winter 2011-12 analogs

[nzucker]

The STJ was pretty much non-existent last year. We briefly had a pseudo STJ in the the 12/26 storm when the polar jet had a huge split flow out in the PAC and sent a southern stream gradient pretty far south. But the STJ zone in the PAC actually had negative zonal anomalies which is normal for a potent Nina.

I think it was mostly the Pacific jet diving abnormally far south last winter that gave us our snowstorms. The blocking allowed the Pacific jet to dig towards the Gulf for the 12/26 and first part of the 1/12 storms...we also had a very potent northern stream that gave us a good deal of clippers as well as the big SW flow events on 1/18 and 2/2.

OT but are you saying that 12/26 was a triple phaser?

It was not a triple phaser, as there was no phase with the polar vortex. All you had was a phase between the two streams of the Pacific jet, which had a split flow due to the blocking.

[ORH_wxman]

OT but are you saying that 12/26 was a triple phaser?

No...it was a very impressive double phased storm though.

[ORH_wxman]

I think it was mostly the Pacific jet diving abnormally far south last winter that gave us our snowstorms. The blocking allowed the Pacific jet to dig towards the Gulf for the 12/26 and first part of the 1/12 storms...we also had a very potent northern stream that gave us a good deal of clippers as well as the big SW flow events on 1/18 and 2/2.

It was not a triple phaser, as there was no phase with the polar vortex. All you had was a phase between the two streams of the Pacific jet, which had a split flow due to the blocking.

The NAO forced the polar jet very far south frequently last winter...which is why the southeast had a frigid winter despite a potent Nina. But since most of the storms were still dominated by the northern stream energy, that is why the M.A. got the shaft south of Philly. The 12/26 storm could have easily gotten DC/BWI, but it took a perfect wide turn and left hook to screw them...but that was more bad luck than anything as that storm was a Miller A.

[nzucker]

The NAO forced the polar jet very far south frequently last winter...which is why the southeast had a frigid winter despite a potent Nina. But since most of the storms were still dominated by the northern stream energy, that is why the M.A. got the shaft south of Philly. The 12/26 storm could have easily gotten DC/BWI, but it took a perfect wide turn and left hook to screw them...but that was more bad luck than anything as that storm was a Miller A.

The Southeast had, I believe, its coldest December on record. RDU (Raleigh, NC) was -8.1F and had 14 days with double-digit negative departures. Atlanta was -7.1F and had six days that were at least fifteen degrees below average. This is incredible for a strong La Niña, just shows that the Atlantic signal really can overpower the Pacific, something we assumed relatively impossible in a strong cold ENSO state. Previously, 55-56 was the best Niña winter for the bigger cities and further south, and even that year only had 35" of snow in NYC.

Actually, much of the South did OK with snowfall. The 12/26 storm destroyed ORF/Virginia Beach with 15" of snow, the 1/12 Nor'easter was originally from a Gulf Low that was disintegrating, but which had dumped some good snows in AL/GA, and NC had some nice clippers in December. I think it was mostly luck, as you say, that BWI and DCA got so little snow...they could have received far, far more in the 12/26 and 1/27 storms.

[ORH_wxman]

The Southeast had, I believe, its coldest December on record. RDU (Raleigh, NC) was -8.1F and had 14 days with double-digit negative departures. Atlanta was -7.1F and had six days that were at least fifteen degrees below average. This is incredible for a strong La Niña, just shows that the Atlantic signal really can overpower the Pacific, something we assumed relatively impossible in a strong cold ENSO state. Previously, 55-56 was the best Niña winter for the bigger cities and further south, and even that year only had 35" of snow in NYC.

Actually, much of the South did OK with snowfall. The 12/26 storm destroyed ORF/Virginia Beach with 15" of snow, the 1/12 Nor'easter was originally from a Gulf Low that was disintegrating, but which had dumped some good snows in AL/GA, and NC had some nice clippers in December. I think it was mostly luck, as you say, that BWI and DCA got so little snow...they could have received far, far more in the 12/26 and 1/27 storms.

Yeah they definitely could have had more, but its always an uphill battle in that area without the STJ. So while each individual storm could have gotten them, the margin for error wasn't large. This is why El Ninos are just so much better for the M.A.

We do not yet know enough about what makes the NAO tick to be very accurate at winter forecasts. As I said in the NE subforum, there are plenty of theories but nothing has really been solved yet. There's some strong correlations, but correlations are just a statistical method and do not explain the physical process behind the relationship.

