LVblizzard Posted January 19, 2011 Share Posted January 19, 2011 I don't think the NAM was all the way west yet at 18Z on the 24th. Unfortunately it seems like no one saved the images but based on the dialogue it seems it was still east of NYC. This is why I absolutely HATE when people don't upload or host their images on here. It would be so much more useful while going back through old threads, and right now it's a bunch of irrelevant images. Link to comment Share on other sites More sharing options...
atownwxwatcher Posted January 19, 2011 Share Posted January 19, 2011 Actually the 18 Z RGEM is further west then the 18 Z NAM... From the black and white images..it appears as the low pressure is essentially on or over CAPE cod... http://www.weatheroffice.gc.ca/data/model_forecast/3295_100.gif While the NAM the same time is well east of Cape Cod.... http://raleighwx.americanwx.com/models/nam/18znam850mbTSLPp06048.gif Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted January 19, 2011 Share Posted January 19, 2011 FWIW, the CRAS model at 12Z showed what could have been if we had a full phase. Keep in mind, the CRAS usually over-spins these systems anyway, but you catch my drift: Link to comment Share on other sites More sharing options...
jasonli18t Posted January 19, 2011 Share Posted January 19, 2011 I wasn't accusing him of wishcasting. Just wrongly attributing a decreasing threat to a lack of phasing. It's true the phase is slower and less ideal on recent model cycles, but that's not why we're unlikely to get a big storm. Rather, that's why we might only get a few inches when it looked like maybe 4 or 6 a few days ago. I also believe you've been misdiagnosing the situation over the past few days - which is something that I expressed previously. Not every storm threat hinges on this nebulous concept of a phase. We also need to be geographically situated to take advantage of the flow evolution. From several days ago it looked like we would be situated too far SW - perfect phase or not - to get more than moderate snowstorm. And that's exactly what I said to you and earth when you guys were fantasizing aloud about "extreme dynamics" and the like, which is what you do for every single storm threat. Your arguments tend to read like the vague thoughts of a conspiracy theorist. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 19, 2011 Share Posted January 19, 2011 I wasn't accusing him of wishcasting. Just wrongly attributing a decreasing threat to a lack of phasing. It's true the phase is slower and less ideal on recent model cycles, but that's not why we're unlikely to get a big storm. Rather, that's why we might only get a few inches when it looked like maybe 4 or 6 a few days ago. I also believe you've been misdiagnosing the situation over the past few days - which is something that I expressed previously. Not every storm threat hinges on this nebulous concept of a phase. We also need to be geographically situated to take advantage of the flow evolution. From several days ago it looked like we would be situated too far SW - perfect phase or not - to get more than moderate snowstorm. And that's exactly what I said to you and earth when you guys were fantasizing aloud about "extreme dynamics" and the like, which is what you do for every single storm threat. I have no idea what you are talking about Eduggs. There has been no misdiagnoses of the current weather events--and the extreme "dynamics" you talk of were an analysis of what the various models were trying to develop. I do suggest you peruse the threads and find any discussion of any meteorologist "booking" this event. 40/60% is what I believe I mentioned 2-3 days ago and the threat the mesoscale models were more correct with their height field amplification and the development of a very amplified East Pac. ridge which would have resulted in a much deeper trough over th CONUS and a full phase. Link to comment Share on other sites More sharing options...
eduggs Posted January 19, 2011 Share Posted January 19, 2011 I think you're being overly analytical. I guess I should have said the phase doesn't happen fast enough, or over a favorable area for us. The NAM runs yesterday and even at 06z were phasing the streams over the MS valley. Today's run has no phase even at 42 hours...the southern stream shortwave is clearly separated and trailing back along the Southern States. Sure the phase happens eventually and affects Newfoundland, but what does that have to do with us? I guess March 2001 was a successful phase, too, but obviously when you ask anyone here they'll tell you that it didn't phase. It's all relative to location. Yes the phase is too slow and/or imperfect on the 18z NAM. But even on the big NAM runs from a day or two ago most of the region still got only a glancing blow (considering the NAM's tendency to overdo QPF and the relative max to our northeast). The bigger issues were that the longwave trof was situated too far north, with no local mid-level center, and moving too progressively to offer reasonable hope of big snows. You can get big snows with or without phasing. But when the height field and evolution is unfavorable, the situation is much more difficult. That's what I have been trying to point out for a few days with some frustration because some people are obsessed with certain key terms that carry more mythological than practical meaning. Link to comment Share on other sites More sharing options...
