CT Rain Posted December 31, 2015 Share Posted December 31, 2015 Very nice discussion here this morning. I think we can break down 2 week periods through most of January and that looks much better vs progs 10 days ago. February can be really good or crap the bed...we should have a better idea in about 2 more weeks. I think that's a fair description. Let's hope for something fun - this boredom is killing me! Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2015 Share Posted December 31, 2015 Windex Monday? Link to comment Share on other sites More sharing options...
Isotherm Posted December 31, 2015 Share Posted December 31, 2015 This graph is misleading. When you look at the temperature/zonal wind anomalies on the GEFS/EPS across the Arctic you can see the PV remaining quite strong. There is some displacement from warming over the Bering Sea through Siberia but the PV itself is just moving a bit not really getting disrupted. The graph is depicting zonal winds at 65N/10hpa. Significant deceleration of these winds is suggestive of the weakening circulation circumnavigating the core of the polar vortex. Yes, the stratospheric vortex itself will not be moving much over the next 7-10 days, but the conditions around it will be changing. Furthermore, past cases indicate that the 10hpa vortex usually doesn't move significantly until < 10 days prior to the official event. That's still at least 10-12 days away, IMO. Note the 10hpa vortex in the January 1958 case. It was relatively stable to the northeast of Greenland until after January 20th, and the official event occurred on the 30th. Link to comment Share on other sites More sharing options...
Isotherm Posted December 31, 2015 Share Posted December 31, 2015 If you look at past SSW events, often we will see a -AO in the tropospheric pattern preceding the SSW. So while the stratospheric vortex might not be destroyed/disturbed yet, I don't think seeing a -AO tropospheric pattern is an argument against further progress later on. I believe the 1958, 1966, and 1987 examples all show this. Often doesn't mean always though...so it's possible we regress back to a +AO late Jan and early February...but it's impossible to say with any certainty right now. I would favor a -AO personally for February right now because it is very common in El Ninos...even strong ones. My hope is that is doesn't get ruined by a mammoth Aleutian low that becomes so big it engulfs the GOA too and then combines with a strong Greenland vortex...that would be how to turn the pattern crappy...even if the AO is negative. 1998 saw this. Agree. I have been bringing up that point as well over the past few weeks (58/66/87). I don't think many realize that tropospheric conditions almost always change prior to an event. It's a myth that we need to wait 2+ weeks following a SSW for tropospheric changes. Link to comment Share on other sites More sharing options...
CT Rain Posted December 31, 2015 Share Posted December 31, 2015 The graph is depicting zonal winds at 65N/10hpa. Significant deceleration of these winds is suggestive of the weakening circulation circumnavigating the core of the polar vortex. Yes, the stratospheric vortex itself will not be moving much over the next 7-10 days, but the conditions around it will be changing. Furthermore, past cases indicate that the 10hpa vortex usually doesn't move significantly until < 10 days prior to the official event. That's still at least 10-12 days away, IMO. Note the 10hpa vortex in the January 1958 case. It was relatively stable to the northeast of Greenland until after January 20th, and the official event occurred on the 30th. I know what it's showing. I'm just saying it's deceptive because the PV is displaced a bit so taking a snapshot of zonal winds at 65N isn't really giving you an accurate depiction of what's occurring with the vortex. Link to comment Share on other sites More sharing options...
ice1972 Posted December 31, 2015 Share Posted December 31, 2015 WTF are you talking about? If you identify a timeframe for a threat, what is wrong with affirming that notion by seeing SOMETHING consistently modeled? I don't think I was obsessing over anything. You weren't.....sorry....it was late.....and my mood regarding this season was in the toilet.....should have been a banter post..... Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 31, 2015 Share Posted December 31, 2015 At least as per the CPC/monitoring division's products, I don't think this is a "SSW" ... Firstly, SSW's almost always materialize first in the very highest sigma levels of the stratospheric component of the PV. Perhaps as high as 5hPa. In this case, we see a modestly warming node that begins in the D4(ish) time range, and matures a little before decaying by D10. However, during that time, we do see a moderate-strong warming node take place in the 50hPa level; that's but non-correlated with typical SSW phenomenon, and may just as well reflect the -AO tropospheric evolution, underneath. ...I think Will just touched on that... Capital Weather Gang put out an interesting article in the Washington Post... The article discusses an very usual event taking place at very high latitudes. The full latitude major storm recently that brought the historic blizzard to west TX, while tornadoes chewed up lives further E... migrated up through the N Atlantic and became a super-storm. One additional freak occurrence ... it spike N-polar temperatures above freezing IN DECEMBER!!! The article can be found here... https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/12/30/freak-storm-has-pushed-north-pole-to-freezing-point-50-degrees-above-normal/ But, the point I was going to make ... one way that -AO's can be triggered (as is refereed/papered) is by terminating WAA events at very high latitudes and altitudes. On a physical sort of 100,000 foot discussion level, that's because WAA tends to raise heights and that can spark off blocking nodes up N. It may just follow then, that the current -AO is really just a dump event at high latitudes, and that we are seeing a kind of thermal inversion in order to physically accommodate the unusual events taking place up underneath in the tropospheric depths. Link to comment Share on other sites More sharing options...