I think I will almost laugh if this winter has a big +NAO when everyone goes for a -NAO in the fall if all of our theories line up supporting it.

[Isotherm]

I think I will almost laugh if this winter has a big +NAO when everyone goes for a -NAO in the fall if all of our theories line up supporting it.

I think I'll cry if that happens.

Past couple winters are starting to spoil us again. Anything under 40" will be a disaster.

[TheTrials]

I posted this yesterday in the blocking thread. My early early prediction.

http://www.americanwx.com/bb/index.php/topic/20920-summer-blocking-pattern-is-looking-familiar/page__view__findpost__p__793930

[SnowGoose69]

I'm still skeptical of those model predictions....I cannot tell from the data I am seeing but it appears to me that at no point in the summers of 1956, 1974 or 75, or 1999 did the ENSO index go above 0 ever....this makes me highly suspicious we are not even going to see a -0.5 anomaly this winter....much less anything lower than that.

[Chris L]

I think I'll cry if that happens.

Past couple winters are starting to spoil us again. Anything under 40" will be a disaster.

Tom, the whole decade of 2000s (exceptions for a few) has spoiled us royality....

[A-L-E-X]

I'm still skeptical of those model predictions....I cannot tell from the data I am seeing but it appears to me that at no point in the summers of 1956, 1974 or 75, or 1999 did the ENSO index go above 0 ever....this makes me highly suspicious we are not even going to see a -0.5 anomaly this winter....much less anything lower than that.

So your thinking right now is neutral? Cool neutral or warm neutral?

[SnowGoose69]

So your thinking right now is neutral? Cool neutral or warm neutral?

I'm thinking we might be between -0.2 and +0.2 most of the period November - March...could be the first true Nada since 01-02.

[A-L-E-X]

I'm thinking we might be between -0.2 and +0.2 most of the period November - March...could be the first true Nada since 01-02.

Hopefully the low solar and nao cycle will keep it from being like 89-90 or 01-02.... but, even so, I have a hard time believing it's going to be anything like the last two winters around here.

[forkyfork]

hopefully we get a strong nina with limited blocking

[MJO812]

hopefully we get a strong nina with limited blocking

I think you should move to San Diego.

[Analog96]

hopefully we get a strong nina with limited blocking

Why would any meteorologist want that? I can understand if you don't like snow, but shouldn't a meteorologist at least want a strong nino with limited blocking, so we can at least get heavy rain?

[TheTrials]

Why would any meteorologist want that? I can understand if you don't like snow, but shouldn't a meteorologist at least want a strong nino with limited blocking, so we can at least get heavy rain?

luckily that has almost zero chance of happening, no matter how hard he wishes it to happen.

[CooL]

Hopefully the low solar and nao cycle will keep it from being like 89-90 or 01-02.... but, even so, I have a hard time believing it's going to be anything like the last two winters around here.

it should be good. If the past 3 years are any indication at a pattern or trend, 31 out of the last 37 months have been -NAO dominated. ( saw that stat in the NE thread). Obviously a -NAO doesnt mean a guaranteed 50"+ winter, but its a good sign nonetheless IMO

[UncleSalty]

I'm thinking we might be between -0.2 and +0.2 most of the period November - March...could be the first true Nada since 01-02.

Even the NASA/GMAO has changed its tune big time compared to previous runs recently.

[Guest Pamela]

Past couple winters are starting to spoil us again. Anything under 40" will be a disaster.

The last 11 winters have been (overall) so anomallously snowy that expecting 2011-12 to follow suit might constitute going to the well once too often, even if every teleconnection on the planet points to a favorable outcome....perhaps February and March 2011 were harbingers that our luck will finally be exhausted....(not something I want...but rather a part of the natural order of things).

[Allsnow]

We are due for a junker. Climo catches up to us, for ever 10-11 winter there is more 07-08 to even out climo. I expect alot of southwest flow events. Earthlight and I ping to rain, while sne post pics of heavy snow.

[green tube]

We are due for a junker. Climo catches up to us, for ever 10-11 winter there is more 07-08 to even out climo. I expect alot of southwest flow events. Earthlight and I ping to rain, while sne post pics of heavy snow.

snow IMBY since 2000

6 years way above ave (over 37").

3 years roughly average (20 to 30").

3 years way below average (under 10").

the previous 12 years (1988 -1999)

2 years above ave.

