December 2022

[Ralph Wiggum]

19 minutes ago, MJO812 said:

We should all hang in there and be patient. Do you really think the models will be wrong with the pattern change and many meteorologists also ?

Probably not. But there have been times when it happened...when some oddity like the MJO or rogue Rosby Wave behavior or a SSWE mucks things up. Let's remain cautiously optimistic.....and patient of course.

[SnowGoose69]

9 hours ago, RedSky said:

Any chance this is the new GFS that sucks because it made some radical changes.

 

 

The strangest thing in the last week is how there has not really been more than 1-2 GFS Op runs showing a good pattern past D10 while the GEFS more or less consistently has, the 06Z run disparity between the Op and ensemble is maybe the best example of that 

[Brian5671]

48 minutes ago, MJO812 said:

We should all hang in there and be patient. Do you really think the models will be wrong with the pattern change and many meteorologists also ?

Certainly possible.  Pattern changes were forecast in years like 01-02, 05-06, 11-12, 19-20 that never came and were always 10 days out.  Twitter and Facebook posts have made it all the worse with hype and clickbait.     Keep expectations low for now, it's still early winter so lots of time for the goods to be delivered.

[wdrag]

Patience, what can go wrong and lack of southern stream and +PNA are important considerations for me to reduce the amped thoughts of our future weeks 2-4. 

I sure hope all the LR -NAO discussion implications pays off.  Right now, I'd like to see some advisory ice/snow I84 in the transition (by the 10th).  So far modeling is not doing it yet (through 06z/3).  

Looking well beyond even with the -NAO block, the 00z/2 GEFS through 800 hours (Jan 5) looks a little light on positive snow depth change, even given climo.  Purple begins 6"... our area is basically ensembled less than 6 by Jan 5. 

I think, we need a southern streamer to help park the high to our north in the confluence of the Canadian depressed jet and the subtropical,  and/or a big +PNA to dig the trough well south into the eastern USA.  So far, not evident.  

I'll keep looking at the modeling but not promising big snow for anyone, at least not yet.  Instead will hang my hat on little wintry events. 

 

[bluewave]

The reason we are seeing the models push things back is that the useful skill days 11-15 is often too low to detect a pattern change.  A useful skill score is defined as 0.6 or greater. So the best that the EPS can do in most cases is about 10.5 days. The GEFS and GEPS are about a day behind at 9.5. So even the highest scoring EPS day 11-15 is still too low skill to detect a pattern change from 1-5 and 6-10 with certainty. So this is why a pattern change showing up day 11-15 needs to make it to 6-10 to be believable. It’s also why we start to see big jumps sometimes right around day 8-10. It’s just the way these models are constructed. But that isn’t to say that a pattern change on the Pacific side can’t eventually happen. Just that you want to see it survive to day 8-10 in order to lock in the specific date.

 

https://www.emc.ncep.noaa.gov/users/verification/headlines/

 

Description: An Anomaly Correlation Coefficient (ACC) score of 1.0 indicates that the forecast was highly accurate (i.e., essentially perfect) across the Northern Hemisphere. A model is said to have "useful skill" when the ACC score is greater than or equal to 0.6. This plot shows the average forecast day (i.e., forecast length) when the ACC score falls below 0.6 and the GFS loses useful skill

 

EPS in green and GEFS black and GEPS red
 

[WX-PA]

27 minutes ago, SnowGoose69 said:

 

The strangest thing in the last week is how there has not really been more than 1-2 GFS Op runs showing a good pattern past D10 while the GEFS more or less consistently has, the 06Z run disparity between the Op and ensemble is maybe the best example of that 

Good point ..the system on December 8th the GFS OP is the only model that doesn't surpress it, and that's 5 days out. I think the new GFS leaves a lot to be desired, so far

 

[Great Snow 1717]

1 hour ago, MJO812 said:

We should all hang in there and be patient. Do you really think the models will be wrong with the pattern change and many meteorologists also ?

We all know that has never happened before....

[MJO812]

4 minutes ago, Great Snow 1717 said:

We all know that has never happened before....

