December Med/Long Range Discussion

[WinterWxLuvr]

Ok, the day 5 forecast now puts us in December.

Good luck to us going forward.

Mods please pin this thread and lock the November thread.

[Bob Chill]

2 minutes ago, Bob Chill said:

I'm not sure why anyone would be pessimistic right now. Maybe I don't see things the same way. Early Dec is absolutely not an easy snow period and rarely a 5"+ event period. 

What I see coming up seems pretty decent for our typical conversational snow events. From the 5th onward the majority of the conus and Canada will have below normal temps. Including our area. A 1-2" event could easily happen with the temp and height patterns being advertised. 

Part of the reason the AO is forecast to go neutral or + is because a trop pv lobe sets up shop north of HB. It's a tradeoff. The lobe brings some good cold into north central Canada. The squeeze between that and the epo ridge sets up a pretty solid cross polar flow too. 

Gefs/eps agree that 850 temps are below normal after the warmup next week. Mean 0c line stays south from d8 through the ends of the runs. 

The period coming up looks like one of the better Dec patterns we've seen since 2010 or 2013. If the look holds it will be better than 2013 because that was a volatile month overall. 

 

[WinterWxLuvr]

6 minutes ago, Bob Chill said:

 

So glad you moved your post.  It's excellent and as I read it I was thinking about copying it over here.

Great thread starter Bob.

[PaEasternWX]

20 minutes ago, WinterWxLuvr said:

Ok, the day 5 forecast now puts us in December.

Good luck to us going forward.

Mods please pin this thread and lock the November thread.

Okay I now see, apparently you have to make it 5 days before.

[Bob Chill]

46 minutes ago, WinterWxLuvr said:

So glad you moved your post.  It's excellent and as I read it I was thinking about copying it over here.

Great thread starter Bob.

It's all about perspective right? I mean just thinking about a repeat of Dec 14 or 15 is depressing. 

For a month straight this fall all we heard about was how the pac jet is hideous and ruining our party. Well, that regime is over for the time being. Big time over with that stout Aleutian ridge presing poleward. I'm not sure I get the worry about the ao/nao. Until a se ridge starts showing up its not a big deal at all. Just speaking over the next couple weeks though. 

The low heights centered off NF keeps heights in the east supressed. It's a good feature. A WAR would be a disaster but no sign of that anywhere. 

If expectations are set at getting a big miller A then yea, the pattern sucks.  I just want to get on the board before mid month. That's a win in general.  Seems like an equal odds proposition to me right now. 

 

[mitchnick]

36 minutes ago, Bob Chill said:

It's all about perspective right? I mean just thinking about a repeat of Dec 14 or 15 is depressing. 

For a month straight this fall all we heard about was how the pac jet is hideous and ruining our party. Well, that regime is over for the time being. Big time over with that stout Aleutian ridge presing poleward. I'm not sure I get the worry about the ao/nao. Until a se ridge starts showing up its not a big deal at all. Just speaking over the next couple weeks though. 

The low heights centered off NF keeps heights in the east supressed. It's a good feature. A WAR would be a disaster but no sign of that anywhere. 

If expectations are set at getting a big miller A then yea, the pattern sucks.  I just want to get on the board before mid month. That's a win in general.  Seems like an equal odds proposition to me right now. 

 

Couldn't agree more Bob. I haven't been posting much simply because it's too early.  He!!, even the great winters (as in run of the mill AN snows and historic) didn't get going until the first week of December,  and many not until late December or January. Give it at least 2 weeks before legit antsy in my eyes.

[packbacker]

39 minutes ago, Bob Chill said:

It's all about perspective right? I mean just thinking about a repeat of Dec 14 or 15 is depressing. 

For a month straight this fall all we heard about was how the pac jet is hideous and ruining our party. Well, that regime is over for the time being. Big time over with that stout Aleutian ridge presing poleward. I'm not sure I get the worry about the ao/nao. Until a se ridge starts showing up its not a big deal at all. Just speaking over the next couple weeks though. 

The low heights centered off NF keeps heights in the east supressed. It's a good feature. A WAR would be a disaster but no sign of that anywhere. 

If expectations are set at getting a big miller A then yea, the pattern sucks.  I just want to get on the board before mid month. That's a win in general.  Seems like an equal odds proposition to me right now. 

