ORH_wxman Posted October 6, 2011 Share Posted October 6, 2011 I had been posting about how we will see a solid 10-14 day warm spell with a possible transient cooldown or two mixed in and that there really had been no signs of it coming to an end. But recently (10/5), both the GFS ensemble and ECMWF ensemble means have hinted at some changes going on in the N PAC that would potentially put an end to the warm regime. The period targeted is mostly around Oct 20th and beyond. Above is the GFS ensemble mean valid for Oct 18th. You can see the AK/Bering vortex has weakened and the Aleutian Ridge is kind of flat looking but not bunched up in a shorter wavelength....so its actually teleconnecting a bit more with troughing over the central U.S. more than supporting a pig ridge. The lower heights from the GOA are being spread more eastward and generally colder regime appears across a larger portion of the CONUS. It doesn't look frigid or anything at this point, but it may put an end to the warm pattern. The Euro ensembles actually looks a little cooler than the composite I have above....but given how far out this is, there is certainly a lot of time for it to change. As we have preached many times on this site, larger scale pattern changes are often rushed by the models and ensmebles, so if it tries to change it just after mid-month, it wouldn't be surprising if it happens the final week instead. But at least its something to follow. Link to comment Share on other sites More sharing options...
snowNH Posted October 6, 2011 Share Posted October 6, 2011 Good post Will. Over the past couple of years what was the date of each pattern change? Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted October 6, 2011 Share Posted October 6, 2011 Later the better....hold it off until November. 1) October cold is useless 2) October warmth is pleasant. 2) November coold very well may start pants tent season early. Novemeber 2002 ftw. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 6, 2011 Share Posted October 6, 2011 Definitely could be the tale-telling signs of a potential pattern change although like you said it could be during a much later period than suggested by the models as they are often too fast with pattern changes. Kind of interesting to note though how the pattern goes from massive ridging from the central to eastern US to a more zonal type flow. Many times when we start seeing the models suggesting a pattern change (usually from warm to cool) we see the models want to drive a really deep trough through the western US through the Plains and then into the East. What the above is suggesting is a more transient change from above-average to probably more average or perhaps just slightly above. Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 6, 2011 Share Posted October 6, 2011 Let's get it done and fast. Warm October's are awful and useless Link to comment Share on other sites More sharing options...
CoastalWx Posted October 6, 2011 Share Posted October 6, 2011 Yeah I mentioned yesterday in the banter thread that the NPAC ridging showed signs of developing in the euro ensembles. Even some hints of slight ridging in Greenland and poking north from central Russia. However, like you said, it may be rushed and I'm gonna wait until it shows up within day 7 or so. It's almost that time of year where Kevin tries to herald in cold, only to be delayed by 3 weeks. Link to comment Share on other sites More sharing options...
weatherwiz Posted October 6, 2011 Share Posted October 6, 2011 Let's get it done and fast. Warm October's are awful and useless Ummm no. Link to comment Share on other sites More sharing options...
dryslot Posted October 6, 2011 Share Posted October 6, 2011 Delayed but hopefully not denied, Would be more concerning if the pattern looked to hold going into mid november Link to comment Share on other sites More sharing options...
Allenson Posted October 6, 2011 Share Posted October 6, 2011 The Euro ensembles actually looks a little cooler than the composite I have above....but given how far out this is, there is certainly a lot of time for it to change. As we have preached many times on this site, larger scale pattern changes are often rushed by the models and ensmebles, so if it tries to change it just after mid-month, it wouldn't be surprising if it happens the final week instead. But at least its something to follow. Is there anything to the notion that the weather has been 'slow' quite a bit over the past few years? It seems to me that we've often been in blocky patterns that take longer to evolve and change than the models 'think' they will. Or is it just more a case of the models being too fast and progressive and thus we get it in our minds that a change is on the way when really it's further out in time? If any of that makes any sense.... Link to comment Share on other sites More sharing options...
