Kaner587 Posted January 26, 2011 Share Posted January 26, 2011 For now. Seriously, it wouldn't be outlandish for a model to back off precip by 1/2 inch. Happens all the time. Not saying it is right, just don't auto-toss it. See what the rest of 0z does. when that half inch is more than 2/3 of what the model consensus is, ya its pretty outlandish. I'm not suggesting there is a 0% chance it verifies but it looks screwy and has no support Link to comment Share on other sites More sharing options...
eduggs Posted January 26, 2011 Share Posted January 26, 2011 This is just plain wrong. The surface low is def. placed to the s and e and misplaced at that. Between 12 and 15 hours the NAM send the surface low chasing a qpf bomb into the atlantic which is classic convective feedback and then tries to correct itself but its too late. All the best moisture is gone and its too late. Very minor changes. I disagree. Link to comment Share on other sites More sharing options...
FreeRain Posted January 26, 2011 Share Posted January 26, 2011 The 9:42 PM OKX statement makes no mention of the NAM. Still bases its forecast on the 12z model suite convergence. Link to comment Share on other sites More sharing options...
jm1220 Posted January 26, 2011 Share Posted January 26, 2011 Very minor changes. I disagree. As I've mentioned, the NAM has a history of producing these weird runs with Gulf originated systems. The NAM at least a couple of runs completely jipped us on 12/26 when the rest of the models were collectively slamming us. I'm not concerned in the least bit until the others follow suit. I doubt they will, given especially the foreign suite's rock solid consistency to this point. Link to comment Share on other sites More sharing options...
wxman Posted January 26, 2011 Share Posted January 26, 2011 I've seen this kind of thing written about various model runs literally dozens of times, usually when there is an outlier solution or a sudden model change. And I have never observed a correlation between error identification and the relative likelihood of the solution verifying. Sometimes the supposed erroneous solution has the right idea, and sometimes it doesn't. And just in my opinion, meteorologists are not good at distinguishing these two cases. I think you would have to be well versed in numerical modeling to correctly spot an error that adversely impacted the result. And even then, I'll always choose the model output over some interpretation. This is not to denigrate forecasting, that's a different matter. But those who look at the model internals and "buy" one aspect, but not another....well the model is the model, and it knows its physics better than anyone. Link to comment Share on other sites More sharing options...
eduggs Posted January 26, 2011 Share Posted January 26, 2011 really? two days before the boxind day storm upton had an in depth discussion I believe by our very own BillG talking about convective feedback on the euro. Every model is subject to it. Its real and the nam does it more than any other model. Yes it is very common but usually does not significantly impact the viability of the solution. And it is very difficult to determine if and when this is the case. I think the NAM is a little dry in and around CT. But in every other respect it is close enough both to its previous runs and to the other models to consider it potentially viable. It is also well within the SREF spread. QPF is the least reliable parameter anyway. Link to comment Share on other sites More sharing options...
eduggs Posted January 26, 2011 Share Posted January 26, 2011 Whenever you see some random QPF bomb out in the Atlantic and some spurious low develop there that robs from everything else, you know convective feedback has to be an issue. The NAM did this with the 12/26 storm as well as the 12/19 storm last year that developed from the Gulf. Each one of those, the NAM had weird runs like this that cut back way too much on the northern extent of the storm. But this looks just like the UKMET. Link to comment Share on other sites More sharing options...
jm1220 Posted January 26, 2011 Share Posted January 26, 2011 But this looks just like the UKMET. You can see how the NAM overdevelops the QPF out over the Gulf Stream east of NC and develops the low there. It robs from the rest of the storm and craps it out once it reaches us. It does this ALL the time and it never verifies with these kind of systems. Link to comment Share on other sites More sharing options...
TheTrials Posted January 26, 2011 Share Posted January 26, 2011 But this looks just like the UKMET. seriously, are you trolling? 00z nam looks nothing like the ukmet. Ukmet had a consolidated low tucked into chesapeake with closed h5 and expansive qpf you would expect from gulf moisture rich system. here is ukmet on ewall. NAM 00Z Same time Link to comment Share on other sites More sharing options...
SACRUS Posted January 26, 2011 Share Posted January 26, 2011 RGEM to 12 Link to comment Share on other sites More sharing options...
isnice Posted January 26, 2011 Share Posted January 26, 2011 Yes it is very common but usually does not significantly impact the viability of the solution. And it is very difficult to determine if and when this is the case. I think the NAM is a little dry in and around CT. But in every other respect it is close enough both to its previous runs and to the other models to consider it potentially viable. It is also well within the SREF spread. QPF is the least reliable parameter anyway. Right around KSWF, right? Link to comment Share on other sites More sharing options...
gkrangers Posted January 26, 2011 Share Posted January 26, 2011 The bright side is that even if the NAM is right, it still snows. Link to comment Share on other sites More sharing options...
eduggs Posted January 26, 2011 Share Posted January 26, 2011 And even then, I'll always choose the model output over some interpretation. This is not to denigrate forecasting, that's a different matter. But those who look at the model internals and "buy" one aspect, but not another....well the model is the model, and it knows its physics better than anyone. That's how I feel as well. It the full spectrum of guidance comes in similar to 18z, I would downplay the NAM based on it being an eastern and dry outlier, not a physics error. The behavior and orientation of the SLP on the NAM does not differ significantly from that of recent UKMET, RGEM, MM5, and some SREF member runs. Link to comment Share on other sites More sharing options...
eduggs Posted January 26, 2011 Share Posted January 26, 2011 Right around KSWF, right? No. Danbury to Hartford I-84 corridor where it's bone dry. I think it looks pretty reasonable around KSWF. Why are you whistling? Link to comment Share on other sites More sharing options...