 

Yep, agreed!  Just wanted to avoid a horror pattern starting in Dec and per the modeling we look we should (knock on wood).  

[WxUSAF]

Nice post, Bob.  It's a bit of a double edged sword with the PV coming over to our side of the pole. It gets the source region cold, but we lose the -NAO. Combine that with the -PNA sets up the risk of the SE ridge, but as you say the low heights in the Canadian maritimes seem to suppress it for now.  Have to see how things evolve.

[WinterWxLuvr]

1 hour ago, PaEasternWX said:

Okay I now see, apparently you have to make it 5 days before.

LOL.  Well that's part of it

[psuhoffman]

I agree bob and I'm not panicking yet just quietly waiting to see how this shakes out. However when looking at the analogs to this year the better snow years where ones where we had significant snow by mid December. Also we need a -nao because a -Pna + nao is going to be a struggle. So seeing the nao break down in the long range is a little unsettling to me. I'm still in a wait and see mode but if we get to mid December with no snow and the pattern looks bad we can probably kiss the better snow analogs goodbye and accept this year will probably be a struggle to get much significant snow. This isn't a year I expect we can go into January doing bad and then turn it around. 

[frd]

1 hour ago, psuhoffman said:

I agree bob and I'm not panicking yet just quietly waiting to see how this shakes out. However when looking at the analogs to this year the better snow years where ones where we had significant snow by mid December. Also we need a -nao because a -Pna + nao is going to be a struggle. So seeing the nao break down in the long range is a little unsettling to me. I'm still in a wait and see mode but if we get to mid December with no snow and the pattern looks bad we can probably kiss the better snow analogs goodbye and accept this year will probably be a struggle to get much significant snow. This isn't a year I expect we can go into January doing bad and then turn it around. 

Seems that the recent Euro run and its ensembles are losing the - AO and the - NAO as we end the first week of December. I wonder the effects of the + QBO on this, if any.  

I read here on the board that in years with a + QBO there is hardly any PV displacements prior to Jan 1 st ( only 6 since the late 1950's  per Isotherm ) and only one PV split before January 1 st occuring in a + QBO dating back as well to the late 1950's. So,  like Isotherm said, a very rare event indeed.  

Also, as I mentioned a couple days ago,  a AO that averages positive during the first ten days of December is an unfavorable signal for the remainder of the month per Bluewave.   

 

  

  

[Bob Chill]

@psuhoffman

For the record, I've never felt this winter was going to be a good snow year. I just don't think it will be a disaster. 

I does seem a little ironic that there was so much griping about the trop pv and coldest air stuck in Siberia for so long and now that's flipping to NA. But it's still bad. Lol. Kinda exemplifies how tricky a good setup in the east is. At least south of SNE anyways. 

Canada is poised to load up on the cold. If it happens then part of our usual problems will be resolved. In fantasy weenie land the pv gets pinned underneath blocking later and we freeze. Lol. 

[CAPE]

6 hours ago, psuhoffman said:

I agree bob and I'm not panicking yet just quietly waiting to see how this shakes out. However when looking at the analogs to this year the better snow years where ones where we had significant snow by mid December. Also we need a -nao because a -Pna + nao is going to be a struggle. So seeing the nao break down in the long range is a little unsettling to me. I'm still in a wait and see mode but if we get to mid December with no snow and the pattern looks bad we can probably kiss the better snow analogs goodbye and accept this year will probably be a struggle to get much significant snow. This isn't a year I expect we can go into January doing bad and then turn it around. 

The -NAO does break down, but if you roll the pattern forward using the weeklies, it comes back around Xmas and beyond, and at the same time there is marked improvement with the EPO/PNA. Yeah it is a ways out there, but seeing that being advertised as a possible evolution to the pattern is better than some alternatives I can think of. I am definitely not discouraged, and like Bob, I am not expecting a banner snow year. Given your location though, you could easily end up at climo or even somewhat below, and make most of the rest of us in this sub forum envious.

[WEATHERBUFF]

7 minutes ago, C.A.P.E. said:

The -NAO does break down, but if you roll the pattern forward using the weeklies, it comes back around Xmas and beyond, and at the same time there is marked improvement with the EPO/PNA. Yeah it is a ways out there, but seeing that being advertised as a possible evolution to the pattern is better than some alternatives I can think of. I am definitely not discouraged, and like Bob, I am not expecting a banner snow year. Given your location though, you could easily end up at climo or even somewhat below, and make most of the rest of us in this sub forum envious.

