Stormchaserchuck1

I can see -PNA's in the Sun. It seems like it's shining more radiant (March sun angle, for example.) Then I check and all models go more -PNA.

GFS and Euro both have something for the 13th. Active STJ https://ibb.co/P63BHFy https://ibb.co/nL6WRnG

Yeah especially because weather is science and has a lot of ongoing reference points.

When the -NAO is lifting up that is our storm chance. The -PNA, if that is the pattern, has a high precip correlation, 0.55 in January https://ibb.co/191HM4P Problem is -PNA's lately have brought south wind all the way to NYC.

Lately, in the mature part of a -PNA cycle, the correlation has been there. Not overall though yeah. It should be noted that the -PNA cycle began when the AMO went +.

A lot of snow for all the insane HL blocking the last 2 Winter's. That N. Pacific -PNA region is really a dominant pattern at this point in time. And the -NAO has a SE ridge correlation since 18-19, and really going back to 2013.

Even though models pinch the Pacific ridge into -EPO/-WPO, it's still a -PNA pattern, and a strong one at that. You guys should really run the composites for -NAO's lately and the -PNA patterns that have happened at the same time. I think +NAO/+PNA is correlating too. GEFS by day 15-16 is really starting to warm things up here, with the NW trough trying to retrograde into +EPO, which happens sometimes after big blocking episodes. +300dm Aleutian island ridge on the mean. -PNA pattern https://ibb.co/fHQdLDL

00z GFS kicks out the -NAO quickly.. These have had no staying power lately. With Pacific ridge pinching into -EPO/-WPO, watch the rising-up-to neutral part of NAO cycle for historical snowstorm threat.

18z gfs not as blocky as 12z Euro, but you still have 498dm moving into the Upper Midwest at Day 10.

The Stratosphere warming started Dec 25, so it's showing again that the lagged -NAO a lot of times works. Lag at this time of the year is +25-30 days, but +19 days shown there isn't a bad fit.

No one mentioned the 12z Euro Day 10 has a block over Alaska and a block over Greenland. Storm moving in. https://ibb.co/r20wwDn Much more snowy pattern if it's true.

Thanks. It's a learning opportunity. Do you see how the storm got sheared out by relative SE ridge in trend. It was because the models were not properly estimating the impacts of -PNA/RNA pattern (N. Pacific High, pretty strong). Last Winter there were a few times at 5-7 days where the models had a +EPO (Alaska trough) and they were showing snow, then it adjusted to the surface level warmth in the closer timeframe. These two patterns, -PNA and +EPO are not conductive to big snows, when they are in a strong phase, so it trended warmer and phased out (in my experience, the models don't totally account for that, for whatever reason). I showed +0.53 charts for PNA-pattern in January. https://ibb.co/mvGCw9F [default positive].

We also have an ongoing record of 10 straights February's with +NAO (CPC) 2014 1.34 2015 1.32 2016 1.58 2017 1.00 2018 1.58 2019 0.29 2020 1.26 2021 0.14 2022 1.68 2023 0.92 1950-60 March -NAO ties the index record with January 09-19 +PNA for 11 consecutive years. 1966 was a very -NAO February, and I know -PNA February's in El Nino's can sometimes pop big -NAO's so we'll see

I think February is a big test as to the decadal -PNA we are in. The N. Pacific anomalies over the last 6 Winter's are the greatest we've ever seen in an area at 500mb on record for the same month over a 6-year period. (Feb 1964-1969 -NAO comes in 2nd)

You really think that's a -pna, with a trough across the N. pacific from Japan to the West coast? It seems like LR models are evolving this way, and my research has highlighted the Jan 19th period as the pattern change, so let's see if it holds going forward. If a trough develops under a -WPO ridge, we may be in business. I would also like that Pacific pattern to develop before the NAO is rising up from negative (KU storms). The SE ridge/Aleutian ridge may linger though, I'm not 100% on that changing before the 19/20. But these are really good trends today in the PNA region for the long range.

It does look like the GEFS wants to spill +heights into the EPO-WPO domain now. I guess it's caving to the EPS in this regard?

I'm thinking they use '91-20 averages for one. Let's see where we're at on the 20th, I bet most places in the eastern US will have above average temps for Jan

rose colored glasses. That pattern isn't going to work (if you want snow in the east). Maybe after the 20th

Yes

No, that's a nasty N. Pacific high, and now SE ridge. We aren't going to snow until that pattern changes.

Our "wheelhouse"? Do you realize it hasn't snowed 1" in 710+ days? Jan 27th is our coldest day of the year, so it's usually somewhat safe to predict colder weather around that day, but I think we could be waiting longer than you currently indicate. I did this research earlier, but it has held true to where it's going to happen that Jan 5-13 is a strong N. Pacific/Aleutian island High building during El Nino. I did 15 analogs (since 1948) matching PNA with opposite or Neutral ENSO state on those dates, and found that there is a strong indication that the pattern completely changes, in about a week after the 13th. This is a really good reversal on the composite, and you usually don't see that, especially in the PNA region, you usually see consistency rolled forward... This rolls forward to a +PNA Jan 18-19->, and East Coast goes to average or below average temps on and after Jan 21-22: https://ibb.co/xzVYnx5 https://ibb.co/kGL4bZp

I still think we're going to go warmer after 18z

I'd be curious to see if a 3 sigma -NAO can overpower a 1 sigma -PNA right now to be honest. The -PNA may verify greater.

It's been since March 2018 that we had -NAO-based trough/cold in the east. Every other time it has happened with a -PNA or +EPO and we have gone warmer.. I don't really see this trend stopping, the correlation is close to 0.40 since 2019. My roll forwards did show the Pacific changing around 1-19.. The GEFS starts doing it 1-18. But the -NAO happens on the model 1-8/17 with it looks like a slight SE ridge. This is something that I think is going to stick, (we are in the heart of this cycle).

The 18z gfs ensembles had a lot of rain members. One even tracked the low into Chicago