS, GEPS and GEFS are retrograding the ridge from AK to the Aleutians. Here’s the new EPS animation:
 

 

 

 

 

 

 

 

you say *canonical la nina* all the time but guess what, a cold December and cold January are also *canonical la nina*, and February is the shortest month of the year so if it's in the 50s and sunny all month, I think we'll all be happy, especially if it's a cold and snowy back half of January, most will be done with winter after this.

[LakeEffectOH]

12 hours ago, Snowstorms said:

Lake effect is nice but incredibly localized. A single squall line could literally be only 15-20 miles long in width meanwhile the people outside that boundary are dry and snowless. 

Made it up to 19.5" here in Toronto thanks to these 1-3" clippers and lake effect. Still running below average though for the ytd. 

Tell me about it...back in early December, Saybrook, OH had over 5 feet of snow via lake effect.  I live about 15 miles from there and there was not even a dusting.  Several days later, I finally had about 6 inches.

[michsnowfreak]

14 hours ago, Snowstorms said:

Lake effect is nice but incredibly localized. A single squall line could literally be only 15-20 miles long in width meanwhile the people outside that boundary are dry and snowless. 

Made it up to 19.5" here in Toronto thanks to these 1-3" clippers and lake effect. Still running below average though for the ytd. 

So true about lake effect. We see lots of flakes from lake effect here but are never in those insane bands so dont know the pleasure of having 3 feet while 10 miles away has nothing. Today will only be the 2nd day of January at Detroit to not see any snowfall. DTW is at 12.5" on the season but at least we have snowcover and the lake ice is getting thicker by the day (other than the blip of mild weather today). Not at all the pattern youd expect in a La Nina but its definitely winter.

[donsutherland1]

Some updates on last week’s thoughts:

1. Dry weather continued in southern California through. Blythe, Camarillo, Lancaster, Los Angeles, and Palm Springs all saw no rainfall.

2. There was no significant (6”+) snowstorm in the big cities of the Middle Atlantic and southern New England regions (Richmond to Boston) during the upcoming week. The heaviest snowfall amounts for the week were as follows: Baltimore: Trace; Boston: Trace; New York City: Trace; Philadelphia: 0.4“; Richmond: None; and, Washington, DC: 0.1”.

3. A strong cold shot affected the Great Lakes Region Tuesday through Thursday. Indianapolis saw the temperature bottom out at -1°. Detroit saw two consecutive single-digit lows (coldest temperature: 8°). Chicago saw the temperature fall to 5° and three consecutive single-digit lows.  

Four Thoughts Going Forward:

1. Dry weather will continue in southern California through the week. Little or no rainfall is likely in such cities as Blythe, Camarillo, Lancaster, Los Angeles, and Palm Springs.

2. A snowstorm will affect the Middle Atlantic and southern New England regions (Washington, DC to Boston) later tomorrow into Monday. A general 3”-6” is likely in Boston, New York City, and Philadelphia. A 2”-4” snowfall is likely in Baltimore and Washington, DC. 

3. A severe cold shot will affect the Great Lakes Region and East Coast from Sunday through Thursday. Chicago, Detroit, and Indianapolis will all see one or more subzero lows.  Baltimore, Boston, New York City, Newark, and Philadelphia will likely see one or more low temperatures in the single digits. Washington, DC could also see the temperature dip below 10°. 

The last single-digit lows were as follows:

Baltimore: December 24, 2022 (6°)
Boston: February 4, 2023 (-10°)
New York City: February 4, 2023 (3°)
Newark: February 4, 2023 (5°)
Philadelphia: December 24, 2022 (7°)
Washington, DC: December 24, 2022 (9°)

Highs could reach no higher than the teens in New York City and perhaps Philadelphia during the peak of the cold. The last time both cities had high temperatures in the teens was:

New York City: December 24, 2022 (15°)
Philadelphia: December 24, 2022 (18°)

There is a chance that New York City could see two consecutive highs in the teens for the first time since January 6-7, 2018 when the highs were 13° and 18° respectively.

All in all, this Arctic blast, which will have a Siberian connection, will likely be Winter 2024-2025’s coldest air mass. 

4. A storm will likely bring snow to parts of the Deep South Tuesday, Wednesday, and possibly Thursday. Measurable snow is likely in cities including Atlanta, Charleston, and Savannah. There is a chance that Tallahassee could experience its first measurable snowfall since January 3, 2018 when 0.1” fell. New Orleans could see its first measurable snowfall since December 4, 2009. The last storm that brought measurable snowfall to both New Orleans and Tallahassee occurred during February 9-10, 1973.

Longer-Range:

A slow moderation in temperatures is likely to commence during the closing week of January or the start of February. Above normal temperatures could develop in the eastern quarter of the United States after the first week of February. Precipitation could increase to above normal levels during the last week of February in the Southeast. The Pacific Northwest could see the development of a wet period during the closing days of January or opening of February.

[PhiEaglesfan712]

1 hour ago, donsutherland1 said:

2. A snowstorm will affect the Middle Atlantic and southern New England regions (Washington, DC to Boston) later tomorrow into Monday. A general 3”-6” is likely in Boston, New York City, and Philadelphia. A 2”-4” snowfall is likely in Baltimore and Washington, DC.

Eagles snow game, I'm so excited!

