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About Tim198

  • Birthday 08/17/1989

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  1. It could, but you have to remember that the pacific/EPO is more strongly correlated to temps than the AO or NAO. For example, the AO was negative for almost the entire winter of 2012-13 yet that winter was warm for almost the entire country thanks to the pacific. December 2001 had a negative AO AND NAO and was the warmest December on record for New York City until 2015. The list goes on... I know the easterlies are forcing related, but look, for example, how the very east based easterly QBO years, the ones that failed to produce and Alaskan vortex were behaving compared to this year, It's RADICALLY different. I think a six week period is more than enough time to gauge how the atmosphere is behaving.
  2. I'm going to actually have to disagree with most of what you said here. http://ionlyusethegfs.blogspot.com/2012/04/qbo-aleutian-high-relationship.html First of all, you claim that a negative/easterly QBO is favorable for western ridging. I can't find any evidence or research to support that. The only definitive research I've found regarding the QBO comes from Anthony Masiello. I have posted the link to that. His research shows that in roughly 80% of easterly years the pacific ridge is flatter/displaced further southward. This allows low heights to develop over Alaska. The opposite is true during westerly years. You also mention that this event is east based. Well, that's true, but only when you focus on SST's. Atmospherically, It's very west based. I've posted a graphic of the 850mb wind anomalies so far for this Autumn. It indicates a very west based event with all of the strong easterlies focused west of the dateline. There are actually only a few years I've found that were similar to this year in that regard. The best match was easily 1999, and I've posted the wind anomalies below for comparison, but other years like 1998 and 2011 were quite similar also. What's interesting is that these winters were all quite similar in the pacific. There was a very strong and persistent vortex over Alaska that allowed most of the CONUS to be flooded with warm pacific air for the majority the winter. I think there's a good chance something similar happens this year not only because of how west based the event is but also because this is also an easterly QBO year. You mention 2000-2001 as an analog for the winter. I disagree with that. You claim the PDO was responsible for forcing the ridge in the west that year but if you look at the PDO data you'll see that PDO didn't really begin to rise until AFTER that +PNA/-EPO pattern set up in November/December. I think the reason the ridge developed in the west was because there was a large amount of enhanced westerly flow in the tropics that year. In the graphic I posted below you can see a large band of westerlies draped across almost the entire tropical north pacific with just a small area of enhanced easterlies by the Philippines. This pattern was quite unusual and I can't find another year nina or cold neutral year that was quite like it. If anything, it was more similar to some Nino years.
  3. I never said he was forecasting a positive AO this winter. Indeed, it sounds like he believes it will be negative. I was just responding to Snowman's post which was discussing reasons the NAO might be positive and wanted to add what Masiello said about how research suggests high geomagnetic activity favors a positive NAO/AO. I personally believe the AO may average negative this winter but others factors will not allow for a cold winter.
  4. Good post snowman. Anthony Masiello's also saying on twitter that the recent high geomagnetic activity could argue for a positive NAO/AO winter. https://twitter.com/antmasiello/status/791650919997841408
  5. I wouldn't worry about the SOI too much. It can be very volatile at times. The 30 day was near +14 just a couple weeks ago. The trade winds near the dateline are still fairly strong (and are forecast to strengthen at the beginning of November). The oceanic heat content has also decreased. So while I don't necessarily see much strengthening I think the weak nina will stick around for a while longer.
  6. Yes, I do realize that there's a lot of warm water SE of Hawaii and that's definitely not typical of a negative PDO. But, you also need to look at what's going on in the north PAC. When you look at this past September, for example, you can the warmest SSTs are closer to 150W rather than hugging the west coast. There's actually a weak cool tongue along the west coast. That indicates a negative PDO. A great example of a positive PDO regime would be September 1995 (which registered at 1.02 on the NOAA dataset). You can see the warmest water is hugging the west coast with colder SST further west.
  7. I personally don't consider any data that's not from NOAA to be official. That website must use a different method for calculating the PDO than NOAA. The NOAA SST maps have clearly shown a negative PDO for the past few months and it's official index supports that. I just posted the 500mb height anomalies for October 1998 and that year also had an Alaskan ridge and NW trough. That year was a moderate/borderline strong nina. I suspect this pattern might be caused by the lingering effects of the strong Nino we had that year and also this year, as well as tropical forcing. The PDO for September of this year (-1.06) was much closer to 1998 (-1.54) than 1984 (0.14) in the official NOAA dataset.
  8. I've heard a lot of talk about the year 2013 as a possible analog for this year but the tropical forcing is behaving quite differently so far. This year has far more supression near the dateline then 2013 did. There was also more forcing in the western Indian Ocean and less in the east that year. 2013 also didn't have the strong westerly zonal wind anomaly in the Indian Ocean. It was actually slightly negative (easterly) that year. There was also no strong negative IOD like we saw this year. The IOD was neutral to slightly positive that year.
  9. If you look at things strictly from the SST perspective then yes, it is a piss poor excuse for a Nina. But if you look at tropical forcing it tells a different story. I took a look at the Autumn OLR anomalies for all negative neutral and weak nina years since 1979 (peak ONI of less than -1.0). The years I included were 1980, 1981, 1983, 1985, 1989, 1996, 2000, 2001, 2005, 2008, 2011, 2012 and 2013. I found the forcing to be in a more nina like state (suppression near the dateline and enhanced forcing in western pacific and indian ocean) this year then in any of those other years. The closest match out of all of those years is probably 1996 but I actually found the much stronger nina year of 1998 to be a better match then any of the weaker years.
  10. Here is the POAMA snowfall forecast. It shows well below normal snowfall for the east.
  11. Here is the latest 500MB height forecast for the winter from the POAMA model. It does appear to have a negative NAO for December but overall looks quite warm for most of the CONUS.
  12. I know there's been some discussion on the subject already, but Anthony Masiello had a few interesting tweets regarding the Indian Ocean and tropical forcing. He noted how strong the westerly wind anomalies have been in the Indian Ocean have been so far this autumn and also provided a list of the other years with strong westerly wind anomalies in the autumn. He also noted how similar the tropical forcing is this year compared to those years. (The exception is that there's more off-equator OLR this year. He blamed that on the positive QBO and global warming.) I decided to take a look at what the tropical forcing was like during the winters of the years on the list and found that the tropical forcing in the Indian Ocean does tend to weaken and the strongest forcing shifts north toward the Philippines. It's interesting that the POAMA model suggests the same thing will happen this winter and, indeed, it's OLR forecast for winter looks very similar to the other years on the list. As far as winter is concerned, it's interesting to note that the years on the list generally led to warm winters in the east. The more recent years in particular were very warm in the east. It will be interesting to see what happens this year.
  13. The UKMET forecast I posted is the H5 anomaly forecast. It supports warmth with a strong WAR. The CanSIPS also has a strong WAR. I don't have the forecasts from the NMME and POAMA.
  14. Even though the EURO has done well in recent years I have to treat it with some skepticism. Why? Because it's an outlier compared to most of the other seasonal models. The NMME, CanSIPS, POAMA and UKMET all have a warm look for the east and most of the CONUS in general.