December 2022

[lee59]

15 minutes ago, Volcanic Winter said:

Isn’t that just a resolution issue though? Because back then, they didn’t have the tools to observe the mechanism behind those patterns the way we do today. And I think there are plenty of examples of seasons that go back and forth, like last winter where January was a stark reversal from December. 

Yea there are reasons why this happens but to a casual weather observer it is a pretty good rule of thumb, stormy on one coast and quiet on the other. It can go back and forth but it is not common for both coasts to be in the action zone at the same time.

[SnoSki14]

39 minutes ago, Allsnow said:

Gefs have continued to look poor in the pac area. Any changes in that area now kicked to the 18-19th

I don't think we're gonna get a good pacific this season. The best we can hope for is that it's not overly hostile.

[Stormlover74]

Gfs continues the dual rainstorm idea for this week

[MJO812]

8 minutes ago, Stormlover74 said:

Gfs continues the dual rainstorm idea for this week

Further south

Gfs is different once again

[bluewave]

I will give the models credit for getting the -NAO and -AO pattern correct. But both the GEFS and EPS have been underestimating the strength of the -PNA trough days 11-15. So we could have another warmer than average December if the cooldown keeps getting pushed back.
 

New 240 hr forecast for 12-14

 

Old 360 hr forecast 12-14

 

 

 

[MJO812]

Few threats to watch mid month on the GFS

Cmc has a big coastal at 240

These runs keep changing every suite. 

[MANDA]

27 minutes ago, bluewave said:

I will give the models credit for getting the -NAO and -AO pattern correct. But both the GEFS and EPS have been underestimating the strength of the -PNA trough days 11-15. So we could have another warmer than average December if the cooldown keeps getting pushed back.
 

New 240 hr forecast for 12-14

 

Old 360 hr forecast 12-14

 

 

 

Moral of all of this is:

-Not all -NAO / - AO's are created equal and with a -PNA may not deliver the desired results.  EPO is also a factor but I believe PNA is more crucial.  By the end of this coming week we'll have a rather clear view to 12/18 or so.   If December is going to be "saved" in terms of BN temperatures and at least normal snow if will be in the period 12/20 - 12/31.  It always has been that period but originally the period starting 12/7 was supposed to start trending at least colder.  That is now delayed.  Don't want any additional delays beyond 12/18.  At least there is no blow torch in the cards.  Next 7-10 days look to average modestly above normal, on the order of about +2.  That will leave the first half of December above.  I think if things fall into place we could beat the positives back to normal or a little below for the month but until things become clearer that is not a given.  Leaning toward a solid period of BN temps last 1/3 of the month but confidence only about 60% as of now.

[eduggs]

On 11/30/2022 at 12:14 AM, eduggs said:

There looks to be some longshot potential for something wintry mid to late week next week. Some encouraging hints on the op runs, but nothing specific to get excited about yet.

I still think this is true - but it would be late week not mid-week. The CMC, ICON, and EC bring frozen precip. near or to the area. It's exciting to get a wintry threat as close as 5 days out! That said, the GFS remains much warmer and wetter and the other models have been shifting northward for a few cycles. My gut says this ends up rain with a few high elevation cat paws or sleet pellets. I expect high inter-cycle and inter-model variability in this regime.

[eduggs]

1 week of near-continuous precipitation (mostly rain) on the GFS is 

I think I would be mildly excited about snow potential if I lived in the higher elevations of northern or western New England. But if I kind of squint at the charts I can even imagine a long-duration fantasy snow scenario for the Cities. To get any local snow out of the medium range I think we would need the cold air source to push a little further south than currently modeled. 

[cleetussnow]

Army Navy next weekend looks nautical.  Like last year.  Storm arrives Friday (when we set up our tailgate) then backs up  saturday with the LP overhead.  40s and driving rain winds out of the north. Terrific.  

[IrishRob17]

3 minutes ago, cleetussnow said:

Army Navy next weekend looks nautical.  Like last year.  Storm arrives Friday (when we set up our tailgate) then backs up  saturday with the LP overhead.  40s and driving rain winds out of the north. Terrific.  

GO ARMY BEAT NAVY

[SnoSki14]

16 minutes ago, MJO812 said:

Few threats to watch mid month on the GFS

Cmc has a big coastal at 240

These runs keep changing every suite. 

Not much frozen in this pattern. It's a stormy but mild look as pacific jet brings the storms, the block helps to amplify them but there's no cold air to be found. 

[eduggs]

15 minutes ago, MJO812 said:

These runs keep changing every suite. 

Should we expect otherwise? It would be a fluky coincidence to have two relatively unchanged runs at the surface 7+ days out. Small changes aloft can lead to large changes locally at the surface.

[Stormlover74]

1 minute ago, SnoSki14 said:

Not much frozen in this pattern. It's a stormy but mild look as pacific jet brings the storms, the block helps to amplify them but there's no cold air to be found. 

Really stormy. Pressure is below 1000mb like half the run

[MJO812]

18 minutes ago, SnoSki14 said:

Not much frozen in this pattern. It's a stormy but mild look as pacific jet brings the storms, the block helps to amplify them but there's no cold air to be found. 

