Early December Pattern Discussion

[Tropopause_Fold]

Yeah but Phil posted yesterday about how the Euro looked better than it had and no much above normals

i was just saying what it showed...wasn't saying it was right. just 12 hours earlier it had a huge cutter going into the Lakes.

[Tropopause_Fold]

Last winter was a lot more fun. I hate the possible warm outcome as much as anyone here. This morning's 60° temperatures were as depressing as it can get in December.

i thought this post was good - i like when the respected posters don't hide their distaste for this weather.

it's december. it should be cold. it should snow. the grass should not be growing.

[HM]

This whole month has been a torch. Pick any time period and you will be right...lol.

The next 2 weeks + will be above normal.

I see what you are saying but in a high-consensus long range forecast from various sources for a "cold December" back in September and October, this was a signal that was showing up the strongest. The late Nov failure affected the first part of December and I rightfully admit I got that one wrong and had to make changes; however, the mid-December warm-up was always something I anticipated based on the increasing AO and tropical forcing. The original idea also stressed it would be brief and a cooler air mass may try to return toward the holidays and especially New Years.

While the AO will likely average positive through the holidays and possible spike again (not to nearly the same strength as early Dec) during the last week of December, expect a notable shift again in the Pacific toward New Years that would favor renewed cold air into the Northeast. The combination of a weak MJO progression through the IO and -u anomalies to 60N will bring a period of cold / snow. Then we wait for any potential stratospheric warming-aided blocking later in January.

[weathafella]

I am thinking about rubberbands

Kind of like 2001-02. The rubber band snapped and it was a bitter spring with snow showers in May. The rubber band snapping theory is funnuy and not based on anything. Look at the global pattern...we are cooked for many weeks from now with possible brief intrusions of seasonal at times. I'll be interested to see if you can get more than 2-3 inches of snow from this event that looked to whiff you 3 days ago but now has you too far east and not elevated enough...

[CoastalWx]

I see what you are saying but in a high-consensus long range forecast from various sources for a "cold December" back in September and October, this was a signal that was showing up the strongest. The late Nov failure affected the first part of December and I rightfully admit I got that one wrong and had to make changes; however, the mid-December warm-up was always something I anticipated based on the increasing AO and tropical forcing. The original idea also stressed it would be brief and a cooler air mass may try to return toward the holidays and especially New Years.

While the AO will likely average positive through the holidays and possible spike again (not to nearly the same strength as early Dec) during the last week of December, expect a notable shift again in the Pacific toward New Years that would favor renewed cold air into the Northeast. The combination of a weak MJO progression through the IO and -u anomalies to 60N will bring a period of cold / snow. Then we wait for any potential stratospheric warming-aided blocking later in January.

Oh don't take it the wrong way....It wasn't to be taken as a jab in any way. More or less commenting on how this December has been.

[CoastalWx]

Hopefully some of those signals materialize in the future. By -U wind anomalies, I assume you mean more ridging in the NPAC? I feel like the models have been too bullish with that, but hopefully we can finally get some help with a little NPAC ridging down the road. I saw the EC ensembles hint at it, but I've also seen it before. I would think eventually it does come, sooner or later.

[Organizing Low]

its amazing that we have gone from record negative AO's to record positive AO.

how's that for a rubberband?

[HM]

Hopefully some of those signals materialize in the future. By -U wind anomalies, I assume you mean more ridging in the NPAC? I feel like the models have been too bullish with that, but hopefully we can finally get some help with a little NPAC ridging down the road. I saw the EC ensembles hint at it, but I've also seen it before. I would think eventually it does come, sooner or later.

I expect some negative tendency to arrive around that time, enhancing the 60N easterly component:

http://www.esrl.noaa.gov/psd/map/images/reanalysis/aam_total/gltend.sig.90day.gif

You'll start to see signs of this from the 20th on in the Mid Latitudes when cyclonic wave breaking commences. Ultimately, these will pull the jet stream south or "equatorward" toward the holidays. The AAM cannot get any worse than late Nov-early Dec! lol

[Ginx snewx]

I see what you are saying but in a high-consensus long range forecast from various sources for a "cold December" back in September and October, this was a signal that was showing up the strongest. The late Nov failure affected the first part of December and I rightfully admit I got that one wrong and had to make changes; however, the mid-December warm-up was always something I anticipated based on the increasing AO and tropical forcing. The original idea also stressed it would be brief and a cooler air mass may try to return toward the holidays and especially New Years.

While the AO will likely average positive through the holidays and possible spike again (not to nearly the same strength as early Dec) during the last week of December, expect a notable shift again in the Pacific toward New Years that would favor renewed cold air into the Northeast. The combination of a weak MJO progression through the IO and -u anomalies to 60N will bring a period of cold / snow. Then we wait for any potential stratospheric warming-aided blocking later in January.

