HM Posted March 21, 2014 Share Posted March 21, 2014 Who said the double barrel look was wrong? huh? We see that a lot. I've read it more than once. I won't name anyone specifically but you can probably guess who are some of the likely suspects. I really have not been on twitter..maybe I should check it out..lol. Or not. lol good man. Link to comment Share on other sites More sharing options...
HM Posted March 21, 2014 Share Posted March 21, 2014 Gotchya. Reading between the lines and what you posted earlier means we are stuck in a wait and see. Too many "if this then this" variables to stress or hug any solution. It's nice that there's going to be a big storm. That part is pretty cool. Haven't really had one all year. 2/12-13 was big but not the same way that this one evolves. I don't have a lot of armchair knowledge and experience with a setup like this. Definitely no where near enough to make any definitive weenie statements. I'm kinda baffled on which way to hedge. Believe me, if there was a way to gain an edge here, I would let you know. What I do know is that the things I'm skilled at the most in the MR/LR that signal things cannot possibly help me here. They did a good job at signaling a "trough" etc. but they cannot tell me those specifics. Just keep an eye on the things I brought up earlier and see how they evolve over the weekend. You'll start to get the "feel" of them and then know which way to hedge. Link to comment Share on other sites More sharing options...
Heisy Posted March 21, 2014 Share Posted March 21, 2014 Who said the double barrel look was wrong? huh? We see that a lot. Rainshadow was mentioning it on Philly forums, as some others. Not to call out forecasters, it makes for good discussion. Link to comment Share on other sites More sharing options...
CoastalWx Posted March 21, 2014 Share Posted March 21, 2014 Rainshadow was mentioning it on Philly forums, as some others. Not to call out forecasters, it makes for good discussion. Is he referring to the weak low or semi-trough in the Ohio Valley ahead of the stronger s/w? Just want to be sure. Link to comment Share on other sites More sharing options...
IsentropicLift Posted March 21, 2014 Share Posted March 21, 2014 Who said the double barrel look was wrong? huh? We see that a lot. I'm not dismissing the double barreled low, but when if ever have we seen two sub 980mb lows in as close proximity as what the 00z GGEM showed? I think the safe bet here is not to ignore it, but put it on the back burner as just another possibility out of many possible solutions. Link to comment Share on other sites More sharing options...
paulythegun Posted March 21, 2014 Share Posted March 21, 2014 Serious question - how often do two twin bombed out lows (bombotwinesis) sit next to each other like that? I could only find one analog to the 00z CMC: Link to comment Share on other sites More sharing options...
chris87 Posted March 21, 2014 Share Posted March 21, 2014 Things I keep reading that are incorrect: 1. The double barrel structure means the model is incorrect. 2. There's errors with the track because of convection. 3. The out to sea tracks are due to only the lack of phasing. 4. The precip will have a tight edge because strong UVM must be compensated by DVM. 5. The seasonal trends means..."fill-in" It's like these forecasters have never seen a nor'easter before. 6. "X" piece of energy hasn't been sampled properly...expect changes... my personal favorite, although convective feedback is a close second. Link to comment Share on other sites More sharing options...
Amped Posted March 21, 2014 Share Posted March 21, 2014 Serious question - how often do two twin bombed out lows (bombotwinesis) sit next to each other like that? I could only find one analog to the 00z CMC: More often then you think. When you look at a hires slp map, storms look different than they do in a textbook. There is often one low over the gulf stream and a sevond one further west near the upper level low, even with ots tracks. Link to comment Share on other sites More sharing options...
CoastalWx Posted March 21, 2014 Share Posted March 21, 2014 I'm not dismissing the double barreled low, but when if ever have we seen two sub 980mb lows in as close proximity as what the 00z GGEM showed? I think the safe bet here is not to ignore it, but put it on the back burner as just another possibility out of many possible solutions. Well if it's in reference to the Canadian and Euro...I admit that is not a common look and it did give me pause...but when you look at 500mb and how the 1st low moves off...It's not surprising why it shows that. Two models are showing that as well. Sometimes you do have that sort of tucked in look...almost like an inv trough with a center of low pressure well west of the low. The Canadian just goes bonkers with that look. The more I look at this, the more I see what it is doing. Link to comment Share on other sites More sharing options...
paulythegun Posted March 21, 2014 Share Posted March 21, 2014 More often then you think. When you look at a hires slp map, storms look different than they do in a textbook. There is often one low over the gulf stream and a sevond one further west near the upper level low, even with ots tracks. Thanks! And good point on looking at the hires slp map. Link to comment Share on other sites More sharing options...
