Storm chaser Posted February 12, 2014 Share Posted February 12, 2014 Every time I catch myself defaulting to the play that the GFS has broader resolution, etc I stop for a second. Because the model has made me look like a fool for assuming that several times in the past. In this scenario though, I just can't believe its precipitation distribution and RH fields given the dynamics at play aloft and from the upper to mid levels. Everything argues for expansive precipitation with enhanced lift and dynamics, from the jet positioning straight down to the low level jet. If it is correct in its idea that precipitation will struggle due to mid level winds and a compressed flow in that regard, I will really have to tip my cap. Do u think it is one of those things that will show up in tomorrow morning's run since all the "other" elements were there except the expected outcome ? Link to comment Share on other sites More sharing options...
earthlight Posted February 12, 2014 Share Posted February 12, 2014 Do u think it is one of those things that will show up in tomorrow morning's run since all the "other" elements were there except the expected outcome ? To be completely honest I don't know and that is almost impossible to predict. I think a lot of forecast confidence from tonight hinges on what the remaining global models show. If the Canadian and Euro tick southeast with a similar track to the NAM/GFS and have a more expansive CCB development, I think we'll know which direction this is headed. But something tells me they won't be so quick to move, especially the Euro. It has been remarkably consistent. I think I can count on one hand the amount of times it has backed down from something like it has now and even partially caved to the ideas of the NAM or another model. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted February 12, 2014 Share Posted February 12, 2014 Every time I catch myself defaulting to the play that the GFS has broader resolution, etc I stop for a second. Because the model has made me look like a fool for assuming that several times in the past. In this scenario though, I just can't believe its precipitation distribution and RH fields given the dynamics at play aloft and from the upper to mid levels. Everything argues for expansive precipitation with enhanced lift and dynamics, from the jet positioning straight down to the low level jet. If it is correct in its idea that precipitation will struggle due to mid level winds and a compressed flow in that regard, I will really have to tip my cap. It's an odd combination of having the extremely amplified/developmental components in the Gulf and the Atlantic, where convection could easily give havoc -- but even if on its own the GFS were able to handle that "okay," you then have the strong synoptic aspect of the pattern where the wavelengths are quite zonal across the US with a strong west-to-east jet with that kicker. Each of those individual things, the GFS is probably fine with -- but put the two together and one will be de-emphasized (enhanced lift and dynamics), and one will be overly emphasized (the kicker). That being said, the kicker being stronger and pushing this thing east a bit might be a real trend. Pretty strong zonal jet streak... Link to comment Share on other sites More sharing options...
danstorm Posted February 12, 2014 Share Posted February 12, 2014 Every time I catch myself defaulting to the play that the GFS has broader resolution, etc I stop for a second. Because the model has made me look like a fool for assuming that several times in the past. In this scenario though, I just can't believe its precipitation distribution and RH fields given the dynamics at play aloft and from the upper to mid levels. Everything argues for expansive precipitation with enhanced lift and dynamics, from the jet positioning straight down to the low level jet. If it is correct in its idea that precipitation will struggle due to mid level winds and a compressed flow in that regard, I will really have to tip my cap. Yes, but wouldn't the shortwave to the west inhibit lift as the storm's best dynamics shift into New England as well? The feature is still there and if it is indeed impinging on the flow, you would expect this to continue, right? Well, maybe... but the storm is deepening to the SE of NE... But it is deepening to the SE of us, too - the WAA and PVA processes look mighty in our neck of the woods yet the end result is tepid QPF. I'm calling BS here ... track is classic, mid levels close off just at the right time... that is not a run of the mill event the GFS is showing. It does this every once in a while and I think hasn't caught up with itself this time, so to speak... Link to comment Share on other sites More sharing options...