Interesting evolution, perhaps as standard and normal to climo as we have seen in several years. folks dismissing winter today by the dozens, I just do not see the need for panic. A shuffling of the deck seems to be in order per your post, good news.

[CoastalWx]

I expect some negative tendency to arrive around that time, enhancing the 60N easterly component:

http://www.esrl.noaa...d.sig.90day.gif

You'll start to see signs of this from the 20th on in the Mid Latitudes when cyclonic wave breaking commences. Ultimately, these will pull the jet stream south or "equatorward" toward the holidays. The AAM cannot get any worse than late Nov-early Dec! lol

Ahh...gotcha. Cool...hopefully it works out. It's amazing how stable this pattern has been...including the Stratosphere. Those -U anomalies closer to the surface north of the equator have been drilling the MJO into the crappy phases. I hope the feature you mentioned can finally help breakup the pattern we've seen so far.

[weathafella]

Interesting evolution, perhaps as standard and normal to climo as we have seen in several years. folks dismissing winter today by the dozens, I just do not see the need for panic. A shuffling of the deck seems to be in order per your post, good news.

I completely understand this reasoning. Here's the problem to me: The vast majority of winters with such anomalously warm entire autumns and the first part of December were dead ratters. This is as stable a pattern as I ever remember. Will it break? Yes eventually. Heck....1959-60 was a sub par winter but well worth the wait for the 3/3/60 and maybe that's what's in store for us. But I think at least the first half of met winter is in the toity. Hopefully I'm wrong.

[CoastalWx]

I completely understand this reasoning. Here's the problem to me: The vast majority of winters with such anomalously warm entire autumns and the first part of December were dead ratters. This is as stable a pattern as I ever remember. Will it break? Yes eventually. Heck....1959-60 was a sub par winter but well worth the wait for the 3/3/60 and maybe that's what's in store for us. But I think at least the first half of met winter is in the toity. Hopefully I'm wrong.

I think we could end up having a decent second half, but my confidence on that is not high...lol.

[weathafella]

Well us wastrels will waste not. This is a VIM TOOT winter it seems.

[Clinch Leatherwood]

I completely understand this reasoning. Here's the problem to me: The vast majority of winters with such anomalously warm entire autumns and the first part of December were dead ratters. This is as stable a pattern as I ever remember. Will it break? Yes eventually. Heck....1959-60 was a sub par winter but well worth the wait for the 3/3/60 and maybe that's what's in store for us. But I think at least the first half of met winter is in the toity. Hopefully I'm wrong.

Same here but my hope is this is such a historic torch we see something different for an outcome. This has been so sustained and so warm I can only hope that the "reaction" on the other end we see is a hail mary cold. The other alternative is it never gets cold.

It's so warm your squirrels are putting their nuts back.

[Ginx snewx]

I completely understand this reasoning.  Here's the problem to me:  The vast majority of winters with such anomalously warm entire autumns and the first part of December were dead ratters.  This is as stable a pattern as I ever remember.  Will it break?  Yes eventually.  Heck....1959-60 was a sub par winter but well worth the wait for the 3/3/60 and maybe that's what's in store for us.  But I think at least the first half of met winter is in the toity.  Hopefully I'm wrong.

Could be but it is dec 7th and to say winter is a bust or you will bust badly is kind of premature. I can recall many a winter in the 60's and 70's with torch conditions up to Christmas week before winter set in. Maybe a torch start to finish but basing a whole winter ahead on conditions so far is premature.

[Clinch Leatherwood]

Could be but it is dec 7th and to say winter is a bust or you will bust badly is kind of premature. I can recall many a winter in the 60's and 70's with torch conditions up to Christmas week before winter set in. Maybe a torch start to finish but basing a whole winter ahead on conditions so far is premature.

I'm not doubting you but is there any data on any fall period this warm for this long that turned significantly around?

[doug1991]

I'm not doubting you but is there any data on any fall period this warm for this long that turned significantly around?

That is my point. What are the chances?????

[weathafella]

Could be but it is dec 7th and to say winter is a bust or you will bust badly is kind of premature. I can recall many a winter in the 60's and 70's with torch conditions up to Christmas week before winter set in. Maybe a torch start to finish but basing a whole winter ahead on conditions so far is premature.

I urge you to visit the dailies on all the winters you're thinking about. The only one that comes close for me is 1993.

And it's not that winter's a bust...it's just that it is evident now that the first half is LIKELY a bust. I'm personally thinking it will be better during the second half but not a satisfying winter in the big picture and probably below normal snow. Hopefully I'm wrong. What's playing out now is exactly what I feared last spring.

