Winter 2011-2012

[dryslot]

Thank you. Looking forward to the snow season!

As well.....

[CoastalWx]

[CoastalWx]

That freakin' radar animation has all the classic components to a snowstorm. Deformation banding out by MRG. CCB plowing into SNE. CSI and even a little CI near the southern edge of that band. Dryslot and -EPV enhanced banding curving in from PYM to PVD, also like near MRG too. You name it..it has it.

[dryslot]

Hope to see that image all winter long, That brought 15.5" here....

[nzucker]

The La Niña is really showing impressive cooling, especially in the eastern regions near 80W.

Here is the map from 9/15 with eastern areas still warm:

Here is Monday's 9/19 map showing large areas of -4C to -5C anomalies in the eastern areas:

The wind anomaly chart shows another impressive burst of trades, and the current SOI is +24.7:

[ORH_wxman]

ECMWF forecast is now borderline moderate. I remember just 3 months ago when it was still not even weak threshold

[CoastalWx]

Yep, Nina coming on big time now. Low end moderate seems within reach now.

[Joe Vanni]

The one thing I've noticed about the ENSO forecasts from the CFS and the ECMWF is how it's keeping the NINO 4 region a decent amount warmer compared to region 3 and 3.4. This should be more centrally/east based compared to most recent La Ninas. I know there are many other factors, but I'm sure it can't hurt; right?

[ORH_wxman]

Yep, Nina coming on big time now. Low end moderate seems within reach now.

Pretty amazing to see the subsurface animation

[ORH_wxman]

Loop should be working now. For some reason it wasn't animating before.

[SoCoWx]

Good to hear it's east-based. Here's to hoping it stays that way as east-based Nina's can turn out a lot prettier than a Nina normally would for some of us.

[CoastalWx]

Loop should be working now. For some reason it wasn't animating before.

It worked before...lol, not sure what happened. Anyways I got a good look at that and yeah, those colder subsurface anomalies keep building. Those trade wind anomalies that Nate posted are telling as well.

[ORH_wxman]

Good to hear it's east-based. Here's to hoping it stays that way as east-based Nina's can turn out a lot prettier than a Nina normally would for some of us.

Its not really all that east-based right now. 3.4 is the coldest region on the weeklies and we are seeing a good burst of trade winds right now in western regions. I rarely look at Nino 1+2 because its so volatile.

[tamarack]

Hope to see that image all winter long, That brought 15.5" here....

And 7" just 40 miles to your north.

[tacoman25]

ECMWF forecast is now borderline moderate. I remember just 3 months ago when it was still not even weak threshold

CFS has been leading the way. Has been catching on to ENSO trends way sooner than the ECMF in recent years.

Speaking of ENSO, something to consider...October really seems to be a telling month for -ENSO years in particular.

[SoCoWx]

Its not really all that east-based right now. 3.4 is the coldest region on the weeklies and we are seeing a good burst of trade winds right now in western regions. I rarely look at Nino 1+2 because its so volatile.

Considering where the coldest subsurface anomalies are, I consider it east-central based. NOAA has also said it is currently east based and the anomalies are migrating eastward in their ENSO update.

All in all, I fully expect an east-central based Nina much like last Winter (NOT implying this winter will be last winter again).

[ORH_wxman]

CFS has been leading the way. Has been catching on to ENSO trends way sooner than the ECMF in recent years.

Speaking of ENSO, something to consider...October really seems to be a telling month for -ENSO years in particular.

Those are some interesting composites. I haven't looked at each individual year on those yet but I would lean something closer to the 2nd composite this winter.

Off the top of my head I know that Oct 2010 was pretty warm across all of the CONUS and that 2008 was not...so those might not fit those composites all that well. Doesn't mean they are wrong in general though. Clearly some of those warmer Octobers meant more SE ridge in Nina years.

[ORH_wxman]

Considering where the coldest subsurface anomalies are, I consider it east-central based. NOAA has also said it is currently east based and the anomalies are migrating eastward in their ENSO update.

All in all, I fully expect an east-central based Nina much like last Winter (NOT implying this winter will be last winter again).

It could end up east based. It will depend on how much damage these bursts of trade winds do to the western regions and how far east they propagate.

I'd never predict a winter like last year based on statistics alone. That was an extreme anomaly. I think more typical negative ENSO profile will be existent this winter, but it could still be below average in the east if the NAO is stubbornly negative. I probably wouldn't forecast a well below average southeast again.

[dryslot]

I really like the idea of 1970-71 and 2008-09 winters keep coming up, More so 70-71 in what may be expected for the upcoming winter season

[tacoman25]

Those are some interesting composites. I haven't looked at each individual year on those yet but I would lean something closer to the 2nd composite this winter.

Off the top of my head I know that Oct 2010 was pretty warm across all of the CONUS and that 2008 was not...so those might not fit those composites all that well. Doesn't mean they are wrong in general though. Clearly some of those warmer Octobers meant more SE ridge in Nina years.

