am19psu Posted October 30, 2013 Share Posted October 30, 2013 Haven't seen anyone comment on this elsewhere so figured I'd ask...is this legit?: https://www.facebook.com/notes/wxriskcom/-alert-major-development-for-the-winter-of-2013-14-negative-nao-is-likely/595932400454022I can't read that. Do you have a link to the actual regression work? Without knowing this guy's methods, I can't really comment. Link to comment Share on other sites More sharing options...
CVA Posted October 30, 2013 Share Posted October 30, 2013 I can't read that. Do you have a link to the actual regression work? Without knowing this guy's methods, I can't really comment. He claims that it's proprietary, but I'm not sure why. His only "hint" is that it's something to do with zonal winds in May and September. Or May TO September, I'm not sure. Link to comment Share on other sites More sharing options...
am19psu Posted October 30, 2013 Share Posted October 30, 2013 He claims that it's proprietary, but I'm not sure why. His only "hint" is that it's something to do with zonal winds in May and September. Or May TO September, I'm not sure.Then I wouldn't put a lot of stock in it. As far as the leading indicators go, this season should be more +AO than -AO. Link to comment Share on other sites More sharing options...
NaoPos Posted October 30, 2013 Share Posted October 30, 2013 Indian summer? Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted October 31, 2013 Share Posted October 31, 2013 Indian summer? 0z euro bringing adam torch for a few days next week Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 0z euro bringing adam torch for the rest of the monthfyp Link to comment Share on other sites More sharing options...
Quakertown needs snow Posted October 31, 2013 Share Posted October 31, 2013 0z euro bringing adam torch for rest of the month. fyp today is end of the month so no torch? Link to comment Share on other sites More sharing options...
HM Posted October 31, 2013 Author Share Posted October 31, 2013 fyp Are you worried about the second half's increasing AAM state and possible EPO? As long as the N PAC high isn't poleward, the low-level cold will not make it here. But, if the EPO is assertive enough, the SE ridge will end up bootleg, as we say, not providing the warmth it would appear to do, otherwise. Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 Are you worried about the second half's increasing AAM state and possible EPO? As long as the N PAC high isn't poleward, the low-level cold will not make it here. But, if the EPO is assertive enough, the SE ridge will end up bootleg, as we say, not providing the warmth it would appear to do, otherwise.I'm betting on the SE ridge at this time... but I'm happy to listen to alternatives. Shouldn't the strengthening PV keep the N PAC high from getting too far north? Link to comment Share on other sites More sharing options...
HM Posted October 31, 2013 Author Share Posted October 31, 2013 I'm betting on the SE ridge at this time... but I'm happy to listen to alternatives. Shouldn't the strengthening PV keep the N PAC high from getting too far north? Usually, I would bet on the warm anomaly in the N PAC retrograding too. However, the Ural Mountain PV may limit that, initially. Then, of course, there is this lol http://www.atmos.albany.edu/facstaff/roundy/waves/hovsdet/7.5S_7.5N/2013.png Definitely not as robust today with the MJO, and rightfully so...There are 30-31c SST sitting between 150-180. LOL Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 Usually, I would bet on the warm anomaly in the N PAC retrograding too. However, the Ural Mountain PV may limit that, initially. Then, of course, there is this lol http://www.atmos.albany.edu/facstaff/roundy/waves/hovsdet/7.5S_7.5N/2013.png Definitely not as robust today with the MJO, and rightfully so...There are 30-31c SST sitting between 150-180. LOL True, but there is still a KW collocated with the MJO. I'd hazard a guess that the VP/OLR response is still pretty strong over the Maritime Continent mid-month and probably stronger than currently forecast. I agree with you that late Nov-early Dec is setting up for some potential here, but I think we'll have to go through a torch first. Link to comment Share on other sites More sharing options...
HM Posted October 31, 2013 Author Share Posted October 31, 2013 What if the heart of the warm anomalies sit more in the S-C USA and expand outwardly from there to cooler near the border instead of the classic blowtorch look? Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 What if the heart of the warm anomalies sit more in the S-C USA and expand outwardly from there to cooler near the border instead of the classic blowtorch look?Like what the Euro ENS means show today? Link to comment Share on other sites More sharing options...
HM Posted October 31, 2013 Author Share Posted October 31, 2013 True, but there is still a KW collocated with the MJO. I'd hazard a guess that the VP/OLR response is still pretty strong over the Maritime Continent mid-month and probably stronger than currently forecast. I agree with you that late Nov-early Dec is setting up for some potential here, but I think we'll have to go through a torch first. Yeah, I think I may have been too late with my original thoughts on everything from a couple weeks ago. The torch in November and possible interesting wintry period in December may all shift earlier. But, there's still time... Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 Yeah, I think I may have been too late with my original thoughts on everything from a couple weeks ago. The torch in November and possible interesting wintry period in December may all shift earlier. But, there's still time...Also, you have to include my persistent early bias, so if I think late Nov-early Dec, you're mid-Dec call might be spot on Link to comment Share on other sites More sharing options...
