jojo762 Posted August 27, 2015 Share Posted August 27, 2015 I'm probably the furthest thing from an expert there is in here, but I don't see how the tropical model intensity forecasts, and the global model track forecasts, are anything but codependent. I mean, how can you trust an intensity forecast without the context of a track - there's obviously a lot more than internal dynamics at play (shearing, dry air, mountains - all track dependent). And, at the same time, as intensity shapes track (see recent debate on Danny), how can you forecast track without a good model of intensity? Bottom line - and I'm sure this is a gross oversimplification of the middle ground between TH and DTK - but don't both global and tropical models have something useful to contribute to the forecasts that Mets derive from their analyses of both? This would be a correct hypothesis. The NHC, for example, often mentions the GFS and EURO and other globals models, as well as hi-res hurricane models when creating their forecasts for both track and intensity. If they used either one (hi-res or global) too much they would often get bunk forecasts, since there is usually no exact consensus between the two. Such as for intensity, at least this go around, if one used only hurricane models like the GFDL/HWRF they would get stronger storms, then compared to the global models. Compare the GFDL to any other model... GFDL shows a 120-140kt intense Hurricane north of the Bahamas at 126hrs. HWRF shows something somewhat similar, at 100-110kts, but to a lesser degree. Most over guidance does not show quite this strong of a storm at that time, at least 18Z guidance, and the 00Z guidance that is in so far. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 The 00z GFS is much, much better through 60hrs Weaker and keeps it south :/ Link to comment Share on other sites More sharing options...
Superstorm93 Posted August 27, 2015 Share Posted August 27, 2015 Completely decoupled system through 60 hours. Once this MCS dies off tomorrow and we get a new ingest of UL data into all the models from the Gulfstream flight, things should become a bit more clear. Right now this is getting rather old. Link to comment Share on other sites More sharing options...
jojo762 Posted August 27, 2015 Share Posted August 27, 2015 The 00z GFS is much, much better through 60hrs How so? It shows something similar to what it did at 18Z at that same time frame. Link to comment Share on other sites More sharing options...
CCHurricane Posted August 27, 2015 Share Posted August 27, 2015 It's about more than looking at QPF Not sure what you are looking at but it looks weaker for sure, disorganized, and south... Link to comment Share on other sites More sharing options...
jojo762 Posted August 27, 2015 Share Posted August 27, 2015 The 00z GFS is much, much better through 60hrs Still don't understand how... Link to comment Share on other sites More sharing options...
IsentropicLift Posted August 27, 2015 Share Posted August 27, 2015 My post was about the first 60 hours. Really the first 48. The GFS keeps the circulation in tact. Beyond that I could care less what bogus intensity it's predicting over the almost 90 degree waters in the Bahamas. Link to comment Share on other sites More sharing options...
IsentropicLift Posted August 27, 2015 Share Posted August 27, 2015 And for posterity the GFS is still going to bomb it out near the FL coast again Link to comment Share on other sites More sharing options...
jojo762 Posted August 27, 2015 Share Posted August 27, 2015 Reason why the GFS shows a weak system... It takes the coc right over PR and HSP. It is however does still keep the circulation intact... and then moves it over the 90 degree water mentioned above, so that intensity of <34kts is a bit questionable. Link to comment Share on other sites More sharing options...
andyhb Posted August 27, 2015 Share Posted August 27, 2015 Let the model hallucinations begin. They began a long time ago. Link to comment Share on other sites More sharing options...
IsentropicLift Posted August 27, 2015 Share Posted August 27, 2015 Reason why the GFS shows a weak system... It takes the coc right over PR and HSP.PR yes, HP no. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 Barely making landfall. MAYBE this might get interesting.... Link to comment Share on other sites More sharing options...
AvantHiatus Posted August 27, 2015 Share Posted August 27, 2015 They began a long time ago. Blame the GEM and GFS Ensembles. The GFS is likely too conservative but I will see how the system looks tommorow in order to pass judgement. Link to comment Share on other sites More sharing options...