earthlight Posted February 12, 2014 Share Posted February 12, 2014 It's an odd combination of having the extremely amplified/developmental components in the Gulf and the Atlantic, where convection could easily give havoc -- but even if on its own the GFS were able to handle that "okay," you then have the strong synoptic aspect of the pattern where the wavelengths are quite zonal across the US with a strong west-to-east jet with that kicker. Each of those individual things, the GFS is probably fine with -- but put the two together and one will be de-emphasized (enhanced lift and dynamics), and one will be overly emphasized (the kicker). That being said, the kicker being stronger and pushing this thing east a bit might be a real trend. Pretty strong zonal jet streak... My thing is, as a forecaster, are you really willing to take that bet with the GFS precipitation distribution being correct? I mean, even the vertical velocities and lift are poor compared to almost every other piece of model guidance. I think the NAM and the high resolution models are going to end up being too wet and too dynamic as usual. With these events especially, they really struggle and can end up 1" too high in some cases. But the meteorology of this argues that the jet positioning and developmental aspect of the system will produce heavy precipitation at the very least initially pushing northward as the storm develops. With PVA surging up the coast and the increasingly strong fetch of low level moisture plus enhanced lift, you have to assume the GFS is being too broad with its precipitation development in that aspect. That's the money moment when the high resolution models are picking up on the heavy stuff. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted February 12, 2014 Share Posted February 12, 2014 Yes, but wouldn't the shortwave to the west inhibit lift as the storm's best dynamics shift into New England as well? The feature is still there and if it is indeed impinging on the flow, you would expect this to continue, right? Well, maybe... but the storm is deepening to the SE of NE... But it is deepening to the SE of us, too - the WAA and PVA processes look mighty in our neck of the woods yet the end result is tepid QPF. I'm calling BS here ... track is classic, mid levels close off just at the right time... that is not a run of the mill event the GFS is showing. It does this every once in a while and I think hasn't caught up with itself this time, so to speak... I do believe some sort of lag could exist with the explosion of the precipitation due to the compression, but once this thing really gets going, it should be able to override any of that, especially considering it is deepening SE of us. 4-8" of snow from the CCB alone would not surprise me, at all. The GFS did show some signs of it blossoming over us, but its mid-level temperatures were tainted, due to a combination of perhaps poor resolution and a lack of precipitation to begin with. The NAM does not close off at H5, which is why its CCB is not too impressive and gets going late. Link to comment Share on other sites More sharing options...
jm1220 Posted February 12, 2014 Share Posted February 12, 2014 Keep the talk about TV mets' predictions or others in the Vendor thread or elsewhere. Posts like that will be deleted, thanks Link to comment Share on other sites More sharing options...
Zelocita Weather Posted February 12, 2014 Share Posted February 12, 2014 36 hour ggem low 999 bout 100 miles s of OBX Link to comment Share on other sites More sharing options...
earthlight Posted February 12, 2014 Share Posted February 12, 2014 Yes, but wouldn't the shortwave to the west inhibit lift as the storm's best dynamics shift into New England as well? The feature is still there and if it is indeed impinging on the flow, you would expect this to continue, right? Well, maybe... but the storm is deepening to the SE of NE... But it is deepening to the SE of us, too - the WAA and PVA processes look mighty in our neck of the woods yet the end result is tepid QPF. I'm calling BS here ... track is classic, mid levels close off just at the right time... that is not a run of the mill event the GFS is showing. It does this every once in a while and I think hasn't caught up with itself this time, so to speak... I don't know if maybe it is a function of the model feeling the compression of the height field from the approaching shortwave over the Great Lakes, or maybe it is simply a delay in maturity of the mid level centers. The GFS has a more elongated look to the mid level lows as they track up the east coast until about 40/70 when they mature. The H5 low reaches Long Islands latitude and seems to finally come into its own. In the mid levels the GFS has a massive dry slot at 500mb but over time you can see the rapid development of the CCB in the later frames over Long Island (both below). Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted February 12, 2014 Share Posted February 12, 2014 GGEM doesn't look bad to my eyes. It's not the NAM but it's seems plenty cold. Classic track. Link to comment Share on other sites More sharing options...
StatenWx Posted February 12, 2014 Share Posted February 12, 2014 Ggem 982 over the benchmark on the b&w maps. Link to comment Share on other sites More sharing options...
