Winter 2024-25 Discussion/Speculation

[40/70 Benchmark]

20 hours ago, frd said:

Big drop in the AO arriving.  Good early season sign. 

 

 

Why is an AO drop in September a good sign for the winter?

[Maestrobjwa]

Just now, 40/70 Benchmark said:

Why is an AO drop in September a good sign for the winter?

Why is any index a good sign for the winter? Wait...do good indexes even exist anymore? 

[frd]

4 hours ago, 40/70 Benchmark said:

Why is an AO drop in September a good sign for the winter?

Why not ?

Several mentions online recently that it prevents a raipid strong early season PV development.  But, regardless we all know its going to be a warm and snowless winter.  

 

[40/70 Benchmark]

6 hours ago, frd said:

Why not ?

Several mentions online recently that it prevents a raipid strong early season PV development.  But, regardless we all know its going to be a warm and snowless winter.  

 

I really don't think it matters. There is plenty of time for recovery prior to winter...look at 2006....huge NAO block that fall.

[Stormchaserchuck1]

In January-February-March, the October NAO actually has a pretty good opposite correlation with the NAO of those months.. it's about 45%. This is impressive because no other months of the year have a correlation <50%. 

Default of these maps is positive, so it's showing after a + index state

I know this -NAO is falling into the realm of September, but just barely.. because it's the last few days of the month, it probably has a 49% correlation to the Winter NAO (since Oct is 45% and Sept is 51%).  

[Terpeast]

For a week in a row, CFS has shows February, not December to be the best winter month. Skeptical because it goes against the nina grain and what we’ve seen in the last several winters. Precip pattern shows a coastal track, too.

Not particularly putting any weight on this, just not much more than a “hmm” moment.

 

[psuhoffman]

On 9/15/2024 at 6:45 AM, CAPE said:

The more poleward Aleutian ridge is the most important feature for our area in a Nina. That along with the stretched/southward displaced TPV idea the climate models have been hinting at would provide a mechanism for cold air delivery at times. During colder periods the thermal boundary could push over/just to the south of us. Models have also been hinting at possible HL blocking. Fwiw the advertised h5 look on the latest CFS runs look quite acceptable for Jan, and Feb too.

Your micro analysis is correct. But on the macro we live at a location that needs a decent negative departure to get snow and consistently for years every projection shows 80% of the hemisphere red. 

[SnowenOutThere]

2 hours ago, psuhoffman said:

Your micro analysis is correct. But on the macro we live at a location that needs a decent negative departure to get snow and consistently for years every projection shows 80% of the hemisphere red. 

It's ok, I'm sure the dastardly underwater volcanoes causing that will calm down soon. 

[Maestrobjwa]

5 hours ago, Terpeast said:

For a week in a row, CFS has shows February, not December to be the best winter month. Skeptical because it goes against the nina grain and what we’ve seen in the last several winters. Precip pattern shows a coastal track, too.

Not particularly putting any weight on this, just not much more than a “hmm” moment.

 

That's when you know it's wrong--ain't no February the best month in a nina, lolol Man this has the be the easiest winter to forecast ever! Don't even have to go to school to do it 

[Terpeast]

22 minutes ago, Maestrobjwa said:

That's when you know it's wrong--ain't no February the best month in a nina, lolol Man this has the be the easiest winter to forecast ever! Don't even have to go to school to do it 

Well, we thought a cold and active february was a lock even the last week of jan this year. Models were showing it for months. Then it slipped away at the last minute.

You never know. 

[CAPE]

5 hours ago, psuhoffman said:

Your micro analysis is correct. But on the macro we live at a location that needs a decent negative departure to get snow and consistently for years every projection shows 80% of the hemisphere red. 

I have learned to largely ignore the colors on the super LR tools and follow the height lines, focusing instead on the flow around/between upper level features. That look should bring some cold southward. Ofc it's a single panel attempting to depict the general longwave pattern for an entire month. 

[GaWx]

6 minutes ago, CAPE said:

I have learned to largely ignore the colors on the super LR tools and follow the height lines, focusing instead on the flow around/between upper level features. That look should bring some cold southward. Ofc it's a single panel attempting to depict the general longwave pattern for an entire month. 

But don’t forget that the mean H5 shown on this and other long range models could easily be wrong. Last winter is just one example. If H5 had even been close, last winter would have been much better. They’ve overall averaged too cold in recent years in the E US.

[CAPE]

4 minutes ago, GaWx said:

But the mean H5 shown on this and other long range models could easily be wrong. Last winter is just one example. If H5 had even been close, last winter would have been much better. They’ve overall averaged too cold in recent years in the E US.

Certainly could be. These tools have proven to be variable and quite limited, and thus the 'Fwiw' disclaimer when I post them.