Rising confidence in favorable period for snow Dec 15 - Jan 1

[Guest Pamela]

The CPC's composite 6 to 10 & 8 to 14 day outlooks look warm & wet in the eastern U.S.  That would cover the period from about December 2nd to December 10th. 

[Guest Pamela]

You should see some of the deleted posts about the upcoming warmth on the ensembles. 

 

You are brilliant...every weather related post you make proves it...but what would be the reason to delete posts that are just mentioning model output?  Unless it was a seriously misinterpreted regurgitation of model output...

[SnowGoose69]

Of course there's no guarantee about anything especially snows even if the pattern turns favorable. Last March and even late February were good examples of that.

However a better pattern makes it more likely we get something with blocking greatly increasing the odds. With blocking probably coming in January moreso than December it's not out of the question our first solid storm comes in January rather than December.

 

With the El Nino and likely -NAO it helps a bunch...right now I'd be surprised if we get out of December with less than about 3-5 inches of snow in NYC

[PB GFI]

The CPC's composite 6 to 10 & 8 to 14 day outlooks look warm & wet in the eastern U.S. That would cover the period from about December 2nd to December 10th.

I'm basing my opinion off the euro ensembles. The euro is very good and has been very good with its neg EPO placement in the last year but just washes troughs out on the EC In its day 7 plus

I don't know what it's problem is but troughs keep magically appearing in the east over time. I say magically but it's really a result of a neg EPO and that pumps the ridge. So today's ensembles dig the trough back S of the Aleutian s and that teleconnect to a Trough in the east

Even the gfs ensembles see that in its 15 day at 500 . Today's euro OP digs a trough back in next week. That's now on the ensembles and was no where to be found over the last 5 days for that time period

My opinion is the euro is great west of the Rockies in the LR and just plain bad on the EC.

IMO any warm ups are muted until I see the PAC blowup and with those SST s I think it's Gona be hard pressed to keep a ridge S of the Aleutian s

[jm1220]

You are brilliant...every weather related post you make proves it...but what would be the reason to delete posts that are just mentioning model output?  Unless it was a seriously misinterpreted regurgitation of model output...

Did you look yesterday about the supposedly mis-posted Weatherbell maps and where the R/S line is and who's biased for their backyard and who reported who and etc etc? Model related posts are what often flares up into s**t fits more than anything. 

[Guest Pamela]

Did you look yesterday about the supposedly mis-posted Weatherbell maps and where the R/S line is and who's biased for their backyard and who reported who and etc etc? Model related posts are what often flares up into s**t fits more than anything. 

 

I don't know much about that; though your emotive tone certainly lends credence to your second sentence. 

[PB GFI]

While the pattern favors the Aleutian Low coming back during December, the Euro is a

little different in its placement than the GFS at day 10. Notice how the Euro ensembles

have the low displaced further east so they result in more of a +EPO/+PNA pattern

instead of a -EPO/+PNA pattern. This would allow the lower 48 to be dominated

by milder Pacific Air for a time early in the month. The key is going to be where

the Aleutian low sets up for the sensible weather for the first half of the month.

EDH101-240.gif

The only thing I will say about that day 10 look is no where last week on any of the euro ensembles was there a trough in the east for next week. We have the current trough to deal w through sunday and lo and behold at 168 here comes another trough

So Yeh I think it's sensible to never expect a wire to wire cold look

I would b cautious about long warm ups in the east the pacific SST s are just too dominant a player here

my opinion is every time we warm it's muted and you're going to get a recycling not a pattern change

[PB GFI]

Taken verbatim the 10 day Euro is what can sometimes happen under a +PDO/El Nino pattern

when the Aleutian low is too far east and the EPO ridge can't build. At the very least, the coldest

air will remain locked up in Canada. Whether we are closer to normal averaged out or milder

for the first week to ten days of December remains to be seen.

It is always good to see Canada stay cold. Once we get a rise in the PNA that air will get displaced over the CONUS.

Next week the torch is off. If week 2 is dominated with PAC air by week 3 we may circle back .

[PB GFI]

It's only the start of the month so we have time to see how things verify and evolve from there.

But we'll have to see if the Aleutian Low is further east into the EPO region like the Euro ensemble

mean thinks that it will be. If that verifies, we would probably need a AL retrogression to get the

pattern moving in a colder direction again.

ecmwf-ens_z500a_nhem_11.png

If you go back 5 days ago and on the euro ensembles and look what it had for this upcoming wed at 500 you would b looking at that map.

Today there's a trough coming through the lakes for Wednesday now .

There's something wrong w the euro on the EC past day 7 .

I wanted to add the Canadian brings a new trough the lakes every 3 to 5 days with warm ups in between. So the pacific zonal flow post day 7 on the euro looks suspect to me

[CIK62]

Stormvista CFS Monthlies never show below normal 500mb heights in the northeast or almost anywhere else in the USA for their 8 month duration!   The closest we come to  normal heights is in Jan., June, and July now.   Hudson Bay is below normal at times in the winter.  But of course their depiction for this month was wrong, and that was the call in the short range.   Another screwup coming due to a new typhoon following a favorable course?   Comments?