[Ginx snewx]

I urge you to visit the dailies on all the winters you're thinking about.  The only one that comes close for me is 1993.

And it's not that winter's a bust...it's just that it is evident now that the first half is LIKELY a bust.  I'm personally thinking it will be better during the second half but not a satisfying winter in the big picture and probably below normal snow.  Hopefully I'm wrong.  What's playing out now is exactly what I feared last spring.

I still think I make my predicted levels and will not bust badly as you said, cripes in some areas I am 33% there for annual, tomorrow adds even more to my prolific NNE call

[mahk_webstah]

Kind of like 2001-02. The rubber band snapped and it was a bitter spring with snow showers in May. The rubber band snapping theory is funnuy and not based on anything. Look at the global pattern...we are cooked for many weeks from now with possible brief intrusions of seasonal at times. I'll be interested to see if you can get more than 2-3 inches of snow from this event that looked to whiff you 3 days ago but now has you too far east and not elevated enough...

Well yesterday I thought it was a 4-8er for me and Brian. DT still thinks it is btw according to his last call. Thank goodness I am out of the country until Saturday night. We might not be as cooked as you for the next few weeks, just given how the fall has gone. In terms of rubberbands....did 2001 2002 feature extremely warm Nov and Dec? This is a very long very warm stretch...that is suggestive of a rubberband that snaps much sooner. Last winter didn't get cranking until Boxing Day. To me,the pattern will shift and it still may be shifted by Dec 25, the day of the birth of a most famous Jew. Start davening Rebbe.

[Ginx snewx]

I'm not doubting you but is there any data on any fall period this warm for this long that turned significantly around?

57/75

[Ginx snewx]

Well yesterday I thought it was a 4-8er for me and Brian.  DT still thinks it is btw according to his last call.  Thank goodness I am out of the country until Saturday night.  We might not be as cooked as you for the next few weeks, just given how the fall has gone.  In terms of rubberbands....did 2001 2002 feature extremely warm Nov and Dec?  This is a very long very warm stretch...that is suggestive of a rubberband that snaps much sooner.   Last winter didn't get cranking until Boxing Day.  To me,the pattern will shift and it still may be shifted by Dec 25, the day of the birth of a most famous Jew.  Start davening Rebbe.

you do well tmr Marko, i agree with your sentiments, time will tell

[mahk_webstah]

you do well tmr Marko, i agree with your sentiments, time will tell

Well GYX says 1-3 for my region....if we get the high end then it will be waiting for me when I'm back on Saturday. Yes time will tell...but i expect us to have our snowpack established by Xmas.

[snowman21]

I'm not doubting you but is there any data on any fall period this warm for this long that turned significantly around?

Well considering how anomalous this fall has been, it would be hard to find comparisons. But here are some stats...

   ---- WINTER -----
YEAR  FALL   AVG   D/J   F/M
----------------------------
1946   2.8   0.2   1.8  -1.4
2007   2.5   0.6   1.0   0.1
1941   2.1  -0.5   0.0  -1.0
1961   2.1  -2.1  -1.3  -3.0
1983   2.1  -1.4  -2.6  -0.2
1971   2.1  -0.7   1.8  -3.2
2005   2.0   1.3   2.6   0.0
1990   2.0   2.9   2.8   3.1
2001   1.9   4.7   6.4   3.0
1953   1.8   1.6   1.0   2.2
1975   1.7  -0.3  -3.5   3.0
1948   1.7   2.4   3.4   1.3
1999   1.6   2.2   0.7   3.7
2010   1.6  -1.9  -2.6  -1.2
2006   1.4   1.1   5.5  -3.3
1963   1.3  -2.8  -3.7  -1.8
1947   1.3  -3.8  -5.0  -2.6
1994   1.1   2.1   4.9  -0.8
-----------------------------
AVG	1.8   0.3   0.7  -0.1

These are composites of BDL, BOS, PVD, and ORH based on 1981-2010 normals and how each winter turned out following an anomalously warm fall. To define anomalously warm fall, I had to come up with some criteria that would yield a decent sample size. My two rules were at least two of the sites with a fall departure of +2 or more, or a four-site average of +1 or more. I'm also only using a history of about 60 years, so if I added in some of the earlier Hartford and Providence data, we could probably add in a few more years.

To summarize, out of the 18 warm falls above...

* There was essentially no signal in determining whether the four-month winter would average above or below average since the resultant winters are split roughly 50-50 (10-8).

* Relative to the fall departure, winter "cools" off 72% of the time as one would expect since maintaining anomalous departures over longer time periods becomes less likely.

* The first half of winter (Dec-Jan) averaged above normal 61% of the time, and the second half of winter (Feb-Mar) averaged below normal 61% of the time.

[Ginx snewx]

Well considering how anomalous this fall has been, it would be hard to find comparisons. But here are some stats...