HM Posted October 31, 2013 Author Share Posted October 31, 2013 Like what the Euro ENS means show today? I've only got them through day 10 but it appears to be heading that way then, yes. GEFS seemed to go that way somewhat too. Link to comment Share on other sites More sharing options...
HM Posted October 31, 2013 Author Share Posted October 31, 2013 Let's not forget the peak +QBO currently dominating Pacific Circulation (classic poleward anticyclones, off-equator forcing etc). Finally, the ITCZ and warm SST have shifted back toward the Equator. Will this connection work to keep the Aleutian High more poleward? My findings tried to focus on cooler ENSO regimes when the official state was "neutral" by the tri-monthly numbers. This ENSO state could be too warm...? Link to comment Share on other sites More sharing options...
NJwinter23 Posted October 31, 2013 Share Posted October 31, 2013 True, but there is still a KW collocated with the MJO. I'd hazard a guess that the VP/OLR response is still pretty strong over the Maritime Continent mid-month and probably stronger than currently forecast. I agree with you that late Nov-early Dec is setting up for some potential here, but I think we'll have to go through a torch first. Adam, I'm wondering if this is a very warm signal though this time of the year...the composites seem mixed about it...that tough time of the year with wavelengths. Link to comment Share on other sites More sharing options...
forkyfork Posted October 31, 2013 Share Posted October 31, 2013 the euro ens mean has a beast of a pv over the pole days 10-15 Link to comment Share on other sites More sharing options...
NJwinter23 Posted October 31, 2013 Share Posted October 31, 2013 the euro ens mean has a beast of a pv over the pole days 10-15 It does indeed have a stout +AO/NAO signal..but there is quite the blip of ridging that goes over alaska and into NW Canada between roughly days 7-13 that makes me a bit uneasy....by day 14-15 that ridge flattens out big time over the North pacific and it is fully ugly Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 Adam, I'm wondering if this is a very warm signal though this time of the year...the composites seem mixed about it...that tough time of the year with wavelengths.Yeah, HM and I were talking about that, too, offline. Stupid lambda. Link to comment Share on other sites More sharing options...
NJwinter23 Posted October 31, 2013 Share Posted October 31, 2013 Yeah, HM and I were talking about that, too, offline. Stupid lambda. Canada is looking very cold in the mid-range, do we behave more like winter wavelengths?? hmmmm Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 Canada is looking very cold in the mid-range, do we behave more like winter wavelengths?? hmmmmBattle zone would appear to be around here, because we should see an enhanced SE ridge. Link to comment Share on other sites More sharing options...
NJwinter23 Posted October 31, 2013 Share Posted October 31, 2013 Battle zone would appear to be around here, because we should see an enhanced SE ridge. No doubt...love love love that.... Link to comment Share on other sites More sharing options...
CVA Posted October 31, 2013 Share Posted October 31, 2013 Again, this is a very difficult concept differentiating between speed and momentum. Friction and westerly flow in the Mid Latitudes are always happening. We aren't saying these things are stopping. If the westerlies have intensified, this is a product of added momentum exceeding the effects of frictional dissipation. This added momentum can be from a mountain torque a couple of days ago or perhaps a wave train or convection. All exchanges with the Earth happen at the surface and the only sources/sinks for AAM are at the surface. AAM can be transported through the middle-upper troposphere / lower stratosphere but it can never be a source/sink. It can give an overall tendency or state of circulation that may affect the surface torques, but it cannot cause an AAM anomaly directly. Do all wave trains increase AAM? Does all tropical convection increase AAM? Trying to put together what you say above: if the active phase of the MJO is typically associated with low level westerlies, then the exchange at the surface must be a negative frictional torque. So maybe that should contribute to a negative d(AAM)/dt . However, there will obviously be a substantial upper level outflow, but this cannot itself be a source of AAM because in the closed earth-atmosphere system exchanges can only occur at the surface. So as far as I can tell: The WWB naturally increases the global AAM, but this begins to be damped (as soon as it starts?) by the frictional torque at the surface. So this leads to another question: does the increase in AAM in the region of active MJO get transported poleward, or is it completely damped by the friction so rapidly that it essentially goes nowhere? Or a little of both? What is the actual mechanism of poleward transport? What does it look like? Are we talking tropical sourced WCB's? The corollary is: what does equatorward transport actually look like (synoptically)? Example: Feb 2012, MJO active in western Pacific. (JMA image in Coral Sea) Though I'm a meteorologist this framework is entirely unfamiliar to me, so I have to do a lot of legwork. I do notice that the internet discussions can be fairly hand wavy, and you see statements like "there is currently a strong east Asian mountain torque event, and this may lead to x then y then z". I'm always thinking "slow down there". Explain step 1 to me! There is less asking of "well, why is there a strong mountain torque right now? What is actually happening? What are the physics behind this?". e.g. with the recent event, I can only surmise that it was favored by an anticyclone over the Tibetan Plateau combined with the remnants of TC Phailin SW of the Himalaya. But is this even right? It make sense to me, but most people seem content with just ogling the torque charts and leaving it at that. This is at 925hPa, even though that would be "underground" on the TP. Suggested literature: I have Weickmann/Kiladis/Sardeshmukh 1997, also the Berry/Weikmann MJO/GOW paper from a few years ago. Is there anything which looks even more synoptically/operationally at these things? I am probably stuck in my "small town operational" ways. When someone says things like "addition of westerly winds throughout the global tropics", I cannot logically follow any further because I cannot get out of the local perspective, where this "addition" may mean nothing operationally. If I were to treat the AAM as a diagnostic of current wind and pressure patterns (which....it surely must be?), then could a synoptic link be attained by running composites of high/low AAM months historically, to see (example below) what a high AAM November actually looks like in terms of synoptics? These are high AAM (>1SD from mean) Novembers. In the NH, boundary layer winds are "less westerly" in the North Atlantic and North Pacific, and something of a -AO pattern is evident. The "more westerly" areas are through the subtropics - is this related to enhanced subtropical jets? Is this to be expected in high AAM years? The question is: is THIS what a high AAM November should (must?) look like? Sorry for being a right pain and derailing the thread. Link to comment Share on other sites More sharing options...
