2013-14 MA Winter Disco - 'cause it's never too early.

[Fozz]

Me either plus that winter was cold, here are some stats from that winter:

 

 

* January and February were the third-coldest pairing of those months in the Northeast since 1895.

* January was Maryland's eighth-coldest January during the past 100 years.

* Snowfall in Maryland varied widely, like the Northeast in miniature. Oakland, in western Garrett County, had counted 146 inches by Friday, 3 inches short of last year's record. On the Eastern Shore, Chestertown had counted 11 inches.

* Local governments in the Baltimore area spent $10.3 million to clear roads, two to four times what they had budgeted. The state spent $23 million -- twice its budget.

* About 223,000 tons of salt and abrasives were applied in the Baltimore area. State highway crews spread 302,000 tons statewide.

* On Jan. 18, power demand across the five-state power grid from New Jersey to the District of Columbia was 8.5 percent higher than during the last winter peak in 1989.

 

It was a fantastic winter where I am in Lancaster so a repeat of that would be amazing, but it had such a sharp gradient that seasonal snow totals rapidly dropped off south of 40N. The +NAO may be a big reason. Still very cold and icy.

[HM]

 

I don't really get his reasoning about a southern stream....but maybe he'll be right...

 

While I agree that 93-94 is a terrible analog, there will be occasional bouts of STJ. It seems like one could be on the way in early December but that is making the assumption everything propagates as planned. Looks like Dec could start off chilly and possibly trend milder mid-month? I guess a lot depends on how slow/fast the forcing moves. 

I think our ENSO state is as bad as it gets in terms of getting a big event....which is a problem because the models are going to taunt us all winter...I'd like to see a 3-4" event that doesn't happen at the end of March

Yeah, I'm hating the ENSO numbers right now, statistically.

[WxUSAF]

300-384 6z GEFS mean looks about as good as I've seen yet.  -AO/-NAO/-EPO

 

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f300.html

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f384.html

[mappy]

How can you tell its -AO/-NAO/-EPO?

[WxUSAF]

How can you tell its -AO/-NAO/-EPO?

I'm eyeballing.  Didn't actually look at calculated index numbers.  But, there's ridging (warm colors) in all 3 regions:  over the pole for the AO, over and north of Alaska for the EPO and over Greenland for the NAO.  

[mappy]

OK -- thanks

[Bob Chill]

300-384 6z GEFS mean looks about as good as I've seen yet. -AO/-NAO/-EPO

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f300.html

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f384.html

Euro op and ens show another arctic shot d9-10. Really trying to pop a 570+dm ridge into GL. Probably transient but who knows. All things considered things look pretty good to keep fears of a major fail into early Dec at bay.

[usedtobe]

300-384 6z GEFS mean looks about as good as I've seen yet.  -AO/-NAO/-EPO

 

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f300.html

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f384.html

If you look at the correlation between the ens mean pnA index forecasts and observed at 14 days, the correlation is -0.027.   probably lower than the correlation between the redskins points differential each week and the index.  That suggests you should be very leery about using the ens mean right now as it probably even less skillful than normal at the longer time ranges.  Also,  the AO index forecasts over the past couple of weeks have been much lower than observed.  Not saying a neg ao and epo can't happen but that I'd be very careful using the forecasts right now.

[snow.]

 

 

While I agree that 93-94 is a terrible analog, there will be occasional bouts of STJ. It seems like one could be on the way in early December but that is making the assumption everything propagates as planned. Looks like Dec could start off chilly and possibly trend milder mid-month? I guess a lot depends on how slow/fast the forcing moves. 

Yeah, I'm hating the ENSO numbers right now, statistically.

 

 

We saw that the last 2 winters, but nothing could amplify on its own, so we ended up with 1012 amorphous lows ambling off the coast and/or a primary to our west..Even in these cases when we have a southern stream, I am always concerned about whether it is robust enough that a storm can pull itself up by the bootstraps and come up the coast without help from the northern stream which usually means a track to our west.....I think the best we did last winter was get a storm or 2 up to SW/central VA...there was that one that the models got up here and even maybe 0.25" to Philly on a couple runs but we didn't see a flake...may have given SW VA and CHO a few inches....our best chance is to manufacture a southern stream by getting a split flow..though I think early or late season are better times for a southern track....

 

I am on board for a warm december....for us, unless we get a stable cold pattern, we usually go +7, +8, -3, -2, -4, +11 or something like that...and often on the 1st cold day we get counterfeited with an overnight max of like 62 with afternoon temps in the 40s....I am thinking progressive/variable which means warm...

[snow.]

