bluewave Posted November 27, 2017 Share Posted November 27, 2017 58 minutes ago, Ralph Wiggum said: Overnight ensemble means definitely took a step back in the LR. While not a bad look, clearly not the fantasy runs from last couple days. NAO is weaker and block is shifted farther East, ridging out West less extreme, trof out West slower to move due to decrease in ridging over British Columbia. GEPS which had been most aggressive with -NAO loses it completely in the LR and even attempts a shift to a +NAO. Hope these LR teases that are taken away arent a repeat of last year. Again, not a horrible look on the EPS/GEFS at all.....just not the same perfection from past few runs. Didnt expect that look to remain constant for next 10-16 days anyway. Actually, there was a shift to stronger blocking in the EPO and PNA regions which may turn out to be colder for us. It's a -EPO/+PNA ridge that connects over the top to the -AO block near Greenland. New run features a stronger -EPO/+PNA block Old run Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted November 27, 2017 Share Posted November 27, 2017 Actually, there was a shift to stronger blocking in the EPO and PNA regions which may turn out to be colder for US. It's a -EPO/+PNA ridge that connects over the top to the -AO block near Greenland. New run features a stronger -EPO/+PNA block PAC is really chaotic this year.....massive changes from one run to the next. Look at that deep trof now showing up S of the Aleutian chain pumping the EPO ridge you noted. Wasnt even there before. Im finding it a challenge to trust much of this data past day 7 or so. This early season seems even more prone to major changes than recent years for whatever reason especially upstream in the PAC which obviously yields big changes downstream. Maybe the general fast La Nina flow out there has something to do with this? Link to comment Share on other sites More sharing options...
PB GFI Posted November 27, 2017 Share Posted November 27, 2017 25 minutes ago, bluewave said: Actually, there was a shift to stronger blocking in the EPO and PNA regions which may turn out to be colder for US. It's a -EPO/+PNA ridge that connects over the top to the -AO block near Greenland. New run features a stronger -EPO/+PNA block I would love for there to be an actual SW out in the south west at day 11 under that block It would roll through the M/A. But I agree the models look very good for deeper negative on the east coast in the LR. That doesn't always mean snow but we scream because these are the sets ups we need for it to snow . Those things are just uncontrollable. Link to comment Share on other sites More sharing options...
snowman19 Posted November 27, 2017 Share Posted November 27, 2017 9 hours ago, IntenseBlizzard2014 said: It wouldn't have been negative. It would have made things more interesting. Gotta wait for next winter. Tropical volcanic eruptions that release sulfate aerosols and reach the stratosphere have immediate effects. You don’t have to wait until the following winter to feel the effects. Research has shown that immediately following an eruption, it works to cool the stratosphere and strengthen the stratospheric polar vortex, causing +AO. The following winter is when it has the -AO effect. The global temp cooling effects are also more pronounced and found to be significantly so when you have an eruption during a La Niña. The global temp cooling effects are not nearly as pronounced during an El Niño Link to comment Share on other sites More sharing options...
swamplover56 Posted November 27, 2017 Share Posted November 27, 2017 1 minute ago, snowman19 said: Tropical volcanic eruptions that release sulfate aerosols and reach the stratosphere have immediate effects. You don’t have to wait until the following winter to feel the effects. Research has shown that immediately following an eruption, it works to cool the stratosphere and strengthen the stratospheric polar vortex, causing +AO. The following winter is when it has the -AO effect. The global temp cooling effects are also more pronounced and found to be significantly so when you have an eruption during a La Niña. The global temp cooling effects are not nearly as pronounced during an El Niño Please post something to back this statement up Link to comment Share on other sites More sharing options...
snowman19 Posted November 27, 2017 Share Posted November 27, 2017 1 minute ago, swamplover56 said: Please post something to back this statement up Read up: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.143.5116&rep=rep1&type=pdf Link to comment Share on other sites More sharing options...
bluewave Posted November 27, 2017 Share Posted November 27, 2017 24 minutes ago, Ralph Wiggum said: 52 minutes ago, bluewave said: Actually, there was a shift to stronger blocking in the EPO and PNA regions which may turn out to be colder for US. It's a -EPO/+PNA ridge that connects over the top to the -AO block near Greenland. New run features a stronger -EPO/+PNA block PAC is really chaotic this year.....massive changes from one run to the next. Look at that deep trof now showing up S of the Aleutian chain pumping the EPO ridge you noted. Wasnt even there before. Im finding it a challenge to trust much of this data past day 7 or so. This early season seems even more prone to major changes than recent years for whatever reason especially upstream in the PAC which obviously yields big changes downstream. Maybe the general fast La Nina flow out there has something to do with this? The MJO looks like it may be providing an assist for us as the forcing is shifting just west of 180 right before the big pattern change. This is displaced a little further east than is usually the case during a La Nina December. Link to comment Share on other sites More sharing options...
