jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 72hr looks like 992 around bm 72 hour is near central NJ not the benchmark. Link to comment Share on other sites More sharing options...
OceanStWx Posted February 12, 2015 Share Posted February 12, 2015 Translation? We know that air parcels like to follow lines of constant potential temp. If those lines of potential temp are widely spaced we can infer potential instability. Lines of potential temp slope towards the cold air and won't "cross over" each other (think if you were looking straight up over your head). If you introduce diabatic processes (latent heat release) you can get air parcels to leave their original potential temp line. This is accounted for in equivalent potential temp (theta-e). Theta-e lines can cross over each other, and when that happens you have an area of potential instability. Link to comment Share on other sites More sharing options...
Bostonseminole Posted February 12, 2015 Share Posted February 12, 2015 72 hour is near central NJ not the benchmark. 78 fixed it Link to comment Share on other sites More sharing options...
eduggs Posted February 12, 2015 Share Posted February 12, 2015 How can you not see that, while the tick isn't considered extreme, it is still a tick to the south. Look at the difference in the QPF fields between the 18z run and the 00z run GFS. It is amazing. QPF is the least telling and least reliable parameter. And yet it has been, along with the other parameters, very consistent for the past 3 GFS runs. The orientation of the height fields were slightly changed this run, but overall the runs were about as close as could ever be expected for a highly anomalous setup. This is not the usual open wave development scenario where trends east and west are easy to diagnose. We have an extremely deep and sharp ULL dropping SE. When the GFS starts swinging the ULL through PA I'll acknowledge a south trend. Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 75 or 78 hours there is stretched out E-W surface low from the BM to NYC. Link to comment Share on other sites More sharing options...
Ginx snewx Posted February 12, 2015 Share Posted February 12, 2015 Thanks so much, James! I'll certainly check out that site.brohttp://www.weather5280.com/models/gfs/00z/conus/ Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 We know that air parcels like to follow lines of constant potential temp. If those lines of potential temp are widely spaced we can infer potential instability. Lines of potential temp slope towards the cold air and won't "cross over" each other (think if you were looking straight up over your head). If you introduce diabatic processes (latent heat release) you can get air parcels to leave their original potential temp line. This is accounted for in equivalent potential temp (theta-e). Theta-e lines can cross over each other, and when that happens you have an area of potential instability. Awesome explanation, I learned about the adiabatic processes and air parcels in my intro to meteorology class back in 2009, but that is as far as I got with my met knowledge, most of the things I know is from personal experiences. Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 Thanks so much, James! I'll certainly check out that site. Your welcome, anything to help out someone else. Link to comment Share on other sites More sharing options...
weathercoins Posted February 12, 2015 Share Posted February 12, 2015 CMC is quite south Link to comment Share on other sites More sharing options...
dryslot Posted February 12, 2015 Share Posted February 12, 2015 That inv trough look on the GGEM is fugly Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 Eduggs, I think you saw the QPF fields, they acknowledge where the model seems the precip falling the heaviest, its a good indicator for the amount of precip to fall and where the heaviest precip does fall. While the fine details are not exact, its a good outline. Link to comment Share on other sites More sharing options...
CoastalWx Posted February 12, 2015 Share Posted February 12, 2015 Yeah Ray, it's technical, but to really dumb it down..a nice stable atmosphere is not supposed to have these theta-e surfaces fold back as you move up in the atmosphere...even if there is some weak instability it won't. When they do fold back...it means you basically have the potential for convection. Link to comment Share on other sites More sharing options...
powderfreak Posted February 12, 2015 Share Posted February 12, 2015 at ratios that's pretty impressive for what I thought was an underplayed qpf output GFS precip...though its total precip and contains both the clipper and Sunday's system. That's a nice 4-5 day total in a very cold airmass. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted February 12, 2015 Author Share Posted February 12, 2015 Thanks for the explanation, guys Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 00z GGEM is still over Cape Cod with the heaviest precipitation, Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 So Scott, potential instability could mean the potential for extreme lift and convection over eastern MA during this storm? Could we actually see insane snowfall rates mature over our heads? GFS shows extreme lift in the 700mb level. Link to comment Share on other sites More sharing options...
