bluewave Posted November 8, 2014 Share Posted November 8, 2014 ........ Link to comment Share on other sites More sharing options...
Kory Posted November 8, 2014 Share Posted November 8, 2014 Didn't we transition to a -PDO regime around the turn of the 21st century? That would be a somewhat short -PDO regime, if I recall correctly, they usually last 20-30 years. I think the next several months will be telling if we are transitioning into a +PDO regime. Could this be like the late 50s? That was an overall -PDO regime, but had a 2 year period of +PDO values. Link to comment Share on other sites More sharing options...
thewxmann Posted November 9, 2014 Share Posted November 9, 2014 Didn't we transition to a -PDO regime around the turn of the 21st century? That would be a somewhat short -PDO regime, if I recall correctly, they usually last 20-30 years. I think the next several months will be telling if we are transitioning into a +PDO regime. Could this be like the late 50s? That was an overall -PDO regime, but had a 2 year period of +PDO values. There can be transient +PDO spikes within a long-term -PDO cycle. For the sake of CA I hope the PDO can turn negative again. Link to comment Share on other sites More sharing options...
SoCoWx Posted November 9, 2014 Share Posted November 9, 2014 There can be transient +PDO spikes within a long-term -PDO cycle. For the sake of CA I hope the PDO can turn negative again. I sure do hope they get some rain this winter, really I do. But us snow lovers out east also need the PDO positive. Link to comment Share on other sites More sharing options...
JBG Posted November 9, 2014 Share Posted November 9, 2014 Didn't we transition to a -PDO regime around the turn of the 21st century? That would be a somewhat short -PDO regime, if I recall correctly, they usually last 20-30 years. I think the next several months will be telling if we are transitioning into a +PDO regime. Could this be like the late 50s? That was an overall -PDO regime, but had a 2 year period of +PDO values.The consensus is that we transitioned, I believe,in 2007, though some use the end of the Super Niño of 1998 as the switchover date. My own evolving view is that the PDO periods were less drastic prior to the 1917 witch to PDO positive and that we may be headed to a less pronounced oscillation. Link to comment Share on other sites More sharing options...
wildweatherman179 Posted November 9, 2014 Share Posted November 9, 2014 I like that you mentioned 1917-18 there. That was a very extreme case but has been on my mind since August. The early frosts in the north and the overall description of that autumn to date are uncannily similar. Didn't actually know about the PDO flip that year but I don't think it to be mere coincidence. Link to comment Share on other sites More sharing options...
JBG Posted November 10, 2014 Share Posted November 10, 2014 I like that you mentioned 1917-18 there. That was a very extreme case but has been on my mind since August. The early frosts in the north and the overall description of that autumn to date are uncannily similar. Didn't actually know about the PDO flip that year but I don't think it to be mere coincidence.Similar time to 1977-9. I don't know that the flip was exactly that year but I believe it was 30 years or so before 1947, the time of the flip in the other direction, towards cold phase. Link to comment Share on other sites More sharing options...
andyhb Posted November 10, 2014 Share Posted November 10, 2014 Similar time to 1977-9. I don't know that the flip was exactly that year but I believe it was 30 years or so before 1947, the time of the flip in the other direction, towards cold phase. The flip to a +PDO regime in that time period was around 1924. Link to comment Share on other sites More sharing options...
JBG Posted November 10, 2014 Share Posted November 10, 2014 The flip to a +PDO regime in that time period was around 1924.Thanks. Years such as 1969-70 and 1970-71 would thus be analagous in terms of distance to the flip. I remember those featuring bone-warping cold, and being snowy to inconsistent on snow. Link to comment Share on other sites More sharing options...
Kory Posted November 10, 2014 Share Posted November 10, 2014 Here's a good graph, showing general transition periods. This is using the University of Washington's data. Link to comment Share on other sites More sharing options...
wildweatherman179 Posted November 10, 2014 Share Posted November 10, 2014 It appears on the chart that 1917-18 would have been a spike in an overall pdo- correct? Link to comment Share on other sites More sharing options...
GaWx Posted November 18, 2014 Share Posted November 18, 2014 Third highest October +PDO since 1950. http://jisao.washington.edu/pdo/PDO.latest 1997....1.61 1957....1.50 2014....1.49 1993....1.41 1987....1.36 Pretty impressive. Not surprisingly, only one wasn't during El Niño. Link to comment Share on other sites More sharing options...
skierinvermont Posted November 19, 2014 Share Posted November 19, 2014 I'm not convinced the pdo always has had or will have pronounced 30 year phases. This could be the beginning of a 10 year+ pdo. Or it could bounce positive and negative. Or go back into a negative phase. Link to comment Share on other sites More sharing options...
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