HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 No what the NAM does is allow for convection to run wild because it's what we call non-hydrostatic. It's not the same parameterization like the gfs has. It's trying to mimic real life, but the problem with that is in real life we have checks and balances as to why the atmosphere isn't turned upside down. Sometimes the NAM doesn't fully get that. I would love to sit and listen to you explain this. Modeling is so much beyond my comprehension. It is amazing to me that it can be done with any accuracy. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 So hard to keep daytime temps below zero these days. Last time I saw it personally was probably 1999 or 2000 up at Lyndon State. Would be interesting if I could pull it off. Getting frigid temps (day or night) through advection has been a tough task.. Was it close in Jan 2004 in ORH? Prob like 2F-5F for a high that one day Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 31, 2013 Share Posted December 31, 2013 . I really don't recall it happening much where temps are so cold and we get a stormHistorical time machine from the scrolls of the Museum, Feb 1934 and the great cold storm of 1899. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 I only recall the Jan '04 clipper being below zero...but it was a clipper. The larger SWFE in January 1999 started off as like 3F and snow I remember. And I also now recall around 5F and snow in January 1994 during one of those storms...but it didn't last long...usually on the front end. I cannot recall near zero temps in the cold conveyor belt of a system around here. I'm sure its happened at some point, but it has to be extremely rare. Dec 1980/Jan 1981? I know it was darn cold and I seem to recall snow events Link to comment Share on other sites More sharing options...
ice1972 Posted December 31, 2013 Share Posted December 31, 2013 I would love to sit and listen to you explain this. Modeling is so much beyond my comprehension. It is amazing to me that it can be done with any accuracy. Yup....sorry but modeling sometimes is like watching Tony Romo....oh god...I'm sorry Link to comment Share on other sites More sharing options...
Whineminster Posted December 31, 2013 Share Posted December 31, 2013 I would love to sit and listen to you explain this. Modeling is so much beyond my comprehension. It is amazing to me that it can be done with any accuracy. Yeah I always thought you just blended the models for a happy medium, but clearly theres much more too it Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 Historical time machine from the scrolls of the Museum, Feb 1934 and the great cold storm of 1899. Feb 1934 is sacred. I don't know much about 1899. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2013 Share Posted December 31, 2013 EURO out in a half hour? Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 Yup....sorry but modeling sometimes is like watching Tony Romo....oh god...I'm sorry Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 31, 2013 Share Posted December 31, 2013 Reason number one to go with the Euro for East coast cyclogenesis when a warm Atlantic meets the Arctic, it's an ocean coupled Model. Link to comment Share on other sites More sharing options...
Whineminster Posted December 31, 2013 Share Posted December 31, 2013 Yup....sorry but modeling sometimes is like watching Tony Romo....oh god...I'm sorry Frustrating? Inconsistent? Streaky? Good analogy! Link to comment Share on other sites More sharing options...
weatherMA Posted December 31, 2013 Share Posted December 31, 2013 EURO out in a half hour? Are you new here? Link to comment Share on other sites More sharing options...
weathafella Posted December 31, 2013 Share Posted December 31, 2013 GEFS was wetter. 0.75 line west of the op. ORH to BDL on east. 1.0 just south of BOS and SE. Link to comment Share on other sites More sharing options...
ice1972 Posted December 31, 2013 Share Posted December 31, 2013 Reason number one to go with the Euro for East coast cyclogebesis when a warm Atlantic meets the Arctic, it's an ocean coupled Model. Wait are you saying American models don't factor in Ocean temps? Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 31, 2013 Share Posted December 31, 2013 . Was it close in Jan 2004 in ORH? Prob like 2F-5F for a high that one day ORH had a high of 2F and 3F on back to back days in Jan '04. They had a high of 1F in Jan 1994. January 1981 was the last time ORH had a high of 0F or colder. Its only happened a handful of times and def won't happen this time. None of the snow events in January 1981 occurred with temps below 5F. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2013 Share Posted December 31, 2013 Are you new here? I don't stay up for it much anymore...I have a life. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 ORH had a high of 2F and 3F on back to back days in Jan '04. They had a high of 1F in Jan 1994. January 1981 was the last time ORH had a high of 0F or colder. Its only happened a handful of times and def won't happen this time. None of the snow events in January 1981 occurred with temps below 5F. thanks Link to comment Share on other sites More sharing options...
weatherMA Posted December 31, 2013 Share Posted December 31, 2013 I don't stay up for it much anymore...I have a life. Haha, yeah I know. I would think it would be out to the range of this storm by 1:05- 1:10 Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 31, 2013 Share Posted December 31, 2013 Wait are you saying American models don't factor in Ocean temps?I will let our resident expert explain thatFrom DTK .....I think that we (the GFS) do have a legitimate issue when it comes to east coast cyclogenesis events. We currently use a coarse resolution, infrequently updated Sea Surface Temperature product to provide boundary conditions to the model (as we are currently running an atmospheric only model, not dynamically coupled to an ocean model). I do not think that the SST product we current use provides the necessary information that the model needs in space and time off in the regions of high baroclinicity, i.e. the gulf stream region. It is also updated too infrequently, in my opinion, which can lead to discontinuities in forecasts from cycle to cycle. We hope to get this addressed, finally, in the next GFS implementation. Link to comment Share on other sites More sharing options...