[Yanksfan]

It is always good to see Canada stay cold. Once we get a rise in the PNA that air will get displaced over the CONUS.

Next week the torch is off. If week 2 is dominated with PAC air by week 3 we circle back to this we will have a chance to b cold from Nov 1 thru the end of Dec with 1 warm week.

" if " that how it plays out that's impressive

This upcoming pattern means business. It looks pretty damn dominate. With that in mind, its difficult to have a prolonged relaxed period which was once portrayed for the first half of december. Models have been backing off on the length of this so called mild period coming up. If anything, I can see temps in this time frame to be more seasonable if nothing else, before this loaded pattern ultimately hits us like a runaway freight train by mid month. Going forward, I feel we will have occasional relaxed periods during the winter albeit brief. 

[NaoPos]

Great disco in here guys. Just down thoughts to throw in.

The +PNA will probably be driven by the PDO /ssta along the west coast.

The mjo will be in phase 4-6 which Is a warm signal for the eastern conus. Once that gets around to 7-1 then game on. Just be careful

On the progression of it (modeled too fast). Give the pattern till about dec 20th to see the changes. The PAC will cooperate. Til then, warm signal with sneaky gradient setting up somewhere along the NE corridor.

[PB GFI]

It's still a day 10 forecast so we are just going to have to wait and see. But even though the GEFS have the Aleutian

low further west with more of a -EPO, the temperatures are just less warm than the Euro and not really cold for

this time of year here. So it looks like the choices for the first 10 days of the month will be close to normal

or above normal with not a really cold signal showing up for the December 1-10 average so far.

 

gfs-ens_z500a_nhem_41.png

You do have support week 2 on the Jma weeklies

For warmth through that period.

But I think it's a week max

[SnoSki14]

We may really be waiting another month before things get started. Looks like a meh type signal overall according to Euro ensembles even toward and post mid month. The NAO won't be going negative anytime soon and may not at all in December. I won't mind punting December if Jan-Feb could really produce but it will make me feel uneasy especially if it's late December and things still don't look great. 

[PB GFI]

Great disco in here guys. Just down thoughts to throw in.

The +PNA will probably be driven by the PDO /ssta along the west coast.

The mjo will be in phase 4-6 which Is a warm signal for the eastern conus. Once that gets around to 7-1 then game on. Just be careful

On the progression of it (modeled too fast). Give the pattern till about dec 20th to see the changes. The PAC will cooperate. Til then, warm signal with sneaky gradient

setting up somewhere along the NE corridor.

Unfortunately the euro propagating through 4 5 6 is prob right .

I believe ncep s were 4 then into the COD .

I think it's a 7 to 10 day stretch . Canada never warms . That means once the pna bulges down the shoot it will come. And if that's the 10 or 15th not sure.

But I like John mid month idea. It's just that next week is below normal so there's no more 2 week interlude I think it's down to 1.

And when models start shrinking the ideas of pattern retreats I tend to think that's a positive

[PB GFI]

We may really be waiting another month before things get started. Looks like a meh type signal overall according to Euro ensembles even toward and post mid month. The NAO won't be going negative anytime soon and may not at all in December. I won't mind punting December if Jan-Feb could really produce but it will make me feel uneasy especially if it's late December and things still don't look great.

Don't punt.

[REDMK6GLI]

Don't punt.

yea this statement is VERY premature. prudent to wait till the end of next week to wait and see if the mid month ramp up is right. that will bring us to December 6th, little more than a week from mid month.

[PB GFI]

Good post blue. When I first saw the SST s this fall for the winter and saw the warmer water displaced slightly further east than last year the weenie in me extrapolated a corresponding trough further east than last year. Which was centered over the lakes .
The risk is to warm to far east does bring the trough onto the west coast or at least to close for comfort.

A side note that MJO us hauling ass on the euro and will get to 7 before we know it.

I like the Canadian ensembles it pops the ridge and teleconnects the trough downstream I just watched the European all last winter verify great west of the Rockies on the LR but constantly correct on the EC.

If we were in a warm pattern and the European LR kept shrinking the coming cold I think we would be wary of a pattern change. Right now we are in a colder period and I like when I see muted warn ups.

 

[NEG NAO]

We may really be waiting another month before things get started. Looks like a meh type signal overall according to Euro ensembles even toward and post mid month. The NAO won't be going negative anytime soon and may not at all in December. I won't mind punting December if Jan-Feb could really produce but it will make me feel uneasy especially if it's late December and things still don't look great. 

If you punt December very good chance you are punting a good part of January and or  February - take a look at the snowfall history in NYC most of the above to much above snowfall winters included above to much above snowfall in December and many of the below normal snowfall winters had below normal or just normal snowfall in December 

 

http://www.erh.noaa.gov/okx/climate/records/monthseasonsnowfall.html

[Weathergun]

Latest GEFS has faster MJO progression into phases 7/8/1 than EC ENS. LIkely why the EC ENS has lower heights into GOA, in first half on the month. Also think this current stratospheric warming event, will wane without translating much to our side. So we will likely see -AO/-NAO regress during this period. Which will allow the ridge to build east, if the Euro GOA trough is correct.