Isotherm Posted December 31, 2015 Share Posted December 31, 2015 I know what it's showing. I'm just saying it's deceptive because the PV is displaced a bit so taking a snapshot of zonal winds at 65N isn't really giving you an accurate depiction of what's occurring with the vortex. Well, I would say that it's still an important factor to consider and you definitely want to see that deceleration as the process continues. But yes, it will not show you what's happening with core vortex behavior/location itself. Link to comment Share on other sites More sharing options...
mahk_webstah Posted December 31, 2015 Share Posted December 31, 2015 Agree that this is a phenomenal discussion and debate. Great input from Mets and very smart hobbyists. Naive question but doesn't the "sudden" in SSW imply that we can't forecast it, that we wouldn't be seeing signs yet anyhow? Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2015 Share Posted December 31, 2015 Agree. I have been bringing up that point as well over the past few weeks (58/66/87). I don't think many realize that tropospheric conditions almost always change prior to an event. It's a myth that we need to wait 2+ weeks following a SSW for tropospheric changes. Yeah I'm not saying it doesn't matter that we have a good tropospheric pattern, We actually want that. My argument was that this is definitely not related to some SSW or SAI deal. I see some trying to say that. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted December 31, 2015 Share Posted December 31, 2015 I have contemplated that possibility as well, but I think if we do see a resurgence of -VP, it'll likely be fairly transient [in the upcoming 2 month period]. Interestingly enough, upon examining the IO forcing progression of a few of my top analog years, there was a propensity for enhanced IO forcing during the month of December. This generally transitioned into a more suppressive regime for Jan/Feb. December 1965/1957: December 1986 had fairly active IO convection as well. VP anomalies so far this month: Much different regime for January 1966/1958: February maintained the overall suppressive IO (as did with 1987): The CFS forecasts for chi 200hpa haven't been too great so far this year, though it's possible we have a 7-10 day pulse of IO forcing. I definitely wouldn't be surprised to see a reload period. But I strongly doubt a return to the December pattern or even a pattern that favors above / much above temperatures. The current empirical wave propagation suggests a transient IO pulse the last 10 days of the month before a return to conducive forcing again. Oh wow, the better forcing starts returning pretty quickly. That's nice to see. But the one annoying thing about the IO convection that the analogs might not capture is just how warm the IO waters are right now. This could lead to more convection in the IO than usual. Regardless, an SSW hopefully occurring later in January could help thwart any break period that could try to ensue when the forcing temporarily becomes unfavorable again. Link to comment Share on other sites More sharing options...
Isotherm Posted December 31, 2015 Share Posted December 31, 2015 Yeah I'm not saying it doesn't matter that we have a good tropospheric pattern, We actually want that. My argument was that this is definitely not related to some SSW or SAI deal. I see some trying to say that. Yeah - I think we actually agree on this. I should clarify that the actual stratospheric warming process is trop --> strat wave driving with warmth in the upper stratosphere downwelling. The processes occurring right now is bottom-up into the stratosphere (actually, there are multiple processes ongoing concurrently - bottom up and wave driving to the upper strat).Though these changes in tropospheric polar cap heights should be expected in the weeks prior to a possible strat event as we continue to perturb the vortex. Link to comment Share on other sites More sharing options...