Typhoon Tip Posted October 6, 2011 Share Posted October 6, 2011 Ha ha... You guys feel about autumn about how I feel about Aprils. Forget the record this or that broken over the weekend or beyond do to the current warm signal... Let's just leap completely over that interesting Meteorology (for a select few, I know...), grasp at distant straws. I know, I know. I hate the drizzly dreary backdoor season just as much and tend to look for early heat. It's a human thing. Anyway, although I am basing my opinions on the GFS cluster - seeing as I don't have access to the ECM's save for what is exposed through discussions and so forth - IMO we don't break cold until the AO changes the current mode. It gets a bit additionally mirky too when we consider that the hemispheric cold release from any relaxing +AO does not carry with it any guarantee that any dumps will be into the Canadian shield (a fairly clear pre-requisite relay so that mid latitude teleconnectors can then drill it the rest of the way on down). But...excluding the possibility of 2006-2007 redux where the cold structured into Eurasia, while N/A baked until Jan 10 ... within the current predominating + mode there will be frets of dips in the index, but a meaningful flip seems pretty required here. The reason why is because the SE ridge associated with this sort of ENSO is fairly well favored and currently established - whether directly ESNO caused is tough to say currently, but so long as it is there, the absence of a polar field involvement (which is what positive values up N connotes) does favor the -PNA/-PNAP. Ie., warm. What intrigues me in all this is thta we are still in the decline of the AO/NAO multi-decadal signal. That sign flipped negative recently, and given the last 2 years of behavior is more or less supportive. Right now we are building snow and recovering sea ice nicely... quite consistent with +AO at this time of year. This is good... that of course as discussed in a good precursor for cold thickness production heading deeper into the cold season. So the "duh" factor here is that the background -AO (should it behave ..errr...), might butt heads with the ENSO and make things interesting.... Link to comment Share on other sites More sharing options...
OKpowdah Posted October 6, 2011 Share Posted October 6, 2011 My thoughts exactly John. Well said. We may get transient intrusions of cooler air with a few days of negative departures, but I do not see this breaking for a while. We are looking at a high index NAM dominating the pattern. While we do have a fairly amplified flow, the westerlies are displaced northward, and are stronger, over a background enhanced gradient. These in combination have led to the cut off lows in the last month. The inter-seasonal cycle of the NAM is being displayed very well here, and we can expect a predominantly positive AO through the next month and a half at least. This preset may be enhanced even by the residual westerly QBO descending. Now, when the NAM long cycle switches states, likely in late November / early December, there's no guarantee that cold air reaches the CONUS, as Tip said. In fact, I highly doubt it does. The SSTs in the GOA are a testament to that point. I think we may have to deal with the zonal flow a little longer into early December, while the cold air stays bottled up in western Canada. This is where La Nina gets on our side. As we see more influence from convection around Indonesia, we should see amplification of the downstream ridging over the North Pacific into the Aleutians. The proceeding frictional torque event sends a significant trough diving out of the vortex over western Canada into the central Plains, unleashing some of the cold air. Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 6, 2011 Author Share Posted October 6, 2011 Is there anything to the notion that the weather has been 'slow' quite a bit over the past few years? It seems to me that we've often been in blocky patterns that take longer to evolve and change than the models 'think' they will. Or is it just more a case of the models being too fast and progressive and thus we get it in our minds that a change is on the way when really it's further out in time? If any of that makes any sense.... Models definitely struggle to break down blocks more so than faster zonal patterns. We are not in a blocky pattern right now, but that doesn't mean the pattern changes do not get rushed. I think we will exit the extreme warm regime at some point toward the end of the month...but not sure when exactly. The ensemble have been trying to raise heights to our northeast over the NAO region too which will also promote more troughiness or at least less ridging in the northeast. This is not to be confused with saying that we will be entering a cold regime as some already seem to be implying...simply that the warm regime would be ending and we'd probably be in a period of ups and downs but closer to normal on the mean. Link to comment Share on other sites More sharing options...