earthlight Posted January 19, 2011 Share Posted January 19, 2011 I also believe you've been misdiagnosing the situation over the past few days - which is something that I expressed previously. Not every storm threat hinges on this nebulous concept of a phase. I couldn't disagree with this post more. First of all, I don't think the situation has been misdiagnosed in the least bit. Your statement that I bolded is absolutely correct. You can have a big storm without having to worry about a phase at all. But the past few threats, and this one included, revolve heavily around the phasing of two shortwaves. To say that the phase is not a major player, if not the major player in getting the storm to develop this far south would be, to be quite frank, wrong. Of course our location has something to do with it, and getting the storm to develop further southwest is important But guess what gets that to happen, the phase between the two shortwaves. Earlier runs of the NAM and other models which were phasing the two shortwaves were bringing the northern stream feature further south as a result of a more well positioned southern stream shortwave over the Mississippi and Tennessee Valley. The shortwaves interaction caused an area of extreme vorticity and positive vorticity advection to the northeast...and height rises along the east coast, owing to that, allowed for the storm system to develop more rapidly and further southwest. The latest runs of the operational models and ensemble means have the southern stream shortwave less enthused with the phase as it is further south and slower to eject northeast. As a result, the phase happens weaker, and later, and the storm system can never really develop into a mature cyclone at this latitude. That's really all there is to it. To say that the phase isn't a huge player in this storm is a misleading statement--and to say one of the better synoptic forecasters I have ever seen is misdiagnosing the situation is also incorrect. I think his diagnosis was spot on and the changes advertised on the operational NAM-WRF which I posted below completely back up his diagnosis. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 19, 2011 Share Posted January 19, 2011 I don't think the NAM was all the way west yet at 18Z on the 24th. http://www.americanw...5/page__st__520 Unfortunately it seems like no one saved the images but based on the dialogue it seems it was still east of NYC. http://www.americanw...5/page__st__920 Even 0Z on the 25th was still significantly east. EC's 0Z run was way west of the NAM. I will have to find some images. Some of the disco threads may have better ones. 12Z GFS came in beefy. 18Z was also, and I remember 18Z NAM was far enough W because HPC tossed all three. Link to comment Share on other sites More sharing options...
eduggs Posted January 19, 2011 Share Posted January 19, 2011 I have no idea what you are talking about Eduggs. There has been no misdiagnoses of the current weather events--and the extreme "dynamics" you talk of were an analysis of what the various models were trying to develop. I do suggest you peruse the threads and find any discussion of any meteorologist "booking" this event. 40/60% is what I believe I mentioned 2-3 days ago and the threat the mesoscale models were more correct with their height field amplification and the development of a very amplified East Pac. ridge which would have resulted in a much deeper trough over th CONUS and a full phase. Yes. More amplified EPac ridge and deeper trof over the US! This is exactly what I've been pointing to. Sure, an early and complete phase can be helpful (or not if storm tracks inland). But the northern stream can dig sufficiently to do the work on its own (even if it squashes would be phasing shortwaves). But without the deeper trof in particular, a phase was not sufficient to give us more than a moderate glancing blow. This is what I mean when I say I believe you misdiagnosed the situation. And I stand 100% behind this contention. Don't be fooled by no red tag. Link to comment Share on other sites More sharing options...
