WxUSAF Posted July 16, 2012 Share Posted July 16, 2012 Any idea what new factor/teleconnection/index will emerge in the fall that has never been discussed before but is suddenly incredibly important and looks horrible for EC winter? Long-term J-field sector alignments look very unfavorable Link to comment Share on other sites More sharing options...
Deck Pic Posted July 16, 2012 Share Posted July 16, 2012 I'm trying to draw a strong correlation between strength of ENSO events after ninos/ninas/neutral and our winter but I think too many factors. Also. When the hell did 52-53 become a niño! Link to comment Share on other sites More sharing options...
MN Transplant Posted July 16, 2012 Share Posted July 16, 2012 I'm trying to draw a strong correlation between strength of ENSO events after ninos/ninas/neutral and our winter but I think too many factors. Also. When the hell did 52-53 become a niño! They changed the baselines. Only Nino to start as late as DJF. Looks like we also picked up 58/59. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 16, 2012 Share Posted July 16, 2012 I've been trying to find a way to articulate this best and I think I have found something interesting and low confidence but worth a look as more of a tendency and less as a rule We have had 12 ninos that have flipped from Nina/neutral negative the previous winter. THE WEAK ONES The 4 weakest of the bunch (none had a NDJ or DJF anomaly of 1.2 or higher) averaged 10" of snow with all right around 10". They were mixed on warm versus cold. 51-52 was warm 68-69 tended normal/cold 76-77 was cold 06-07 was warm but had the frigid February Snow makes sense since the 4 likely had the weakest southern streams and a more dominant northern stream THE MODERATES 6 were moderate/low end strong- all had either or both the NDJ/DJF anomaly at or above 1.2 and below 2.0 57-58 63-64 65-66 86-87 02-03 09-10 5 were cold and 1 was normal but leaned cold(86-87) We know about snow. All were well well above with an average of 38.3". All had KU's. 12 full blown cases among the bunch. Epic winters. Every single one. THE STRONG 72-73, 82-83 (each had either or both a NDJ/DJF anomaly of a over 2.1) Both were warm with an average February. We know one was a complete dud and the other had 3 decent storms with one epic KU. CONCLUSION: Obviously lots of other factors at play and insufficient sample. But I will strongly weight NIÑO in my winter outlook. If it looks to be on the weaker side, I will probably go average temps with at least one cold month and one warm month of course weighing other factors as well and 8-12 for DCA. If it looks to be in the bullseye I will go 2/3 months cold and overall cold and snowy. Probably 25-30". Certainly at least 20-25" If it looks to be strong I will really have to rely on other factors but would probably go warm in DEC/JAN and normal FEB and overall warm. Snow will be a crapshoot but would probably really rely on the AO/NAO prospects to make a call but hedging toward the median. But ENSO will be biggest factor and much more than in a Nina or Neutral Link to comment Share on other sites More sharing options...
Feb Posted July 16, 2012 Share Posted July 16, 2012 I've been trying to find a way to articulate this best and I think I have found something interesting and low confidence but worth a look as more of a tendency and less as a rule We have had 12 ninos that have flipped from Nina/neutral negative the previous winter. THE WEAK ONES The 4 weakest of the bunch (none had a NDJ or DJF anomaly of 1.2 or higher) averaged 10" of snow with all right around 10". They were mixed on warm versus cold. 51-52 was warm 68-69 tended normal/cold 76-77 was cold 06-07 was warm but had the frigid February Snow makes sense since the 4 likely had the weakest southern streams and a more dominant northern stream THE MODERATES 6 were moderate/low end strong- all had either or both the NDJ/DJF anomaly at or above 1.2 and below 2.0 57-58 63-64 65-66 86-87 02-03 09-10 5 were cold and 1 was normal but leaned cold(86-87) We know about snow. All were well well above with an average of 38.3". All had KU's. 12 full blown cases among the bunch. Epic winters. Every single one. THE STRONG 72-73, 82-83 (each had either or both a NDJ/DJF anomaly of a over 2.1) Both were warm with an average February. We know one was a complete dud and the other had 3 decent storms with one epic KU. CONCLUSION: Obviously lots of other factors at play and insufficient sample. But I will strongly weight NIÑO in my winter outlook. If it looks to be on the weaker side, I will probably go average temps with at least one cold month and one warm month of course weighing other factors as well and 8-12 for DCA. If it looks to be in the bullseye I will go 2/3 months cold and overall cold and snowy. Probably 25-30". Certainly at least 20-25" If it looks to be strong I will really have to rely on other factors but would probably go warm in DEC/JAN and normal FEB and overall warm. Snow will be a crapshoot but would probably really rely on the AO/NAO prospects to make a call but hedging toward the median. But ENSO will be biggest factor and much more than in a Nina or Neutral What's your odds right now Matt regarding the nino? Reading the board right now it looks like a toss up between weak and moderate with strong being a long shot. Is that how you see it right now? Link to comment Share on other sites More sharing options...