CoastalWx Posted October 6, 2011 Share Posted October 6, 2011 Models definitely struggle to break down blocks more so than faster zonal patterns. We are not in a blocky pattern right now, but that doesn't mean the pattern changes do not get rushed. I think we will exit the extreme warm regime at some point toward the end of the month...but not sure when exactly. The ensemble have been trying to raise heights to our northeast over the NAO region too which will also promote more troughiness or at least less ridging in the northeast. This is not to be confused with saying that we will be entering a cold regime as some already seem to be implying...simply that the warm regime would be ending and we'd probably be in a period of ups and downs but closer to normal on the mean. I get the feeling November may be all over the place. Obviously it's a transition month prone to swings in temperature, but it just seems like it may be a rollercoaster of temps. I kind of like how nw Canada looks to stay near or slightly below normal forthe next 2 weeks or so, with storminess. Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 6, 2011 Author Share Posted October 6, 2011 I get the feeling November may be all over the place. Obviously it's a transition month prone to swings in temperature, but it just seems like it may be a rollercoaster of temps. I kind of like how nw Canada looks to stay near or slightly below normal forthe next 2 weeks or so, with storminess. Yeah I'm not feeling a frigid november either at this point. Obviously a 2 week period can break a month though so if we flipped to a very cold regime around Nov 15th and rode it past Thanksgiving, then the month could end up pretty cold. 2007 was a pretty cold November after the torch October and then of course we rode that cold regime right into the first 3 weeks of December for the most part with only a brief break at the end of Nov. We'll see how the NAO behaves as we start nearing the end of this month. Euro ensembles near the end of their period really want to retrograde the WC trough offshore which teleconnects to more EC troughing and mountain west ridging. There is some more cross polar flow going on N of AK during this time...certainly nothing all that noteworthy, but we are not choked off with a huge warm regime across most of the CONUS in that setup. Link to comment Share on other sites More sharing options...
Allenson Posted October 6, 2011 Share Posted October 6, 2011 Models definitely struggle to break down blocks more so than faster zonal patterns. We are not in a blocky pattern right now, but that doesn't mean the pattern changes do not get rushed. I think we will exit the extreme warm regime at some point toward the end of the month...but not sure when exactly. The ensemble have been trying to raise heights to our northeast over the NAO region too which will also promote more troughiness or at least less ridging in the northeast. This is not to be confused with saying that we will be entering a cold regime as some already seem to be implying...simply that the warm regime would be ending and we'd probably be in a period of ups and downs but closer to normal on the mean. Aye, thanks! Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 8, 2011 Author Share Posted October 8, 2011 Long range Euro has a hell of a gradient pattern. Maybe a sign of the winter setup? Link to comment Share on other sites More sharing options...
WeatherX Posted October 9, 2011 Share Posted October 9, 2011 Long range Euro has a hell of a gradient pattern. Maybe a sign of the winter setup? Yep, nice +PNA setting up...... Link to comment Share on other sites More sharing options...
Mr Torchey Posted October 9, 2011 Share Posted October 9, 2011 Long range Euro has a hell of a gradient pattern. Maybe a sign of the winter setup? Absolutely, talked with WeatherX on the phone about this last week, dont really see a SBTJ this year, I think the ridge for the most part holds strong, but it should be just far enough west to allow for some troughiness across much of new england. Could very well be that the south coast is on the wrong side of the show, or we may luck out, big year for ski country, and if I loved winter I would be concerned from nyc south. Link to comment Share on other sites More sharing options...
weatherMA Posted October 9, 2011 Share Posted October 9, 2011 Absolutely, talked with WeatherX on the phone about this last week, dont really see a SBTJ this year, I think the ridge for the most part holds strong, but it should be just far enough west to allow for some troughiness across much of new england. Could very well be that the south coast is on the wrong side of the show, or we may luck out, big year for ski country, and if I loved winter I would be concerned from nyc south. Good thing you're north. Link to comment Share on other sites More sharing options...
Mr Torchey Posted October 9, 2011 Share Posted October 9, 2011 Good thing you're north. not really Link to comment Share on other sites More sharing options...
nzucker Posted October 9, 2011 Share Posted October 9, 2011 not really I am in a great spot for this type of pattern. Link to comment Share on other sites More sharing options...
