Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 Well I wasn;t implying that the storms would be cutting up into Ottawa...but OH Valley runners are common in a -NAO if the PNA is negative...they just often redevelop south of us and scoot east....not a "Nor Easter" per say...but sfc pressure getting squeezed south of us ala 12/13/07, 12/19/08, 12/20/70, etc....an overrunning storm that may "normally" be a cutter, but it gets stuffed going in for the layup and pushed east by the low height anomaly to our northeast induced by the -NAO. (or in the case of the 2007 systems...the "pseudo -NAO" which was really just a massive west based +NAO so big that it caused low heights north of Maine) Oh I see - yeah, you get that kind of system that starts as snow, then the radar shreds and you get flipping between sleet, snow and rain or freezing rain, but falling lightly, with a cutting ENE bite to the wind. But that's kind of a species of the Miller B, just not ideally wrapped up after redevelopment. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 cold ak is not the same as an Ak vortex ding ding, quite true. In fact, prior to a lot of cold lower Canada regime there is a period of AK cold pooling, and often it's purely a light NE flow off the frozen arctic sea, with a big Siberian high offering the gradient...it just load and loads and loads, then the flow tips - Link to comment Share on other sites More sharing options...
weathafella Posted December 7, 2012 Share Posted December 7, 2012 Valdez has had 20 inches of snow to date. Last year at this point they had 88. It's a different year. Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 7, 2012 Author Share Posted December 7, 2012 Oh I see - yeah, you get that kind of system that starts as snow, then the radar shreds and you get flipping between sleet, snow and rain or freezing rain, but falling lightly, with a cutting ENE bite to the wind. But that's kind of a species of the Miller B, just not ideally wrapped up after redevelopment. Right...and it doesn't even have to be sleet...as in the case of the 12/13/07 and 12/19/08 examples....those were all snow. The mid-levels held enough to keep it snow. Visually...here is what I mean...you can see no closed mid-level centers...but the sfc refelction squeezed south of us...but we remain snow...5H certainly looks nothing like a coastal...a vortmax traveling quickly in the SW flow just under us....rtaher than being allowed to amplify into a big cutter Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 Valdez has had 20 inches of snow to date. Last year at this point they had 88. It's a different year. Yes the powerful and predominating positive AO last year bottled cold and storm tracks across the N/NE Pacific and nailed Alaska. This year the AO is favoring negative so far. Link to comment Share on other sites More sharing options...
NJwinter23 Posted December 7, 2012 Share Posted December 7, 2012 About a month ago or a little less, Chris and I developed ideas for -NAO blocking developing 12/5-10 and finishing up toward the 20th. While the first part didn't quite work out the way I wanted it to, the second part still has a chance. Chris speculated then that perhaps 12/18-20 or so was the main time frame to watch. As we inch closer, I think he may be right. The only thing preventing me from doing the "usual" is that I'm worried that the stratosphere isn't enough or the tropical forcing. However, those two things can easily change by then to allow for this signal. On a completely timing related note, the wave behavior may be similar to 2009-10. It is unfortunate that the waves in the Tropics and Stratosphere are weaker. The cold vortex and disturbed vortex periods that winter may be similar in timing to this winter, even if the results are different. I feel like having the tropics cooperate was a big part of our equation in that discussion, hence why im a bit modest about taking any credit for the threat..We'll see how it pans out though! definitely looks like a nice chance for new england, but we can still hold hopes and dreams in phl-nyc lol. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 Right...and it doesn't even have to be sleet...as in the case of the 12/13/07 and 12/19/08 examples....those were all snow. The mid-levels held enough to keep it snow. Visually...here is what I mean...you can see no closed mid-level centers...but the sfc refelction squeezed south of us...but we remain snow...5H certainly looks nothing like a coastal...a vortmax traveling quickly in the SW flow just under us....rtaher than being allowed to amplify into a big cutter You know ... in a way for snow pack lovers you want that, because a solid underneather drops powder/lower ratio pack that succumbs to anything over freezing. But these offer a higher water content in back side refreeze, and that pack resists warm ups better. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 Not all that dissimilar to Will's example above as near as 84 hours in this 00z GFS run - Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 7, 2012 Author Share Posted December 7, 2012 Not all that dissimilar to Will's example above as near as 84 hours in this 00z GFS run - A lot warmer...but the CAD is there and the high is there. We just never get the true arctic boundary in here prior to the storm...if we did, I would be gung ho on a wintry mess over the interior for about the duration. As is...maybe some mix or ice to start but the airmass isn't quite dense enough to hold for frozen I don't think....but it could morph into a nasty 37F rain for a long period though. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 A lot warmer...but the CAD is there and the high is there. We just never get the true arctic boundary in here prior to the storm...if we did, I would be gung ho on a wintry mess over the interior for about the duration. As is...maybe some mix or ice to start but the airmass isn't quite dense enough to hold for frozen I don't think....but it could morph into a nasty 37F rain for a long period though. You're right, but I'm seeing cold as outperforming model guidance, similar to this current air mass, going into that. I'm thinking ice scenario as I was in the other thread - where Kevin tried to pin ice storm on me -ha Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 You're right, but I'm seeing cold as outperforming model guidance, similar to this current air mass, going into that. I'm thinking ice scenario as I was in the other thread - where Kevin tried to pin ice storm on me -ha GFS took a step in that direction. Just not sure how good the antecedent airmass is in SNE. Definitely a higher elevation thing Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 7, 2012 Share Posted December 7, 2012 GFS not so nuts with the -NAO but a nice Bering Sea ridge/-EPO saves the pattern and makes it pretty nice. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 GFS not so nuts with the -NAO but a nice Bering Sea ridge/-EPO saves the pattern and makes it pretty nice. Yeah, the operational has been oscillating between -EPO and -NAO Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 Well like we stated yesterday, more model ying and yang last night. EC ensembles really had a great pattern at the end for here. Weak and westward moving -NAO combined with a little weak +PNA...would think Miller B potential, if it were to happen of course. I would like to see this through the weekend, but it still doesn't change the fact that confidence is increased on our chances for winter threats here. The MJO also wants to come alive, but again..I want to see how this transpires through the weekend. Link to comment Share on other sites More sharing options...
OSUmetstud Posted December 7, 2012 Share Posted December 7, 2012 Well like we stated yesterday, more model ying and yang last night. EC ensembles really had a great pattern at the end for here. Weak and westward moving -NAO combined with a little weak +PNA...would think Miller B potential, if it were to happen of course. I would like to see this through the weekend, but it still doesn't change the fact that confidence is increased on our chances for winter threats here. The MJO also wants to come alive, but again..I want to see how this transpires through the weekend. +PNA? Is this day 11 onward? Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 +PNA? Is this day 11 onward? Yeah, but I would call it more of a weak ridge. Link to comment Share on other sites More sharing options...
HM Posted December 7, 2012 Share Posted December 7, 2012 Lol hey I appreciate the praise, but i tend to think this threat materializing was more luck in the end, since the pattern isnt progressing quite how I imagined it when first mention of an 18th-20th threat. You are too critical in my opinion. You are never going to "narrate the story" perfectly, especially with sensible weather and departures. However you did predict a wave 2 NAO response to develop which looks to be correct and you predicted the right type. You then went to say it would possibly retrograde some before diminishing and bring a storm threat before a possible relaxation period at the end of the month. All of this is certainly possible per the modeling trends. Just because early December had a more "rollercoaster-type" temperature regime doesn't mean other things were incorrect. I feel like having the tropics cooperate was a big part of our equation in that discussion, hence why im a bit modest about taking any credit for the threat..We'll see how it pans out though! definitely looks like a nice chance for new england, but we can still hold hopes and dreams in phl-nyc lol. Yeah the MJO not working out was a failure and I can't believe how warm 30mb has remained since mid-November. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 The split flow look with higher then normal heights over Hudson Bay while a weak ridge forms out west is interesting later in the 11-15 day. If that were to happen, I think it would promote the chance of a larger QPF event or perhaps east coast cyclogenesis. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 I suppose if I had to be picky, I would like to see a little more amped ridge in the Aleutians. There is a tendency to try and flatten it from time to time, but towards the end it tries to rebuild. Link to comment Share on other sites More sharing options...