North Balti Zen Posted July 16, 2012 Share Posted July 16, 2012 I've been trying to find a way to articulate this best and I think I have found something interesting and low confidence but worth a look as more of a tendency and less as a rule We have had 12 ninos that have flipped from Nina/neutral negative the previous winter. THE WEAK ONES The 4 weakest of the bunch (none had a NDJ or DJF anomaly of 1.2 or higher) averaged 10" of snow with all right around 10". They were mixed on warm versus cold. 51-52 was warm 68-69 tended normal/cold 76-77 was cold 06-07 was warm but had the frigid February Snow makes sense since the 4 likely had the weakest southern streams and a more dominant northern stream THE MODERATES 6 were moderate/low end strong- all had either or both the NDJ/DJF anomaly at or above 1.2 and below 2.0 57-58 63-64 65-66 86-87 02-03 09-10 5 were cold and 1 was normal but leaned cold(86-87) We know about snow. All were well well above with an average of 38.3". All had KU's. 12 full blown cases among the bunch. Epic winters. Every single one. THE STRONG 72-73, 82-83 (each had either or both a NDJ/DJF anomaly of a over 2.1) Both were warm with an average February. We know one was a complete dud and the other had 3 decent storms with one epic KU. CONCLUSION: Obviously lots of other factors at play and insufficient sample. But I will strongly weight NIÑO in my winter outlook. If it looks to be on the weaker side, I will probably go average temps with at least one cold month and one warm month of course weighing other factors as well and 8-12 for DCA. If it looks to be in the bullseye I will go 2/3 months cold and overall cold and snowy. Probably 25-30". Certainly at least 20-25" If it looks to be strong I will really have to rely on other factors but would probably go warm in DEC/JAN and normal FEB and overall warm. Snow will be a crapshoot but would probably really rely on the AO/NAO prospects to make a call but hedging toward the median. But ENSO will be biggest factor and much more than in a Nina or Neutral Awesome post and thanks for the work and sharing your thoughts, Matt. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 16, 2012 Share Posted July 16, 2012 What's your odds right now Matt regarding the nino? Reading the board right now it looks like a toss up between weak and moderate with strong being a long shot. Is that how you see it right now? I really don't know. I havent been paying a ton of attention yet and not sure there is skill at this range. I know Will said he is not confident about a moderate event. Off the top of my head I think euro and NASA have a good track record and they are both pretty bullish. Ignore the statistical models. Following a 2 year Nina I would be very concerned with a weak niño in a -pdo cycle here in DC and if it looks to be in the 0.7-1.0 range I would probably be pretty bearish about winter. Probably something like a +1 to +2 type winter, 8-12". Have to see the other factors too. If I had my druthers I'd want to see a tri-monthly peak in the 1.6-1.8 range. Link to comment Share on other sites More sharing options...