Arnold214 Posted December 31, 2013 Share Posted December 31, 2013 Feb 1934 is sacred. I don't know much about 1899. They had gulf effect snow in Tampa following the east coast blizzard in the middle of Feb 1899. Link to comment Share on other sites More sharing options...
ORH_wxman Posted December 31, 2013 Share Posted December 31, 2013 This is actually the coldest ob for snow I just found in January 2004 during the clipper...it was -4F actually...that is pretty tough to beat. KORH 151020Z AUTO 02004KT 1 3/4SM -SN OVC011 M20/M23 A2973 RMK AO2 P0000 TSNO Link to comment Share on other sites More sharing options...
CoastalWx Posted December 31, 2013 Share Posted December 31, 2013 Dumb question. What is the diff between that and convective feedback?? Well now I'd have to think lol. So a model like the GFS isn't made to handle real life convection. It's given parameters to help it handle convection because convection is too small to handle on its grid scale. So it's given these complicated approximations to help it handle growth and decay of convection. Now these can go wrong And as a result the latent heat released messes up the MSLP fields, heights etc and can cause a weak spurious low to form when in reality it should not have formed. What the NAM does is that it is allowed to try and handle convection like it thinks it would happen in real life. The problem here is that it starts to go nuts if it doesn't handle it properly and now it develops these intense lows that begin to take on a life of its own. There are braking terms to cyclogenesis in real life. Think about it. When you have warm air advection in general it rises and cools. That is an offsetting process. When you have cold advection in general it sinks and sinking air warms. Offsetting process. The NAM will sometimes ignore some of the processes going on to slow down cyclogenesis. But it has become much better than it used to Be. I probably should research it more, but that's off the top of my head. Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2013 Share Posted December 31, 2013 I will let our resident expert explain that From DTK .....I think that we (the GFS) do have a legitimate issue when it comes to east coast cyclogenesis events. We currently use a coarse resolution, infrequently updated Sea Surface Temperature product to provide boundary conditions to the model (as we are currently running an atmospheric only model, not dynamically coupled to an ocean model). I do not think that the SST product we current use provides the necessary information that the model needs in space and time off in the regions of high baroclinicity, i.e. the gulf stream region. It is also updated too infrequently, in my opinion, which can lead to discontinuities in forecasts from cycle to cycle. We hope to get this addressed, finally, in the next GFS implementation. Nice Find. Yea, not making the EURO Night. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 Geez, Ginx. So the GFS and NAM are really out to lunch with this type of setup? Is this a big factor? Link to comment Share on other sites More sharing options...
Ginx snewx Posted December 31, 2013 Share Posted December 31, 2013 They had gulf effect snow in Tampa following the east coast blizzard in the middle of Feb 1899.Jerry was on vacation, remembers it well. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 They had gulf effect snow in Tampa following the east coast blizzard in the middle of Feb 1899. Sweet. I need to read up on that Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 Jerry was on vacation, remembers it well.Squirrels in palm trees that winter Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted December 31, 2013 Share Posted December 31, 2013 Well now I'd have to think lol. So a model like the GFS isn't made to handle real life convection. It's given parameters to help it handle convection because convection is too small to handle on its grid scale. So it's given these complicated approximations to help it handle growth and decay of convection. Now these can go wrong And as a result the latent heat released messes up the MSLP fields, heights etc and can cause a weak spurious low to form when in reality it should not have formed. What the NAM does is that it is allowed to try and handle convection like it thinks it would happen in real life. The problem here is that it starts to go nuts if it doesn't handle it properly and now it develops these intense lows that begin to take on a life of its own. There are braking terms to cyclogenesis in real life. Think about it. When you have warm air advection in general it rises and cools. That is an offsetting process. When you have cold advection in general it sinks and sinking air warms. Offsetting process. The NAM will sometimes ignore some of the processes going on to slow down cyclogenesis. But it has become much better than it used to Be. I probably should research it more, but that's off the top of my head. Good stuff. Thanks. Will, rip me off a text if the EURO is any good. Link to comment Share on other sites More sharing options...
Diego Posted December 31, 2013 Share Posted December 31, 2013 Historical time machine from the scrolls of the Museum, Feb 1934 and the great cold storm of 1899. Jan. 18/19, 1857. Link to comment Share on other sites More sharing options...
HoarfrostHubb Posted December 31, 2013 Share Posted December 31, 2013 Thanks Scooter for that info. How much different is the GFS vs Euro resolution? 10%? Link to comment Share on other sites More sharing options...
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