2 years roughly average.

8 years below average.

[Allsnow]

snow IMBY since 2000

6 years way above ave (over 37").

3 years roughly average (20 to 30").

3 years way below average (under 10").

the previous 12 years (1988 -1999)

2 years above ave.

2 years roughly average.

8 years below average.

Real nice post green tube. Shows how spoiled we been and how climo evens out.

[JBG]

However, almost none of the models are showing a robust El Niño anymore, as the surge of warmth in the subsurface has mainly dissipated. I believe that a weak negative ENSO regime tends to be favorable for NYC metro, as the PV has more chance of being on the Canadian side of the hemisphere, the globe is slightly cooler, and we can see the presence of a subtropical jet although this is less likely given the La Niña "hangover" we will probably experience, unlike in 95-96, a weak La Niña that followed a moderate El Niño. Decent analogs for this winter could include 56-57, 59-60, 60-61, 71-72, 74-75, 00-01, and 08-09. The temperature composite looks like this:

I'd toss out 71-72 and 74-75 unless you expect little blocking. Also, nothwithstanding decent stats from 71-72 there was nothing exciting about that winter; a few inches before a change to rain is still a few inches before a change to rain, even if it adds up to 25-30 inches.

[Nikolai]

The last 11 winters have been (overall) so anomallously snowy that expecting 2011-12 to follow suit might constitute going to the well once too often, even if every teleconnection on the planet points to a favorable outcome....perhaps February and March 2011 were harbingers that our luck will finally be exhausted....(not something I want...but rather a part of the natural order of things).

Both 09-10 and 10-11 featured rather abrupt endings to winter, both occurring in February. 09-10 was particularly notable in DC as it snowed repeatedly and massively from 12/19-2/11 then stopped completely afterwards. 10-11 was similar in NYC, featuring non-stop cold/snow from 12/26-2/10 or so and then just thawing out completely. The dumps of snow in DC were definitely better than the storms in NYC, but the duration of the cold/snow in NY this past winter was much more impressive than what happened in DC, as the snow cover was continuous for almost two months, which was just unreal.

At this point I have a good feeling for NYC regarding the upcoming winter. Forecast out soon.

[SnowGoose69]

Both 09-10 and 10-11 featured rather abrupt endings to winter, both occurring in February. 09-10 was particularly notable in DC as it snowed repeatedly and massively from 12/19-2/11 then stopped completely afterwards. 10-11 was similar in NYC, featuring non-stop cold/snow from 12/26-2/10 or so and then just thawing out completely. The dumps of snow in DC were definitely better than the storms in NYC, but the duration of the cold/snow in NY this past winter was much more impressive than what happened in DC, as the snow cover was continuous for almost two months, which was just unreal.

At this point I have a good feeling for NYC regarding the upcoming winter. Forecast out soon.

There were a series of posts last year showing how the start/end periods of winter seem to cycle a bit with the various phases of the PDO and other factors...you often get blocks of snowier late Novembers/early Decembers with snowless Marches and then blocks of very little snow in the early winter and snowy March periods, the 60s and 70s were not very snowy in March but the 80s and 90s were, even the very poor winters often saw more snow in March than they did from December 1 -January 15...the last few years have definitely shown a tendency to be less snowy in March from what we'd been seeing.

[A-L-E-X]

There were a series of posts last year showing how the start/end periods of winter seem to cycle a bit with the various phases of the PDO and other factors...you often get blocks of snowier late Novembers/early Decembers with snowless Marches and then blocks of very little snow in the early winter and snowy March periods, the 60s and 70s were not very snowy in March but the 80s and 90s were, even the very poor winters often saw more snow in March than they did from December 1 -January 15...the last few years have definitely shown a tendency to be less snowy in March from what we'd been seeing.

I'd rather have the snow in December than in March lol-- lower sun angle means it stays on the ground longer, plus it's colder and it's the holidays!

[JBG]

There were a series of posts last year showing how the start/end periods of winter seem to cycle a bit with the various phases of the PDO and other factors...you often get blocks of snowier late Novembers/early Decembers with snowless Marches and then blocks of very little snow in the early winter and snowy March periods, the 60s and 70s were not very snowy in March but the 80s and 90s were, even the very poor winters often saw more snow in March than they did from December 1 -January 15...the last few years have definitely shown a tendency to be less snowy in March from what we'd been seeing.

The 1950's winters (if they could be called that) , 1966-7 and 1983-4 were very March-weighted.