IsentropicLift Posted March 21, 2014 Share Posted March 21, 2014 Well if it's in reference to the Canadian and Euro...I admit that is not a common look and it did give me pause...but when you look at 500mb and how the 1st low moves off...It's not surprising why it shows that. Two models are showing that as well. Sometimes you do have that sort of tucked in look...almost like an inv trough with a center of low pressure well west of the low. The Canadian just goes bonkers with that look. The more I look at this, the more I see what it is doing. When I examined H5 on the 00z GGEM I was under the impression that this solution was the result of a sloppy phase initially. Then the last piece of energy amplifies around the periphery of the trough and bingo. Link to comment Share on other sites More sharing options...
HM Posted March 21, 2014 Share Posted March 21, 2014 Rainshadow was mentioning it on Philly forums, as some others. Not to call out forecasters, it makes for good discussion. Well he's actually not who I had in mind and I'm a bit surprised, honestly. But I haven't read his thoughts so I cannot comment. I'll check them out later. Double lows are very normal...1996 comes to mind off the top of my head. The way to think of it is: at some pressure contour, it's 1 low. Link to comment Share on other sites More sharing options...
IsentropicLift Posted March 21, 2014 Share Posted March 21, 2014 Well he's actually not who I had in mind and I'm a bit surprised, honestly. But I haven't read his thoughts so I cannot comment. I'll check them out later. Double lows are very normal...1996 comes to mind off the top of my head. The way to think of it is: at some pressure contour, it's 1 low. You make a good point about 1996, you can see looping back how the system starts off as lone consolidated low pressure and then almost splits the energy as it reaches the mid-atlantic. Link to comment Share on other sites More sharing options...
IsentropicLift Posted March 21, 2014 Share Posted March 21, 2014 I was curious about the 00z GGEM so I just went back and looked at 850mb. It has two separate 850mb lows, one tucked right in over the NJ coast and a second one about 250 miles east. Does that argue that the GGEM solution was truly two separate entities? Link to comment Share on other sites More sharing options...
famartin Posted March 21, 2014 Share Posted March 21, 2014 Rainshadow Tony's thoughts from elsewhere: "Structurally this (0z) ecmwf run was much more coherent. It was the can ggem to take the convective feedback hit, it basically cocooned a core of upper 50s total totals out of those warm waters east of Delaware. It got so wrapped up, it would be raining along the immediate NJ coast." Link to comment Share on other sites More sharing options...
cae Posted March 21, 2014 Share Posted March 21, 2014 Thanks HM and all the other mets. Very much appreciated. Below are the 500 mb plots from the latest 12z and 00z runs of the GGEM, for 00z next Wednesday. The 00z gave a distinct double-barrel low with snow for our region, and the 12z created something similar but farther east. I see three systems lined up. I'm not sure what to call them all, but this is how I currently think of them: the first is the upper level low over Illinois, the second is the shortwave over the VA / WV border, and the third is the coastal low. If I've mislabeled these, I apologize. Eventually the shortwave phases with the coastal, creating a new upper level low center. It would seem to me that the stronger the shortwave is between the two systems, the greater our chances of getting heavy snow. Obviously there are a lot of other factors at play, but I'm trying to simplify this to something I can understand. If anyone else has any thoughts I'd be interested to hear them. 12z: 00z: Link to comment Share on other sites More sharing options...
Bob Chill Posted March 21, 2014 Share Posted March 21, 2014 GFS won't make friends this run. No phase and a tad east of 6z. Link to comment Share on other sites More sharing options...
ACFD FIREMAN Posted March 21, 2014 Share Posted March 21, 2014 6. "X" piece of energy hasn't been sampled properly...expect changes... my personal favorite, although convective feedback is a close second. I would normally agree...but doesn't it lend to more credence with potentially phased systems? Link to comment Share on other sites More sharing options...
stormtracker Posted March 21, 2014 Share Posted March 21, 2014 The GFS hates us. It even screws SNE now Link to comment Share on other sites More sharing options...
SEVAsNOwSTORM Posted March 21, 2014 Share Posted March 21, 2014 Doesn't hate SE VA. Link to comment Share on other sites More sharing options...
mattie g Posted March 21, 2014 Share Posted March 21, 2014 Doesn't hate SE VA. Check out the soundings. Link to comment Share on other sites More sharing options...
