February Medium/Long Range Thread

[Stormchaserchuck1]

3 minutes ago, mitchnick said:

I don't dispute the indexes, but when you look at mean 850 temps, they are cold thru days 10-15. It's not until day 16 when they are warm. The link below starts day 10.

https://www.pivotalweather.com/model.php?m=epsens_opendata&p=850tw-mean&rh=2025013012&fh=240&r=conus&dpdt=&mc=&pwplus=1

 

Part of it could be that the Pacific ridge extends into Alaska.. that is colder at the surface in the US. The other part may actually be model error, as they are maybe coming off a really cold period and running that forward? Save those maps, I bet in verification it will either be warmer, or the H5 will adjust differently to match the colder surface.  It's a pretty strong -PNA/+NAO happening in the long range.. that usually trends warmer to the day of. 

[mitchnick]

4 minutes ago, Stormchaserchuck1 said:

Part of it could be that the Pacific ridge extends into Alaska.. that is colder at the surface in the US. The other part may actually be model error, as they are maybe coming off a really cold period and running that forward? Save those maps, I bet in verification it will either be warmer, or the H5 will adjust differently to match the colder surface. 

I definitely don't buy the model error idea, but I did consider it before posting. I just can't see how the ensembles are that flawed. An operational at range? Sure, but not an ensemble mean.

I think it coukd be the cold is undercutting the higher heights in the east.

[Ralph Wiggum]

43 minutes ago, CAPE said:

-NAO not always required for snow.

I'm a firm believer Pac side > Atl for snowfall potential. However, If you are  big dog hunting a NAO ridge certainly helps. But yeah, we can score in a -NAO. Just keep the cold air source (-EPO?) in tact and the SER non-raging.

[Stormchaserchuck1]

1 minute ago, mitchnick said:

I definitely don't buy the model error idea, but I did consider it before posting. I just can't see how the ensembles are that flawed. An operational at range? Sure, but not an ensemble mean.

I think it coukd be the cold is undercutting the higher heights in the east.

I just can't see 500mb High between Aleutian islands and Hawaii at +300dm, and southern Greenland having negative 500mb and it not being above average.. maybe the 500mb pattern will change in future runs, it has been going back and forth a little the last few days. 

[CAPE]

Improvement in the NA on the 18z GEFS- a little closer to a useful NAO block, thermal boundary pressed further south with below avg temps pushing into the MA for mid month. Still waiting on the Pacific to shift a bit.

[Stormchaserchuck1]

^See, these are the two biggest regions for downstream East Coast troughs/ridges (-PNA/+NAO)

[clskinsfan]

1 hour ago, CAPE said:

-NAO not always required for snow.

Agree. Not always. But heading into February and March. Yeah. We are gonna need it. Or it will be cutter city. Hope I am wrong. 

Edit: I will add. Any precip is good for my garden so bring it. But no -NAO means the SE ridge will dominate. Is what it is. 

[ravensrule]

3 hours ago, Scarlet Pimpernel said:

You win the interwebs today, sir!!  LOL!!!

And that plot...just seems like a @ravensrule bat signal right there!

I didn’t even notice that on first look. I’m so disappointed in myself. 

[clskinsfan]

15 minutes ago, Ralph Wiggum said:

But yeah, we can score in a -NAO

In late winter. Not really. Just saying. No -Nao means cutter city.

[mitchnick]

14 minutes ago, CAPE said:

Improvement in the NA on the 18z GEFS- a little closer to a useful NAO block, thermal boundary pressed further south with below avg temps pushing into the MA for mid month. Still waiting on the Pacific to shift a bit.

Chuck, I posted that days 10-15 on the Gefs had cold 850's but got warm on day 16. 378hrs that CAPE posted is day 16 and that is warm. But day 16 forecasts, including ensembles, will undoubtedly change one way or the other.

[Stormchaserchuck1]

6 minutes ago, mitchnick said:

Chuck, I posted that days 10-15 on the Gefs had cold 850's but got warm on day 16. 378hrs that CAPE posted is day 16 and that is warm. But day 16 forecasts, including ensembles, will undoubtedly change one way or the other.

Ok.. I'm saying the Pacific, if it looks like this with the highest anomaly ridge this far south, is a warm pattern..

Maybe in future runs it will show the H further north or over Alaska.. that will get you colder at the surface. I've seen that kind of change happen in the last few days. But beyond Day 10 on 18z GEFS, the Pacific -PNA ridge is pretty far south, and would verify as an above normal temp pattern most likely. 

[Ralph Wiggum]

28 minutes ago, clskinsfan said:

In late winter. Not really. Just saying. No -Nao means cutter city.

Some of our largest late season storms were + nao phases.

[Stormchaserchuck1]

That we're seeing another strong February RNA is just insane, here's the last 7 consecutive years! 

The trend has often carried into March, although not as strong as Feb

[clskinsfan]

12 minutes ago, Ralph Wiggum said:

Some of our largest late season storms were + nao phases.

In Feb and March? Examples? As the longwave pattern starts to change in spring we need a -NAO for bombs. I cannot think of a single example of a big snowstorm on the coastal plain without it. Now out here and up there? Yeah. we can score. Because we hold CAD. 

[87storms]

Ok.. I'm saying the Pacific, if it looks like this with the highest anomaly ridge this far south, is a warm pattern..

Maybe in future runs it will show the H further north or over Alaska.. that will get you colder at the surface. I've seen that kind of change happen in the last few days. But beyond Day 10 on 18z GEFS, the Pacific -PNA ridge is pretty far south, and would verify as an above normal temp pattern most likely. 

We need to find a way to pinch off another pv lobe.

[Ralph Wiggum]

20 minutes ago, clskinsfan said:

In Feb and March? Examples? As the longwave pattern starts to change in spring we need a -NAO for bombs. I cannot think of a single example of a big snowstorm on the coastal plain without it. Now out here and up there? Yeah. we can score. Because we hold CAD. 

March 13, 1993

March 1958

[Ralph Wiggum]

19 minutes ago, clskinsfan said:

In Feb and March? Examples? As the longwave pattern starts to change in spring we need a -NAO for bombs. I cannot think of a single example of a big snowstorm on the coastal plain without it. Now out here and up there? Yeah. we can score. Because we hold CAD. 

Coastal plain. Yeah. But you didn't mention that in your op

[clskinsfan]

2 minutes ago, Ralph Wiggum said:

March 13, 1993

You have to bring up the "Storm of the Century" to dispute my point. Damn Ralph. Thats rough for me to counter. 

[Maestrobjwa]

59 minutes ago, mitchnick said:

Chuck, I posted that days 10-15 on the Gefs had cold 850's but got warm on day 16. 378hrs that CAPE posted is day 16 and that is warm. But day 16 forecasts, including ensembles, will undoubtedly change one way or the other.

Yeah Day 15+ is can kick territory, imo

[Ralph Wiggum]

4 minutes ago, Maestrobjwa said:

Yeah Day 15+ is can kick territory, imo

We are definitely in a lull/reload when we are debating teleconnections 15+ days out. Watch something sneak up now mid range and the warmup get muted.

[winter_warlock]

 Looks like cold air is trying to I made the usa again in next 8 to 14 days..

[Stormchaserchuck1]

GFS trend.. It will be interesting too see if the long range does this, or if the H5 shifts away from a pretty far south -PNA in the Pacific 

https://ibb.co/BVGSHXvY