earthlight Posted January 19, 2011 Share Posted January 19, 2011 Yes the phase is too slow and/or imperfect on the 18z NAM. But even on the big NAM runs from a day or two ago most of the region still got only a glancing blow (considering the NAM's tendency to overdo QPF and the relative max to our northeast). The NAM had four or more runs where there was a 988 or lower mb low pressure system developing northeast from Ocean City, MD to just south of Montauk. All of those runs featured a well timed phase. Does that really go into your dictionary as a glancing blow? Link to comment Share on other sites More sharing options...
famartin Posted January 19, 2011 Share Posted January 19, 2011 I will have to find some images. Some of the disco threads may have better ones. 12Z GFS came in beefy. 18Z was also, and I remember 18Z NAM was far enough W because HPC tossed all three. I'm still fairly confident that it was the 12Z NAM on the 25th that was the first NAM run to show a big hit (foot plus) all the way west into NJ. Then the 18Z NAM went totally bonkers with huge QPF all the way to Philly... something that SnowGoose predicted in advance, if I recall correct. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 19, 2011 Share Posted January 19, 2011 Yes. More amplified EPac ridge and deeper trof over the US! This is exactly what I've been pointing to. Sure, an early and complete phase can be helpful (or not if storm tracks inland). But the northern stream can dig sufficiently to do the work on its own (even if it squashes would be phasing shortwaves). But without the deeper trof in particular, a phase was not sufficient to give us more than a moderate glancing blow. This is what I mean when I say I believe you misdiagnosed the situation. And I stand 100% behind this contention. Don't be fooled by no red tag. No you are so very wrong--it really is pathetic and silly. The amplification and deeper trough would have resulted in a slower developing and ejecting eventual wave--and this was why it was needed in the first place--so the western wave would have time to eject east ahead of the trough for a full phase. Link to comment Share on other sites More sharing options...
RowanBrandon Posted January 19, 2011 Share Posted January 19, 2011 Glenn just showed less than 1" for most of South Jersey. I don't get it. Haven't the models been cold enough for all snow? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 19, 2011 Share Posted January 19, 2011 No you are so very wrong--it really is pathetic and silly. The amplification and deeper trough would have resulted in a slower developing and ejecting eventual wave--and this was why it was needed in the first place--so the western wave would have time to eject east ahead of the trough for a full phase. There is no magical meteorology going on here--and it was clear the cold air was displaced aloft in the upper trough. Without sufficient development of the upper level cold front downward, this trough would have been DOA--doesn't matter how far S it amplifies. The southern wave was necessary for the development of an active dynamic tropopause and rapid development. You have no idea what you are talking about. If so, I suggest you post images and dynamically break down the forecast. Trough amplification alone does not equate to rapid development. Link to comment Share on other sites More sharing options...
earthlight Posted January 19, 2011 Share Posted January 19, 2011 I'm still fairly confident that it was the 12Z NAM on the 25th that was the first NAM run to show a big hit (foot plus) all the way west into NJ. Then the 18Z NAM went totally bonkers with huge QPF all the way to Philly... something that SnowGoose predicted in advance, if I recall correct. Didn't the 00z run on the 25th (christmas eve) show some considerable QPF back to the west as well? I remember plenty of people texting my like crazy while I was at Christmas Eve dinner saying the NAM was west. Link to comment Share on other sites More sharing options...
tmagan Posted January 19, 2011 Share Posted January 19, 2011 You know what is ironic is that the UKMET is the most optimistic (including today's 18Z run) for a borderline moderate snowfall. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 19, 2011 Share Posted January 19, 2011 I'm still fairly confident that it was the 12Z NAM on the 25th that was the first NAM run to show a big hit (foot plus) all the way west into NJ. Then the 18Z NAM went totally bonkers with huge QPF all the way to Philly... something that SnowGoose predicted in advance, if I recall correct. Well I think the differences here are general semantics as the 12Z ECMWF was OTS and not even close. 18Z NAM may not have been a bombastic bomb--but it was definitely not OTS and quite honestly the initial trend W to begin with was hugely important--not the solution it had verbatim. If we are talking about which model correctly nailed the event--than they all pretty much fail--as the models did with the last nor'easter last week. Showing the potential and remaining consistent with certain features was far more important that the model solution. Link to comment Share on other sites More sharing options...
