So Far We Are Following The -PDO/+AMO Playbook

[bluewave]

The last time the -PDO overlapped with the +AMO for an extended period of time was from 1946-1963.

When that period is viewed in its totality,a pattern emerges that is similar to our recent weather and climate events.

Its interesting to note that the recent very snowy winters resemble winter patterns that we experienced during that era.

One feature that jumps out at you is the very snowy Decembers back then.

12/26-12/27,1947 26.4 inches of snow in Central Park

12/19-12/20,1948 16.0

12/11-12/12,1960 15.2

12/26-12/27 2010 20.0

monthly snowfall amounts

DEC 1947......29.6

DEC 1948.... 25.3

DEC 1959....15.8

DEC 1960.... 18.6

DEC 2010....20.9

seasonal snowfall totals

Back to back heavy snowfall seasons

47-48.....63.2

48-49.....46.6

59-60.....39.2

60-61.....54.7

09-10.....51.4

10-11.....61.9

2009-2010 was the snowiest strong El Nino winter since 57-58 when 44.7 inches fell in Central Park.

The MEI registered +1.7 during both those winters.

While the blocking of the last two winters was record breaking,that era saw a weaker version of the pattern.

54-63 winters

10-11 winter

The back to back hot summers that we are currently experiencing were common during the late 40's into the 50's.

A big ridge north of Hawaii and corresponding ridge in the East was a persistent summer pattern.

48-57 summers

09-10 summer

100 degree days at Central Park.

http://www.erh.noaa....100degdays.html

East Coast hurricane and tropical storm potential will be something to watch for in this pattern.

While the increase began in the 1930's and 1940's,the 51-60 period was extremely

active for the East Coast.Hanna back in 2008 was a weaker version of storms from that

era.

[TheTrials]

It's on its way. Looking forward to seeing the late summer and fall trends. Excellent work as always bluewave

[bluewave]

It's on its way. Looking forward to seeing the late summer and fall trends. Excellent work as always bluewave

Thanks.It will be interesting to watch going forward.

[TheTrials]

Thanks.It will be interesting to watch going forward.

I'm feeling it, especially given how quiet the sun is.

[CAT5ANDREW]

Excellent research!!! We are loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong overdue for a true hurricane here.I am talking about one that actually produces 75+MPH winds in the 5 boroughs and Nassau cty.Belle in AUG 1976 was the most intense tropical storm in my lifetime.70MPH winds and several inches of intense rainfall.

[uncle W]

great job...The 1950's was a lean snow decade but tropical storms were frequent...

[SnowGoose69]

You'd figure sooner or later a significant hurricane is going to hit long island...its been amazing how inactive the past 16 years have been considering the activity in the Atlantic basin as a whole...if you told me in November 1996 following the 2nd straight active season that we'd be saying in 2011 that a direct hit had yet to happen on L.I. since Bob I'd have laughed.

[SACRUS]

Great stuff Bluewave. I always look fwd to reading your threads. Its intersting going through the records for our area and seeing so many in this timeframe, especially in July. I havent seen the precip dpeartures but suspect the period was drier on whole as well. It seems that since last year we have been drier than the prior few years.

[CAT5ANDREW]

Great stuff Bluewave.  I always look fwd to reading your threads.  Its intersting going through the records for our area and seeing so many in this timeframe, especially in July.  I havent seen the precip dpeartures but suspect the period was drier on whole as well.  It seems that since last year we have been drier than the prior few years.

We are overdue for a prolonged dry spell.Everytime we get one to start,it is reversed by heavy rainfall.Sooner or later we are going to have a 12 month period where we average 15-20% less in precip.

[Isotherm]

Good post as usual Bluewave. The period we're in now pretty much intersects with the -PDO/+AMO time frame of the 1950s. The start of the -NAO decadal cycle also occurred around 1946-47 with that stretch of snowy winters.

The main difference b/t then and now is the solar regime. Geomag activity extremely low to non-existant the past few years and the prolonged minimum has no doubt aided in lengthening the duration of the -NAO as well as intensifying it. Aside from a handful of months here and there, we've essentially seen a negative modality of the NAO since 2008. Does this continue into the upcoming winter? Well this summer is once again featuring polar blocking, much like the past 2 summers, and with ENSO neutralizing in the means, I see no forcing atm that promotes a +NAO. Will have to monitor solar trends this autumn, but it should be interesting to follow.

As far as the Aug/Sept pattern, I favor a trough sitting in the Lakes/OH valley which is conducive for east coast tropical activity. Don't know whether we'll get hit directly, but I anticipate a rapid awakening of the tropics within the next couple weeks.