It's only early December 

[the_other_guy]

1 hour ago, Brian5671 said:

first half of the month will be +2 to +3 that will be hard to erase.  

I mean, if it was November, it would’ve been erased.

When was last time we have had a well BN (or normal) second half of Dec?

[North and West]

Certainly possible.  Pattern changes were forecast in years like 01-02, 05-06, 11-12, 19-20 that never came and were always 10 days out.  Twitter and Facebook posts have made it all the worse with hype and clickbait.     Keep expectations low for now, it's still early winter so lots of time for the goods to be delivered.

Have we mentioned sun angle yet


.

[Uniblab]

2 minutes ago, North and West said:

Have we mentioned sun angle yet


.

Soon. 

[Great Snow 1717]

11 minutes ago, MJO812 said:

It's only early December 

..and what does that have to do with the models and mets possibly being wrong???...

[TWCCraig]

7 minutes ago, the_other_guy said:

I mean, if it was November, it would’ve been erased.

When was last time we have had a well BN (or normal) second half of Dec?

2017

Though that was more/less a below average month in general with a few warmups here and there. Last week of Dec was very cold, over a week of sub-freezing highs

[Brian5671]

7 minutes ago, the_other_guy said:

I mean, if it was November, it would’ve been erased.

When was last time we have had a well BN (or normal) second half of Dec?

Dec 2010.   Dec 2017 was cold the last week into Jan with the blizzard ending that cold spell.

[MJO812]

8 minutes ago, Great Snow 1717 said:

..and what does that have to do with the models and mets possibly being wrong???...

It's not even winter and we know how the models can adapt as soon as we get closer 

[Great Snow 1717]

Just now, MJO812 said:

It's not even winter and we know how the models can adapt as soon as we get closer 

that does not answer my question....you are essentially doing what victims of fraud do....they want to believe so badly that they discount unfavorable possibilities/outcomes...

[Great Snow 1717]

56 minutes ago, wdrag said:

Patience, what can go wrong and lack of southern stream and +PNA are important considerations for me to reduce the amped thoughts of our future weeks 2-4. 

I sure hope all the LR -NAO discussion implications pays off.  Right now, I'd like to see some advisory ice/snow I84 in the transition (by the 10th).  So far modeling is not doing it yet (through 06z/3).  

Looking well beyond even with the -NAO block, the 00z/2 GEFS through 800 hours (Jan 5) looks a little light on positive snow depth change, even given climo.  

I think, we need a southern streamer to help park the high to our north in the confluence of the Canadian depressed jet and the subtropical,  and/or a big +PNA to dig the trough well south into the eastern USA.  So far, not evident.  

I'll keep looking at the modeling but not promising big snow for anyone, at least not yet.  Instead will hang my hat on little wintry events. 

 

As always, thanks for sharing your thoughts with the rest of us!

[bluewave]

It’s been tough to get colder patterns later in December since that period is warming more quickly than the early part of the month since 1981. The late December Arctic cold of 2017 was one of the greatest temperature outliers of recent times. This is also why we have seen so much warmth around the solstice to Christmas in recent years.

 

 

[CIK62]

To make you feel better.      This is the mate to the OP T's posted earlier.     Maybe we get to 25 for the lowest T.        It still only has a slight chance for any snow, however........not shown.

[EastonSN+]

Iist say I woke up very pleased that the GEFS finally caved to the EPS w/r/t the PAC. 

Both have the block, so that's of the most confidence.

I honestly feel like everything is going a according to how all of them Mets on this board have been saying. Will take a few weeks, all said beyond the 15th. 

I have seen nothing yet that can ruin the upcoming pattern.

Now yes, nothing in life or weather are guaranteed, and there is a SMALL chance that it's a complete failure, but until we see any signs of that (GEFS and EPS Lossing the 6z look), or any MET on this board says we are in trouble, I see no reason to worry unless you were hopeful for the change before the 15th.

You are seeing things get pushed back which is common and we see it every year, even when we are in a good pattern the models push back the collapse of said pattern.

All is on schedule IMO.

[EastonSN+]

One thing to add, most failures of the past were different. 19/20 the change was never in the ensembles but rather the weeklies. This change is on the ensembles.

