Big O Posted January 6, 2012 Share Posted January 6, 2012 The value of 2 will be corrected to 3 next month... doesn't make it any less remarkable though. AO flips hyper-neg going into Feb... could be similar to December 1978 flip IMO... here is my reasoning in three pictures: And yes, that thing in the third pic IS what you think it is. What effect would the depiction on the maps posted above have on sensible weather in the CONUS if it verifies? When would any such effect begin showing up in the models? Would arctic cold be limited to eastern 1/3, central, or western 1/3 of US? Link to comment Share on other sites More sharing options...
okie333 Posted January 6, 2012 Share Posted January 6, 2012 Larry Cosgrove's winter forecast describes where the cold would be best IMO, but I can't share that map, so here's one that's very close to it. Might extend a bit farther west than this though Link to comment Share on other sites More sharing options...
Geos Posted January 7, 2012 Share Posted January 7, 2012 Looks like a wind reversal has occurred at 60°N. Link to comment Share on other sites More sharing options...
wxmx Posted January 7, 2012 Share Posted January 7, 2012 Looks like a wind reversal has occurred at 60°N. No, it hasn't .... yet...black line is a forecast...and that's the 1mb level, for a SSW we should look at the 10mb level Link to comment Share on other sites More sharing options...
Geos Posted January 7, 2012 Share Posted January 7, 2012 No, it hasn't .... yet...black line is a forecast...and that's the 1mb level, for a SSW we should look at the 10mb level Ok, got it. Link to comment Share on other sites More sharing options...
wxmx Posted January 7, 2012 Share Posted January 7, 2012 SSW Jan 18-20th looking good now. I'm fairly confident this time. Link to comment Share on other sites More sharing options...
Srain Posted January 7, 2012 Share Posted January 7, 2012 SSW Jan 18-20th looking good now. I'm fairly confident this time. I agree, Jorge. The pattern is looking better by the day... Link to comment Share on other sites More sharing options...
NCMET Posted January 7, 2012 Share Posted January 7, 2012 Why are you so confident now (i.e. what has changed since yesterday)? SSW Jan 18-20th looking good now. I'm fairly confident this time. Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 7, 2012 Share Posted January 7, 2012 Maybe this? Link to comment Share on other sites More sharing options...
okie333 Posted January 7, 2012 Share Posted January 7, 2012 12Z isn't as impressive with the temps but it splits the vortex pretty well. Link to comment Share on other sites More sharing options...
WidreMann Posted January 7, 2012 Share Posted January 7, 2012 12Z isn't as impressive with the temps but it splits the vortex pretty well. Let's get some forecasts that have a timestamp from less than 144 hours in the future. Link to comment Share on other sites More sharing options...
usedtobe Posted January 7, 2012 Share Posted January 7, 2012 Why are you so confident now (i.e. what has changed since yesterday)? Probably that the forecast 10 mb zonal winds are forecast to go to negative and the 30 mb winds are decreasing. However, as I've said before, not all ssw events end up crushing the tropospheric vortex. The ones that do tend to have their ep flux vectors pointed towards the poles and the progs still show the vectors pointed away from the poles. Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 7, 2012 Share Posted January 7, 2012 Link to comment Share on other sites More sharing options...
NCMET Posted January 7, 2012 Share Posted January 7, 2012 Thanks for the response. I read your article yesterday and really enjoyed it. I don't understand nor pretend to understand the stratosphere and how it impacts the tropospheric pattern as the connections are poorly understood. But, you make things so much easier to understand and I really appreciate it. Probably that the forecast 10 mb zonal winds are forecast to go to negative and the 30 mb winds are decreasing. However, as I've said before, not all ssw events end up crushing the tropospheric vortex. The ones that do tend to have their ep flux vectors pointed towards the poles and the progs still show the vectors pointed away from the poles. Link to comment Share on other sites More sharing options...
usedtobe Posted January 7, 2012 Share Posted January 7, 2012 Thanks for the response. I read your article yesterday and really enjoyed it. I don't understand nor pretend to understand the stratosphere and how it impacts the tropospheric pattern as the connections are poorly understood. But, you make things so much easier to understand and I really appreciate it. Thanks, here's an article on the life cycle of ssw events. http://www-k12.atmos.washington.edu/~dennis/Limpasuvan_etal_JClim_04.pdf Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 7, 2012 Share Posted January 7, 2012 It appears in this forecast that there is a vector change toward the north as time goes on, and at an increasing rate. Link to comment Share on other sites More sharing options...
HM Posted January 7, 2012 Share Posted January 7, 2012 Wes makes a great point. Let's just say that the vortex breaks down completely and this thing downwells for February....so what. The problem then will become the AAM dropping off a cliff and the forcing heading back to phase 4-6. Now, if the Tropical Pacific behaves itself, then we have a very different story. Link to comment Share on other sites More sharing options...
wxmx Posted January 7, 2012 Share Posted January 7, 2012 Wes makes a great point. Let's just say that the vortex breaks down completely and this thing downwells for February....so what. The problem then will become the AAM dropping off a cliff and the forcing heading back to phase 4-6. Now, if the Tropical Pacific behaves itself, then we have a very different story. I'm not sure how this will end up, but one thing is almost certain, someone in the CONUS has the potential for a big change come early Feb... I see nothing like the almost record positive AO in December, even if the warming doesn't fully propagate. Cross polar flow/Arctic air will be available this time, IMO. Link to comment Share on other sites More sharing options...