_AR_ Posted January 19, 2011 Share Posted January 19, 2011 Didn't the 00z run on the 25th (christmas eve) show some considerable QPF back to the west as well? I remember plenty of people texting my like crazy while I was at Christmas Eve dinner saying the NAM was west. Yes I am sure there were a couple runs that showed considerable snow back this way. Link to comment Share on other sites More sharing options...
famartin Posted January 19, 2011 Share Posted January 19, 2011 Didn't the 00z run on the 25th (christmas eve) show some considerable QPF back to the west as well? I remember plenty of people texting my like crazy while I was at Christmas Eve dinner saying the NAM was west. West of where it had been, sure. Not like the GFS by any means, though. My memory tells me that the NAM was one of the most eastern models and slowly but surely plugged its way west... well behind the GFS. The snow map plot on that second link suggests that the NAM was still significantly lagging in its westward plod. Link to comment Share on other sites More sharing options...
Njwinter Posted January 19, 2011 Share Posted January 19, 2011 HM Accu. Has NYC in the 6-12 zone on his updated map. What is he looking at. I hope he is right for once. Link to comment Share on other sites More sharing options...
Allsnow Posted January 19, 2011 Share Posted January 19, 2011 the 18z gfs is .25+ for all of us temps look to be in the mid-upper 20's for the event hr 48 snowfall map is 2-4 from phl-nyc Link to comment Share on other sites More sharing options...
famartin Posted January 19, 2011 Share Posted January 19, 2011 Well I think the differences here are general semantics as the 12Z ECMWF was OTS and not even close. 18Z NAM may not have been a bombastic bomb--but it was definitely not OTS and quite honestly the initial trend W to begin with was hugely important--not the solution it had verbatim. If we are talking about which model correctly nailed the event--than they all pretty much fail--as the models did with the last nor'easter last week. Not gonna argue with that. Every model was wrong for at least a couple runs in a row. The main thing I remember was that the 0Z EC jumped back on board with the GFS matching its 1" QPF all the way back to western NJ. I went all in at that point with 8-16" for a general forecast for Jersey... and if you cut the lower number in two and multiply the upper number by two you'll get the range of actual reports Link to comment Share on other sites More sharing options...
LVblizzard Posted January 19, 2011 Share Posted January 19, 2011 the 18z gfs is .25+ for all of us temps look to be in the mid-upper 20's for the event Not in the Poconos and NW NJ. Link to comment Share on other sites More sharing options...
IsentropicLift Posted January 19, 2011 Share Posted January 19, 2011 the 18z gfs is .25+ for all of us temps look to be in the mid-upper 20's for the event Where are you getting this from? I'm showing it only out to 30hrs on the NCEP site. Link to comment Share on other sites More sharing options...
Thunder Road Posted January 19, 2011 Share Posted January 19, 2011 I'm still fairly confident that it was the 12Z NAM on the 25th that was the first NAM run to show a big hit (foot plus) all the way west into NJ. Then the 18Z NAM went totally bonkers with huge QPF all the way to Philly... something that SnowGoose predicted in advance, if I recall correct. I agree with this. Here is what I recall: 12z GFS on 12/24 had a moderate hit. HPC tossed it. 18z NAM on 12/24 had a moderate hit (about 4-6"), and 18z GFS on 12/24 had 12+"... HPC tossed both. 0z NAM on 12/25 still had 4-6", 0z RGEM on 12/25 agreed, 0z GFS and 0z ECM on 12/25 had a major hit. NAM stuck with a moderate event until its 18z run on 12/25. By that point, the RGEM had been upping its amounts already. Link to comment Share on other sites More sharing options...