dmillz25 Posted November 27, 2017 Share Posted November 27, 2017 1 hour ago, snowman19 said: Tropical volcanic eruptions that release sulfate aerosols and reach the stratosphere have immediate effects. You don’t have to wait until the following winter to feel the effects. Research has shown that immediately following an eruption, it works to cool the stratosphere and strengthen the stratospheric polar vortex, causing +AO. The following winter is when it has the -AO effect. The global temp cooling effects are also more pronounced and found to be significantly so when you have an eruption during a La Niña. The global temp cooling effects are not nearly as pronounced during an El Niño Actually there’s a 2-3 month lag, it’s not immediate Link to comment Share on other sites More sharing options...
Isotherm Posted November 27, 2017 Share Posted November 27, 2017 1 hour ago, snowman19 said: Read up: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.143.5116&rep=rep1&type=pdf This study discussed boreal winter conditions subsequent to tropical volcanic eruptions preferentially occurring in the spring / summer; there were a couple cases in October, but not nearly as late as current. Further, it is much too early to ascertain VEI or stratospheric aerosol loading. Hypothetically speaking, if this eruption becomes sufficiently strong, the effects would begin manifesting in the AO by mid to late winter. All of those studied eruptions were VEI 4 or greater. We will need to monitor. Link to comment Share on other sites More sharing options...
WeatherFeen2000 Posted November 27, 2017 Share Posted November 27, 2017 Gfs 12z and Gefs look great in the long range- plenty of blocking showing up now past December 8th Link to comment Share on other sites More sharing options...
forkyfork Posted November 27, 2017 Share Posted November 27, 2017 5 hours ago, bluewave said: Actually, there was a shift to stronger blocking in the EPO and PNA regions which may turn out to be colder for us. It's a -EPO/+PNA ridge that connects over the top to the -AO block near Greenland. hasn't this happened in recent years with other modeled -nao blocks in the long range? Link to comment Share on other sites More sharing options...
bluewave Posted November 27, 2017 Share Posted November 27, 2017 31 minutes ago, forkyfork said: hasn't this happened in recent years with other modeled -nao blocks in the long range? The EPS did pretty well with the recent -3.5 AO drop. Link to comment Share on other sites More sharing options...
uncle W Posted November 27, 2017 Share Posted November 27, 2017 todays ao forecast has two members near -5 while the rest are negative too...no membrs are positive in the forecast period...of course tomorrow will change but it is a great sign at this time... Link to comment Share on other sites More sharing options...
Morris Posted November 27, 2017 Share Posted November 27, 2017 EPS flips the patttern the 6th into the 7th. Not getting later in time. Link to comment Share on other sites More sharing options...
uncle W Posted November 27, 2017 Share Posted November 27, 2017 most of the big snows around hear were pna driven with help from a negative ao...12/10 had a negative pna leading up to the blizzard...it almost hit neutral before falling off again...the negative ao and nao were the drivers of that storm... Link to comment Share on other sites More sharing options...
danstorm Posted November 27, 2017 Share Posted November 27, 2017 20 minutes ago, bluewave said: Check out how strong the combined -EPO/+PNA/-AO block is in around 10 days. We have not seen all 3 indices this strongly impacted by a block at the same time in a while. Does the block impact the indices or are the indices causing the block? Good lord, that is one crazy West Coast ridge! Link to comment Share on other sites More sharing options...
Morris Posted November 27, 2017 Share Posted November 27, 2017 Just now, uncle W said: most of the big snows around hear were pna driven with help from a negative ao...12/10 had a negative pna leading up to the blizzard...it almost hit neutral before falling off again...the negative ao and nao were the drivers of that storm... EPS has a long-lasting raging +PNA days 5-15. Link to comment Share on other sites More sharing options...
Morris Posted November 27, 2017 Share Posted November 27, 2017 3 minutes ago, danstorm said: Does the block impact the indices or are the indices causing the block? Good lord, that is one crazy West Coast ridge! Aren't they different terms for the same thing? Link to comment Share on other sites More sharing options...
MJO812 Posted November 27, 2017 Share Posted November 27, 2017 Weeklies look very good moving into December Very strong +PNA and -NAO Link to comment Share on other sites More sharing options...
bluewave Posted November 27, 2017 Share Posted November 27, 2017 On November 27, 2017 at 5:50 PM, Snow88 said: Weeklies look very good moving into December Very strong +PNA and -NAO This was the coldest looking weeklies run in years. Triple -EPO/+PNA/-AO block for the entire run. Link to comment Share on other sites More sharing options...