[A-L-E-X]

Good post as usual Bluewave. The period we're in now pretty much intersects with the -PDO/+AMO time frame of the 1950s. The start of the -NAO decadal cycle also occurred around 1946-47 with that stretch of snowy winters.

The main difference b/t then and now is the solar regime. Geomag activity extremely low to non-existant the past few years and the prolonged minimum has no doubt aided in lengthening the duration of the -NAO as well as intensifying it. Aside from a handful of months here and there, we've essentially seen a negative modality of the NAO since 2008. Does this continue into the upcoming winter? Well this summer is once again featuring polar blocking, much like the past 2 summers, and with ENSO neutralizing in the means, I see no forcing atm that promotes a +NAO. Will have to monitor solar trends this autumn, but it should be interesting to follow.

As far as the Aug/Sept pattern, I favor a trough sitting in the Lakes/OH valley which is conducive for east coast tropical activity. Don't know whether we'll get hit directly, but I anticipate a rapid awakening of the tropics within the next couple weeks.

I was thinking about the comparison to the 50s also, and wondering why the winters and the tropical activity patterns havent matched up so far and this would be the reason why. The solar regime is vastly different now than it was back then. Interesting how it isnt really affecting our hot summers though lol.

[A-L-E-X]

We are overdue for a prolonged dry spell.Everytime we get one to start,it is reversed by heavy rainfall.Sooner or later we are going to have a 12 month period where we average 15-20% less in precip.

I miss the dry summers of the 80s and 90s, glad we're getting back to that now I would like to get rain once a week or so but not every other day lol.

[bluewave]

I was thinking about the comparison to the 50s also, and wondering why the winters and the tropical activity patterns havent matched up so far and this would be the reason why. The solar regime is vastly different now than it was back then. Interesting how it isnt really affecting our hot summers though lol.

The early 50's winter pattern was similar to 2008 with the low snowfall amounts due to the lack of blocking.

The winter of 1947-1948 was similar to 2010-2011 here with snowfall and the progression from December blocking to a February SE Ridge pattern.

This time around we had record breaking blocking pattern that was more intense than back then.

Dec 47

Feb 48

Dec 10

Feb 11

[bluewave]

Great stuff Bluewave. I always look fwd to reading your threads. Its intersting going through the records for our area and seeing so many in this timeframe, especially in July. I havent seen the precip dpeartures but suspect the period was drier on whole as well. It seems that since last year we have been drier than the prior few years.

Thanks.I really enjoy reading reading your threads and posts also.You're right that it was a drier period back then.NYC dropped just under the 50 inch precip mark in 2010 for the first time since 2003.

[bluewave]

Good post as usual Bluewave. The period we're in now pretty much intersects with the -PDO/+AMO time frame of the 1950s. The start of the -NAO decadal cycle also occurred around 1946-47 with that stretch of snowy winters.

The main difference b/t then and now is the solar regime. Geomag activity extremely low to non-existant the past few years and the prolonged minimum has no doubt aided in lengthening the duration of the -NAO as well as intensifying it. Aside from a handful of months here and there, we've essentially seen a negative modality of the NAO since 2008. Does this continue into the upcoming winter? Well this summer is once again featuring polar blocking, much like the past 2 summers, and with ENSO neutralizing in the means, I see no forcing atm that promotes a +NAO. Will have to monitor solar trends this autumn, but it should be interesting to follow.

As far as the Aug/Sept pattern, I favor a trough sitting in the Lakes/OH valley which is conducive for east coast tropical activity. Don't know whether we'll get hit directly, but I anticipate a rapid awakening of the tropics within the next couple weeks.

Thanks,It will be interesting to see how things go.At least with the few analogs that we have for great winter blocking events,there was some blocking carry over into the

third season.We'll have to montior the fall pattern going into the winter to see how its going.

[bluewave]

Excellent research!!! We are loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong overdue for a true hurricane here.I am talking about one that actually produces 75+MPH winds in the 5 boroughs and Nassau cty.Belle in AUG 1976 was the most intense tropical storm in my lifetime.70MPH winds and several inches of intense rainfall.

great job...The 1950's was a lean snow decade but tropical storms were frequent...

You'd figure sooner or later a significant hurricane is going to hit long island...its been amazing how inactive the past 16 years have been considering the activity in the Atlantic basin as a whole...if you told me in November 1996 following the 2nd straight active season that we'd be saying in 2011 that a direct hit had yet to happen on L.I. since Bob I'd have laughed.

Thanks.I guess that the delay happened here since 2001-2010 was really a Gulf of Mexico and Florida decade.

[Alpha5]

Just a quick question..... How does the pdo affect the jet inthe pacific. In other words how does if affect our weather? I did some research but can't find anything conclusive