Ababa Posted January 11, 2011 Share Posted January 11, 2011 what did you have for JFK? 18.1. Ratios only 5:1, 6:1 for a couple of hours while the storm is at hour 26 and 27. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 11, 2011 Share Posted January 11, 2011 I would have been alot less confident if the Euro and it's ensembles hadn't come so far northwest on the latest 00z run. The GFS is out on it's own..not counting crazy uncle Ukie...I just wonder what kind of problem it is having here. Could it score the coup here? Sure...but I wouldn't bet my money on it at this moment in time. We have to stay up for the ensembles lol. Link to comment Share on other sites More sharing options...
SnowGoose69 Posted January 11, 2011 Share Posted January 11, 2011 I wonder if having the euro and nam together and the ggem trending towards them means its much more likely the gfs is wrong. Yes it does....there was one storm somewhere between 2006-2009 though where the GFS was correct with its further east solution but I can't remember which one, might have been 3.2.09 Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 Anybody else see the difference here? Maybe its not that much of the difference...I might be nit-picking :axe: http://www.meteo.psu.edu/~gadomski/AVNEAST_6z/f27.gif http://www.meteo.psu.edu/~gadomski/WRFEAST_6z/f27.gif Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 11, 2011 Share Posted January 11, 2011 18.1. Ratios only 5:1, 6:1 for a couple of hours while the storm is at hour 26 and 27. ahhh, wetter snow but no changeover, rain/snow line probably within 10 miles of here-- sounds like the first day of the Dec 2003 blizzard. Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 By the way, how about the ETA and the NAM being near carbon copies of each other? I'll take the E/N rule. http://www.meteo.psu.edu/~gadomski/ETAEAST_6z/f27.gif Link to comment Share on other sites More sharing options...
Ababa Posted January 11, 2011 Share Posted January 11, 2011 If GFS verifies there will be a lot of heartbreak here on Wednesday morning. SREFS/EURO/RGEM/NAM vs. GFS and out to lunch this season UKIE. Gotta like the odds. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 11, 2011 Share Posted January 11, 2011 Yes it does....there was one storm somewhere between 2006-2009 though where the GFS was correct with its further east solution but I can't remember which one, might have been 3.2.09 That was a slight bust for NJ and NYC (more of a bust in NJ)..... I remember the original forecast was for 10-18 inches of snow and it was like 8 inches in NYC..... western LI got the 10-12 inch end of the range but the higher amts verified in eastern suffolk. Link to comment Share on other sites More sharing options...
nzucker Posted January 11, 2011 Share Posted January 11, 2011 Anybody else see the difference here? Maybe its not that much of the difference...I might be nit-picking It's a major difference in guidance...the 6z NAM is tucked under LI at 30 hours, whereas the 6z GFS has already moved the low south of ACK. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 Anybody else see the difference here? Maybe its not that much of the difference...I might be nit-picking :axe: http://www.meteo.psu...EAST_6z/f27.gif http://www.meteo.psu...EAST_6z/f27.gif The height field is nearly the same. I still give the edge to the non-hydrostatic meso models. GFS simply wasn't made to simulate such a system. The GFS being on its own really isn't much of a worry to me. The ECMWF is also a global, but it has a much higher horizontal resolution. Link to comment Share on other sites More sharing options...
Dark Energy Posted January 11, 2011 Share Posted January 11, 2011 I wonder if having the euro and nam together and the ggem trending towards them means its much more likely the gfs is wrong. The NAM/Euro combo is not a crazy one. I have seen it many times before. WHen you get it, it's usually a good thing! With the GEM included, its a really good thing. Remember the last little event we had? That 2 incher in NYC? Well, the GEM had that close to the coast low vice the rest of the guidance and it was RIGHT. So to have all 3 in tandem, it's pretty much a lock. But I'll eat my words of course probly. LOL. Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 If resolution is the argument, what say you about the ETA? The model is producing a NAM solution with a very poor resolution in comparison to the GFS, even. Link to comment Share on other sites More sharing options...