You could actually add a couple other -ENSO years to the first composite (1944-45 and 1967-68) and the correlating signal for warm west/cold east in October followed by warm west/cold east for winter becomes even stronger. If this October ends up cold in the east, that would be a solid signal for another cold eastern winter, I think.

[mahk_webstah]

See that heavy band setting up just north of Concord? That stayed put... 22.5 inches later....

[ORH_wxman]

You could actually add a couple other -ENSO years to the first composite (1944-45 and 1967-68) and the correlating signal for warm west/cold east in October followed by warm west/cold east for winter becomes even stronger. If this October ends up cold in the east, that would be a solid signal for another cold eastern winter, I think.

I wonder what the correlation of this is...I recall a lot of years where the winter flipped from the October temp pattern during Ninas. It worked out pretty well in '07 and '08 but failed last year and other previous years like 1999.

[CoastalWx]

I wonder what the correlation of this is...I recall a lot of years where the winter flipped from the October temp pattern during Ninas. It worked out pretty well in '07 and '08 but failed last year and other previous years like 1999.

The November temp signal likely holds the most weight correct? I always felt like the October to winter correlation was not terribly strong, but then Tacoman put those charts up and it made me think.

[tacoman25]

The November temp signal likely holds the most weight correct? I always felt like the October to winter correlation was not terribly strong, but then Tacoman put those charts up and it made me think.

I think it probably depends partially on what ENSO state and what region you are looking at. From a national perspective, it sure seems that during -ENSO years at least, the October pattern tends to give major hints for the coming winter.

One thing to keep in mind is that I started my analysis by looking at what -ENSO winters heavily favored the east for cold (1903, 1917, 1933 1944, 1966, 1967, 2010) and then went back and looked at the October pattern for those years. And then did the same thing for -ENSO winters that heavily favored the West. So the correlation is more related to the extremes than years where cold was more evenly distributed across the country. A good follow up would be to look at all -ENSO Octobers that were warm west/cold east and vice versa, and see the correlation the following winters just based off of that. My hunch is that it wouldn't be terribly different, though.

[HM]

I wonder what the correlation of this is...I recall a lot of years where the winter flipped from the October temp pattern during Ninas. It worked out pretty well in '07 and '08 but failed last year and other previous years like 1999.

That's probably because there is no correlation.

[ORH_wxman]

The November temp signal likely holds the most weight correct? I always felt like the October to winter correlation was not terribly strong, but then Tacoman put those charts up and it made me think.

I'm wondering of those charts he posted are weighted heavily by some extreme years...esp prior to 1950. But it might be worth looking into each year.

Here are the Nina years that seemed to follow October well...

2008

2007

1998

1984

1975

1973

1971

1967

1964

1956

One's that didn't...

2010

2000 (it was cold in New England for October, but the rest of the east torched)

1999

1995

1988

1974

1970

1962 (cold in New England again in October but a torch for the rest)

1955

1954

If we are New England-centric in October, it seems to work a little better..but otherwise there seems to be no pattern

[tacoman25]

That's probably because there is no correlation.

See my post above.

[OKpowdah]

Sorry, but I take any statistical "correlation" to surface temp over New England with a very small grain of salt.

In terms of long range forecasting, I look at surface temps for only two cases: 1) Over the south (along with soil moisture) for a feedback mechanism that could continue through the winter. 2) Over Canada and the arctic (in November) for the *capacity* of the airmass that could impact the northern tier.

Otherwise, there are number of patterns that may produce above normal or below normal temperatures at the surface in New England. The physical connection to the winter pattern is nearly non-existent / too convoluted to possibly apply in a forecast

[tacoman25]

I realized that I left 1995-96 and 1962-63 off the list of -ENSO years that heavily favored the east. The amended map is below. The point of the maps was just to see if there was a signal that tended to come up before winters like last where the anomalies bucked the "normal" -ENSO trend...ie. lack of SE ridge, ridge in the SW instead, etc. Not every year follows it, but there is a general signal it seems in October.

The same general pattern signal carries through November, a bit stronger. However, it should be noted that the inverse signal for cold western winters does not show up in November as it does in October.

The same warm west/cold east signal is also somewhat present in September, though to a lesser degree.

[ORH_wxman]

Sorry, but I take any statistical "correlation" to surface temp over New England with a very small grain of salt.

In terms of long range forecasting, I look at surface temps for only two cases: 1) Over the south (along with soil moisture) for a feedback mechanism that could continue through the winter. 2) Over Canada and the arctic (in November) for the *capacity* of the airmass that could impact the northern tier.

Otherwise, there are number of patterns that may produce above normal or below normal temperatures at the surface in New England. The physical connection to the winter pattern is nearly non-existent / too convoluted to possibly apply in a forecast

I think the October NAO correlation has merit and therefore you can have some meaningful correlation with the winter temps. But I do agree "October temps=winter temps" here is a very dubious connection. Especially since the October NAO correlation is actually an inverse correlation...and the temp correlation is quite small to the NAO in October as well.