am19psu Posted October 31, 2013 Share Posted October 31, 2013 Sorry for being a right pain and derailing the thread.You're not being a pain. This is exactly the purpose for which this thread is intended. Link to comment Share on other sites More sharing options...
Rainshadow Posted October 31, 2013 Share Posted October 31, 2013 CVA, Good questions. El Nino years the aam is normally higher so I would expect a stronger subtropical jet. Ed(?) Berry who used to be the SOO at WFO Goodland had a blog in which he went into much detail about the MJO and GWO. Unfortunately he left the NWS and I dont know if his private sector job prevents him from espousing. The literature you mentioned was one of the very few sources I could find myself. Link to comment Share on other sites More sharing options...
Met1985 Posted October 31, 2013 Share Posted October 31, 2013 Wow guys some great stuff in here. Most is over my head but learning a lot. Link to comment Share on other sites More sharing options...
Mike.Ventrice Posted November 1, 2013 Share Posted November 1, 2013 CVA, Good questions. El Nino years the aam is normally higher so I would expect a stronger subtropical jet. Ed(?) Berry who used to be the SOO at WFO Goodland had a blog in which he went into much detail about the MJO and GWO. Unfortunately he left the NWS and I dont know if his private sector job prevents him from espousing. The literature you mentioned was one of the very few sources I could find myself. Ed was at EarthRisk for a little while before moving to a new company sometime during the past 3-4 months I think somewhere in the central U.S., maybe OK? He's still in private sector and still writing about the GWO Link to comment Share on other sites More sharing options...
CVA Posted November 1, 2013 Share Posted November 1, 2013 CVA, Good questions. El Nino years the aam is normally higher so I would expect a stronger subtropical jet. Ed(?) Berry who used to be the SOO at WFO Goodland had a blog in which he went into much detail about the MJO and GWO. Unfortunately he left the NWS and I dont know if his private sector job prevents him from espousing. The literature you mentioned was one of the very few sources I could find myself. Thanks. I am sure I can't be the only person questioning the very basic mechanisms of this stuff! I did read a lot of the old atmospheric insights stuff, but as a "looking back and learning" resource it's a tricky one. You needed to be there it seems! I have dug up old powerpoint presentations from Ed Berry, along with material on the GSDM, and scouring the internet for forum discussions (e.g. http://forum.netweather.tv/topic/52083-gwo-and-global-angular-momentum/). Apart from this, there's a precious lack of "let's start from the ground up" material. Regarding your comment about the STJ and El Nino and AAM, I can at least make sense of that. It seems reasonable. I plotted GLAAM against SOI to see how they relate: Disclaimer: no fancy-dan statistics or filtering applied. Data grabbed. Data plotted. That's it. January only. OK! That seems decent enough. Higher SOI's (Nina) are typically located during periods of low AAM, and vice versa, though of course there are exceptions. Then I got a bit carried away. I must admit to being a bit gutted when I was plotting some composites and noticed that both January 1963 and January 1989 appeared as "low AAM years". That was somewhat dispiriting. I don't memorise seasons from the past, but I know those months were drastically different across the NH. So I plotted AAM against NAO for Jan, and really ought not be surprised in the mess that results: But I am surprised. If we pick a moderately high NAO value like 1.50 (ish), it seems like that can occur in both seriously high AAM periods and seriously low AAM periods. Perhaps a better approach would be to frequency bin these (or think about lag?), but the above chart is not promising, and actually is a little annoying. Surely there ought to be some sort of relationship? Link to comment Share on other sites More sharing options...
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