[uncle W]

this is not updated for March 2011...the 1940's have the highest December average and the 1910's March...the 1950's were second for March...the 2000's were second for December...

NYC decade snow averages...

decade.......................Oct.....Nov.....Dec.....Jan.....Feb.....Mar.....Apr

.....total

1870-71 to 1879-80......0.1.....0.9.....6.7......9.7......8.8.....4.1......1.6.....31.9

1880-81 to 1889-90........0......1.8.....7.1......8.8......7.6.....6.8......0.7.....32.8

1890-91 to 1899-00........0......3.3.....4.3......8.7....10.6.....7.1......0.8.....34.8

1900-01 to 1909-10........0......0.3.....6.2......9.1......9.2.....4.8......0.6.....30.2

1910-11 to 1919-20........0......0.2.....7.5......4.8......9.5.....8.3......2.3.....32.6

1920-21 to 1929-30......0.1.....0.1.....4.2......8.5....10.1.....2.2......0.9.....26.1

1930-31 to 1939-40........T......2.2.....4.3......6.4......8.5.....3.5......0.8.....25.7

1940-41 to 1949-50........T......0.6.....9.1......7.4......8.6.....4.8......1.1.....31.6

1950-51 to 1959-60......0.1.....0.5.....4.7......5.2......3.4.....8.0......0.8.....22.7

1960-61 to 1969-70........T......0.3.....7.4......7.7....10.6.....4.6......0.1.....30.7

1970-71 to 1979-80........T......0.3.....1.7......7.3......9.5.....2.4......0.1.....21.3

1980-81 to 1989-90........0......0.6.....2.1......7.8......5.3.....2.9......1.1.....19.8

1990-91 to 1999-00........0......0.3.....2.9......6.9......9.1.....5.4......0.2.....24.8

2000-01 to 2009-10........T........T.....7.8......6.5.....13.3.....3.5......0.4.....31.5

2010-11 to 2019-20........0........T.....20.1...36.0......4.8

1870-71 to 2009-10........T......0.8.....5.4......7.5......8.9.....4.9......0.8.....28.3

1980-81 to 2009-10........T......0.3.....4.3......7.1......9.2.....4.0......0.6.....25.4

[A-L-E-X]

From Tipster.....

Typhoon Tip, on 24 July 2011 - 07:21 PM, said:

I won't speak for all of August but I am noticing something intriguing up N.

The AO index is positive for the first time in months. More so, nearing August 1st in doing so. Also, the GLAAM is trending to neutralize from its nader, which is an indication that mean torque is elevating - that supplies at least a background signal for increased zonal flow. Zonal flows tend to lead to the burgeoning of subtropical ridges... Another way to back into this conclusion is to observe that the JJA, NAO/GLAAM correlation coefficient is roughly .2 - not a huge positive value, no, but for atmospheric parlance that's actually a decent suggestion there for one reflecting - to some degree - the others phase state. It simple terms, with the AAM shedding the negative vibe, the NAO may tend to shed some of that negative vibe, too. The AO being positive is also a nice fit for that seeing as the AO and NAO obviously share domain space.

This is good for winter weather enthusiasts, though it tortures their wait. The reason it is good is that there is a fairly robust correlation between +AO phase states in ASO, leading -A0 during the winter. The reason (it is thought) that lag is there is because the +AO contracts storminess at high latitudes toward the poles where land-based snow and ice accumulation gets underway hard and fast and early. This lengthens the residence of the cryosphere, which is a huge positive feed-back on pooling negative anomalies for later transport scenarios. Throw in that we've entered a multi-decadal -NAO means good things for transport...

The index is not hugely positive, but is so nonetheless. Moreover, the last months verifications show somewhat of a bias to keep it negative by the GFS ensemble system - not hugely so, but there just the same. Bottom line, the longer the AO is positive in August --> September, the better.

Thanks for your very insightful post, John.... this explains my hot summer ----> snowy winter idea really well. I dont mind it scorching to oblivion right now, and then reaping white gold in the winter

[uncle W]

July's oni index was 0.0...The mei was -.147...We are in neutral territory now but will it stay this way or does a La Nina develop again or better an El Nino???La nada is the worse scenario...No year that rose above 0.2 on the oni index after being negative the previous winter became a la nina the next winter...they all became el nino's...I think the warming has ended and we will see negative oni readings again...Hopefully a weak la nina develops...