2024-2025 La Nina

[snowman19]

4 minutes ago, mitchnick said:

You're re-posting Cohen when he posts a 384 hr Gfs operational map because it supports your warmanista agenda? Oye

I did it just to get this reaction. Thank you. Made me laugh 

[mitchnick]

3 minutes ago, snowman19 said:

I did it just to get this reaction. Thank you. Made me laugh 

Yeah...right. What else could you say.

[GaWx]

2 hours ago, GaWx said:

Followup:

The 5 highest tabular Dec +PNAs for non-Nino on record (2024 progged to have good chance to be new highest):

2020: +1.58

1960: +1.46

1985: +1.39

2005: +1.38

2000: +1.23

 

 Where were the subsequent Jan tabular PNAs for these non-Nino high +PNA Dec?

2021 +0.19

1961 +1.41 (4th highest on record for non-Nino)

1986 +0.97 (tied for 7th highest on record for non-Nino)

2006 +0.43

2001: +1.51 (3rd highest on record for non-Nino)

Avg Jan for these 5: +0.90

 So, as I think @Stormchaserchuck1was suggesting (actually he was suggesting for all ENSO), +PNA in Dec tends to carryover into Jan for non-Nino. Three of the 5 did strongly and one weakly. The other (2020-1) went to neutral. So, none even went to a weak -PNA.

@Terpeast

Followup to followup:

 So, the above suggests a good shot at a +0.75+ PNA in Jan. These 9 non-Nino Jans since 1950 had a +0.75+ PNA (all cold ENSO except RONI neutral 1961 and 1981):

Year/PNA/E US temps
1961 +1.41 cold

1981 +2.42 cold

1984 +0.97 cold

1985 +1.63 cold 

1986 +0.97 normal

2001 +1.51 normal

2011 +1.29 cold

2014 +0.97 cold

2022 +1.01 cold

 

 So, the current cold and strongly +PNA Dec has totally changed my thinking for Jan to a good chance for much colder than I originally thought using the Dec to Jan analog method.

[jbenedet]

 

4 hours ago, michsnowfreak said:

They are somewhat similar but I wouldn't say basically the same. Snow is much deeper in Canada and the temps couldn't be more different the last 2 decembers. The lack of snow in many locations is due to how dry it has been the last several weeks.

 

Okay guy. You got me, alright. 

[jbenedet]

Numbers aren’t gonna get closer than that down to the day.

Interestingly too, following last year’s pattern, next few weeks are tilted to warm/wet in the northeast.

It is following very closely.

[GaWx]

Newest from BAMwx: I haven’t watched it yet. Hoping it like the last couple provides sound reasoning for cold Jan and doesn’t hype:

 

[Maestrobjwa]

2 minutes ago, GaWx said:

Newest from BAMwx: I haven’t watched it yet. Hoping it like the last couple provides sound reasoning for cold Jan and doesn’t hype:

 

That thumbnail isn't a good "no-hype" first impression, lol

[Terpeast]

3 minutes ago, Maestrobjwa said:

That thumbnail isn't a good "no-hype" first impression, lol

Marketing for views and putting out a credible forecast are two very different things. 

Like oil and water. 

[Maestrobjwa]

25 minutes ago, Terpeast said:

Marketing for views and putting out a credible forecast are two very different things. 

Like oil and water. 

My question is why do people buy into it...particularly after the last 8 years? I mean at least before that  you had just had that heater the Mid Atlantic and Norrheast went on between 2010 and 2016...but now isn't hype more of the boy who cried wolf?

[so_whats_happening]

Last about month and a half the subsurface Nina state seems to be making a little comeback, the overall look is a lot more of a Nina look than it has been for awhile. It will be interesting to see if we do indeed get the weakening of trades showing up on models toward the first week of January.

[snowman19]

I knew as soon as JB started hyping a big east coast snowstorm for next weekend and started hemming and hawing about how the models were wrong about any warmup in the east between Christmas and New Year’s “my hurricane analogs say!!” It was definitely doomed. That guy is the ultimate kiss of death for winter in the east

[bluewave]

3 hours ago, so_whats_happening said:

Last about month and a half the subsurface Nina state seems to be making a little comeback, the overall look is a lot more of a Nina look than it has been for awhile. It will be interesting to see if we do indeed get the weakening of trades showing up on models toward the first week of January.