eduggs Posted February 12, 2015 Share Posted February 12, 2015 GFS and CMC kind of underwhelming. That H5 setup would look so much better if the trof structure were cutoff or translating northeast. The SE momentum with this just pulls everything offshore before it can really get going. Link to comment Share on other sites More sharing options...
dendrite Posted February 12, 2015 Share Posted February 12, 2015 Eduggs, I think you saw the QPF fields, they acknowledge where the model seems the precip falling the heaviest, its a good indicator for the amount of precip to fall and where the heaviest precip does fall. While the fine details are not exact, its a good outline.QPF is one of, if not the worst, modeled parameter. Link to comment Share on other sites More sharing options...
N. OF PIKE Posted February 12, 2015 Share Posted February 12, 2015 GFS and CMC kind of underwhelming. That H5 setup would look so much better if the trof structure were cutoff or translating northeast. The SE momentum with this just pulls everything offshore before it can really get going. Is the GFS and CMC really that similiar w ML low tracks Link to comment Share on other sites More sharing options...
CoastalWx Posted February 12, 2015 Share Posted February 12, 2015 So Scott, potential instability could mean the potential for extreme lift and convection over eastern MA during this storm? Could we actually see insane snowfall rates mature over our heads? GFS shows extreme lift in the 700mb level. Well maybe..I wouldn't get excited over it right now. Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 Honestly eduggs, it looks fine for eastern SNE right now, we have room for improvement still. We have a 492dm powderkeg running south of our region, something is gonna give. Link to comment Share on other sites More sharing options...
Ginx snewx Posted February 12, 2015 Share Posted February 12, 2015 GEM is better than peeps are implying Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 Well maybe..I wouldn't get excited over it right now. What has to happen for you to like the setup? confidence through multi model consensus? Link to comment Share on other sites More sharing options...
eduggs Posted February 12, 2015 Share Posted February 12, 2015 Is the GFS and CMC really that similiar w ML low tracks They are a bit different... meaning the difference between a target area of coastal ME and Cape Cod. The NAM is sort of a compromise. Generally a light to moderate snowfall, increasing to the east. The 12z Euro was best. Link to comment Share on other sites More sharing options...
CoastalWx Posted February 12, 2015 Share Posted February 12, 2015 What has to happen for you to like the setup? confidence through multi model consensus? How about getting within 48 hrs..lol. Link to comment Share on other sites More sharing options...
SR Airglow Posted February 12, 2015 Share Posted February 12, 2015 That inv trough look on the GGEM is fugly Yeah that run screams one or two posters are thrilled and everyone else is calling bust lol. Would much rather take the GFS look over that as everyone would see at least a few inches on the GFS whereas on the GGEM if you weren't in the IVT I'd have a hard time envisioning much QPF. Euro solution is far superior to both however... Link to comment Share on other sites More sharing options...
ORH_wxman Posted February 12, 2015 Share Posted February 12, 2015 GEM is def better than the GFS..but still is a bit too stretched out for my liking if we are talking a larger event (like 10"+ widespread) Link to comment Share on other sites More sharing options...
eduggs Posted February 12, 2015 Share Posted February 12, 2015 GEM is better than peeps are implying Yeah better for Moosup than the GFS. Link to comment Share on other sites More sharing options...
jamesnichols89 Posted February 12, 2015 Share Posted February 12, 2015 How about getting within 48 hrs..lol. True, Ginxy that's hurricane force wind gusts. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted February 12, 2015 Share Posted February 12, 2015 Ukie @72h. 500mb track looks to track under LI. Link to comment Share on other sites More sharing options...
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