300-384 6z GEFS mean looks about as good as I've seen yet.  -AO/-NAO/-EPO

 

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f300.html

http://www.meteo.psu.edu/ewall/ENSHGTAVGNH_6z/f384.html

 

 

looks good and has some support from canadian and euro ens.....as Wes said, little skill at this range

 

One thing to be cautious about with that pattern is how much ridging there is in the PNA region....often in December we are still warm or normal in that pattern, because the air masses become very modified and there is a reverse gradient temp anomaly with the -negative height anomaly and storm track to our north...we end up normal with the neg departures to our north and northwest...we live in such a crappy area....since the monster cold December of 89-90 we have only been cold 7 out of 23 decembers...and they were all ninos or winters  in warm enso periods or following a nino...HM and others have mentioned this winter might not be your typical neutral after nina type winter, partly  because of last winter's neutral but also partly because of that fake nino we got in the fall....hopefully that is the case...otherwise I think warm/normal december is a pretty safe call even with a cold signal to start the month

[Bob Chill]

I was messing around with ESRL climate composites this morning and picked up on some similarities to the current pattern and what late Nov of 78 looked like. Then I took a look at what transpired in Dec of 78.

 

Nov of 78 had a whopping +AO but it collapsed into a cold and blocky winter. I'm not saying I think that will be the case this year at all. Just that there are some similarities to the last 15 days and what the second half of Nov looked like in 78. The PAC is a really good match overall.

 

78 on left and last 15 days on the right.

 

 

December of 78 completely flipped in the AO/NAO domain space with anomalously high heights.

 

First and second half of Dec 78 side by side:

 

 

 

What caught my attention is now the lr is hinting at building heights in the NAO domain and collapsing the +AO. Some ens member now take the AO and NAO negative but that's way out there and nothing ever happens as fast as progged with anomalous patterns like the one we're in right now.

 

 

 

 

So, do we enter Dec with a favorable epo region AND some help from way up north? Hard to say. At least it's happened in the past with a record +AO in Nov. 

 

 

[snow.]

I was messing around with ESRL climate composites this morning and picked up on some similarities to the current pattern and what late Nov of 78 looked like. Then I took a look at what transpired in Dec of 78.

 

Nov of 78 had a whopping +AO but it collapsed into a cold and blocky winter. I'm not saying I think that will be the case this year at all. Just that there are some similarities to the last 15 days and what the second half of Nov looked like in 78. The PAC is a really good match overall.

 

78 on left and last 15 days on the right.

 

78-13.JPG

 

December of 78 completely flipped in the AO/NAO domain space with anomalously high heights.

 

First and second half of Dec 78 side by side:

 

Dec78.JPG

 

 

What caught my attention is now the lr is hinting at building heights in the NAO domain and collapsing the +AO. Some ens member now take the AO and NAO negative but that's way out there and nothing ever happens as fast as progged with anomalous patterns like the one we're in right now.

 

11.12 ao forecast.JPG

 

11.12 nao forecast.JPG

 

 

So, do we enter Dec with a favorable epo region AND some help from way up north? Hard to say. At least it's happened in the past with a record +AO in Nov. 

 

we torched in December 1978 with no snow and you can see why...primarily the lack of blockiness west and NW of AK so there was no cold delivery mechanism, plus the -PNA look and the SE ridge and storm track to our north and west.. so the -NAO didn't help us....

[Bob Chill]

we torched in December 1978 with no snow and you can see why...primarily the blockiness west and NW of AK so there was no cold delivery mechanism, plus the -PNA look and the SE ridge and storm track to our north and west.. so the -NAO didn't help us....

 

I wasn't trying to draw finite conclusions moreso than pointing out that the big +AO/NAO combo we're seeing now may not persist like some think. Our odds simply increase for more potential in Dec if the bias shifts more towards a -ao/nao combo than what we have in place right now. 

 

12z GFS is showing some significant changes again at the top of the world. Have to wait and see what the ens say and of course wait a couple weeks but my hand is still far from the panic button. I hate wasting more than half of Dec basking in 40's and 50's...and dare i say 60's....

[EasternUSWX]

This is promising. 

 

 

[snow.]

I wasn't trying to draw finite conclusions moreso than pointing out that the big +AO/NAO combo we're seeing now may not persist like some think. Our odds simply increase for more potential in Dec if the bias shifts more towards a -ao/nao combo than what we have in place right now. 

 

12z GFS is showing some significant changes again at the top of the world. Have to wait and see what the ens say and of course wait a couple weeks but my hand is still far from the panic button. I hate wasting more than half of Dec basking in 40's and 50's...and dare i say 60's....