Ian Posted March 21, 2014 Share Posted March 21, 2014 I'm out till the Euro clobbers us again. Link to comment Share on other sites More sharing options...
mitchnick Posted March 21, 2014 Share Posted March 21, 2014 I'm out till the Euro clobbers us again. DT meteo school graduate, ehh? Link to comment Share on other sites More sharing options...
mitchnick Posted March 21, 2014 Share Posted March 21, 2014 GGEM east, but a monster DCA/BWI clipped (but not much qpf) Link to comment Share on other sites More sharing options...
chris87 Posted March 21, 2014 Share Posted March 21, 2014 I would normally agree...but doesn't it lend to more credence with potentially phased systems? no, not in my opinion -- the idea that some feature needs to be within the radiosonde network is a fallacy -- radiosondes are important observations but ultimately people feel that forecast certainty increases when a wave is sampled coming into the west coast but in reality that forecast is more certain because its a shorter lead time forecast of a non-linear dynamical system that exhibits non-linear error growth and in most cases has very little to do with radiosonde sampling of a wave that was heavily sampled off-shore by remote sensing obs if radiosondes were necessary for improved forecasting wouldn't there be a discernible bias in NWP performance over the western US (vs eastern US) where waves aren't sampled by the radiosonde network and are largely sampled by satellite? Link to comment Share on other sites More sharing options...
famartin Posted March 21, 2014 Share Posted March 21, 2014 no, not in my opinion -- the idea that some feature needs to be within the radiosonde network is a fallacy -- radiosondes are important observations but ultimately people feel that forecast certainty increases when a wave is sampled coming into the west coast but in reality that forecast is more certain because its a shorter lead time forecast of a non-linear dynamical system that exhibits non-linear error growth and in most cases has very little to do with radiosonde sampling of a wave that was heavily sampled off-shore by remote sensing obs if radiosondes were necessary for improved forecasting wouldn't there be a discernible bias in NWP performance over the western US (vs eastern US) where waves aren't sampled by the radiosonde network and are largely sampled by satellite? I have a lot to say on this subject as a western US forecaster, but I don't have numbers to back me, so I'll keep my comments to myself. Link to comment Share on other sites More sharing options...
ACFD FIREMAN Posted March 21, 2014 Share Posted March 21, 2014 I have a lot to say on this subject as a western US forecaster, but I don't have numbers to back me, so I'll keep my comments to myself. Chris 87, thanks for your response. As for the western US, I agree and understand your point, but how many explosive, developing phased systems do they get like the potential east coast system coming up? I would imagine that more sample data would be more beneficial for timing the phase as opposed to a non-phased low pressure meandering across the country and it's potential impact. Link to comment Share on other sites More sharing options...
chris87 Posted March 21, 2014 Share Posted March 21, 2014 I have a lot to say on this subject as a western US forecaster, but I don't have numbers to back me, so I'll keep my comments to myself. i'm sure you do have specific forecasting problems out in Elko -- if you like to attribute them to data sampling I'd hear you out -- i think my statement may have come across as diminishing those obs which isn't intended, i'd rather have them than not Link to comment Share on other sites More sharing options...
dman Posted March 21, 2014 Share Posted March 21, 2014 I have a lot to say on this subject as a western US forecaster, but I don't have numbers to back me, so I'll keep my comments to myself. You're a met, so I assume you have an intelligent argument to support your viewpoint, even if not backed up with research and numbers--why not post your views, maybe someone else here does have additional data or ideas to support or contest the viewpoint, aka discussion. Link to comment Share on other sites More sharing options...
chris87 Posted March 21, 2014 Share Posted March 21, 2014 Chris 87, thanks for your response. As for the western US, I agree and understand your point, but how many explosive, developing phased systems do they get like the potential east coast system coming up? I would imagine that more sample data would be more beneficial for timing the phase as opposed to a non-phased low pressure meandering across the country and it's potential impact. i'm not sure who gets more but plenty of cases of explosive cyclogenesis have occurred in the pacific -- you don't even have to go back that far, look at the storm that affected CA in late Feb. -- sub-970 mb low. data sampling is important but not sure if we went out to the pacific and launched a bunch of radiosondes/dropsondes that it would lead to much -- especially at this lead time. Link to comment Share on other sites More sharing options...
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