IntenseBlizzard2014 Posted January 20, 2013 Share Posted January 20, 2013 http://www.erh.noaa.gov/box/tables/snowfall-meltwater.html Link to comment Share on other sites More sharing options...
jdt Posted January 20, 2013 Share Posted January 20, 2013 I believe snow ratios are tied to two issues. Cold temps resulting in dry powdery snow, the fluff factor, and also conditions in the snow growth region of the atmosphere which determines the type of flakes that form. Cold temps aloft are just one part of that equation. The type (shape and structure) of flakes determine how they accumulate. Certain shapes create greater air spaces thus less total volume of snow accumulates to a greater depth. It is possible to have a dry powdery snow with snow flake structure not conducive to very high ratios. Being cold ratios will be higher and probably in the 12-16 to 1 range but much higher than that will require some serious optimal snow growth conditions. I am sure some one who knows the technical issues can explain this further and better. Link to comment Share on other sites More sharing options...
jasonli18t Posted January 20, 2013 Share Posted January 20, 2013 will check back after event. i expect to see at least one 40:1 LE to snow ratio or an apology you'll get one from me if you can provide the goods. Link to comment Share on other sites More sharing options...
Edge Weather Posted January 20, 2013 Share Posted January 20, 2013 there will be no 40:1 ratios anywhere on this forum. In NW NJ I have had 40:1 ratios many times with these types of clipper situations depicted on the 84 hr NAM. Areas to the East for NYC and so on would likely be in the 20:1 range. Again, I am speaking of the Wednesday night storm depicted on the 84hr NAM. Right now the model shows surface temps of around 18 degrees here at 7pm on Wednesday with the 850 level at -20. Snow is on our doorsteps at that point. Link to comment Share on other sites More sharing options...
Dsnowx53 Posted January 20, 2013 Share Posted January 20, 2013 I believe snow ratios are tied to two issues. Cold temps resulting in dry powdery snow, the fluff factor, and also conditions in the snow growth region of the atmosphere which determines the type of flakes that form. Cold temps aloft are just one part of that equation. The type (shape and structure) of flakes determine how they accumulate. Certain shapes create greater air spaces thus less total volume of snow accumulates to a greater depth. It is possible to have a dry powdery snow with snow flake structure not conducive to very high ratios. Being cold ratios will be higher and probably in the 12-16 to 1 range but much higher than that will require some serious optimal snow growth conditions. I am sure some one who knows the technical issues can explain this further and better. This is correct. I'm mobile now so I don't have the time to elaborate too much but this is definitely true. You also need good omega (lift) in the snow growth region, and you want your snow growth region saturated with temperatures between -12 C and -18 C. Link to comment Share on other sites More sharing options...
Allsnow Posted January 20, 2013 Author Share Posted January 20, 2013 Hr 39 light snow on gfs Link to comment Share on other sites More sharing options...
Allsnow Posted January 20, 2013 Author Share Posted January 20, 2013 Hr 42 light from NYC- east Link to comment Share on other sites More sharing options...
Allsnow Posted January 20, 2013 Author Share Posted January 20, 2013 Less then .10 this run of gfs Link to comment Share on other sites More sharing options...
Edge Weather Posted January 20, 2013 Share Posted January 20, 2013 12z GFS .04 at NYC .05 at Burlington-Monmouth Airport .05 at JFK .05 at Laguardia .05 at Somerset .06 at Caldwell .06 at Morristown .07 at Andover .08 at Sussex .10 at Islip Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 20, 2013 Share Posted January 20, 2013 I cant see much more than a coating from NYC east with a good chance of nothing at all for the city. Link to comment Share on other sites More sharing options...
PB GFI Posted January 20, 2013 Share Posted January 20, 2013 The European is prob goin to look just dry , You just gotta look at the finer high res models for QPF from here on in . The globals look at at bigger picture , the high res are coarser and sometimes pick up mesoscale features better . Link to comment Share on other sites More sharing options...
WintersGrasp Posted January 20, 2013 Share Posted January 20, 2013 I'm still thinking of a coating to an inch for NYC and nearby suburbs in NJ....maybe a little more over Long Island and then a max of 3-5" over southeastern New England Link to comment Share on other sites More sharing options...
Edge Weather Posted January 20, 2013 Share Posted January 20, 2013 Great discussion from a Met in the New England forum I am posting below about why the globals won't get this one right. the globals aren't going to come around in the sense they aren't going to accurately represent the NORLUN trough feature by low-level convergence or qpf. In terms of general snowfall across SNE, they're going to be alright...but not the NORLUN feature itself. I mean the GFS might have 1/4" of QPF in a LES area that gets 2 ft of snow lol. A 30km spectral model doesn't have the resolution or non-hydrostatic dynamic to resolve something like that. You'd like to see the Euro bump up stuff to a degree though, since it has 12km resolution it can at least attempt to resolve more mesoscale features. Link to comment Share on other sites More sharing options...