 

 

I hear ya...I am little less optimistic that a -NAO will make a difference for us, if the PAC is not great..particularly in December....So I am not really focused on it.   Perhaps I should be since without it we are kind of doomed for snow, even though with it doesn't necessarily mean much.

[snow.]

This is promising. 

 

 

 

 

I'm significantly more interested in the EPO than the NAO for december,...fortunately there is some indication it might be negative going into the month

[Bob Chill]

I hear ya...I am little less optimistic that a -NAO will make a difference for us, if the PAC is not great..particularly in December....So I am not really focused on it.   Perhaps I should be since without it we are kind of doomed for snow, even though with it doesn't necessarily mean much.

 

Outside of not expecting big storms or a climo+ snow year, this DJF seems particularly difficult to wrap heads around. Here we are in mid-Nov and there is little confidence anywhere as to how the month as a whole shakes out. In a way it's fun and in a way it's not...lol

 

I'm strictly focusing on temps right now. The first half of Dec needs decent neg departures to have any chance at snow. I'm hoping some sort of pattern sets up that allows for that at least. Adding snow in there would be a huge bonus. 

 

I will admit that I seeing the big +ao pop and crappy lr guidance in late October had me starting to rethink Dec as a whole but there seems to be enough signs showing up to not expect a torch....yet...

[snow.]

Outside of not expecting big storms or a climo+ snow year, this DJF seems particularly difficult to wrap heads around. Here we are in mid-Nov and there is little confidence anywhere as to how the month as a whole shakes out. In a way it's fun and in a way it's not...lol

 

I'm strictly focusing on temps right now. The first half of Dec needs decent neg departures to have any chance at snow. I'm hoping some sort of pattern sets up that allows for that at least. Adding snow in there would be a huge bonus. 

 

I will admit that I seeing the big +ao pop and crappy lr guidance in late October had me starting to rethink Dec as a whole but there seems to be enough signs showing up to not expect a torch....yet...

 

 

there are signs of it, but we also had a false signal last year when a lot of people though december might be normal or slightly below and we torched....

[Ji]

there are signs of it, but we also had a false signal last year when a lot of people though december might be normal or slightly below and we torched....

 

We torched till it counted...then we got 2 winter events from Dec 20 through the end of the year and a white Christmas for some lol

[HM]

 

 

We saw that the last 2 winters, but nothing could amplify on its own, so we ended up with 1012 amorphous lows ambling off the coast and/or a primary to our west..Even in these cases when we have a southern stream, I am always concerned about whether it is robust enough that a storm can pull itself up by the bootstraps and come up the coast without help from the northern stream which usually means a track to our west.....I think the best we did last winter was get a storm or 2 up to SW/central VA...there was that one that the models got up here and even maybe 0.25" to Philly on a couple runs but we didn't see a flake...may have given SW VA and CHO a few inches....our best chance is to manufacture a southern stream by getting a split flow..though I think early or late season are better times for a southern track....

 

I am on board for a warm december....for us, unless we get a stable cold pattern, we usually go +7, +8, -3, -2, -4, +11 or something like that...and often on the 1st cold day we get counterfeited with an overnight max of like 62 with afternoon temps in the 40s....I am thinking progressive/variable which means warm...

 

 

I agree with you overall. I could see something where anomalies tend warmer as you head north up the East Coast. Just because an El Nino-like hybrid period may be on the way, doesn't mean it will be cold/snowy. It could end up wall-to-wall above normal for much of the country if the vortex sits closer to North America. In fact, Decembers in El Nino-winters typically aren't the coldest anyway. The typical ENSO-->AO connection is for an inverse relationship starting mid to late Jan. Other factors would have to be in play to speed up the -AO...like 2009.

 

What we know for sure is that the tropical forcing coming through the IO will be progressing toward the W PAC and ultimately C PAC again by the end of the month, easy. Will we see another bout of Aleutian Low, like we did this past Oct? Will it be enough for a split stream? Will it help anchor in a +EPO/-NAO (warm signal) after a brief bout of +PNA?

[Scarlet Pimpernel]

The only way will do well is if the King in your avatar can stay where it is.

 

Ha!  Well, not to get way off topic but that board set up is actually what's called "mutual zugzwang" in chess, if you're familiar with it.  If it's white to move, then all he can get out of the game is a draw (king vs. king), even though he's got a pawn one rank from becoming a queen (normally a huge advantage of course).  White's only legal move is to either move the king away from protecting the pawn which black will immediately then take (forcing the draw), or else move behind the pawn which stalemates black right away.  If it's black to move, he loses outright because any move he can make guarantees white's pawn will queen, and that's the game right there!  So in either case, you're at a *disadvantage* if it's your move, which is the underlying principle of being in "zugzwang" (German word that more or less means "disagreeable obligation to move").  Granted, that's a staged set-up, but similar ones do occur in actual games where you're forced to put yourself at a disadvantage when it's your move, and you'd be better off not moving at all!