Rjay Posted February 12, 2014 Share Posted February 12, 2014 ggem at hr 48...close to the BM Link to comment Share on other sites More sharing options...
Zelocita Weather Posted February 12, 2014 Share Posted February 12, 2014 GGEM doesn't look bad to my eyes. It's not the NAM but it's seems plenty cold. Classic track. Ggem 982 low just s/w of bm Link to comment Share on other sites More sharing options...
Dsnowx53 Posted February 12, 2014 Share Posted February 12, 2014 My thing is, as a forecaster, are you really willing to take that bet with the GFS precipitation distribution being correct? I mean, even the vertical velocities and lift are poor compared to almost every other piece of model guidance. I think the NAM and the high resolution models are going to end up being too wet and too dynamic as usual. With these events especially, they really struggle and can end up 1" too high in some cases. But the meteorology of this argues that the jet positioning and developmental aspect of the system will produce heavy precipitation at the very least initially pushing northward as the storm develops. With PVA surging up the coast and the increasingly strong fetch of low level moisture plus enhanced lift, you have to assume the GFS is being too broad with its precipitation development in that aspect. That's the money moment when the high resolution models are picking up on the heavy stuff. I certainly am not, especially considering the overwhelming evidence on other guidance. And yes, I would think the GFS would do more poorly handing PVA enhanced precipitation streaming from the ocean (convective, perhaps?) rather than blossoming the CCB. The fact that the GFS is coming around more with the CCB is a good sign, anyway. Link to comment Share on other sites More sharing options...
Rjay Posted February 12, 2014 Share Posted February 12, 2014 http://weather.gc.ca/model_forecast/global_e.html color maps coming out (slowly) now for the ggem...here's a link for anyone who's interested still only out to hr 24 on the color maps...be careful it switches back to 12z at hr 36 until it finishes with that frame Link to comment Share on other sites More sharing options...
eduggs Posted February 12, 2014 Share Posted February 12, 2014 Most guidance shows a solid to extreme front end that clips the metro and moves northeast into SNE. After the initial ~6 hr burst, all models show lighter intensity precip. I think this period of lighter precip might be legit. Models show varying degrees of a lull before a possible commahead rotates through. Some places could get a big hit from both parts, e.g., N or W Mass, maybe NCT... far enough east for a strong front end, and far enough northwest to get into any wraparound. Other areas might kind of miss both... I'm thinking maybe EPA or NEPA, ENY, and possibly NWNJ. On the 0z GFS and NAM, western Orange Co would struggle to reach advisory criteria. And the GFS basically spares all of PA heavy precip. And that's not even considering any ptype issues. This seems like a situation where there could be big winners and big losers. Link to comment Share on other sites More sharing options...
Juliancolton Posted February 12, 2014 Share Posted February 12, 2014 The CMC doesn't seem to suggest nearly the ccb precip that the GFS showed. Link to comment Share on other sites More sharing options...
Ralph Wiggum Posted February 12, 2014 Share Posted February 12, 2014 Most guidance shows a solid to extreme front end that clips the metro and moves northeast into SNE. After the initial ~6 hr burst, all models show lighter intensity precip. I think this period of lighter precip might be legit. Models show varying degrees of a lull before a possible commahead rotates through. Some places could get a big hit from both parts, e.g., N or W Mass, maybe NCT... far enough east for a strong front end, and far enough northwest to get into any wraparound. Other areas might kind of miss both... I'm thinking maybe EPA or NEPA, ENY, and possibly NWNJ. On the 0z GFS and NAM, western Orange Co would struggle to reach advisory criteria. And the GFS basically spares all of PA heavy precip. And that's not even considering any ptype issues. This seems like a situation where there could be big winners and big losers. Disagree. Those areas are progged to likely get hit the hardest, not the least. Especially after 0Z suite so far. Link to comment Share on other sites More sharing options...