IsentropicLift Posted January 19, 2011 Share Posted January 19, 2011 HM Accu. Has NYC in the 6-12 zone on his updated map. What is he looking at. I hope he is right for once. link? Link to comment Share on other sites More sharing options...
earthlight Posted January 19, 2011 Share Posted January 19, 2011 There is no magical meteorology going on here--and it was clear the cold air was displaced aloft in the upper trough. Without sufficient development of the upper level cold front downward, this trough would have been DOA--doesn't matter how far S it amplifies. The southern wave was necessary for the development of an active dynamic tropopause and rapid development. You have no idea what you are talking about. If so, I suggest you post images and dynamically break down the forecast. Trough amplification alone does not equate to rapid development. Yup, this is pretty much what I was saying. I don't understand how there can be much of an argument. I posted the image on the last page but here it is again for reference. It's not even close, and it's pretty cut and dry (no pun intended) as to why the NAM is less amplified, doesn't have the cyclogenesis nearer to the coast, and is much later to develop the cyclone. Link to comment Share on other sites More sharing options...
Allsnow Posted January 19, 2011 Share Posted January 19, 2011 Not in the Poconos and NW NJ. still close to .25 and you get 2-4 of snow.... Link to comment Share on other sites More sharing options...
Allsnow Posted January 19, 2011 Share Posted January 19, 2011 Where are you getting this from? I'm showing it only out to 30hrs on the NCEP site. paid site Link to comment Share on other sites More sharing options...
eduggs Posted January 19, 2011 Share Posted January 19, 2011 I couldn't disagree with this post more. First of all, I don't think the situation has been misdiagnosed in the least bit. Your statement that I bolded is absolutely correct. You can have a big storm without having to worry about a phase at all. But the past few threats, and this one included, revolve heavily around the phasing of two shortwaves. To say that the phase is not a major player, if not the major player in getting the storm to develop this far south would be, to be quite frank, wrong. Of course our location has something to do with it, and getting the storm to develop further southwest is important But guess what gets that to happen, the phase between the two shortwaves. Earlier runs of the NAM and other models which were phasing the two shortwaves were bringing the northern stream feature further south as a result of a more well positioned southern stream shortwave over the Mississippi and Tennessee Valley. The shortwaves interaction caused an area of extreme vorticity and positive vorticity advection to the northeast...and height rises along the east coast, owing to that, allowed for the storm system to develop more rapidly and further southwest. The latest runs of the operational models and ensemble means have the southern stream shortwave less enthused with the phase as it is further south and slower to eject northeast. As a result, the phase happens weaker, and later, and the storm system can never really develop into a mature cyclone at this latitude. That's really all there is to it. To say that the phase isn't a huge player in this storm is a misleading statement--and to say one of the better synoptic forecasters I have ever seen is misdiagnosing the situation is also incorrect. I think his diagnosis was spot on and the changes advertised on the operational NAM-WRF which I posted below completely back up his diagnosis. Northern stream was never progged to dive very far south - even on the great NAM runs. Reason being it was embedded in progressive ridge/trof sequence. Without a deep trof in the center of the US, even if the southern stream s/w were to get out ahead and phase into the downstream flank, the developing SLP would move quickly to the NE until slowing somewhere up toward the Maritimes (upon interacting with upper level lows). Even those good NAM runs bombed out the low to our NE. So of course I agree the timing and location of phasing is/was important here, but it was never my primary concern with respect to getting a decent snowstorm across our area. If we had some north atlantic blocking that would jam up the flow and allow the northern stream to dig south, that could have produced a good storm even if it had squashed the southern stream energy. In short, it was the largescale features that were misplaced, not so much to quality of the phase that I was keying on. I said from the start I thought this would be moderate snowstorm at BEST and the low would bomb too late (for us) in the Maritimes... because of the overall synoptic pattern. I thought we were too far SW even with a good phase for a major snow. I was cautious and I contested terms like historical and epic and argued my case. BI tends to lean towards the hype and the upper end of possibilities. That sometimes rubs me the wrong way, especially in situations that are unideal from the start. Being a good forecasters means recognizing situations where odds are stacked against you. He has yet to demonstrate that kind of perception to me. Link to comment Share on other sites More sharing options...
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