       ---- WINTER -----
YEAR  FALL   AVG   D/J   F/M
----------------------------
1946   2.8   0.2   1.8  -1.4
2007   2.5   0.6   1.0   0.1
1941   2.1  -0.5   0.0  -1.0
1961   2.1  -2.1  -1.3  -3.0
1983   2.1  -1.4  -2.6  -0.2
1971   2.1  -0.7   1.8  -3.2
2005   2.0   1.3   2.6   0.0
1990   2.0   2.9   2.8   3.1
2001   1.9   4.7   6.4   3.0
1953   1.8   1.6   1.0   2.2
1975   1.7  -0.3  -3.5   3.0
1948   1.7   2.4   3.4   1.3
1999   1.6   2.2   0.7   3.7
2010   1.6  -1.9  -2.6  -1.2
2006   1.4   1.1   5.5  -3.3
1963   1.3  -2.8  -3.7  -1.8
1947   1.3  -3.8  -5.0  -2.6
1994   1.1   2.1   4.9  -0.8
-----------------------------
AVG    1.8   0.3   0.7  -0.1

These are composites of BDL, BOS, PVD, and ORH based on 1981-2010 normals and how each winter turned out following an anomalously warm fall. To define anomalously warm fall, I had to come up with some criteria that would yield a decent sample size. My two rules were at least two of the sites with a fall departure of +2 or more, or a four-site average of +1 or more. I'm also only using a history of about 60 years, so if I added in some of the earlier Hartford and Providence data, we could probably add in a few more years.

To summarize, out of the 18 warm falls above...

* There was essentially no signal in determining whether the four-month winter would average above or below average since the resultant winters are split roughly 50-50 (10-8).

* Relative to the fall departure, winter "cools" off 72% of the time as one would expect since maintaining anomalous departures over longer time periods becomes less likely.

* The first half of winter (Dec-Jan) averaged above normal 61% of the time, and the second half of winter (Feb-Mar) averaged below normal 61% of the time.

Good stuff, how about snowfall wise? Thanks in advance

[Tropopause_Fold]

coldest weather since late last winter saturday pm - sunday pm?

[Damage In Tolland]

Not an awful looking Euro run today at all. In fact even thru day 10 looks decent.

[OSUmetstud]

euro doesn't really look like a torch...probably just slightly above normal through the period but rather boring. Maybe if you're lucky one of those clippers deliver.

[Damage In Tolland]

coldest weather since late last winter saturday pm - sunday pm?

Yup..if "they"re" out at the GTG.."They"re" gonna be pretty cold and taut"

[weathafella]

Well considering how anomalous this fall has been, it would be hard to find comparisons. But here are some stats...

   ---- WINTER -----
YEAR  FALL   AVG   D/J   F/M
----------------------------
1946   2.8   0.2   1.8  -1.4
2007   2.5   0.6   1.0   0.1
1941   2.1  -0.5   0.0  -1.0
1961   2.1  -2.1  -1.3  -3.0
1983   2.1  -1.4  -2.6  -0.2
1971   2.1  -0.7   1.8  -3.2
2005   2.0   1.3   2.6   0.0
1990   2.0   2.9   2.8   3.1
2001   1.9   4.7   6.4   3.0
1953   1.8   1.6   1.0   2.2
1975   1.7  -0.3  -3.5   3.0
1948   1.7   2.4   3.4   1.3
1999   1.6   2.2   0.7   3.7
2010   1.6  -1.9  -2.6  -1.2
2006   1.4   1.1   5.5  -3.3
1963   1.3  -2.8  -3.7  -1.8
1947   1.3  -3.8  -5.0  -2.6
1994   1.1   2.1   4.9  -0.8
-----------------------------
AVG	1.8   0.3   0.7  -0.1

These are composites of BDL, BOS, PVD, and ORH based on 1981-2010 normals and how each winter turned out following an anomalously warm fall. To define anomalously warm fall, I had to come up with some criteria that would yield a decent sample size. My two rules were at least two of the sites with a fall departure of +2 or more, or a four-site average of +1 or more. I'm also only using a history of about 60 years, so if I added in some of the earlier Hartford and Providence data, we could probably add in a few more years.

To summarize, out of the 18 warm falls above...

* There was essentially no signal in determining whether the four-month winter would average above or below average since the resultant winters are split roughly 50-50 (10-8).

* Relative to the fall departure, winter "cools" off 72% of the time as one would expect since maintaining anomalous departures over longer time periods becomes less likely.

* The first half of winter (Dec-Jan) averaged above normal 61% of the time, and the second half of winter (Feb-Mar) averaged below normal 61% of the time.

Very helpful!

1946 baby.....a weenie was born!