Bob Chill Posted July 16, 2012 Share Posted July 16, 2012 Based on the last 5 tri-monthlies, there's a fair case for saying that the Nino probably won't get any stronger than +1.2ish. I agree with zwyts about 1.6-1.8 being where we would like to see it but I think the odds are stacked against that. Based on the current rate of warming and the last 5 tri monthlies, there are a couple of past Ninos that look pretty similar. 86-87 and 06-07 seem quite similar. Especially 06-07. 09-10 would be the best case of course and that isn't off the table. We just need region 3.4 to not stall right now but I have some concerns there. I know the Nina pac hangover effect is in all of our minds but to be honest, I'm more interested/concerned about the state of the AO/NAO (i wish I saw Wes' presentation). We had a front row seat last season irt what happens when those teleconnections are stuck in a bad + pattern. I would have to assume that a repeat is highly unlikely. If anything, you would think the pattern would "snap back" a bit this winter. Link to comment Share on other sites More sharing options...
WEATHER53 Posted July 16, 2012 Share Posted July 16, 2012 Based on the last 5 tri-monthlies, there's a fair case for saying that the Nino probably won't get any stronger than +1.2ish. I agree with zwyts about 1.6-1.8 being where we would like to see it but I think the odds are stacked against that. Based on the current rate of warming and the last 5 tri monthlies, there are a couple of past Ninos that look pretty similar. 86-87 and 06-07 seem quite similar. Especially 06-07. 09-10 would be the best case of course and that isn't off the table. We just need region 3.4 to not stall right now but I have some concerns there. I know the Nina pac hangover effect is in all of our minds but to be honest, I'm more interested/concerned about the state of the AO/NAO (i wish I saw Wes' presentation). We had a front row seat last season irt what happens when those teleconnections are stuck in a bad + pattern. I would have to assume that a repeat is highly unlikely. If anything, you would think the pattern would "snap back" a bit this winter. I did not live here then but my uncle is a keen weather observer and he says 86-87 is the most underrated snow winter for DC and that 81-82 is the most underrated cold winter for DC. Link to comment Share on other sites More sharing options...
WVclimo Posted July 16, 2012 Share Posted July 16, 2012 Based on the current rate of warming and the last 5 tri monthlies, there are a couple of past Ninos that look pretty similar. 86-87 and 06-07 seem quite similar. Especially 06-07. 09-10 would be the best case of course and that isn't off the table. We just need region 3.4 to not stall right now but I have some concerns there. I'd sign for either of those winters right now, and cede the slight chance of a '09-'10. The PDO looks a lot worse at this point than those years did, though. Until that eases, my tempered expectations are for a '72-'73 type Nino, which would be a horrific outcome after the heat we've endured since March 2010. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 Based on the last 5 tri-monthlies, there's a fair case for saying that the Nino probably won't get any stronger than +1.2ish. I agree with zwyts about 1.6-1.8 being where we would like to see it but I think the odds are stacked against that. Based on the current rate of warming and the last 5 tri monthlies, there are a couple of past Ninos that look pretty similar. 86-87 and 06-07 seem quite similar. Especially 06-07. 09-10 would be the best case of course and that isn't off the table. We just need region 3.4 to not stall right now but I have some concerns there. I know the Nina pac hangover effect is in all of our minds but to be honest, I'm more interested/concerned about the state of the AO/NAO (i wish I saw Wes' presentation). We had a front row seat last season irt what happens when those teleconnections are stuck in a bad + pattern. I would have to assume that a repeat is highly unlikely. If anything, you would think the pattern would "snap back" a bit this winter. both winters got started around the same time, but 86-87 had the real juicy storms....we probably need something at least that strength...06-07 would be too weak imo...86-87 is about the bottom end of the range we need.... Link to comment Share on other sites More sharing options...