I do believe location means more this year, interior sections will be okay as they are in a Nina. The coastal plain will need blocking.

[WinterWxLuvr]

1 hour ago, Bob Chill said:

@psuhoffman

For the record, I've never felt this winter was going to be a good snow year. I just don't think it will be a disaster. 

I does seem a little ironic that there was so much griping about the trop pv and coldest air stuck in Siberia for so long and now that's flipping to NA. But it's still bad. Lol. Kinda exemplifies how tricky a good setup in the east is. At least south of SNE anyways. 

Canada is poised to load up on the cold. If it happens then part of our usual problems will be resolved. In fantasy weenie land the pv gets pinned underneath blocking later and we freeze. Lol. 

Canada cold is a very good thing.

Snowfall predictions are hit and miss. So much of it depends on luck, timing up a little precip with moisture.  But the alternative, trying to time cold up with precip is even tougher.  Persistent cold works well as it did in 14-15.

And as always, I'm going to point out that precip is the usual enemy.  If we get enough of it in a neutral or low end Nina I think we'll be happy in the end.

[Bob Chill]

31 minutes ago, WEATHERBUFF said:

I do believe location means more this year, interior sections will be okay as they are in a Nina. The coastal plain will need blocking.

It's a paltry nina at best. It may never even meet official nina status. Latest trend is up in enso regions. I'm not discounting that enso ssta's won't play a factor but the pdo is making a massive comeback after complete dessimation. Thats anti nina. It's a tricky year and far from classic anything nino/nina. 

Imho- the MA fate is more in the hands of chaos and making it happen when things are semi aligned. Interior is almost always favored in any year down here.  I doubt this year will be looked back on as "it was a Nina and behaved like one".

 

[psuhoffman]

1 hour ago, Bob Chill said:

@psuhoffman

For the record, I've never felt this winter was going to be a good snow year. I just don't think it will be a disaster. 

I does seem a little ironic that there was so much griping about the trop pv and coldest air stuck in Siberia for so long and now that's flipping to NA. But it's still bad. Lol. Kinda exemplifies how tricky a good setup in the east is. At least south of SNE anyways. 

Canada is poised to load up on the cold. If it happens then part of our usual problems will be resolved. In fantasy weenie land the pv gets pinned underneath blocking later and we freeze. Lol. 

I am still not throwing in the towel this moves towards a better look but I was feeling better a week ago when the prospect of a -nao into December looked likely.  It may turn into something better later in the month and that could be a blessing in disguise so I'm just in wait and see mode.  

6 hours ago, frd said:

Seems that the recent Euro run and its ensembles are losing the - AO and the - NAO as we end the first week of December. I wonder the effects of the + QBO on this, if any.  

I read here on the board that in years with a + QBO there is hardly any PV displacements prior to Jan 1 st ( only 6 since the late 1950's  per Isotherm ) and only one PV split before January 1 st occuring in a + QBO dating back as well to the late 1950's. So,  like Isotherm said, a very rare event indeed.  

Also, as I mentioned a couple days ago,  a AO that averages positive during the first ten days of December is an unfavorable signal for the remainder of the month per Bluewave.   

 

  

  

The QBO isn't off the charts positive. 95/96 had a weak positive qbo. A few other blocky good snow years has a qbo in a similar range to now. If the qbo starts getting up above 15 I would worry more. 

[psuhoffman]

57 minutes ago, C.A.P.E. said:

The -NAO does break down, but if you roll the pattern forward using the weeklies, it comes back around Xmas and beyond, and at the same time there is marked improvement with the EPO/PNA. Yeah it is a ways out there, but seeing that being advertised as a possible evolution to the pattern is better than some alternatives I can think of. I am definitely not discouraged, and like Bob, I am not expecting a banner snow year. Given your location though, you could easily end up at climo or even somewhat below, and make most of the rest of us in this sub forum envious.

