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13 minutes ago, SnowGoose69 said:

The difference in February with a raging -PNA and -AO/NAO is that due to wavelength change the pattern would be markedly different than Dec...you would never have a massive SER in February or March under those same conditions

Yeah this is why I am not looking at the return of the RNA in Feb as the end to a good stretch. To me it will have little negative affect to our snow chances as compared to now.

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3 minutes ago, bluewave said:

That’s why we discuss the 500 mb patterns where the actual height anomalies are located. Raw teleconnection indices by themselves don’t tell you very much. Models are good at identifying the long range long wave patterns. These 500 mb patterns give a good broad sketch of what type of weather is possible within a certain domain. Back in December, the deep Western Trough that the models forecast from mid to late November was the dominant feature. So the lack of snow then was no surprise given the type of 500 mb pattern being shown. As soon as the trough began to lift out of the West in early January, we got the 6-10” snow event. This has matched the past climatology for our area following Pacific pattern changes. 

Yup, and the RNA in Feb can actually lead to a favorable snow pattern for us. I can see us col and dry this month and multiple overrunning events in February.

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2 minutes ago, Allsnow said:

Gfs op cold and dry for the rest of the month. Gefs out to sea with any threat next weekend 

One way too look at it, but also every model has a LP system pop off the coast next weekend with the Canadian having it in the nicest position before heading out to see. With the NW trends we keep seeing it's probably best it's showing up, but heading out for sea on every model right now lol

gem_mslp_pcpn_frzn_us_30.png

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8 minutes ago, Jt17 said:

One way too look at it, but also every model has a LP system pop off the coast next weekend with the Canadian having it in the nicest position before heading out to see. With the NW trends we keep seeing it's probably best it's showing up, but heading out for sea on every model right now lol

gem_mslp_pcpn_frzn_us_30.png

We want it out to sea right now with no indication of blocking. 

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The low of 10° in NYC is colder than the last two winters that didn’t drop below 14°. 
 

Time Series Summary for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.
Ending Date
Lowest Min Temperature Oct 1 to Apr 30
Missing Count
2022-04-30 10 105
2021-04-30 14 0
2020-04-30 14 0
2019-04-30 2 0
2018-04-30 5 0
2017-04-30 14 0
2016-04-30 -1 0
2015-04-30 2 0
2014-04-30 4 0
2013-04-30 11 0
2012-04-30 13 0
2011-04-30 6 0
2010-04-30 13 0
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2 hours ago, EastonSN+ said:

I do agree. Example would be February 2018 where all the Teles we're against snowfall and we had a 4 to 8 inch snow event.

Just looking at the teles would say we had no shot at snow.

Dont fear the MJO phase 5!

One has to be careful how one uses the teleconnections. A given combination e.g., AO-/PNA+ may have resulted in X% days with measurable snowfall, while an AO+/PNA- resulted in Y% days with measurable snowfall (much less, in this case than X%). In neither case is the percentage 0%. So, one has a quick idea—a starting point—that one pattern typically sees more frequent measurable snowfall than another.

Existence of a given pattern does not guarantee any outcomes. The error many make is that they place too much certainty on outcomes (deterministic thinking over probabilistic thinking).

One can proceed further to break each general scenario into clusters (500 mb, etc.) for further insight. Again, even if one cluster has had a high percentage of measurable snowfall outcomes, nothing is assured. 

Without a storm system, there is no precipitation. Without sufficient cold (atmosphere and near surface), there is no snowfall. Without a good alignment of synoptic features, one can see scenarios ranging from rainfall to no precipitation at all.

One sees similar issues in thinking when it comes to other widely-cited variables such as the MJO. There are cases where a high amplitude MJO passage through one of the Phases leads to outcomes that differ markedly from the more typical outcomes. 

The same also applies to ENSO. Seasonal and sub-seasonal outcomes may well vary widely from the so-called canonical outcomes. 

No one variable—ENSO, MJO, SSTA distributions, teleconnections—explains more than a small piece of the overall picture. The deterministic line of reasoning—if variable is in X state then expect Y outcome—oversimplifies things and can create forecasting blind spots.

These forecasting blind spots can be especially large when one is relying on analogs. Sometimes things work out well, but just because one case evolved into a given outcome over a 1-3 month timeframe, there is no assurance that a similar case will do so. If one recalls, Social Media was abuzz with the 1995-1996 analog back in early December. Nothing remotely like that exceptional winter season has played out (and given differing states of the PDO, among other things, the probability of such an evolution was always low).

One needs to look deeper. The models and ensembles make this possible. Even then, one should beware of model limitations and the reality that there remains a degree of uncertainty. 

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Just now, dmillz25 said:

As long as the -PNA doesn’t go crazy like in December we should be fine especially if we get a -NAO

Yup. This IS a repeat of December which is good as....

1.) Highly unlikely we go recorded RNA twice in one season

2.) As Don and Snowgoose alluded to RNA is less hostile in February (2nd half).

Also this may mean that the January look returns in March!

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2 hours ago, EastonSN+ said:

Thanks Don. Curious if there are stats on February's with an RNA negative AO combo (basically a subdued December repeat).

Like you said the larger events are probably heavily skewed towards end of the month.

I wouldn’t compare it to December. Shorter wave lengths can lead to troughs in the East. 

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3 minutes ago, EastonSN+ said:

Yup. This IS a repeat of December which is good as....

1.) Highly unlikely we go recorded RNA twice in one season

2.) As Don and Snowgoose alluded to RNA is less hostile in February (2nd half).

Also this may mean that the January look returns in March!

I wouldn’t compare it to December also for the simple fact that I don’t think we see -NAO this time around. The long range models are suggesting +NAO in February 

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