ORH_wxman Posted July 17, 2012 Share Posted July 17, 2012 I really don't know. I havent been paying a ton of attention yet and not sure there is skill at this range. I know Will said he is not confident about a moderate event. Off the top of my head I think euro and NASA have a good track record and they are both pretty bullish. Ignore the statistical models. Following a 2 year Nina I would be very concerned with a weak niño in a -pdo cycle here in DC and if it looks to be in the 0.7-1.0 range I would probably be pretty bearish about winter. Probably something like a +1 to +2 type winter, 8-12". Have to see the other factors too. If I had my druthers I'd want to see a tri-monthly peak in the 1.6-1.8 range. I still think moderate is more likely than weak...but for DCA purposes, lets call moderate 1.2 or higher...in that case, I think its a lot closer to a toss up. 1.1 usually gets classified as a moderate Nino, but we know that's not really the case from a sensible wx standpoint...esp for DC. There's kind of that distinct line around +1.2-+1.3. Obviously the NAO/AO need to be hanging out at least around neutral, but assuming we could achieve that, I definitely agree with your thinking that DC will have a good winter if we can get past that threshold defined above. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 Based on the last 5 tri-monthlies, there's a fair case for saying that the Nino probably won't get any stronger than +1.2ish. I agree with zwyts about 1.6-1.8 being where we would like to see it but I think the odds are stacked against that. Based on the current rate of warming and the last 5 tri monthlies, there are a couple of past Ninos that look pretty similar. 86-87 and 06-07 seem quite similar. Especially 06-07. 09-10 would be the best case of course and that isn't off the table. We just need region 3.4 to not stall right now but I have some concerns there. I know the Nina pac hangover effect is in all of our minds but to be honest, I'm more interested/concerned about the state of the AO/NAO (i wish I saw Wes' presentation). We had a front row seat last season irt what happens when those teleconnections are stuck in a bad + pattern. I would have to assume that a repeat is highly unlikely. If anything, you would think the pattern would "snap back" a bit this winter. I'm not that worried about the Atlantic....that will fall into place..I am much more worried about the Pacific...once the PAC cooperates the Atlantic in a moderate NIno will generally be favorable or at least not hostile....I know they are all interrelated but I think our biggest enemy will be if we punt 2/3 of winter with a nasty vortex somewhere over or near AK, ridge over Aleutians and Trough over the pac NW, and of course a lack of a southern stream....DEC May suck no matter what though...nothing we can do about that...hopefully we sneak something in, but it is pretty doubtful we will have much of a southern stream at that point so we will need some help Link to comment Share on other sites More sharing options...
Ian Posted July 17, 2012 Share Posted July 17, 2012 I'm not that worried about the Atlantic....that will fall into place..I am much more worried about the Pacific...once the PAC cooperates the Atlantic in a moderate NIno will generally be favorable or at least not hostile....I know they are all interrelated but I think our biggest enemy will be if we punt 2/3 of winter with a nasty vortex somewhere over or near AK, ridge over Aleutians and Trough over the pac NW, and of course a lack of a southern stream....DEC May suck no matter what though...nothing we can do about that...hopefully we sneak something in, but it is pretty doubtful we will have much of a southern stream at that point so we will need some help why's that? Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 I still think moderate is more likely than weak...but for DCA purposes, lets call moderate 1.2 or higher...in that case, I think its a lot closer to a toss up. 1.1 usually gets classified as a moderate Nino, but we know that's not really the case from a sensible wx standpoint...esp for DC. There's kind of that distinct line around +1.2-+1.3. Obviously the NAO/AO need to be hanging out at least around neutral, but assuming we could achieve that, I definitely agree with your thinking that DC will have a good winter if we can get past that threshold defined above. I think that low end moderate coming out of a 2 year Nina smack in the middle of a persistent -PDO will be dicey.....DEC may kind of suck anyway..If we are going to have a 6-week winter no matter what, I at least want to have a good storm track with a robust moisture feed during the peak...I think we had a pretty good STJ in Feb 2007....but maybe the northern stream was still too strong?...the storm track kind of sucked Link to comment Share on other sites More sharing options...