Rjay Posted February 12, 2014 Share Posted February 12, 2014 0z ggem. be careful to make sure it says 2/12/14 0z http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type/pcpn_type_gem_reg.html Link to comment Share on other sites More sharing options...
IsentropicLift Posted February 12, 2014 Share Posted February 12, 2014 The GGEM has the wrap around CCB but temperature profiles are a mess. Link to comment Share on other sites More sharing options...
eduggs Posted February 12, 2014 Share Posted February 12, 2014 Disagree. Those areas are progged to likely get hit the hardest, not the least. Especially after 0Z suite so far. That's where it looked like we were heading earlier today. But if you check the model charts, there is a distinct lack of UVVs on the NW flank until the slp is southeast of LI. All guidance shows this aspect to varying degrees. By the time the lift increases to the NW of the low, it has pulled in tighter towards the center of circulation. I definitely think there could be a relative QPF minimum somewhere between EPA and ENY, unless the SLP tucks in closer to the NJ coast. Link to comment Share on other sites More sharing options...
Juliancolton Posted February 12, 2014 Share Posted February 12, 2014 That's where it looked like we were heading earlier today. But if you check the model charts, there is a distinct lack of UVVs on the NW flank until the slp is southeast of LI. All guidance shows this aspect to varying degrees. By the time the lift increases to the NW of the low, it has pulled in tighter towards the center of circulation. I definitely think there could be a relative QPF minimum somewhere between EPA and ENY, unless the SLP tucks in closer to the NJ coast. Yeah... I'm not enthusiastic up here by Poughkeepsie. 12z and 18z looked like I was in for a blockbuster, but the 00z suite so far has left me feeling about as uncertain as last night at this time. Assuming the Euro falls in line with the Canadian, GFS, etc., I think a final result of something like 6 to 11" would be reasonable for the areas you described. Link to comment Share on other sites More sharing options...
snywx Posted February 12, 2014 Share Posted February 12, 2014 Yeah... I'm not enthusiastic up here by Poughkeepsie. 12z and 18z looked like I was in for a blockbuster, but the 00z suite so far has left me feeling about as uncertain as last night at this time. Assuming the Euro falls in line with the Canadian, GFS, etc., I think a final result of something like 6 to 11" would be reasonable for the areas you described. Considering those same areas have 12"+ already on the ground that should make for a very interesting scene. Link to comment Share on other sites More sharing options...
Morris Posted February 12, 2014 Share Posted February 12, 2014 GEFS? Link to comment Share on other sites More sharing options...
mob1 Posted February 12, 2014 Share Posted February 12, 2014 GEFS?Very close to the BM, wetter than the OP but still warm. Link to comment Share on other sites More sharing options...
Overcast Posted February 12, 2014 Share Posted February 12, 2014 Now the big question. Does the Euro pull a Euro and stay locked in? Link to comment Share on other sites More sharing options...
Rjay Posted February 12, 2014 Share Posted February 12, 2014 0z GGEM hr 36 hr 42 hr 48 Link to comment Share on other sites More sharing options...
rochesterdave Posted February 12, 2014 Share Posted February 12, 2014 Well, at this rate euro is gonna be way off shore. Big trend east which kinda plays to this years overall trends. Early west, then way east, then gradual steps to west until 42 hrs out and then back east. How many times have we seen it? I hope the computers are sampling and learning. Link to comment Share on other sites More sharing options...
David-LI Posted February 12, 2014 Share Posted February 12, 2014 ggem 980 inside the benchmark. hows the 850s on the ggem? Link to comment Share on other sites More sharing options...
ag3 Posted February 12, 2014 Share Posted February 12, 2014 ggee 980 inside the benchmark. hows the 850s on the ggem? For NYC, ggem is 20-25mm of precip as snow and only 4-5mm as rain. Ukmet is even better because it has a great CCB. 850s never go above and surface goes above for a short time to 33-34 degrees and quickly crashes as ccb cranks. 34mm of precip. Conservatively, 25-30mm of it as snow. Link to comment Share on other sites More sharing options...
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