You are basing it off the GFS which chances every 6 hours 

[Wxoutlooksblog]

Emerging is a blocky pattern which can yield big and long duration events depending on how the overall weather pattern sets up but with the mostly strongly -PNA odds favor storms tracking initially well to the north and west of the forecast area then they run into the block and tend to re-develop south and east on the east coast near the east coast, etc. But it is the precise location of where these storms re-develop which will determine precip type. Factors stacked against us include higher than normal heights over the southeast tending to force re-development further north and the -PNA. It could take most of the winter season before we get a system in this pattern to re-develop in the sweet spot but not always. In the meantime a very rainy dreary and mild week ahead.

WX/PT

 

[CIK62]

HORROR SHOW Continues.....................for those who like snow and cold.     If correct, the 27 low from Nov. 21 is quite alive one month later.

[HeadInTheClouds]

49 minutes ago, MJO812 said:

Few threats to watch mid month on the GFS

Cmc has a big coastal at 240

These runs keep changing every suite. 

We know operationals are garbage beyond 5 days. I still have no idea why the GFS goes out 16 days. It's as useless as tits on a bull. 

[SnoSki14]

11 minutes ago, CIK62 said:

HORROR SHOW Continues.....................for those who like snow and cold.     If correct, the 27 low from Nov. 21 is quite alive one month later.

This is the dreaded pacific puke pattern in a nutshell.

Stormy but never cold enough for snow and not pleasant enough to enjoy either. It's basically March weather all winter. 

This is still just a forecast though. No guarantee it plays out that way either 

[EastonSN+]

18 minutes ago, Wxoutlooksblog said:

Emerging is a blocky pattern which can yield big and long duration events depending on how the overall weather pattern sets up but with the mostly strongly -PNA odds favor storms tracking initially well to the north and west of the forecast area then they run into the block and tend to re-develop south and east on the east coast near the east coast, etc. But it is the precise location of where these storms re-develop which will determine precip type. Factors stacked against us include higher than normal heights over the southeast tending to force re-development further north and the -PNA. It could take most of the winter season before we get a system in this pattern to re-develop in the sweet spot but not always. In the meantime a very rainy dreary and mild week ahead.

WX/PT

 

Would be brutal is we get this rare type of blocking and have mostly rain this winter. 97/98 was that way but the PAC was much worse.

[brooklynwx99]

the 12z GEFS is pretty interesting with the weekend storm... definitely starting to see some slowing down and amplifying of this shortwave as we move forward in time

also really nice HP location and strength to bring in some cold air. this bears watching IMO

[the_other_guy]

So the pattern change 3 weeks out went bust? Go figure! 

48F to kick of a nice November, ahem December week.

Wet, wild, and mild continue! 

[MJO812]

5 minutes ago, the_other_guy said:

So the pattern change 3 weeks out went bust? Go figure! 

48F to kick of a nice November, ahem December week.

Wet, wild, and mild continue! 

What's a bust ?

[donsutherland1]

To date, Atlantic blocking has developed (AO: -1.913; NAO: -1.377). That blocking is forecast to strengthen and slowly retrograde. The PNA remains negative (-0.742) but is forecast to slowly rise toward neutral levels (probably getting there around December 20). The strong blocking typically leads to the development of elongated troughs beneath the block (showing up on the latter periods of the ensembles).

Below are illustrations of December cases where the AO bottomed out between -5.000 and -3.500 or peaked between +3.500 and +5.000. Even more extreme cases where the AO fell below -5.000 or rose above +5.000 were excluded. Some NYC statistics are provided for each.

Personally, I'd rather be in a situation where the AO is forecast to fall below -3.000 then the opposite scenario. There are no guarantees, but at least the odds of snow and cold much better in the former case than the latter. In cases where the AO falls to -4.000 or below in December for the minimum value, 40% of cases had 10" or more snow and 50% had 8" or more snow.

[SnowGoose69]

One notable change the last 48 hours is the GEFS now almost unanimously agree on the PNA going to neutral, the spread with the crazy -2s 12/10-12/15 are now gone

[EasternLI]

Zero issues from my point of view. I love that the -PNA showed up for early December. I have an increasing feeling that it pays us dividends, later. This is not last year. Not even close. Different animal. 

[eduggs]

12z EC shifted a little south with the weak upper level wave sliding east at the end of the week, reversing a northward trend of the past few cycles. This will likely leave precip. just south of us, but I prefer this scenario to the GFS washout. It's also a colder solution, which IMO increases the changes of wintry precip. on Fri or Friday night. Right now I'd prefer to get the cold first and worry about the precipitation later.

[eduggs]

Regardless of the surface outcome, I like this 12z EC run so far. It's the first OP run in a while that I've been excited about. Maybe it's the Irish Coffee I just drank putting me in an optimistic mood... not really sure.

[eduggs]

The block is blocking on the EC. We have cold/coldish air!

[MANDA]

18 minutes ago, SnowGoose69 said:

One notable change the last 48 hours is the GEFS now almost unanimously agree on the PNA going to neutral, the spread with the crazy -2s 12/10-12/15 are now gone

If this is real, and I suspect it is then this is going to help the cause.  Neutral or weak positive is better than a -1 or greater.