WeatherX Posted October 9, 2011 Share Posted October 9, 2011 not really Nothing has been revealed yet as far as the winter pattern is concerned, imo. It seems that the transitional period is taking its sweet time as evidenced by the multiple late season tropical systems and the continued sub tropical ridge which is delivering our splendid weather this weekend . TS one looks good for effect and plentiful amounts of rain, after that we need to start breaking down the Atlantic ridge and part of that might be a subsiding of West Pac tropics and building some ridging into the Indian Ocean and some ridging near the Aleutians wouldn't hurt......so many moving parts Joe..... Link to comment Share on other sites More sharing options...
weathafella Posted October 9, 2011 Share Posted October 9, 2011 1993-94. That is all. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted October 9, 2011 Share Posted October 9, 2011 1993-94. That is all. :snowman: More details to follow? Link to comment Share on other sites More sharing options...
weathafella Posted October 9, 2011 Share Posted October 9, 2011 <img src='http://208.71.34.143/public/style_emoticons/<#EMO_DIR#>/thumbsupsmileyanim.gif' class='bbc_emoticon' alt='' /> <img src='http://208.71.34.143/public/style_emoticons/<#EMO_DIR#>/Snowman.gif' class='bbc_emoticon' alt='' /> <img src='http://208.71.34.143/public/style_emoticons/<#EMO_DIR#>/thumbsupsmileyanim.gif' class='bbc_emoticon' alt='' /> <img src='http://208.71.34.143/public/style_emoticons/<#EMO_DIR#>/Snowman.gif' class='bbc_emoticon' alt='' /> <img src='http://208.71.34.143/public/style_emoticons/<#EMO_DIR#>/Snowman.gif' class='bbc_emoticon' alt='' /> <img src='http://208.71.34.143/public/style_emoticons/<#EMO_DIR#>/Snowman.gif' class='bbc_emoticon' alt='' /> More details to follow? Yes. I reverted to in iPad but need another device....and one is kaput and another always in use. Probably will pick up another one next weekend. Huge meeting this week with me moderating many sessions. This followed by out of town work 10/23-6 so not sure when....hopefully week of 10/17. Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 12, 2011 Author Share Posted October 12, 2011 It looks like ensembles are still agreeing on ending the warm regime, but it does not look like we will be entering any type of longer term cold regime for the foreseeable future. Basically seasonable. No real sign of arctic air in Canada either during this time. Everything still on the other side of the pole. Link to comment Share on other sites More sharing options...
moneypitmike Posted October 12, 2011 Share Posted October 12, 2011 It looks like ensembles are still agreeing on ending the warm regime, but it does not look like we will be entering any type of longer term cold regime for the foreseeable future. Basically seasonable. No real sign of arctic air in Canada either during this time. Everything still on the other side of the pole. Normal is good. 51.1/46, .02" Link to comment Share on other sites More sharing options...
Damage In Tolland Posted October 12, 2011 Share Posted October 12, 2011 It looks like ensembles are still agreeing on ending the warm regime, but it does not look like we will be entering any type of longer term cold regime for the foreseeable future. Basically seasonable. No real sign of arctic air in Canada either during this time. Everything still on the other side of the pole. Any chance of Tip's snowstorm? Link to comment Share on other sites More sharing options...
snowNH Posted October 12, 2011 Share Posted October 12, 2011 Any chance of Tip's snowstorm? Look at 18z GFS... its pretty close at 138 Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 12, 2011 Author Share Posted October 12, 2011 Normal is good. 51.1/46, .02" Yeah its fine this time of year. My guess is 10/20-10/31 ends up slightly above normal, but close enough to normal for most not to notice whether its slightly above or slightly below. I usually like to see some distinct cold shots (even if transient) to think a 10+ day chunk will average anything colder than normal. We may have a storm cut west of us too in the beginning of that period which would be quite mild for that first day. Link to comment Share on other sites More sharing options...
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