ORH_wxman Posted July 17, 2012 Share Posted July 17, 2012 I think that low end moderate coming out of a 2 year Nina smack in the middle of a persistent -PDO will be dicey.....DEC may kind of suck anyway..If we are going to have a 6-week winter no matter what, I at least want to have a good storm track with a robust moisture feed during the peak...I think we had a pretty good STJ in Feb 2007....but maybe the northern stream was still too strong?...the storm track kind of sucked Pretty good bet...'09 and '02 are the exceptions rather than the rule. Otherwise you have to hope for a fluke like 1957 or 1982 in the midst of a garbage pattern. I was just posting to Scott in the NE forum how BOS seems to be a better jackpot spot when the Nino has its best month in February versus January...not sure if that is true in DC though. Jan '87 was much better in DC than BOS (but epic just west of BOS) Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 why's that? all of my 10 examples of weak/mod ninos had serviceable to great Atlantics once the PAC got into shape... The biggest impediment to the crappy ninos or bad parts of the good ones was the Pacific.....they work in sync.... Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 all of my 10 examples of weak/mod ninos had serviceable to great Atlantics once the PAC got into shape... The biggest impediment to the crappy ninos or bad parts of the good ones was the Pacific.....they work in sync.... Wes seemed to focus more on the AO though the AO-NAO often work lockstep.....I can't speak for Wes but when he looks for high latitude blocking I think he is also looking over to the EPO region.... Link to comment Share on other sites More sharing options...
Bob Chill Posted July 17, 2012 Share Posted July 17, 2012 I'm not that worried about the Atlantic....that will fall into place..I am much more worried about the Pacific...once the PAC cooperates the Atlantic in a moderate NIno will generally be favorable or at least not hostile....I know they are all interrelated but I think our biggest enemy will be if we punt 2/3 of winter with a nasty vortex somewhere over or near AK, ridge over Aleutians and Trough over the pac NW, and of course a lack of a southern stream....DEC May suck no matter what though...nothing we can do about that...hopefully we sneak something in, but it is pretty doubtful we will have much of a southern stream at that point so we will need some help - Great points about the PAC. It's can be a real kick in the teeth when something big and ugly sets up shop. As much as we want it to break down quickly it always ends up being a waiting game and then the risk of the pattern change not cooperating is there. I have some good data irt Dec probably not being a good month but it isn't organized. Once I put it in "readable" format I'll post it. TBH- I'm actually hoping for a crappy pac in mid nov - xmas. I wouldn't always say something so crazy but I totally agree that this type of enso pattern will favor a Jan-Feb window more than anything. It would be a kick in the teeth to have the pac, ao, and NAO cooperate for 4-6 weeks before the ss gets going. It's always such a gamble down here. Subtle missing parts to a pattern can hose us with ease. I'm a bit optimistic for a climo type winter though. Mixed bag of events with a good one tossed in. I don't think going 20"+ in my suburbs is unreasonable at all. Link to comment Share on other sites More sharing options...
easternsnowman Posted July 17, 2012 Share Posted July 17, 2012 - Great points about the PAC. It's can be a real kick in the teeth when something big and ugly sets up shop. As much as we want it to break down quickly it always ends up being a waiting game and then the risk of the pattern change not cooperating is there. I have some good data irt Dec probably not being a good month but it isn't organized. Once I put it in "readable" format I'll post it. TBH- I'm actually hoping for a crappy pac in mid nov - xmas. I wouldn't always say something so crazy but I totally agree that this type of enso pattern will favor a Jan-Feb window more than anything. It would be a kick in the teeth to have the pac, ao, and NAO cooperate for 4-6 weeks before the ss gets going. It's always such a gamble down here. Subtle missing parts to a pattern can hose us with ease. I'm a bit optimistic for a climo type winter though. Mixed bag of events with a good one tossed in. I don't think going 20"+ in my suburbs is unreasonable at all. This could be another year where elevation and being further away from the cities makes even a bigger difference than usual. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 - Great points about the PAC. It's can be a real kick in the teeth when something big and ugly sets up shop. As much as we want it to break down quickly it always ends up being a waiting game and then the risk of the pattern change not cooperating is there. I have some good data irt Dec probably not being a good month but it isn't organized. Once I put it in "readable" format I'll post it. TBH- I'm actually hoping for a crappy pac in mid nov - xmas. I wouldn't always say something so crazy but I totally agree that this type of enso pattern will favor a Jan-Feb window more than anything. It would be a kick in the teeth to have the pac, ao, and NAO cooperate for 4-6 weeks before the ss gets going. It's always such a gamble down here. Subtle missing parts to a pattern can hose us with ease. I'm a bit optimistic for a climo type winter though. Mixed bag of events with a good one tossed in. I don't think going 20"+ in my suburbs is unreasonable at all. I would say Chance of a good snow in DEC is about 25-75 in a Niño. Usually they are warm or noneventful. Link to comment Share on other sites More sharing options...