 

So much for the chess discussion in a weather forum, sorry for the diversion! ; )

[Scarlet Pimpernel]

I think our ENSO state is as bad as it gets in terms of getting a big event....which is a problem because the models are going to taunt us all winter...I'd like to see a 3-4" event that doesn't happen at the end of March

 

Ah, yes, the event on March 25 this year.  That was a very pretty one (quite picturesque), but too late in the year and it was gone very quickly.  Ironically, that's the heaviest snow event I've seen where I'm at since Commutageddon in January 2011!

[snow.]

I agree with you overall. I could see something where anomalies tend warmer as you head north up the East Coast. Just because an El Nino-like hybrid period may be on the way, doesn't mean it will be cold/snowy. It could end up wall-to-wall above normal for much of the country if the vortex sits closer to North America. In fact, Decembers in El Nino-winters typically aren't the coldest anyway. The typical ENSO-->AO connection is for an inverse relationship starting mid to late Jan. Other factors would have to be in play to speed up the -AO...like 2009.

 

What we know for sure is that the tropical forcing coming through the IO will be progressing toward the W PAC and ultimately C PAC again by the end of the month, easy. Will we see another bout of Aleutian Low, like we did this past Oct? Will it be enough for a split stream? Will it help anchor in a +EPO/-NAO (warm signal) after a brief bout of +PNA?

 

Thanks for your thoughts.  I'd actually be a little surprised by a nino configuration in december, but who knows...October was such a strange month...when doing my outlook none of my potential analog suite looked like that...so I could see why things might be different from my expectation...The last time we had a nino-esque configuration in december in a non-nino was 2005...I always assumed among other reasons that it was a weak enough and late enough developing cold event that on the heels of a 3 year warm event, it acted like a nino...once the event strengthened it became less so...even with the cool-ish February and the K/U..we know January torched

 

I am much less analog reliant than in past outlooks, especially for December.....but december runs warm here so that is usually the way to go when in doubt....I've noticed the PDO region has been cooling so that is something else that might help us 

[snow.]

Outside of not expecting big storms or a climo+ snow year, this DJF seems particularly difficult to wrap heads around. Here we are in mid-Nov and there is little confidence anywhere as to how the month as a whole shakes out. In a way it's fun and in a way it's not...lol

 

I'm strictly focusing on temps right now. The first half of Dec needs decent neg departures to have any chance at snow. I'm hoping some sort of pattern sets up that allows for that at least. Adding snow in there would be a huge bonus. 

 

I will admit that I seeing the big +ao pop and crappy lr guidance in late October had me starting to rethink Dec as a whole but there seems to be enough signs showing up to not expect a torch....yet...

 

I don't think anyone thinks we will see this, so that is a start...

 

 

[Bob Chill]

I don't think anyone thinks we will see this, so that is a start...

 

 

 

LOL. Subtropics loves that look. 

 

I'll need to pack in some - departures during the first 10 days or so of Dec or my call is a fail. Average high/low @ dca is 52/37 on Dec 1st. Much easier to get -5's or cooler there as opposed to 44/29 late month. 

 

One thing about recent warm Dec's is that we seem to accumulate long periods of pretty big + departures before any meaningful change. For whatever reason it's hard to overcome big + departures. - departures on the other hand can get hammered with ease. 

 

In other news...euro ens mean isn't very exciting at d10. Not bad but not anything special. +h5 anoms look ok near greenland but the - anoms dropping down from w canada imply potential for another w coast trough. 

[WxUSAF]

In other news...euro ens mean isn't very exciting at d10. Not bad but not anything special. +h5 anoms look ok near greenland but the - anoms dropping down from w canada imply potential for another w coast trough. 

Folks in other threads who can see it seemed very positive about the Euro ensembles for Day 11-15. 

[Bob Chill]

Folks in other threads who can see it seemed very positive about the Euro ensembles for Day 11-15.

I picked up wxbell for this season but I'm still trying to get a handle on all the maps and site nav. Great maps but nav is kinda clunky. Looks like I only have access to temp maps w/ 16 day ens. Added bonus is a 16 day control run with snow accum. lol. The 10 day ens maps are great though. Especially h5 anoms.