PB GFI Posted November 27, 2017 Share Posted November 27, 2017 8 minutes ago, bluewave said: This was the best looking weeklies run in years. Triple -EPO/+PNA/-AO block for the entire run. The last time this happened during a La Nina was December 2000 and 1985. The whole run averaged out for December looks like this Yeh , a month ( if that verifies ) is hard pressed to look / want better. It doesn't mean snow , but its patterns like that which produce. But I agree , great run. Link to comment Share on other sites More sharing options...
MJO812 Posted November 27, 2017 Share Posted November 27, 2017 Ralieghwx says that the Euro weeklies keeps it cold through mid January. Wow Link to comment Share on other sites More sharing options...
PB GFI Posted November 27, 2017 Share Posted November 27, 2017 14 minutes ago, Snow88 said: Ralieghwx says that the Euro weeklies keeps it cold through mid January. Wow Let's get to Christmas 1st Link to comment Share on other sites More sharing options...
Paragon Posted November 27, 2017 Share Posted November 27, 2017 56 minutes ago, bluewave said: This was the best looking weeklies run in years. Triple -EPO/+PNA/-AO block for the entire run. The last time this happened during a La Nina was December 2000 and 1985. The whole run averaged out for December looks like this Ha I thought you'd say December 2010- January 2011, that was the best start to winter I can remember. December 1995- January 1996 was great too, but we had a big January thaw, but at least winter came back in a big way in February, March and April. Link to comment Share on other sites More sharing options...
Paragon Posted November 27, 2017 Share Posted November 27, 2017 10 hours ago, snowman19 said: Tropical volcanic eruptions that release sulfate aerosols and reach the stratosphere have immediate effects. You don’t have to wait until the following winter to feel the effects. Research has shown that immediately following an eruption, it works to cool the stratosphere and strengthen the stratospheric polar vortex, causing +AO. The following winter is when it has the -AO effect. The global temp cooling effects are also more pronounced and found to be significantly so when you have an eruption during a La Niña. The global temp cooling effects are not nearly as pronounced during an El Niño There was some idea that the February 1983 blizzard was due in part to El Chicon's eruption the year before, though we do get renegade historic snowstorms in February sometimes during big el ninos (or January as was the case a couple of years ago.) Link to comment Share on other sites More sharing options...
Rtd208 Posted November 27, 2017 Author Share Posted November 27, 2017 Earthlight Link to comment Share on other sites More sharing options...
PB GFI Posted November 28, 2017 Share Posted November 28, 2017 14 minutes ago, bluewave said: We always run the risk of cold and suppressed in a pattern like this which happened in 1985. Even December 2000 waited to the end of December to deliver. Hopefully, this one is able to produce for us. Thats definitely a risks and I expect that it's dry for a time. But living here It's either the PAC is too fast and we run the risk of wet and warm or the vortex presses so much that impulses just dive to your south. We are not a snowy climate. The reason a lot of us look at these high latitude blocking patterns favorably is because you just need 1 vort to hug the barroclinic zone combined with a relaxation of HP and if a system slows behind traffic , then it's on. ( clippers aside ). It's why I hump temps in here , thats because sometimes that's the easier part and we need the set up to produce anything. Too often what we want just doesn't happen. Snow / storms will appear and disappear in the guidance and in the end they are just too hard to forecast with any skill from a distance. Link to comment Share on other sites More sharing options...
uncle W Posted November 28, 2017 Share Posted November 28, 2017 since 1989 every December that was colder than average had above average snowfall...Dec 89 had a pretty good -ao for three weeks but it wasn't nearly as strong as 2000, 2009 and 2010... Link to comment Share on other sites More sharing options...
Paragon Posted November 28, 2017 Share Posted November 28, 2017 1 hour ago, uncle W said: since 1989 every December that was colder than average had above average snowfall...Dec 89 had a pretty good -ao for three weeks but it wasn't nearly as strong as 2000, 2009 and 2010... This is where our warmer climate is actually helping us (right now anyway). I hesitate to use the 80s as analogs because that was an entirely different climate- and I would take less cold if that means less chances of suppression and more chances of snow. Borderline cold is all we really need. Link to comment Share on other sites More sharing options...
Ericjcrash Posted November 28, 2017 Share Posted November 28, 2017 Surface is an absolute disaster but that's a nice look. Link to comment Share on other sites More sharing options...
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