HM Posted January 7, 2012 Share Posted January 7, 2012 I'm not sure how this will end up, but one thing is almost certain, someone in the CONUS has the potential for a big change come early Feb... I see nothing like the almost record positive AO in December, even if the warming doesn't fully propagate. Cross polar flow/Arctic air will be available this time, IMO. Definitely. The El Nino-like atmosphere coupled with the extraordinary +AO has made the northern Plains a blowtorch for months. They will see a major turn-around next week begin. Link to comment Share on other sites More sharing options...
usedtobe Posted January 7, 2012 Share Posted January 7, 2012 It appears in this forecast that there is a vector change toward the north as time goes on, and at an increasing rate. I think for downwelling you want the vectors on the plot that was shown baove pointed to the right instead of towards the left as that's the direction of the north pole. Someone can correct me it I'm wrong. Link to comment Share on other sites More sharing options...
HM Posted January 7, 2012 Share Posted January 7, 2012 I think for downwelling you want the vectors on the plot that was shown baove pointed to the right instead of towards the left as that's the direction of the north pole. Someone can correct me it I'm wrong. Keep in mind, the EP vectors did verify, for a few days, slightly poleward with this last warming and the longer-term ECMWF didn't indicate that would happen. I suspect they will trend poleward again with this one. Having said that, the situation with the "wave 2" response may shred that terrible reasoning. Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 7, 2012 Share Posted January 7, 2012 First time in my 56 years I've watched this so I find it extremely interesting. What I was seeing in the vectors was that the further into the forecast, the more "poleward" they were becoming. Instead of pointing left they became vertical, to me indicating they're forecast to veer more toward the north Just learning, correct me if I'm wrong! I see too that the winds at 10 and 30 seem to be slowing and at 1hpa seem to be (forecast) heading the other direction? Am I assuming correctly that the reversal of the winds in a SSW event are more important at the 30 hpa range? Link to comment Share on other sites More sharing options...
wxmx Posted January 7, 2012 Share Posted January 7, 2012 First time in my 56 years I've watched this so I find it extremely interesting. What I was seeing in the vectors was that the further into the forecast, the more "poleward" they were becoming. Instead of pointing left they became vertical, to me indicating they're forecast to veer more toward the north Just learning, correct me if I'm wrong! I see too that the winds at 10 and 30 seem to be slowing and at 1hpa seem to be (forecast) heading the other direction? Am I assuming correctly that the reversal of the winds in a SSW event are more important at the 30 hpa range? When there's a big planetary wave intrusion into the stratosphere you'll see the EP flux vector going more vertical... the flux is enhanced by such wave... but they do not always foretell a change to a poleward direction. As a matter of fact, the average direction of said flux 10 days prior and just a few after of an SSW are the most important according to research...so it doesn't look that promising. Though, EP flux is not the be all, end all of SSW propagations, so it still can happen. Link to comment Share on other sites More sharing options...
brad1551 Posted January 7, 2012 Share Posted January 7, 2012 Thanks, here's an article on the life cycle of ssw events. Great article! http://www-k12.atmos.washington.edu/~dennis/Limpasuvan_etal_JClim_04.pdf Link to comment Share on other sites More sharing options...
DaculaWeather Posted January 7, 2012 Share Posted January 7, 2012 I've been reading that, great stuff. Link to comment Share on other sites More sharing options...
chionomaniac Posted January 8, 2012 Share Posted January 8, 2012 Probably that the forecast 10 mb zonal winds are forecast to go to negative and the 30 mb winds are decreasing. However, as I've said before, not all ssw events end up crushing the tropospheric vortex. The ones that do tend to have their ep flux vectors pointed towards the poles and the progs still show the vectors pointed away from the poles. I have to say, Wes, looking at the ECM update this morning that is my one concern regarding any forthcoming SSW, as well. Looking at the T+240 mean zonal winds chart we see that the negative mean zonal winds are forecast to propagate away from the pole towards mid latitudes. Not what we want at all. We shall see if this changes. Link to comment Share on other sites More sharing options...
usedtobe Posted January 8, 2012 Share Posted January 8, 2012 I have to say, Wes, looking at the ECM update this morning that is my one concern regarding any forthcoming SSW, as well. Looking at the T+240 mean zonal winds chart we see that the negative mean zonal winds are forecast to propagate away from the pole towards mid latitudes. Not what we want at all. We shall see if this changes. The signal is even stronger today than yesterday. That's why I'm not yet buying the euro negative nao look. Usually most of the early changes are not in the north atlantic if I remember the typical progression from the composites. Plus the ens means don't really yet show it going negative. Anyway, this warming event is a great opportunity to learn. Link to comment Share on other sites More sharing options...
buckeye Posted January 8, 2012 Share Posted January 8, 2012 I have to say, Wes, looking at the ECM update this morning that is my one concern regarding any forthcoming SSW, as well. Looking at the T+240 mean zonal winds chart we see that the negative mean zonal winds are forecast to propagate away from the pole towards mid latitudes. Not what we want at all. We shall see if this changes. Wxrisk: "Now that the SSW event is fact and the winds have turned its balls to the wall... for someone" so are the winds favorable or not???? Is this a subjective thing? Link to comment Share on other sites More sharing options...
Nic Posted January 8, 2012 Share Posted January 8, 2012 http://policlimate.com/climate/gfs_ext_ao_bias.html Link to comment Share on other sites More sharing options...
chionomaniac Posted January 8, 2012 Share Posted January 8, 2012 Wxrisk: "Now that the SSW event is fact and the winds have turned its balls to the wall... for someone" so are the winds favorable or not???? Is this a subjective thing? I don't think it is a subjective thing. However, there is a lot that is still to be learnt. So far no SSW has occurred or been reliably forecast to occur. Link to comment Share on other sites More sharing options...
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