 

 

 

[DTWXRISK]

 CORRECT !!

 

The Euro MJO forecasts. Very amplified signal possibly progressing into phases 7/81 later in the month:

 

 

[DTWXRISK]

  There is no basis  for this.....
 

If you punt December very good chance you are punting a good part of January and or  February - take a look at the snowfall history in NYC most of the above to much above snowfall winters included above to much above snowfall in December and many of the below normal snowfall winters had below normal or just normal snowfall in December 

 

http://www.erh.noaa.gov/okx/climate/records/monthseasonsnowfall.html

[uncle W]

1977-78 had a little snow in December and it ended up a great winter...2004-05 also...The long range ao/nao forecast are different every day...The pna looks good in the long range...a little torch during the first ten days of the month is normal...after that the game starts...

[DTWXRISK]

key  text  in red 

 

Yeah, it's important for the EPO to go negative and build over toward the Pole and Greenland at some point

during an El Nino/+PDO December. Otherwise, the Aleutian low cranks too close to the West Coast

and mild Pacific flow dominates. The December 2002, 2009 pattern is what you want to see emerging

as the month progresses. The other El Nino Decembers couldn't close on the more favorable pattern

so the best action was more back-loaded toward later in those winters. Hopefully, the October blocking

signal pays some dividends December 15-31. There is plenty of time to watch how this evolves.

 

favorable December El Nino composite

 

cold.png

 

unfavorable

 

Warm.png

[DTWXRISK]

i see someone  else  has  found those wonderful  ecmwf maps from france....  they   ARE  great  and give   different  perspective from the  n american one  we are use to. This can  be useful 

 

 

While the pattern favors the Aleutian Low coming back during December, the Euro is a 

little different in its placement than the GFS at day 10. Notice how the Euro ensembles

have the low displaced further east so they result in more of a +EPO/+PNA pattern

instead of a -EPO/+PNA pattern. This would allow the lower 48 to be dominated

by milder Pacific Air for a time early in the month. The key is going to be where

the Aleutian low sets up for the sensible weather for the first half of the month.

 

EDH101-240.gif

[uncle W]

remember last month it looked like November was going to start out warm?...November was forecast to be mild...We are having one of the colder snowier Novembers in recent times...the last three Novembers have been cold...I doubt December ends up mild...but it could if things go wrong...the worst it can be is like 1965 and 1982 with 60 degree Christmas's...

[DTWXRISK]

  GREAT  POSTS  BLUE WAVE

 a couple of  points. FIRST...   IF/ when the MJO  swings  around  to  PHASE  7   then  8  that does  happen until DEC 11-12. From  there  it will take  a few days  before we see the impact on the pattern in the CONUS  so we are  talking  DEC 15 or so.

SECOND...  I think the  euro  mean day 10 is  close to being right .  To me  its been  clear for a while that 1st  half of  DEC 2014  was  always  going to be mild or at least not cold. This has been reflected in my winter  forecast.

THIRD....  IF you re- consider the  favorable -EPO/ +PNA/-NAO map   posted  above the  STRONGEST  anomalies is  NOT  a classic  negative   NAO   at all.. it  almost UK Scandinavian ridge. That is NOT  that great  for   eastern US

 

 

FOURTH...  NOV  2014  was kind of   freak or Black  swan event  triggered by the  924 mb Low in the Bering  sea which  was a EXTREME  end of the bell curve  event.  Four arctic outbreaks...  in NOV? 



 

It's only the start of the month so we have time to see how things verify and evolve from there.

But we'll have to see if the Aleutian Low is further east into the EPO region like the Euro ensemble

mean thinks that it will be. If that verifies, we would probably need a AL retrogression to get the

pattern moving in a colder direction again.

 

ecmwf-ens_z500a_nhem_11.png

[NEG NAO]

  There is no basis  for this.....

 

Look at this link and look at all the below normal Decembers in NYC - below normal is less then 4.8 inches - then get back to me after you do your analysis - punting December in NYC in my book is anything less then 4.8 inches -I think some of the problem is some folks around here think 12 inches is the norm - they need to get back down to earth.......

 

http://www.erh.noaa.gov/okx/climate/records/monthseasonsnowfall.html

[SnowGoose69]

Look at this link and look at all the below normal Decembers in NYC - below normal is less then 4.8 inches - then get back to me after you do your analysis - punting December in NYC in my book is anything less then 4.8 inches -I think some of the problem is some folks around here think 12 inches is the norm - they need to get back down to earth.......

 

http://www.erh.noaa.gov/okx/climate/records/monthseasonsnowfall.html

 

The snow total is not always relevant, December 2003 and 48 were both bad patterns but both months were snowy, meanwhile December 89 was great and hardly any snow fell.

[uncle W]

I'd rather have a lousy pattern with snow than a good pattern without it...1951 had the lousiest pattern of all for the first week and some and it got a storm on the 14th with snow/sleet and rain...3" fell...even 1982 with 70 degree temperatures had a snowstorm a week later...we are going thru an up and down sensible weather pattern and it probably will continue for a while...The cold we are getting tonight is colder than some recent Novembers cold spells...