[LibertyBell]

1 hour ago, PhiEaglesfan712 said:

Eagles snow game, I'm so excited!

Perfect timing for the game too!

[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.

 

Verification:

A map calling for historic cold was posted more than 5 weeks in advance with no understanding of the magnitude of cold relative to historic climatology. It is virtually certain that the site aimed to increase engagement with its hyped call.

In the end, BAMWX's forecast met the same fate as General Custer and his army at the Battle of Little Bighorn. The bust was that bad. If anything, the magnitude of the bust was historic in nature. Moreover, as noted in the opening post on the topic, the catastrophe was foreseeable, even as the scale of the bust was even larger than expected.
 

Also, I noted: Further, to show the absurdity of the map, I asked AI (GPT-4o) to generate a random anomaly at tenths of degree fahrenheit using the following prompt: "Generate a random one-week temperature anomaly in tenths of a degree Fahrenheit. The mean long-term anomaly is 0. Assume daily anomalies could range from -50 to +50. The deviations are normally distributed." The random 7-day mean output: -1.7°.  I suspect what amounts to a simple guess will also do better.

The final four-city anomaly was 0.7° below normal. A random pick blew away the BAMWX forecast.

Lessons:
1. Very long-range maps have little skill
2. Due diligence against historic climatology is important for early assessments on likelihood of occurrence
3. The amount of deep cold air in the Northern Hemisphere is important
4. Extreme or historic events require lots of evidence to call for such events

In general, Social Media readers should be wary of sites that hype cold, heat, snow, or other extremes. Such reckless sites lack credibility and do damage to perceptions about meteorology, even as the field is remarkably good at what it does if one excludes those who regularly hype events.

[LibertyBell]

1 hour ago, donsutherland1 said:

Verification:

A map calling for historic cold was posted more than 5 weeks in advance with no understanding of the magnitude of cold relative to historic climatology. It is virtually certain that the site aimed to increase engagement with its hyped call.

In the end, BAMWX's forecast met the same fate as General Custer and his army at the Battle of Little Bighorn. The bust was that bad. If anything, the magnitude of the bust was historic in nature. Moreover, as noted in the opening post on the topic, the catastrophe was foreseeable, even as the scale of the bust was even larger than expected.
 

Lessons:
1. Very long-range maps have little skill
2. Due diligence against historic climatology is important for early assessments on likelihood of occurrence
3. The amount of deep cold air in the Northern Hemisphere is important
4. Extreme or historic events require lots of evidence to call for such events

In general, Social Media readers should be wary of sites that hype cold, heat, snow, or other extremes. Such reckless sites lack credibility and do damage to perceptions about meteorology, even as the field is remarkably good at what it does if one excludes those who regularly hype events.

The field is remarkably good at making specific weather calls within 3 days Don, but the Day 5-7 period and especially beyond Day 7 is very much a toss up.  Outside of very general terms, there should be no forecasts made past 7 days.

[MJO812]

Weeklies?

[Stx_Thunder]

The 'possible strong event' topic tag seriously needs to be taken off here as there's basically a 99% probability now the current La Niña phase is going to remain weak, then likely go back to neutral ENSO going into spring. It was only just about a month ago Niña went official, and was already projected to be a weak Niña on dynamical models even back in November.

I should also point out, CPC did a poor job with the forecasting. Insisting La Niña would return by the summer last year (which did not happen at all).

[40/70 Benchmark]

On 1/16/2025 at 1:44 PM, brooklynwx99 said:

lol. just looking more and more like 2013-14

Except that season actually snowed in New England....nothing like it in terms of snowfall.

[brooklynwx99]

2 hours ago, 40/70 Benchmark said:

Except that season actually snowed in New England....nothing like it in terms of snowfall.

snowfall is much harder to predict at long lead times

[40/70 Benchmark]

4 hours ago, brooklynwx99 said:

snowfall is much harder to predict at long lead times

Right, but it can't be ignored, either.

[brooklynwx99]

2 minutes ago, 40/70 Benchmark said:

Right, but it can't be ignored, either.

true. out of all the years that I thought were analogous, 13-14 might look the most similar at 500mb. we'll see if late Jan into Feb/Mar is any better for snow. it'll get wetter at least

[LakePaste25]

One of the reasons I’d argue why this winter is less snowier outside of the lake effect and upslope mountain regions is the H5 pattern. Compared to 13-14, the mean long wave trough axis is further east.

 

[brooklynwx99]

7 minutes ago, LakePaste25 said:

One of the reasons I’d argue why this winter is less snowier outside of the lake effect and upslope mountain regions is the H5 pattern. Compared to 13-14, the mean long wave trough axis is further east.

 

easily could have been very snowy up here, but we have had shit luck with kickers... one a couple of weeks ago and another this coming week. things just aren't coming together. however, the MA is going to be AN on the year through the end of Jan 

[MJO812]

13 hours ago, MJO812 said:

Weeklies?

Weeklies aren't warm going forward

[40/70 Benchmark]

2 hours ago, brooklynwx99 said:

easily could have been very snowy up here, but we have had shit luck with kickers... one a couple of weeks ago and another this coming week. things just aren't coming together. however, the MA is going to be AN on the year through the end of Jan 

The eastward position of the trough certainly doesn't help.