Met1985 Posted December 31, 2015 Share Posted December 31, 2015 Yeah great disco from everyone fellas. Awsome stuff that's way over my head but very educational. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2015 Share Posted December 31, 2015 Yeah - I think we actually agree on this. I should clarify that the actual stratospheric warming process is trop --> strat wave driving with warmth in the upper stratosphere downwelling. The processes occurring right now is bottom-up into the stratosphere (actually, there are multiple processes ongoing concurrently - bottom up and wave driving to the upper strat).Though these changes in tropospheric polar cap heights should be expected in the weeks prior to a possible strat event as we continue to perturb the vortex. I will also say, that it must be a good thing to have this NPAC warming bubble. I don't see how it could be bad to have a deep layer ridge of warmth extending from the troposphere to the stratosphere in this region. One would think this is somewhat stable? Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 The PV is the First Order and the SSW is the Resistance. The models are our droids, Scott is Luke Skywalker, Will is Han Solo. And you are our Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 It doesn't mean Feb could see a split or SSW...just don't see a big change for at least next few weeks. See, I don't even get what the argument is because I, along with everyone else in this camp, as always maintained that not much will happen until the third week of January...or thereabouts. Anything beforehand is likely transient. Judging the degree of damage done to the vortex at this juncture is akin to grading the winter at the end of December. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 Yeah exactly. Could see a SSW for sure - but this -AO is not due to a SSW. I don't think any one thought, or intimated that it was. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 You weren't.....sorry....it was late.....and my mood regarding this season was in the toilet.....should have been a banter post..... NP...I was confused. Searching long range OP runs for storms is different than keeping a vigil for a nascent, consistent signal for activity within a predetermined period. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2015 Share Posted December 31, 2015 See, I don't even get what the argument is because I, along with everyone else in this camp, as always maintained that not much will happen until the third week of January...or thereabouts. Anything beforehand is likely transient. Judging the degree of damage done to the vortex at this juncture is akin to grading the winter at the end of December. I guess I am not as confident in a good -AO in Feb as some are....I mean a true -AO..not a bootleg one on paper caused by El Nino. I have been more confident in a better Pacific...like what we have coming up, albeit earlier than I thought. I do acknowledge that a true -AO from some sort of SSW or PV breakdown could happen for sure. It would be silly for me to say no. I think the PV lasts through Jan, but perhaps we maintain this NPAC warm bubble. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 I guess I am not as confident in a good -AO in Feb as some are....I mean a true -AO..not a bootleg one on paper caused by El Nino. I have been more confident in a better Pacific...like what we have coming up, albeit earlier than I thought. I do acknowledge that a true -AO from some sort of SSW or PV breakdown could happen for sure. It would be silly for me to say no. I think the PV lasts through Jan, but perhaps we maintain this NPAC warm bubble. That's cool. Remember though, the formidable foe of el nino climo from earlier this season is now in the changing room, ready to emerge draped in a cape. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted December 31, 2015 Author Share Posted December 31, 2015 That's cool. Remember though, the formidable foe of el nino climo from earlier this season is now in the changing room, ready to emerge draped in a cape. Sometimes though , climb doesn't work..food for thought Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 Sometimes though , climb doesn't work..food for thought Yes. Thankfully no one is relying solely upon climo; however it is a factor to consider. Worked well for December. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2015 Share Posted December 31, 2015 That's cool. Remember though, the formidable foe of el nino climo from earlier this season is now in the changing room, ready to emerge draped in a cape. Yeah I always thought Feb would be good relatively speaking, but that was because of the Pacific. We can get these -NAO ridges to form from large low pressure like what the GFS displays at the end of the run, near Greenland. You can get a response from the troposphere, independent of any SSW, for a -NAO too. We seem to have those more in El Nino seasons. That can only help us. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2015 Share Posted December 31, 2015 All I meant was that when we have conflicting signals, its never a bad bet to defer to an overwhelmingly emphatic climo signal, such as the monthly mod-strong el nino composite. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2015 Share Posted December 31, 2015 See to me, December really didn't come to fruition the way I thought it would. Of course it is important to acknowledge a small sample size and one can't always expect December to behave with a sample size of 3....December 2015 was one for the books. Strong Pacific jet with a SE ridge. Didn't expect that one for sure. So while December was mild and forecasted to be so, I think it's just as important to see how it happened. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2015 Share Posted December 31, 2015 All I meant was that when we have conflicting signals, its never a bad bet to defer to an overwhelmingly emphatic climo signal, such as the monthly mod-strong el nino composite. True. Link to comment Share on other sites More sharing options...
powderfreak Posted December 31, 2015 Share Posted December 31, 2015 See to me, December really didn't come to fruition the way I thought it would. Of course it is important to acknowledge a small sample size and one can't always expect December to behave with a sample size of 3....December 2015 was one for the books. Strong Pacific jet with a SE ridge. Didn't expect that one for sure. So while December was mild and forecasted to be so, I think it's just as important to see how it happened. Yeah, I don't think anyone expected the month to absolutely destroy a lot of warm records like it did. It was going to be a rough month, but nothing quite like what transpired. I mean we went like an entire week without going below freezing in northern VT in December. Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 31, 2015 Share Posted December 31, 2015 Whats great is we dont need a SSW for a great period, just stretch that bad boy. Link to comment Share on other sites More sharing options...
dryslot Posted December 31, 2015 Share Posted December 31, 2015 Windex Monday? Oh yes Link to comment Share on other sites More sharing options...
powderfreak Posted December 31, 2015 Share Posted December 31, 2015 Yeah I always thought Feb would be good relatively speaking It seems like a slam dunk that February would be the best month relatively speaking.... but "relatively speaking" right now isn't carrying much weight with how horrific December has gone. Who knows how January plays out, but say February delivers 20" of snowfall over the course of the month, after very little in December and still low totals in January (hypothetically speaking obviously). February can definitely be the coldest and snowiest month of the winter, but I think the real question will be is it something that's remembered fondly or is it more of a "winter tried to show up for a couple weeks to muster a couple events" and then peaced out again. Link to comment Share on other sites More sharing options...
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