donsutherland1 Posted July 17, 2012 Share Posted July 17, 2012 Wes seemed to focus more on the AO though the AO-NAO often work lockstep.....I can't speak for Wes but when he looks for high latitude blocking I think he is also looking over to the EPO region.... For perspective, I'll repost my scatter diagram for KU snowstorms by ENSO-AO I posted last winter. Unfortunately, there was no need to update the chart following the winter. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 For perspective, I'll repost my scatter diagram for KU snowstorms by ENSO-AO I posted last winter. Unfortunately, there was no need to update the chart following the winter. Thanks Don. Your grid says a lot but I think it also shows some very loose indication that the AO usually goes negative in a Niño. Assuming we don't have a strong event in which niño calls all the shots, if it is weak/moderate I think it is almost a foregone conclusion that we will have a blocking pattern at some point and usually with some lasting power. I think there are 2 big questions. 1st, Given the high chance that we don't have a good pacific pattern in December, how long can we expect it to last? Will it be brief? Can we thread the needle even in the bad pattern with a PNA spike or something transient of that nature and take advantage of the brief window? Will we end up punting the 1st half of January as well? And 2nd, once we get a blocking pattern can we capitalize here in the mid Atlantic? And I think a lot of the answer to that is predicated on the strength of the niño with the stronger moderate events giving us a better chance. Link to comment Share on other sites More sharing options...
donsutherland1 Posted July 17, 2012 Share Posted July 17, 2012 Thanks Don. Your grid says a lot but I think it also shows some very loose indication that the AO usually goes negative in a Niño. Assuming we don't have a strong event in which niño calls all the shots, if it is weak/moderate I think it is almost a foregone conclusion that we will have a blocking pattern at some point and usually with some lasting power. I think there are 2 big questions. 1st, Given the high chance that we don't have a good pacific pattern in December, how long can we expect it to last? Will it be brief? Can we thread the needle even in the bad pattern with a PNA spike or something transient of that nature and take advantage of the brief window? Will we end up punting the 1st half of January as well? And 2nd, once we get a blocking pattern can we capitalize here in the mid Atlantic? And I think a lot of the answer to that is predicated on the strength of the niño with the stronger moderate events giving us a better chance. I'll try to check the numbers tonight to take a closer look at the ENSO-AO connection. If I recall correctly, the relationship is a weak one, though more episodes of severe blocking have occurred during El Niño winters than La Niña ones. All things being equal right now, I suspect Winter 2012-13 will be kinder to the Mid-Atlantic than the last one was in terms of snowfall. There's still a lot of time for things to change and the evolution of the widespread drought might be a wildcard in the mix of possible variables. Link to comment Share on other sites More sharing options...