Sorry if my post came off alarmist. I'm kind of indifferent right now. I took a shot at analoging this year and came up with so much spread in similar years it seemed useless. But what I did find was if you eliminated years with early snowfall the remaining analogs were really crappy.  And I don't need climo to be happy. Climo for me is probably somewhere in the 35-40" range. Actually in the 12 years I've been here it's closer to 45" but that's an aberration I think.  I could be happy with a 20-25" year as long as somewhere in there is one decent snowfall and a decent cold stretch with snowcover. That happens up here about 90% of the time. That's why I moved here partially. But some of the analogs that pop up if we eliminate the early snow years fall in that 10% I would not be happy with. 

[mattie g]

FFS...we're not going to keep a -AO/-NAO all winter long. It'll break down and then come back on the regular, so there's no need to "be concerned" if it starts to break down in the long range. It's bound to come back at some point, especially in a year in which most signs have been pointing to an overall -AO/-NAO.

[Sparky]

13 hours ago, psuhoffman said:

Sorry if my post came off alarmist. I'm kind of indifferent right now. I took a shot at analoging this year and came up with so much spread in similar years it seemed useless. But what I did find was if you eliminated years with early snowfall the remaining analogs were really crappy.  And I don't need climo to be happy. Climo for me is probably somewhere in the 35-40" range. Actually in the 12 years I've been here it's closer to 45" but that's an aberration I think.  I could be happy with a 20-25" year as long as somewhere in there is one decent snowfall and a decent cold stretch with snowcover. That happens up here about 90% of the time. That's why I moved here partially. But some of the analogs that pop up if we eliminate the early snow years fall in that 10% I would not be happy with. 

My 23 year snowfall average is 35.5 inches.  I kind of agree with you that I don't need to reach climo to feel happy, but I always feel a little disappointed if I don't get into the lower 30s by winters end.   Upper 20s leaves a bad taste in my mouth.

[Bob Chill]

Heh, pretty big arctic outbreak on the 12z gfs. I want it to happen just so all the people saying the cold is locked in Siberia and warm all Dec will look dumb.

[Wonderdog]

37 minutes ago, Bob Chill said:

Heh, pretty big arctic outbreak on the 12z gfs. I want it to happen just so all the people saying the cold is locked in Siberia and warm all Dec will look dumb.

I like that look on 12/12!!

[Bob Chill]

While many fret over the numerical ao/nao indices losing their negative #s, I'm kinda liking where things are going. It's looking almost like a lock that an artic dump is coming during the next 10-15 days. Even better the pattern looks to reload. 

As is typical with early season arctic dumps, the upper midwest and rockies feel it first. But if its cold enough then moderation would have wiggle room by the time it gets here. If the cold reloads then we could really start to see a window open up. 

Height patterns don't look great for anything significant but a mixed or minor event may come easy before mid month if the cold NA pattern becomes dominant and not hit and run. Over the next week we'll probably start seeing multiple teases on the ops at LR. Hopefully one survives the MR. Or the always fun pop up out of nowhere in the MR. 

I mentioned last week that my guess was our chances would begin sometime around 10th. Still looks like a fair call 

[Eskimo Joe]

I would trade the entire winter for a 5"-8" event Christmas Eve into Christmas Day that everyone cashes in on.

[Wonderdog]

27 minutes ago, Eskimo Joe said:

I would trade the entire winter for a 5"-8" event Christmas Eve into Christmas Day that everyone cashes in on.

I wouldn't. 

[Bob Chill]

5-8"?...Meh

[Kmlwx]

2 hours ago, Eskimo Joe said:

I would trade the entire winter for a 5"-8" event Christmas Eve into Christmas Day that everyone cashes in on.

This is shocking coming from you. I'm tempted to ask if somebody hacked your account. You would meh a 5-8 incher into oblivion on any other day other than Xmas. 

[87storms]

2 hours ago, Eskimo Joe said:

I would trade the entire winter for a 5"-8" event Christmas Eve into Christmas Day that everyone cashes in on.

I would bc it's uncommon and we've had 3 strong winters in a row.  Not really feeling a long drawn out winter.  Craving a normal winter.  2-3 storms and bring on spring. 

[BristowWx]

I would take that 5-8 deal for Santa and punt Feb 15- rest of winter.  

[Eskimo Joe]

1 hour ago, BristowWx said:

I would take that 5-8 deal for Santa and punt Feb 15- rest of winter.  

The sun angle kills you south of I-70 after Valentine's Day...we really only have a month and a half of winter in DC.