01/02 was similar.

12/13 is the best representation of what can go wrong, but we all had snow that month so it was not a complete failure, and half of this forum had above average snowfall for the year thanks to repeat blocking and snowfall in FEB and March. I would sign up for that failure any day.

[EastonSN+]

Ha last point. As Forky alluded to -PNA can HELP in some cases. As long as it's not moderately (or the monstrosity of last December), we will be fine.

[wkd]

1 hour ago, Ralph Wiggum said:

Probably not. But there have been times when it happened...when some oddity like the MJO or rogue Rosby Wave behavior or a SSWE mucks things up. Let's remain cautiously optimistic.....and patient of course.

You say this EVERY winter!!.   Very rarely do you post a positive future outlook.  It's always dampen your expectations, usually because of a SER. 

[bluewave]

18 minutes ago, EastonSN+ said:

Ha last point. As Forky alluded to -PNA can HELP in some cases. As long as it's not moderately (or the monstrosity of last December), we will be fine.

The -PNA is more of a December issue. So we won’t get much snow this month if the Pacific pattern change keeps getting pushed back. But it’s less of an issue in JFM. So root for one of those day 11-15 forecast to finally verify.

[EastonSN+]

Just now, bluewave said:

The -PNA is more of a December issue. So we won’t get much snow this month if the Pacific pattern change keeps getting pushed back. But it’s less of an issue in JFM.

Thanks that's also a good point as to why this "delay" is a good thing. We want this pattern to mature as late as possible.

 

[SnoSki14]

4 minutes ago, bluewave said:

The -PNA is more of a December issue. So we won’t get much snow this month if the Pacific pattern change keeps getting pushed back. But it’s less of an issue in JFM. So root foe those 11-15 day weenie runs to eventually verify.

We've had a lot more luck in January than December and it looks like that will be the case again. 

January may actually turn out really well if the blocking sticks around and we don't have to rely on the Pacific as much 

[Ralph Wiggum]

11 minutes ago, wkd said:

You say this EVERY winter!!.   Very rarely do you post a positive future outlook.  It's always dampen your expectations, usually because of a SER. 

Not 'every' winter. Dont speak in absolutes. But sure I play things cautiously. I wouldnt call it pessimism. But Ninas require alot of patience especially wrt the SER. There really is no getting around that. This isnt a shut the blinds pattern either....but I guess you skipped the part where I mentioned this incessantly too?

[Itryatgolf70]

4 hours ago, EasternLI said:

Absolutely loving the resilient ridging near the Urals. That's always a good thing. 

I personally would like to see more Alaskan ridging instead of Aleutian ridging, which the EPS is trying to do out towards day 14-15. 

[bluewave]

28 minutes ago, EastonSN+ said:

Thanks that's also a good point as to why this "delay" is a good thing. We want this pattern to mature as late as possible.

 

Break out the snow shovels if a pattern like this starts showing up day 8-10. The composite below is the last 10 December 4”+ snowfalls in NYC since 2002. The two most important features are a -AO and Rockies Ridge.  I am judging the +PNA by a ridge axis near the Rockies. The raw PNA numbers aren’t as important. But they are usually neutral -0.5 to +0.5 and higher with a ridge in the Rockies. A trough just off the West Coast or near Vancouver can be fine. We just don’t want a big digging trough over the Rockies. 

Last 10…4”+ December snows in NYC since 2002

 

[forkyfork]

3 minutes ago, bluewave said:

Break out the snow shovels if a pattern like this starts showing up day 8-10. The composite below is the last 10 December 4”+ snowfalls in NYC since 2002. The two most important features are a -AO and Rockies Ridge.  I am judging the +PNA by a ridge axis near the Rockies. The raw PNA numbers aren’t as important. But they are usually neutral -0.5 to +0.5 and higher with a ridge in the Rockies. A trough just off the West Coast or near Vancouver can be fine. We just don’t want a big digging trough over the Rockies. 

Last 10…4”+ December snows in NYC since 2002

 

boxing day happened when the west coast trough sharpened and retrograded. it spiked a rockies ridge which sent a shortwave down the midwest