donsutherland1 Posted July 17, 2012 Share Posted July 17, 2012 Thanks Don. Your grid says a lot but I think it also shows some very loose indication that the AO usually goes negative in a Niño. Assuming we don't have a strong event in which niño calls all the shots, if it is weak/moderate I think it is almost a foregone conclusion that we will have a blocking pattern at some point and usually with some lasting power. I think there are 2 big questions. 1st, Given the high chance that we don't have a good pacific pattern in December, how long can we expect it to last? Will it be brief? Can we thread the needle even in the bad pattern with a PNA spike or something transient of that nature and take advantage of the brief window? Will we end up punting the 1st half of January as well? And 2nd, once we get a blocking pattern can we capitalize here in the mid Atlantic? And I think a lot of the answer to that is predicated on the strength of the niño with the stronger moderate events giving us a better chance. I'll try to check the numbers tonight to take a closer look at the ENSO-AO connection. If I recall correctly, the relationship is a weak one, though more episodes of severe blocking have occurred during El Niño winters than La Niña ones. All things being equal right now, I suspect Winter 2012-13 will be kinder to the Mid-Atlantic than the last one was in terms of snowfall. There's still a lot of time for things to change and the evolution of the widespread drought might be a wildcard in the mix of possible variables. Link to comment Share on other sites More sharing options...
PhineasC Posted July 17, 2012 Share Posted July 17, 2012 I'll try to check the numbers tonight to take a closer look at the ENSO-AO connection. If I recall correctly, the relationship is a weak one, though more episodes of severe blocking have occurred during El Niño winters than La Niña ones. All things being equal right now, I suspect Winter 2012-13 will be kinder to the Mid-Atlantic than the last one was in terms of snowfall. There's still a lot of time for things to change and the evolution of the widespread drought might be a wildcard in the mix of possible variables. In my weenie mind I always assumed a mega-drought in the summer and fall led to a wet winter. Rubber-band and all that. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 I'll try to check the numbers tonight to take a closer look at the ENSO-AO connection. If I recall correctly, the relationship is a weak one, though more episodes of severe blocking have occurred during El Niño winters than La Niña ones. All things being equal right now, I suspect Winter 2012-13 will be kinder to the Mid-Atlantic than the last one was in terms of snowfall. There's still a lot of time for things to change and the evolution of the widespread drought might be a wildcard in the mix of possible variables. I'm not sure how weak the correlation is...even if we look at all ninos regardless of strength or weather they followed a Nina the evidence is there in the means... Link to comment Share on other sites More sharing options...
Bob Chill Posted July 17, 2012 Share Posted July 17, 2012 I'm not sure how weak the correlation is...even if we look at all ninos regardless of strength or weather they followed a Nina the evidence is there in the means... It the magic of an active STJ right? Lower heights through the SE would be naturally balanced with higher heights at higher latitudes. You can totally envision where the pj and stj are placed when looking at the graphic. It's also easy to see why the northern rockies/plains are typically drier during Nino's. Link to comment Share on other sites More sharing options...
Deck Pic Posted July 17, 2012 Share Posted July 17, 2012 It the magic of an active STJ right? Lower heights through the SE would be naturally balanced with higher heights at higher latitudes. You can totally envision where the pj and stj are placed when looking at the graphic. It's also easy to see why the northern rockies/plains are typically drier during Nino's. Even with the crappy ninos in there the map is mostly pretty. Split flow. Blocking. My theory is the pacific drives the pattern and once it gets good the atlantic cooperates. It was my theory last winter and it proved to be a bad one, but the PAC never really got good and I think it is different in a Nina. That's my wAG anyway. Link to comment Share on other sites More sharing options...
Bob Chill Posted July 17, 2012 Share Posted July 17, 2012 I went ahead and pulled the NA 500 anoms for Dec & Feb of 86-87 and 06-07. Totally fits what we're thinking irt Dec and Feb. Another interesting stat is the AO/NAO were positive in December and negative in Feb for both years. 06 was really bad in Dec with a raging +AO but it broke down nicely down the road. The overall evolution of a Nino post Nina makes alot of sense. 85-86 wasn't a technical Nina but was still a cool enso and was on the heels of a multi-year Nina. It takes time for things to re-organize themselves in the PAC. Especially irt the STJ. I know it's too simplisitic to look at a couple years like 86-87 and 06-07 and think that the upcoming winter is "predictable" but at the very least we can set expectations and wait for the proverbial monkey in the wrenchworks as we get closer. Link to comment Share on other sites More sharing options...
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