SACRUS Posted January 26, 2011 Share Posted January 26, 2011 RGEM - 24 (more to come post 24 ) http://www.weatherof...ast/512_100.gif Link to comment Share on other sites More sharing options...
MJO812 Posted January 26, 2011 Share Posted January 26, 2011 RGEM Link to comment Share on other sites More sharing options...
Kaner587 Posted January 26, 2011 Share Posted January 26, 2011 at hr 24 on the RGEM it already has more precip than the whole run of the NAM has for NYC...a little less than 10mm edit: next frame has an additional 20mm or so...guess NAM was onto something Link to comment Share on other sites More sharing options...
gkrangers Posted January 26, 2011 Share Posted January 26, 2011 RGEM brings the 10mm line to NYCs doorstep by 00z Thursday. There should be more to come... Link to comment Share on other sites More sharing options...
eduggs Posted January 26, 2011 Share Posted January 26, 2011 seriously, are you trolling? 00z nam looks nothing like the ukmet. Ukmet had a consolidated low tucked into chesapeake with closed h5 and expansive qpf you would expect from gulf moisture rich system. here is ukmet on ewall. You shouldn't just assume that I don't know what I am talking about. It might lead you to misguided posts like this one. With respect to the elongation of the SLP center off the Atlantic coast and possible "feedback errors," the NAM evolves in a similar manner as the UKMET and a few other models, hence my comment. And if you take a closer look, at every level the two models are a pretty good match. The major difference is QPF. And as I said, I thought the NAM was a little dry compared to consensus. But QPF is not a reliable parameter. Who's the say which model is correct in this regard if we just compare these two? Link to comment Share on other sites More sharing options...
tmagan Posted January 26, 2011 Share Posted January 26, 2011 RGEM cut back qpf http://www.weatherof...ast/512_100.gif Think you spoke too soon. Link to comment Share on other sites More sharing options...
gkrangers Posted January 26, 2011 Share Posted January 26, 2011 RGEM cut back qpf http://www.weatherof...ast/512_100.gif I don't believe the storm is over by 7PM tomorrow... Link to comment Share on other sites More sharing options...
Kaner587 Posted January 26, 2011 Share Posted January 26, 2011 RGEM cut back qpf http://www.weatherof...ast/512_100.gif basically the same as 18z maybe just under 30mm for NYC...24-28mm more likely Link to comment Share on other sites More sharing options...
jm1220 Posted January 26, 2011 Share Posted January 26, 2011 RGEM has a 12-hr max of 25+mm (around 1") down the Jersey shore and pointing up towards LI. Looks nothing like the NAM, at all. Link to comment Share on other sites More sharing options...
ace0927 Posted January 26, 2011 Share Posted January 26, 2011 HOLY MOLY! The RGEM is close to 40mm's for LI and is over on the C NJ shore Link to comment Share on other sites More sharing options...
SACRUS Posted January 26, 2011 Share Posted January 26, 2011 Think you spoke too soon. yes i thought i was at 36. I owe you all a beer for the premature bad news. Link to comment Share on other sites More sharing options...
ag3 Posted January 26, 2011 Share Posted January 26, 2011 RGEM appears at least 25mm for NYC. Link to comment Share on other sites More sharing options...
Kaner587 Posted January 26, 2011 Share Posted January 26, 2011 GGEM has a 12-hr max of 25+mm (around 1") down the Jersey shore and pointing up towards LI. Looks nothing like the NAM, at all. its laughable that people in this thread defend the NAM and then EXPECT the other models to follow suit with a drastic QPF reduction. Its not model-ology its meteorology. Link to comment Share on other sites More sharing options...
jm1220 Posted January 26, 2011 Share Posted January 26, 2011 You shouldn't just assume that I don't know what I am talking about. It might lead you to misguided posts like this one. With respect to the elongation of the SLP center off the Atlantic coast and possible "feedback errors," the NAM evolves in a similar manner as the UKMET and a few other models, hence my comment. And if you take a closer look, at every level the two models are a pretty good match. The major difference is QPF. And as I said, I thought the NAM was a little dry compared to consensus. But QPF is not a reliable parameter. Who's the say which model is correct in this regard if we just compare these two? The UKMET doesn't have a spurious convective blob develop and truck NE, bringing the low with it. The NAM for whatever reason does, and it's a common error for this model. Could it be right? Sure, but probably 90% chance it isn't. Link to comment Share on other sites More sharing options...
kevbo81 Posted January 26, 2011 Share Posted January 26, 2011 yes i thought i was at 36. I owe you all a beer for the premature bad news. thank god you were wrong (no offense) PHEW! Link to comment Share on other sites More sharing options...
Alpha5 Posted January 26, 2011 Share Posted January 26, 2011 RGEM maintains the status quo....25mm generally for the NYC area Link to comment Share on other sites More sharing options...
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