donsutherland1 Posted December 5, 2011 Share Posted December 5, 2011 That can't be right the AO is over +4 right now... It isn't. For some reason, the GFS ensembles have not initialized the AO correctly for at least two days. Yesterday's initialization was off by more than 2 standard deviations. Currently, the AO is +4.850. Link to comment Share on other sites More sharing options...
EasternUSWX Posted December 5, 2011 Share Posted December 5, 2011 It isn't. For some reason, the GFS ensembles have not initialized the AO correctly for at least two days. Yesterday's initialization was off by more than 2 standard deviations. Currently, the AO is +4.850. Where do you get that information? Of course something from the NWS would be dysfunctional. Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 5, 2011 Share Posted December 5, 2011 Where do you get that information? Of course something from the NWS would be dysfunctional. The most recent readings of the major teleconnection indices, including the AO, can be found at: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/daily.index.ascii As for the second issue, any computer system can have periodic issues. The current computer issue does not take away from the many outstanding products offered by NWS. Link to comment Share on other sites More sharing options...
EasternUSWX Posted December 5, 2011 Share Posted December 5, 2011 The most recent readings of the major teleconnection indices, including the AO, can be found at: http://www.cpc.ncep....ily.index.ascii As for the second issue, any computer system can have periodic issues. The current computer issue does not take away from the many outstanding products offered by NWS. They do have good products they just don't work all the time. They could have taken it down if it is not working. Anyway, thanks for the link. Link to comment Share on other sites More sharing options...
brad1551 Posted December 6, 2011 Share Posted December 6, 2011 Looking at the amazing +AO makes me wonder about this years winter. I live in the West Suburbs of Dc Metro Area.The most important thing or lets just say one of the most important factors to having a normal snow totals throughout the winter is the AO. Right now I am not seeing anything to write the winter off. I am a little nervous for the ones who love snow. I can live without it, but I know others like my wife who might be a little dissappointed this year. Its only December and we still have Jan, Feb, March. Anyhting is possible and I mean anything is! In my area it can be mild one week and stormy and snowy the next. I will say it again, this winter in my book will still be average all around the board, its just going to take a little bit to gert started. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 6, 2011 Share Posted December 6, 2011 The stratosphere continues to be ice cold overall. There have been little warm eddies rotating around the vortex at 10mb, but the +AO is here to stay for a while. Link to comment Share on other sites More sharing options...
usedtobe Posted December 6, 2011 Author Share Posted December 6, 2011 The stratosphere continues to be ice cold overall. There have been little warm eddies rotating around the vortex at 10mb, but the +AO is here to stay for a while. I agree, I just want it to last thru dec so I won't look like dummy in my CWG piece as there was at least one CWG guy who doesn't think the AO is predictable past a week or so. I think that's often true but not this year but we'll see. Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 7, 2011 Share Posted December 7, 2011 I agree, I just want it to last thru dec so I won't look like dummy in my CWG piece as there was at least one CWG guy who doesn't think the AO is predictable past a week or so. I think that's often true but not this year but we'll see. The question "what will the AO be?" in X days is very different from the question "Is the AO likely to remain + through X days." Given that 4/5 AO+ regimes during which the AO peaked at +5 or above lasted 40 days or longer, it's a reasonable bet to argue that the AO is likely to remain positive through December. "Likely," of course does not mean "certain." Whether it will be +1, +2, +3, etc. is an entirely different matter. Link to comment Share on other sites More sharing options...
usedtobe Posted December 7, 2011 Author Share Posted December 7, 2011 The question "what will the AO be?" in X days is very different from the question "Is the AO likely to remain + through X days." Given that 4/5 AO+ regimes during which the AO peaked at +5 or above lasted 40 days or longer, it's a reasonable bet to argue that the AO is likely to remain positive through December. "Likely," of course does not mean "certain." Whether it will be +1, +2, +3, etc. is an entirely different matter. I agree but think some in academic world don't look at the stats as much and base their thoughts on predictions mostly on the ensemble mean forecasts and the correlations between the forecast numbers and the observed. In reality, this year if you did some type of bias correction on forecasts I bet the correlations would be quite a bit higher and think that is kind of typical when you have a really potent polar vortex or a really potent blocking pattern that is related to a weaker than normal polar vortex. The problem is its hard to get enough cases to prove statistical significance. 5 cases isn't enough to prove that the next really AO that peaks is really more likely to last over 30 days than not. Forecasters (guys like me) aren't as worried about that since we often play with less than a full deck and still need to try to make some type of guess about the upcoming weather. Link to comment Share on other sites More sharing options...
donsutherland1 Posted December 7, 2011 Share Posted December 7, 2011 I agree but think some in academic world don't look at the stats as much and base their thoughts on predictions mostly on the ensemble mean forecasts and the correlations between the forecast numbers and the observed. In reality, this year if you did some type of bias correction on forecasts I bet the correlations would be quite a bit higher and think that is kind of typical when you have a really potent polar vortex or a really potent blocking pattern that is related to a weaker than normal polar vortex. The problem is its hard to get enough cases to prove statistical significance. 5 cases isn't enough to prove that the next really AO that peaks is really more likely to last over 30 days than not. Forecasters (guys like me) aren't as worried about that since we often play with less than a full deck and still need to try to make some type of guess about the upcoming weather. I strongly agree, Wes. The 5 cases is far from adequate for a competent paper. They might add some insight into venturing a forecast (usual caveats about forecasts are in order). Link to comment Share on other sites More sharing options...
uncle W Posted December 7, 2011 Share Posted December 7, 2011 the November AO was +1.459...Other Novembers with a plus 1.000... 1993...+1.002 1994...+1.779 1978...+2.470 ................................................................ 1978 went from +4 days to -4 days in a few months... Link to comment Share on other sites More sharing options...
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