IsentropicLift Posted August 27, 2015 Share Posted August 27, 2015 Barely making landfall. MAYBE this might get interesting....People always want to jump the gun. Let the run finish. Link to comment Share on other sites More sharing options...
jojo762 Posted August 27, 2015 Share Posted August 27, 2015 PR yes, HP no. I'd say it does. The exact location of the coc is a bit undeterminable, so its close enough. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 RI @ 138 Link to comment Share on other sites More sharing options...
CCHurricane Posted August 27, 2015 Share Posted August 27, 2015 My post was about the first 60 hours. Really the first 48. The GFS keeps the circulation in tact. Beyond that I could care less what bogus intensity it's predicting over the almost 90 degree waters in the Bahamas. If you could care less about the intensity...then how can you care about the track? Both aspects of a tropical cyclone can directly affect the other. Link to comment Share on other sites More sharing options...
IsentropicLift Posted August 27, 2015 Share Posted August 27, 2015 If you could care less about the intensity...then how can you care about the track? Both aspects of a tropical cyclone can directly affect the other.Because global models lack the resolution to properly forecast intensity. Use globals for track and general idea. After that I favor the higher res hurricane models. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 Looks like a weaker Hugo.... Link to comment Share on other sites More sharing options...
IsentropicLift Posted August 27, 2015 Share Posted August 27, 2015 Looks like landfall in SC. GFS says 1000.7mb. I'd say that's pretty awful representation as to the true intensity. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 Landfall at Charleston as a strong TC or weak Hurricane at 153 it looks like. Link to comment Share on other sites More sharing options...
AvantHiatus Posted August 27, 2015 Share Posted August 27, 2015 Steady organization per radar trends. http://www.meteofrance.gp/previsions-meteo-antilles-guyane/animation/radar/antilles Link to comment Share on other sites More sharing options...
Eastatlwx Posted August 27, 2015 Share Posted August 27, 2015 Looks like a weaker Hugo.... it is only out to 120 hrs on tropical tidbits. What model weather page website do you use? Link to comment Share on other sites More sharing options...
cmichweather Posted August 27, 2015 Share Posted August 27, 2015 Steady organization per radar trends. http://www.meteofrance.gp/previsions-meteo-antilles-guyane/animation/radar/antilles Problem is that the convection seems to have pulled it south. If that spin on the radar is indeed the new LLC it would be too far south to miss PR unless it goes NNW from here on. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 it is only out to 120 hrs on tropical tidbits. What model weather page website do you use? instantweathermaps Fastest free model page out. Link to comment Share on other sites More sharing options...
jojo762 Posted August 27, 2015 Share Posted August 27, 2015 Steady organization per radar trends. http://www.meteofrance.gp/previsions-meteo-antilles-guyane/animation/radar/antilles organization of what? The sfc-coc and is still well to the north of all that convection you see on radar. EDIT: nvm. I see what you're getting at... But looks like dual circulations to me. Link to comment Share on other sites More sharing options...
CCHurricane Posted August 27, 2015 Share Posted August 27, 2015 Because global models lack the resolution to properly forecast intensity. Use globals for track and general idea. After that I favor the higher res hurricane models. If intesity plays a significant role in a tropical storms track...then how can you "just" use the track and not take into account that it could be completely wrong based on mis-modeled intensity? You are taking the track as solid data, yet in the same sentence saying the intensity is wrong. The track that is being represented is a result of the modeled intesity. Link to comment Share on other sites More sharing options...
AvantHiatus Posted August 27, 2015 Share Posted August 27, 2015 Problem is that the convection seems to have pulled it south. If that spin on the radar is indeed the new LLC it would be too far south to miss PR unless it goes NNW from here on. Not too concerned about land interaction on PR with such a broad system. The most viable option is to blend the hurricane model intensity with the globals. At least meet them halfway or you begin taking large risks. It seems we will need more than a brush with PR to poof out Erika. Link to comment Share on other sites More sharing options...
SN_Lover Posted August 27, 2015 Share Posted August 27, 2015 Canadian has a weak piece of garbage hitting FL. Models split again.... Link to comment Share on other sites More sharing options...
jojo762 Posted August 27, 2015 Share Posted August 27, 2015 Canadian has a weak piece of garbage hitting FL. Models split again.... How about we just throw darts at a dart board, with each dart color representing a particular model, the one closest to the bulls-eye wins, and see what we get? Link to comment Share on other sites More sharing options...
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