PB GFI Posted January 20, 2013 Share Posted January 20, 2013 Great discussion from a Met in the New England forum I am posting below about why the globals won't get this one right. the globals aren't going to come around in the sense they aren't going to accurately represent the NORLUN trough feature by low-level convergence or qpf. In terms of general snowfall across SNE, they're going to be alright...but not the NORLUN feature itself. I mean the GFS might have 1/4" of QPF in a LES area that gets 2 ft of snow lol. A 30km spectral model doesn't have the resolution or non-hydrostatic dynamic to resolve something like that. You'd like to see the Euro bump up stuff to a degree though, since it has 12km resolution it can at least attempt to resolve more mesoscale features. I only agree with him because he agrees with me . JK . Its true the Euro is coarser then the GFS , so thats a fair point . Link to comment Share on other sites More sharing options...
Edge Weather Posted January 20, 2013 Share Posted January 20, 2013 Here is another met in the New England forum: Even though the Euro has a higher resolution than the GFS it's still a global model. It has different convective parametrization schemes than a mesoscale model and is also hydrostatic.... so while the higher resolution helps for an intrinsically mesoscale (and convective, you could say) phenomenon it may not be of much use. Link to comment Share on other sites More sharing options...
MJO812 Posted January 20, 2013 Share Posted January 20, 2013 Euro is dry. Model wars Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 20, 2013 Share Posted January 20, 2013 The NAM is a garbage model, not sure why people still use it. GFS/EURO/GGEM are all dry for the area, coating at best. Link to comment Share on other sites More sharing options...
MJO812 Posted January 20, 2013 Share Posted January 20, 2013 GFS and GGEM isn't dry. Euro is an outlier here. Link to comment Share on other sites More sharing options...
NorEaster27 Posted January 20, 2013 Share Posted January 20, 2013 GFS and GGEM isn't dry. Euro is an outlier here. less than .10 in this very dry airmass equates to a coating at best with nothing at worst. Link to comment Share on other sites More sharing options...
MJO812 Posted January 20, 2013 Share Posted January 20, 2013 1-2 inches is a good bet right now. Link to comment Share on other sites More sharing options...
green tube Posted January 20, 2013 Share Posted January 20, 2013 1-2 inches is a good bet right now. i assume the 12z euro continues to show zip... or 3 flakes. if every other model said .2 and the euro said zip....... i'd go with zip. i like the word zip. in fact, i think it's the motto of the winter of 2013.... zip. Link to comment Share on other sites More sharing options...
MJO812 Posted January 20, 2013 Share Posted January 20, 2013 Euro doesnt even show alot for Boston. It's alone. Link to comment Share on other sites More sharing options...
TWCCraig Posted January 20, 2013 Share Posted January 20, 2013 NAM showed zip for Thursday night's event while Euro showed around 0.15" to 0.2" of precip for LI. We got zip. Link to comment Share on other sites More sharing options...
WintersGrasp Posted January 20, 2013 Share Posted January 20, 2013 The NAM is a garbage model, not sure why people still use it. GFS/EURO/GGEM are all dry for the area, coating at best. The NAM is NOT a garbage model. It picked up the trends of many many storms before other models have even had a hint, even at its longer range. It is a high resolution model and one of the only ones that picks out small details such as where specific bands will set up. For Monday night and Tuesday, it shows a band of snow moving through PHL and then NYC....a bust for a couple hours that gives around an inch or so. The other models don't show this. It is either because it is not going to happen or the others are not picking up any specifics of what will happen. We'll see....but I am pretty sure it will be the first Link to comment Share on other sites More sharing options...
SR Airglow Posted January 20, 2013 Share Posted January 20, 2013 Usually the EURO would be king but with its failure on the last event, the fact that it stands virtually alone, and the fact that the NAM/SREFS have not backed down makes me think they might be on to something. Usually they jump off their crazy trains after a run or two. But who knows, maybe they all are out to lunch -skisheep Link to comment Share on other sites More sharing options...
WintersGrasp Posted January 20, 2013 Share Posted January 20, 2013 Think of it this way...have you ever seen a quick inch or two from snow showers that wasn't part of a big storm or large organized area of precip? I'm sure we all have....now think....was this modeled to give me an inch or two of snow ? Nope....those situations usually just show up as light green (0.1 or less) of qpf on most models Link to comment Share on other sites More sharing options...
GD0815 Posted January 20, 2013 Share Posted January 20, 2013 stick to the science not the bickering i think it is unlikely the area sees nothing fromthstorm maybe split the difference between the nam and gfs and that is a good way to go. id say 1-2 inches if were guessing with the 2 towards the island. Link to comment Share on other sites More sharing options...
MJO812 Posted January 20, 2013 Share Posted January 20, 2013 Sref shifted east Link to comment Share on other sites More sharing options...
Edge Weather Posted January 20, 2013 Share Posted January 20, 2013 Yes, everyone is still .10+ for the most part, but the .25+ area shifted east again. This is clearly a big hit only for eastern Long Island and eastern New England, but the rest of us should get a dusting to one or two inches. Link to comment Share on other sites More sharing options...
jasonli18t Posted January 20, 2013 Share Posted January 20, 2013 Yes, everyone is still .10+ for the most part, but the .25+ area shifted east again. This is clearly a big hit only for eastern Long Island and eastern New England, but the rest of us should get a dusting to one or two inches. shouldn't someone still get 4 inches with those 40:1 ratios? Link to comment Share on other sites More sharing options...
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