If the EPS and GEFS are correct, then we could see another round of strong EPAC WWBs like we had back in November last week of December. So there could be more EPAC warming around 1+2 into January. Maybe more of a west based La Niña pattern in terms of SSTs since the trades should be stronger initially near the Dateline. 

 

 

[roardog]

31 minutes ago, bluewave said:

If the EPS and GEFS are correct, then we could see another round of strong EPAC WWBs like we had back in November last week of December. So there could be more EPAC warming around 1+2 into January. Maybe more of a west based La Niña pattern in terms of SSTs since the trades should be stronger initially near the Dateline. 

 

 

You’re not wrong but since we just saw this happen recently and it could be at least partially responsible for our current pattern maybe it will cause more competing influences and we’ll go back to the pattern we have now. Maybe we should think about that instead of looking at it from the negative point of view and saying west based Nina pattern when we really don’t know.

[Terpeast]

11 minutes ago, roardog said:

You’re not wrong but since we just saw this happen recently and it could be at least partially responsible for our current pattern maybe it will cause more competing influences and we’ll go back to the pattern we have now. Maybe we should think about that instead of looking at it from the negative point of view and saying west based Nina pattern when we really don’t know.

I don't think he's looking at this from a negative point of view. If we do get another WWB by the end of this month, we'll be crossing into MJO 7 by then and the pattern may become even more favorable after the late-Dec/early-Jan warm up.

[michsnowfreak]

https://x.com/webberweather/status/1867696309160849438?s=46

Lots of variability and wild swings the key takeaway imo

[donsutherland1]

Some updates on last week's thoughts:

1. Warmer air surged back into the northern Mid-Atlantic and southern New England regions earlier this week. Highs included: Baltimore: 64°, Boston: 62°; Hartford: 64°; Islip; 60°; New York City: 60°; Newark: 63°; Philadelphia: 64°; Providence: 61°; and, Washington, DC: 64°

2. A significant rainstorm affected the northern Mid-Atlantic and southern New England areas Tuesday into Wednesday. Rainfall amounts included: Baltimore: 0.92"; Boston: 2.82"; Hartford: 1.54";  Islip: 1.69"; Newark: 0.92"; New York City: 1.11"; Philadelphia: 0.98"; Providence: 4.64"; and, Washington, DC: 0.95".  The Wednesday (December 11) rainfall of 4.60" at Providence was the highest daily rainfall on record there from the October 6 through March 29 period.

3. Frigid temperatures affected parts of the North Central and Great Lakes regions. Lowest temperatures for select cities included: Chicago: 4° (2 consecutive days); Detroit: 10°; Milwaukee: 2°; and Minneapolis: -7° (3 consecutive subzero lows).

4. Phoenix saw the mercury rebound into the 70s. As of December 13th, Phoenix is on track for an annual mean temperature of 78.4°, which would make 2024 that city's warmest year on record.

5. The probability that numerous locations in the eastern third of the U.S. will feature a colder than normal December has increased further. There is currently an implied 78% probability that New York City will have a colder than normal December.

Three thoughts going forward:

1. The changeable weather will continue from the Great Lakes region to the Northeast. The temperature could rocket to much above normal levels early next week. The temperature could reach 50° or above in Detroit and reach the upper 50s in New York City and Philadelphia and likely the 60s in Baltimore and Washington, DC. The week could end with a return to colder conditions.

2. Despite periodic hints of a significant snowfall from Washington, DC to New York City on the operational GFS, any snowfall threat will largely favor interior cities. No significant snowfall appears likely from Washington, DC to New York City given the NAO+ pattern and fast Pacific flow. Even cities such as Chicago, Detroit, and Toronto likely won't see much snowfall next week.

3. As the ongoing PNA+ persists, readings could rise to above normal levels in such cities as Portland and Seattle. Phoenix will see another very warm week.

Long-Range:

The changeable pattern will continue through the end of December. A sharp cold shot could affect the eastern third of the U.S. around or just after the Winter Solstice. Milder air will then overspread the region several days later and the remainder of December now looks to be generally mild.

In addition, the combination of a continuing fast Pacific flow and NAO+ makes prospects for a big East Coast snowstorm unlikely over at least the next 10-14 days.

