tombo82685 Posted December 4, 2012 Share Posted December 4, 2012 Thought it would be a good idea to maybe start a thread for people who want to learn more about weather related things. For instance, what is the MJO? How do you read a skew t? What is a sounding? What is mtn torque and what does it mean? Link to comment Share on other sites More sharing options...
tombo82685 Posted December 4, 2012 Author Share Posted December 4, 2012 I'll throw this one out there, so i don't bother Adam anymore on PM with questions. What is the QBO, and how do you read it and what affects does it have on the world and our pattern? Link to comment Share on other sites More sharing options...
Bobby EPAWA Posted December 4, 2012 Share Posted December 4, 2012 I do know that east based phases of the QBO support blocking, which is further support for a colder winter in the East, and a warmer winter in the West.... and the more negative the better? Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 I'll throw this one out there, so i don't bother Adam anymore on PM with questions. What is the QBO, and how do you read it and what affects does it have on the world and our pattern? I do know that east based phases of the QBO support blocking, which is further support for a colder winter in the East, and a warmer winter in the West.... and the more negative the better? The QBO simply describes the direction of the zonal winds in the stratosphere over the tropics. When the QBO is positive, winds are westerly, and when the QBO is negative, winds are easterly. It's called the quasi-biennial oscillation because it changes roughly every 27 months. The QBO by itself doesn't tell you much about the mid-latitude pattern overall. Yeah, a -QBO probably does have some relationship to the -NAO and -EPO, but it's pretty weak by itself. The DJF monthly correlation between the QBO index and the NAO index is only 0.12. HOWEVER, when you combine the QBO with solar information, you get the somewhat famous Holton-Tan relationship. They were the first to describe the climatology of SSWs with respect to the state of the QBO and solar cycle. When you have a -QBO and low solar, you are more likely to get SSWs in the heart of winter (e.g. 2009-2010) and when the QBO is positive and you're near solar peak, you can get a late winter SSW that locks in a late start to spring. Right now, the QBO is negative, but westerly winds are descending from the top of the stratosphere. If they can make it down to 50-100mb by February or so, we could be looking at the +QBO/+solar relationship. If not, a SSW is unlikely this year. Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 Here's a good paper on the troposphere-stratosphere connection: http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3010.1?journalCode=clim Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 Here are some more papers on the solar/QBO link: http://www.ugcs.caltech.edu/~mel/ge148a/strat_harbingers.pdf http://journals.ametsoc.org/doi/pdf/10.1175/JAS-3297.1 And the seminal Holton-Tan paper: http://www.atmos.washington.edu/~gcg/JR_site/papers/1980_6.pdf Link to comment Share on other sites More sharing options...
tombo82685 Posted December 4, 2012 Author Share Posted December 4, 2012 The QBO simply describes the direction of the zonal winds in the stratosphere over the tropics. When the QBO is positive, winds are westerly, and when the QBO is negative, winds are easterly. It's called the quasi-biennial oscillation because it changes roughly every 27 months. The QBO by itself doesn't tell you much about the mid-latitude pattern overall. Yeah, a -QBO probably does have some relationship to the -NAO and -EPO, but it's pretty weak by itself. The DJF monthly correlation between the QBO index and the NAO index is only 0.12. HOWEVER, when you combine the QBO with solar information, you get the somewhat famous Holton-Tan relationship. They were the first to describe the climatology of SSWs with respect to the state of the QBO and solar cycle. When you have a -QBO and low solar, you are more likely to get SSWs in the heart of winter (e.g. 2009-2010) and when the QBO is positive and you're near solar peak, you can get a late winter SSW that locks in a late start to spring. Right now, the QBO is negative, but westerly winds are descending from the top of the stratosphere. If they can make it down to 50-100mb by February or so, we could be looking at the +QBO/+solar relationship. If not, a SSW is unlikely this year. Thanks Adam, that cleared up somethings. So if im reading that qbo wind map, the positive winds are at around 10hpa right now correct? And you need it get between 50-100? Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 Thanks Adam, that cleared up somethings. So if im reading that qbo wind map, the positive winds are at around 10hpa right now correct? And you need it get between 50-100? Yes and yes Link to comment Share on other sites More sharing options...
tombo82685 Posted December 4, 2012 Author Share Posted December 4, 2012 Yes and yes In those links you gave does it have where to find if its high or low solar activity? And whats the link to that qbo image. Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 In those links you gave does it have where to find if its high or low solar activity? And whats the link to that qbo image. All the stratospheric-tropospheric monitoring stuff is here: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/ TBH, I rely on other people to tell me where we're at in the solar cycle. Solar has been a weakness of mine for some time now, but I haven't had enough time to get into it since I got promoted. Link to comment Share on other sites More sharing options...
Bobby EPAWA Posted December 4, 2012 Share Posted December 4, 2012 Wow it takes that long for westerlies to propagate to 100mb? So much for the clowns saying two weeks What would make the SSW occur so late (February) as you suggested? Very good information here, thank you. FWIW... QBO numbers are in for November, and currently -18.95. Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 Wow it takes that long for westerlies to propagate to 100mb? So much for the clowns saying two weeks What would make the SSW occur so late (February) as you suggested? Very good information here, thank you. FWIW... QBO numbers are in for November, and currently -18.95. I'm not entirely sure about the dynamics of the QBO. The reason why I was suggesting the late SSW is because we are near solar max (if the QBO can flip by February). Link to comment Share on other sites More sharing options...