CT Rain Posted December 7, 2012 Share Posted December 7, 2012 Euro ens and GFS ensembles definitely show the MJO waking up. That should shake up the pattern a bit! Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 7, 2012 Author Share Posted December 7, 2012 I suppose if I had to be picky, I would like to see a little more amped ridge in the Aleutians. There is a tendency to try and flatten it from time to time, but towards the end it tries to rebuild. Yes. I would like to see it amped a little more too...though the way it is on the models is still good enough to keep the arctic air flowing into Canada...but at times it starts to get a little borderline. Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 Yes. I would like to see it amped a little more too...though the way it is on the models is still good enough to keep the arctic air flowing into Canada...but at times it starts to get a little borderline. I wouldn't have an issue if the GEFS worked out the way they show as of now, 12z...but yeah I want that a little more amped. The ensembles have some pretty short wavelengths too as the ridge pushed into srn AK by hr 240 and then redeveloped to the west again. That's going to be fun trying to track storms with s/w's galore. If this MJO push is true, that probably throws another wrench into things, although I'm still a little up in the air as to whether or not it gets that strong. Certainly would be wonderful to see. Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 7, 2012 Author Share Posted December 7, 2012 I wouldn't have an issue if the GEFS worked out the way they show as of now, 12z...but yeah I want that a little more amped. The ensembles have some pretty short wavelengths too as the ridge pushed into srn AK by hr 240 and then redeveloped to the west again. That's going to be fun trying to track storms with s/w's galore. If this MJO push is true, that probably throws another wrench into things, although I'm still a little up in the air as to whether or not it gets that strong. Certainly would be wonderful to see. The poleward extension of the Aleutian ridge has also been changing run to run...seems every time it shows it flattening a bit, the next run beefs it back up and vice versa. My guess is it will remain adequate enough. It really only needs to be far enough north to keep the flow over land from eastern Siberia into AK...cutting across the arctic ocean down through Yukon is more ideal, but not a necessity. Basically...make sure the airmasses are not marine Pacific origin. The Atlantic is where we'll really have to watch. Those lower heights near New Foundland would be huge for us. They would turn a pretty decent pattern into a real weenie pattern for New England. Link to comment Share on other sites More sharing options...
CT Rain Posted December 7, 2012 Share Posted December 7, 2012 Here's what the Euro Ensembles do with the MJO over the next 2 weeks. Pretty noticeable wave they develop and this has been the case for several runs now. GFS ensembles now getting on board. Per Alan's MJO December phase 1 anomalies you can see the teleconnection with a strong Aleutian low and a +PNA with positive height anomalies over BC and Pac NW. Phase 2 is not terribly different but the Aleutian low signal is weaker and the +PNA positive anomalies are more noteworthy out west. P1 is below. The Day 8-10 Euro Ensemble mean is quite a bit different from what you'd expect to see with that MJO signal. But by D15 the Euro ensemble mean does show some noticeable ridging over the Pac NW with a +PNA signal. Will be interesting to watch how this all transpires over the coming days. Link to comment Share on other sites More sharing options...
toronto blizzard Posted December 7, 2012 Share Posted December 7, 2012 With the MJO wave that the models are now cranking out could this mean that the post x-mas torch may be muted? Link to comment Share on other sites More sharing options...
CoastalWx Posted December 7, 2012 Share Posted December 7, 2012 That's a good summary Ryan. Maybe the tropics can come through this time, although it is still warm above the tropopause there. I also think we can agree that the GEFS is not great at all with tropical convection. It tried bringing it into p4 last week. Link to comment Share on other sites More sharing options...
CT Rain Posted December 7, 2012 Share Posted December 7, 2012 That's a good summary Ryan. Maybe the tropics can come through this time, although it is still warm above the tropopause there. I also think we can agree that the GEFS is not great at all with tropical convection. It tried bringing it into p4 last week. lol yup. Nice to see both Euro Ens/GEFS on board with something. Not sure what to make of the MJO teleconnections and how different the progged 11-15 day pattern is. May still be some model shuffling if the MJO does indeed take off. None of it is really bad though for us... just saying I think the Pacific is going to become a bit unstable with the introduction of new tropical forcing. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 7, 2012 Share Posted December 7, 2012 That's a good summary Ryan. Maybe the tropics can come through this time, although it is still warm above the tropopause there. I also think we can agree that the GEFS is not great at all with tropical convection. It tried bringing it into p4 last week. Depends which side of the pond is right ... GFS' cluster is polar opposite Guess I'd put my money on the $-D variable system too, but I don't know if that really helps (Euro) for at least partially oceanic atmospheric coupled physics. I'll go ahead a put my money on whichever solution makes for the worst weather relative to the collective voice's desire. Link to comment Share on other sites More sharing options...
weathafella Posted December 7, 2012 Share Posted December 7, 2012 Depends which side of the pond is right ... GFS' cluster is polar opposite Guess I'd put my money on the $-D variable system too, but I don't know if that really helps (Euro) for at least partially oceanic atmospheric coupled physics. I'll go ahead a put my money on whichever solution makes for the worst weather relative to the collective voice's desire. The cosmic dildo effect? Link to comment Share on other sites More sharing options...
Typhoon Tip Posted December 8, 2012 Share Posted December 8, 2012 The cosmic dildo effect? Pretty much - Link to comment Share on other sites More sharing options...
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