The recent long-range guidance (extended GEFS, ECMWF weeklies, and CFSv2 weeklies) has now reached a consensus that January will start on a warmer than normal note across much of the CONUS and southern Canada. The transition to a possible colder pattern is delayed, but still shows up. The extended range 46-day ECMWF teleconnections forecast shows the development of an EPO-/PNA- pattern for at least the first half of January. 

There are two major clusters of outcomes from such a pattern:

Cluster 1: 62.5% of cases:

Cluster 2: 37.5% cases:

Given the long duration of the forecast pattern, there could be periods where either cluster manifests itself. That means that even if the month starts warm, there could be some opportunity for colder even Arctic air intrusions. January 17-19, 2000 featured single-digit lows in the New York City area. In addition, significant periods of cold developed subsequent to the EPO-/PNA- pattern later in January 2004 and 2005.

At such ranges, ensemble skill is low. What currently shows up are some possibilities. The historic data suggests that there could be an opportunity for January to turn colder in the eastern half of the U.S. For now, that remains the base case. It's premature to suggest that the cold would be sufficient to result in a colder-than-normal outcome there. A colder outcome is more likely from the Pacific Northwest to the North Central U.S., including Canadian Provinces such as British Columbia, Alberta, Saskatchewan, and Manitoba.

 

[BuffaloWeather]

3 hours ago, snowman19 said:

I knew as soon as JB started hyping a big east coast snowstorm for next weekend and started hemming and hawing about how the models were wrong about any warmup in the east between Christmas and New Year’s “my hurricane analogs say!!” It was definitely doomed. That guy is the ultimate kiss of death for winter in the east

 

@bluewave This event has become a classic CP/Modoki “west-based” La Nina. Not surprising to see a warm region 1+2

I'm at 85" already on the year and in the east.

[GaWx]

Parts of upstate NY, Ontario and Quebec appear to be near or at all-time Dec record high SLP with the Massena to Ottawa corridor at ~1050 mb near records for any month: these are from 10AM EST:

 

CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  

MASSENA        SUNNY     18  10  71 NE3       31.01S

MONTREAL       MOSUNNY   16   7  67 N5        31.00R WCI   9 TC  -9    

  

_____REGIONAL ONTARIO LOCATIONS_____  

CITY           SKY/WX    TMP DP  RH WIND       PRES   REMARKS  

OTTAWA         MOSUNNY   14   9  79 NE7       30.99R

 

https://ca.news.yahoo.com/record-breaking-pressure-over-ontario-012208535.html

[roardog]

4 hours ago, snowman19 said:

I knew as soon as JB started hyping a big east coast snowstorm for next weekend and started hemming and hawing about how the models were wrong about any warmup in the east between Christmas and New Year’s “my hurricane analogs say!!” It was definitely doomed. That guy is the ultimate kiss of death for winter in the east

 

@bluewave This event has become a classic CP/Modoki “west-based” La Nina. Not surprising to see a warm region 1+2

We all know what JB is but his call this time around wasn't bad. I have Weatherbell so I read all of them guys that post on there. JB has been saying since early Fall that his hurricane analog showed cold in the east between Thanksgiving and Christmas but it isn't useful beyond that time frame. So it's actually going to end up being a decent call that he made before the models were ever showing any sign of cold in the east in December.

[bluewave]

6 hours ago, roardog said:

You’re not wrong but since we just saw this happen recently and it could be at least partially responsible for our current pattern maybe it will cause more competing influences and we’ll go back to the pattern we have now. Maybe we should think about that instead of looking at it from the negative point of view and saying west based Nina pattern when we really don’t know.

I was discussing the mismatch potential back in October when the early MJO indicator came in similar to December 2020, 2017, and 2010. But I also mentioned at the time that the La Niña was much weaker than those past instances so there could be issues with the comparison past December La Niña mismatch events. While we got the +PNA this month, the Pacific Jet was much stronger than the previous mismatch Decembers. So the ridge axis keeps shifting into the East instead of staying anchored near the West Coast. The faster Pacific Jet is probably related to the WPAC record warmth and forcing competing with the +AAM influence and EPAC forcing. So it’s as if we have an El Niño pattern interfering or running concurrently with La Niña conditions.