There is a lot of support with both the gefs and euro ens for potential w/ pretty cold air and an east based NAO. Pretty decent blocking sig showing up. Euro temp anoms d10-16 are below to well below in the east. Looks like a series of reinforcing shots of arctic air. Impressive pv setting up near hudson for this time of year.

IMO- unless some sort of blocking slows the flow all cold shots will be progressive and we will battle troughs in the west with downstream higher heights in the east. It's only Nov so it really doesn't matter much. It would be a kick in the teeth if early Dec sets up with a solid -pna without blocking. Much is up in the air but there is a solid cold signal setting up for late month. Tday snow showers > tday shorts and t shirts.

[HM]

Thanks for your thoughts.  I'd actually be a little surprised by a nino configuration in december, but who knows...October was such a strange month...when doing my outlook none of my potential analog suite looked like that...so I could see why things might be different from my expectation...The last time we had a nino-esque configuration in december in a non-nino was 2005...I always assumed among other reasons that it was a weak enough and late enough developing cold event that on the heels of a 3 year warm event, it acted like a nino...once the event strengthened it became less so...even with the cool-ish February and the K/U..we know January torched

 

I am much less analog reliant than in past outlooks, especially for December.....but december runs warm here so that is usually the way to go when in doubt....I've noticed the PDO region has been cooling so that is something else that might help us 

 

Even now, things are funny. Most available metrics, besides the actual positioning of the tropical forcing (which suggests cold this time of year. In winter, this kind of forcing would suggest warmth here), would suggest warmth. If you plot the mean heights, big SE ridge for the last week. There are poleward anticyclones throughout the Mid Latitudes with a nice sink in AAM over 30-40N. The AO has been soaring since late October. But, the return to La Nina-like / IO forcing this time of year brings the cold to us, regardless. It's pretty funny to see the current temp anomalies and height anomalies overtop.

 

Anytime we go La Nina-like this year, the +QBO state will combine with it and bring a substantial poleward Aleutian High. Based on my findings, the +QBO seems to module the tropical forcing / circulation to allow for a more poleward high during cold ENSO years. It seems like that signal is destroying anything else right now. So, when and if we shift to El Nino-like, what kind of hybrid scenario could unfold? In October, the forcing managed to push to whole wave train east, sending the Aleutian High into western Canada, +PDO style. That same signal in the winter would do wonders for the East CONUS.

 

The forcing should remain La Nina-like through next 10 days or so and it is no surprise the models are pumping up a classic N PAC to deliver continuous cold shots. A very rough December is on the way, forecasting-wise, since we'll see plenty of regime shifts, presumably.

[snow.]

Even now, things are funny. Most available metrics, besides the actual positioning of the tropical forcing (which suggests cold this time of year. In winter, this kind of forcing would suggest warmth here), would suggest warmth. If you plot the mean heights, big SE ridge for the last week. There are poleward anticyclones throughout the Mid Latitudes with a nice sink in AAM over 30-40N. The AO has been soaring since late October. But, the return to La Nina-like / IO forcing this time of year brings the cold to us, regardless. It's pretty funny to see the current temp anomalies and height anomalies overtop.

 

Anytime we go La Nina-like this year, the +QBO state will combine with it and bring a substantial poleward Aleutian High. Based on my findings, the +QBO seems to module the tropical forcing / circulation to allow for a more poleward high during cold ENSO years. It seems like that signal is destroying anything else right now. So, when and if we shift to El Nino-like, what kind of hybrid scenario could unfold? In October, the forcing managed to push to whole wave train east, sending the Aleutian High into western Canada, +PDO style. That same signal in the winter would do wonders for the East CONUS.

 

The forcing should remain La Nina-like through next 10 days or so and it is no surprise the models are pumping up a classic N PAC to deliver continuous cold shots. A very rough December is on the way, forecasting-wise, since we'll see plenty of regime shifts, presumably.

 

 

That has been by far the most important factor for us as far as a cold December...If that is robust enough, stable and poleward enough, we will probably be cold in December and I will bust..a big -PNA/+AO/+NAO would mitigate it a bit (in 1996 the -PNA was so powerful we torched)...usually the core neg height anomalies are to our north and west, so these air masses are modified..but even in a configuration like 1983 we were cold...

[WxUSAF]

Add another seasonal outlook to the chilly and snowy camp.  Going below normal temps with a very cold February and average to slightly above average snow.  I don't follow Mike Masco, anyone know his track record? 

http://www.abc2news.com/dpp/weather/is-baltimore-destined-for-a-severe-winter-season

 

DT's winter forecast comes out tomorrow.  He's been hinting for awhile he's favoring something like this outlook.