Bobby Posted January 11, 2011 Share Posted January 11, 2011 ahhh, wetter snow but no changeover, rain/snow line probably within 10 miles of here-- sounds like the first day of the Dec 2003 blizzard. Which goes back to my earlier post about lower numbers due to heavier snow. The WORST to shovel. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 If resolution is the argument, what say you about the ETA? The model is producing a NAM solution with a very poor resolution in comparison to the GFS, even. The eta is non-hydrostatic I believe. Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 The height field is nearly the same. I still give the edge to the non-hydrostatic meso models. GFS simply wasn't made to simulate such a system. The GFS being on its own really isn't much of a worry to me. The ECMWF is also a global, but it has a much higher horizontal resolution. The NAM seems much tighter with the height field to me over New England, heights are backed much more towards the coast. The NAM and the other hi-res models just have some type of insane cyclogenesis and upper level process going on...and they will not give up, very steady throughout the entire short term so far. Link to comment Share on other sites More sharing options...
nzucker Posted January 11, 2011 Share Posted January 11, 2011 The eta is non-hydrostatic I believe. I hate to bother you with excessive questions, but what is the difference between a hydrostatic and a non-hydrostatic model? I was a Spanish/French major in college so I don't have the meteorology background but try to follow this stuff reasonably well. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 11, 2011 Share Posted January 11, 2011 And the NAM is west. Truth probably lies in the middle hedging closer to the NAM by like a 70/30 ratio. Basically the other consensus of guidance. So the EURO and its ensembles are about twice as close to the NAM than they are to the GFS, Will? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 I hate to bother you with excessive questions, but what is the difference between a hydrostatic and a non-hydrostatic model? I was a Spanish/French major in college so I don't have the meteorology background but try to follow this stuff reasonably well. I would explain it, but AMS explains it better, haha. In short though, non-hydrostatic models are a much more realistic interpretation of the atmosphere--especially with respect to convection and mesoscale atmospheric phenomena that do not follow hydrostatic equilibrium, but they can have major sensitivity issues due to the noise inherent in models. In other words, they can develop nasty feedback issues. This is why the NAM and other non-hydro models, under certain circumstances, can overdevelop a low. nonhydrostatic model—An atmospheric model in which the hydrostatic approximation is not made, so that the vertical momentum equation is solved.This allows nonhydrostatic models to be used successfully for horizontal scales of the order of 100 m, resolving small-scale mesoscale circulations such as cumulus convection and sea-breeze circulations. In recent years, computer power has made mesoscale weather prediction with nonhydrostatic models feasible, and several such models are in routine use by major meteorological modeling groups and operational centers. See hydrostatic model. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 11, 2011 Share Posted January 11, 2011 The NAM/Euro combo is not a crazy one. I have seen it many times before. WHen you get it, it's usually a good thing! With the GEM included, its a really good thing. Remember the last little event we had? That 2 incher in NYC? Well, the GEM had that close to the coast low vice the rest of the guidance and it was RIGHT. So to have all 3 in tandem, it's pretty much a lock. But I'll eat my words of course probly. LOL. I remember that combo first working out in Jan 1996 The GFS/AVN was the outlier there too. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 11, 2011 Share Posted January 11, 2011 I would explain it, but AMS explains it better, haha. In short though, non-hydrostatic models are a much more realistic interpretation of the atmosphere--especially convection, but they can have major sensitivity issues due to the noise inherent in models. In other words, they can develop nasty feedback issues. This is why the NAM and other non-hydro models, under certain circumstances, can overdevelop a low. nonhydrostatic model—An atmospheric model in which the hydrostatic approximationis not made, so that the vertical momentum equation is solved.This allows nonhydrostatic models to be used successfully for horizontal scales of the order of 100 m, resolving small-scale mesoscale circulations such as cumulus convection and sea-breeze circulations. In recent years, computer power has made mesoscale weather prediction with nonhydrostatic models feasible, and several such models are in routine use by major meteorological modeling groups and operational centers. See hydrostatic model. I was going to ask you too, but I had a guess in mind which turned out to be wrong lol-- based on the term "hydrostatic" being used, I had assumed it meant that the model does a better job resolving the finer details of atmosphere/land/sea coupling. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 I hate to bother you with excessive questions, but what is the difference between a hydrostatic and a non-hydrostatic model? I was a Spanish/French major in college so I don't have the meteorology background but try to follow this stuff reasonably well. I was going to ask you too, but I had a guess in mind which turned out to be wrong lol-- based on the term "hydrostatic" being used, I had assumed it meant that the model does a better job resolving the finer details of atmosphere/land/sea coupling. In short, the GFS and other global models need to "parameterize" both convection and sub-grid scale phenomena while the NAM and non-hydrostatic models can realistically "simulate" those phenomena using the fully discretized Navier-Stokes equations (although sub-grid scale phenomena are still parameterized--think cloud microphysics or cumulus convection). Once again though, noise can be an issue since less aggressive filters are used in the analysis. This is why the NAM can be so unreliable run to run. This is also why global models will remain hydrostatic for a long time to come. Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 It's a major difference in guidance...the 6z NAM is tucked under LI at 30 hours, whereas the 6z GFS has already moved the low south of ACK. Haha agreed...I was joking around in my post. Can't remember a situation recently where we had these dramatic differences at 24 hrs. Link to comment Share on other sites More sharing options...
nzucker Posted January 11, 2011 Share Posted January 11, 2011 In short, the GFS and other global models need to "parameterize" both convection and sub-grid scale phenomena while the NAM and non-hydrostatic models can realistically "simulate" those phenomena using the fully discretized Navier-Stokes equations. Once again though, noise can be an issue since less aggressive filters are used in the analysis. This is why the NAM can be so unreliable run to run. This is also why global models will remain hydrostatic for a long time to come. Is the ECM hydrostatic despite its high resolution? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 Is the ECM hydrostatic despite its high resolution? Yes sir. Link to comment Share on other sites More sharing options...
hudsonvalley21 Posted January 11, 2011 Share Posted January 11, 2011 31.7 Thanks, let me go change my shorts. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 Is the ECM hydrostatic despite its high resolution? Generally high resolution models such as the ARW/NMM NCEP hi-res and the NAM (WRF-NMM) and ETA are non-hydrostatic. SUNY MM5 is also I believe. Otherwise, most other models are hydrostatic, including the regional GEM and all global models. Link to comment Share on other sites More sharing options...
nzucker Posted January 11, 2011 Share Posted January 11, 2011 Generally high resolution models such as the ARW/NMM NCEP hi-res and the NAM and ETA are non-hydrostatic. SUNY MM5 is also I believe. Otherwise, most other models are hydrostatic, including the regional GEM and all global models. Thanks so much for the detailed explanation. BTW, GFS gives NYC metro 1-3" snowfall from a clipper at Day 5. Looks like a solid nuisance event. Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 The positioning of the upper level height field and shortwave really argues for the surface low to be at least 25-50 miles further west and deeper than the GFS places it...and also argues for a precip shield to develop and expand from Delaware northward through New Jersey into the New York area..and then rapidly intensify. I wonder if some sort of shortwave is escaping northeast, or something along those lines, that might be dampening it's height field. The NAM is definitely tighter and closer to the coast w/ the H5 heights even at 21-24 hours as are most other models. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 11, 2011 Share Posted January 11, 2011 Thanks so much for the detailed explanation. BTW, GFS gives NYC metro 1-3" snowfall from a clipper at Day 5. Looks like a solid nuisance event. The last thing I will say before I go is this--this event will be a NOWcast event by 12/15Z. Tracking that coastal low and its placement will likely point to the eventual model of choice. Link to comment Share on other sites More sharing options...
earthlight Posted January 11, 2011 Share Posted January 11, 2011 I'm off to bed..see you dudes tomorrow. Good luck to everybody who's getting up in the early morning. Wishing you all feet and feet of wind driven snow Link to comment Share on other sites More sharing options...
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