[mitchnick]

33 minutes ago, bluewave said:

I was discussing the mismatch potential back in October when the early MJO indicator came in similar to December 2020, 2017, and 2010. But I also mentioned at the time that the La Niña was much weaker than those past instances so there could be issues with the comparison past December La Niña mismatch events. While we got the +PNA this month, the Pacific Jet was much stronger than the previous mismatch Decembers. So the ridge axis keeps shifting into the East instead of staying anchored near the West Coast. The faster Pacific Jet is probably related to the WPAC record warmth and forcing competing with the +AAM influence and EPAC forcing. So it’s as if we have an El Niño pattern interfering or running concurrently with La Niña conditions.

Huh...average a fading Niño with a weak Niña, and what do you get? La Nada...what else! Lol

20NOV2024     22.7 0.8     25.2 0.1     26.7-0.1     28.8 0.1
 27NOV2024     22.5 0.3     24.9-0.2     26.4-0.3     28.5-0.1
 04DEC2024     22.5 0.1     24.8-0.4     26.3-0.3     28.3-0.2

[mitchnick]

Today’s weeklies have come in colder. Even has a large area of BN temps in the east the week of 1/6-1/13.

[Terpeast]

4 minutes ago, mitchnick said:

Today’s weeklies have come in colder. Even has a large area of BN temps in the east the week of 1/6-1/13.

Modeling has been pretty erratic with long term patterns. Probably more useful to look at clustering like @donsutherland1 posted earlier. 

[mitchnick]

6 minutes ago, Terpeast said:

Modeling has been pretty erratic with long term patterns. Probably more useful to look at clustering like @donsutherland1 posted earlier. 

Maybe, but weeklies have been consistent for a while with at or BN starting the week of 1/6, so I'll take the weenie route. Lol

[bluewave]

50 minutes ago, mitchnick said:

Huh...average a fading Niño with a weak Niña, and what do you get? La Nada...what else! Lol

20NOV2024     22.7 0.8     25.2 0.1     26.7-0.1     28.8 0.1
 27NOV2024     22.5 0.3     24.9-0.2     26.4-0.3     28.5-0.1
 04DEC2024     22.5 0.1     24.8-0.4     26.3-0.3     28.3-0.2

The December pattern this year is a first for any El Nino to La Niña transition regardless of strength.

[GaWx]

45 minutes ago, mitchnick said:

Maybe, but weeklies have been consistent for a while with at or BN starting the week of 1/6, so I'll take the weenie route. Lol

 Plus strong non-Nino +PNA/cold Dec analogs suggest to at least be wary about the slightest hint for cold in Jan.

 Indeed the week 1/6-12 is the coldest for it at sfc and at H5 in the E US of any run yet (going back 16 runs) by a good margin.

 More strikingly, look at how much the 1/6-12 BN H5 in E NA sticks out on this global view, which tells me it is a very strong signal especially for being still out at week 4 (a rare occasion that far out on EWs to see that large/intense BN H5 in the current warming era):

 Note fwiw that the ridge is centered W of this month’s W NA ridging allowing a stronger -EPO, which may mean even colder anomalies especially up north.

[donsutherland1]

54 minutes ago, mitchnick said:

Maybe, but weeklies have been consistent for a while with at or BN starting the week of 1/6, so I'll take the weenie route. Lol

The cold should be coming. It might be delayed somewhat. The ECMWF weeklies grew more aggressive. The CFSv2 weeklies have not. I suspect that we'll see variations of both the clusters I posted earlier.

[snowman19]

@Stormchaserchuck1

[snowman19]

9 hours ago, bluewave said:

If the EPS and GEFS are correct, then we could see another round of strong EPAC WWBs like we had back in November last week of December. So there could be more EPAC warming around 1+2 into January. Maybe more of a west based La Niña pattern in terms of SSTs since the trades should be stronger initially near the Dateline. 

 

 

The region 1+2 warming is all consistent with a CP/Modoki Nina event

[bluewave]

13 minutes ago, snowman19 said:

The region 1+2 warming is all consistent with a CP/Modoki Nina event

The big question is whether we can get a strong enough WWB this winter in order to initiate a large enough oceanic kelvin wave so we go back into El Niño by the summer? If not then we would probably see next winters La Niña stronger than this winter as the SSTs with this one are really struggling against the record warm global background state. Still too early to know which way it will go.