Rainshadow Posted December 4, 2012 Share Posted December 4, 2012 I'm not entirely sure about the dynamics of the QBO. The reason why I was suggesting the late SSW is because we are near solar max (if the QBO can flip by February). No matter the cause, doesn't it seem that more SSW events happen in the latter half of the winter than the first half? Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 No matter the cause, doesn't it seem that more SSW events happen in the latter half of the winter than the first half? Right. +QBO/+solar = late season SSWs. -QBO/-solar = Jan/Feb SSWs. Link to comment Share on other sites More sharing options...
Bobby EPAWA Posted December 4, 2012 Share Posted December 4, 2012 So bottom line... pattern change is unlikely by mid to late December, and the Euro weeklies weeks 3 and 4 are probably b/s with the extensive blocking it is suggesting... Link to comment Share on other sites More sharing options...
am19psu Posted December 4, 2012 Share Posted December 4, 2012 So bottom line... pattern change is unlikely by mid to late December, and the Euro weeklies weeks 3 and 4 are probably b/s with the extensive blocking it is suggesting... That's my forecast... but I've been wrong before Link to comment Share on other sites More sharing options...
MGorse Posted December 4, 2012 Share Posted December 4, 2012 No matter the cause, doesn't it seem that more SSW events happen in the latter half of the winter than the first half? Geez, I really should read up on this stuff more. I had to look up what SSW means, which is Sudden Stratospheric Warming. Link to comment Share on other sites More sharing options...
Isotherm Posted December 4, 2012 Share Posted December 4, 2012 I'm not entirely sure about the dynamics of the QBO. The reason why I was suggesting the late SSW is because we are near solar max (if the QBO can flip by February). While true we're approaching solar max, I don't think the same conditions can be applied here given this solar cycle is about 50% of the previous cycle and probably the weakest cycle in general since the 1800s. Monthly sunspot numbers have been hanging in the 60-75 range and recent solar parameters are declining again. Last autumn was actually more active solar flux wise. Point being, with the -QBO still reasonably intact through at least mid winter, if a SSW occurs I would lean toward the period of the next several weeks rather than later winter. Could be wrong but I think we're closer to the -QBO/low solar relationship right now than +QBO/solar max. Link to comment Share on other sites More sharing options...
famartin Posted December 4, 2012 Share Posted December 4, 2012 This thread will be informative for us non-long term forecasters. Link to comment Share on other sites More sharing options...
tombo82685 Posted December 5, 2012 Author Share Posted December 5, 2012 Adam, is this what HM was talking about the wave 1 that affected the pv? and would you say this was a wave 1 response in trying to displace the pv and get a warming event? Link to comment Share on other sites More sharing options...
am19psu Posted December 5, 2012 Share Posted December 5, 2012 Adam, is this what HM was talking about the wave 1 that affected the pv? I think it's more instructive to use this graph (look at the middle one): http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/waves.gif There was a wave 1 and wave 2 signal last week that produced the vortex split. Now the wave 2 effect is going away and we're left with the wave 1 response. and would you say this was a wave 1 response in trying to displace the pv and get a warming event? The PV is going to be displaced. I mean, if you've been following Don S on the main board, he's been talking about AO values <-3. The problem is that it's being displaced over E Canada and Greenland, which still isn't good for us, because it sets up a +NAO. It's kinda like last year's SSW, where everyone else except N America went in the icebox. Sometimes you just get unlucky. Link to comment Share on other sites More sharing options...
tombo82685 Posted December 5, 2012 Author Share Posted December 5, 2012 I think it's more instructive to use this graph (look at the middle one): http://wekuw.met.fu-...cmwf1/waves.gif There was a wave 1 and wave 2 signal last week that produced the vortex split. Now the wave 2 effect is going away and we're left with the wave 1 response. The PV is going to be displaced. I mean, if you've been following Don S on the main board, he's been talking about AO values <-3. The problem is that it's being displaced over E Canada and Greenland, which still isn't good for us, because it sets up a +NAO. It's kinda like last year's SSW, where everyone else except N America went in the icebox. Sometimes you just get unlucky. ok thanks for the clarification. Also, that qbo map that you first posted what is the link to that? I don't see it in the link you sent me. Link to comment Share on other sites More sharing options...
am19psu Posted December 5, 2012 Share Posted December 5, 2012 ok thanks for the clarification. Also, that qbo map that you first posted what is the link to that? I don't see it in the link you sent me. It's the equatorial U wind time series on the CPC link Link to comment Share on other sites More sharing options...
Wow Posted December 5, 2012 Share Posted December 5, 2012 Moved this to the Wx 101 forum.. I left a link in the Phil forum so I will still be visible there. Link to comment Share on other sites More sharing options...
NCsandhills Posted December 5, 2012 Share Posted December 5, 2012 what causes blocking, and what causes it to stop? just the block just diappear or move? Link to comment Share on other sites More sharing options...
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