A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 What if the temperatures drop to -30, then would the snow freeze rock solid? This is a serious question by the way. I dont understand-- snow is ALREADY frozen lol. It would have to melt and then refreeze. Link to comment Share on other sites More sharing options...
famartin Posted January 17, 2011 Share Posted January 17, 2011 Ray, doesnt it freeze "rock hard" from alternating freeze-thaw cycles? Even with daytime temps below freezing, the sun melts some of it, which refreezes at night. If it stays significantly below freezing after the storm as it seems progged to do (and never gets above freezing during the storm itself), then it will take quite a while for that to happen. Especially in January. It really does need to get above freezing for significant melt on top of the snow. When it stays significantly below freezing the only real melting is near structures sticking out of the snow, along the edges of exposed pavement, etc... in other words, any place that absorbs significantly more heat than the snow itself. That doesn't include pavement buried in snow... I've had no trouble shoveling a driveway quite a few days after a significant snowfall... it actually looked better than the part that had been kept clear more in-time with the actual snow. Link to comment Share on other sites More sharing options...
earthlight Posted January 17, 2011 Share Posted January 17, 2011 What are your thoughts? My interest is rather high. I noted in a discussion last night what you alluded to today in regards to the GFS trends (great link by the way, showing the trends over the past few runs). "Attention then turns to a northern stream shortwave which is modeled to dive southeast towards the Central US. We are concerned in regards to this storm threat and it's potential impact on the area..especially considering the trends amongst most guidance suites today. Model guidance is hinting at a pacific jet shortwave breaking off southward towards the Gulf Coast and then ejecting northeast in tandem with this northern stream feature. The trends towards a stronger northern stream are concerning..as any further south..and we would likely be dealing with a partial or full phase with the two features--which would develop a more significant low pressure near or off the east coast. With plenty of cold air in place..as well as significant shortwave energy being modeled..the potential does exist for a winter weather event in this time frame. The GGEM is most robust at this time frame..digging the northern stream far enough south to interact with the shortwave that tracks over the Arklatex and then northeast. The GFS has trended further south with the northern stream it's past 3 model cycles." Not much has really changed since I wrote that early this morning--other than the fact that the GFS is again slowly ticking closer to a phase. It's about to reach a tipping point, any closer and it's going to produce a GGEM-like solution. With the NAM and SREF hedging that way as well...I think there has to be concern for another moderate to high impact event right now given the time-range we are at with this event. Link to comment Share on other sites More sharing options...
famartin Posted January 17, 2011 Share Posted January 17, 2011 What if the temperatures drop to -30, then would the snow freeze rock solid? This is a serious question by the way. No. Maybe people have this glacier idea in their head... but glacier ice only freezes into solid ice because of many tons of snow on top. Link to comment Share on other sites More sharing options...
tombo82685 Posted January 17, 2011 Share Posted January 17, 2011 hr 84 nam simulated reflectivity Link to comment Share on other sites More sharing options...
LVblizzard Posted January 17, 2011 Share Posted January 17, 2011 18z NAM looks like the start of a SECS at 84 hours, we'll see what the DGEX has to say. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 17, 2011 Share Posted January 17, 2011 My interest is rather high. I noted in a discussion last night what you alluded to today in regards to the GFS trends (great link by the way, showing the trends over the past few runs). "Attention then turns to a northern stream shortwave which is modeled to dive southeast towards the Central US. We are concerned in regards to this storm threat and it's potential impact on the area..especially considering the trends amongst most guidance suites today. Model guidance is hinting at a pacific jet shortwave breaking off southward towards the Gulf Coast and then ejecting northeast in tandem with this northern stream feature. The trends towards a stronger northern stream are concerning..as any further south..and we would likely be dealing with a partial or full phase with the two features--which would develop a more significant low pressure near or off the east coast. With plenty of cold air in place..as well as significant shortwave energy being modeled..the potential does exist for a winter weather event in this time frame. The GGEM is most robust at this time frame..digging the northern stream far enough south to interact with the shortwave that tracks over the Arklatex and then northeast. The GFS has trended further south with the northern stream it's past 3 model cycles." Not much has really changed since I wrote that early this morning--other than the fact that the GFS is again slowly ticking closer to a phase. It's about to reach a tipping point, any closer and it's going to produce a GGEM-like solution. With the NAM and SREF hedging that way as well...I think there has to be concern for another moderate to high impact event right now given the time-range we are at with this event. Well said--I fully agree and nice discussion. The ECM I find odd--not sure what to think with the way it handles the western wave. Otherwise, its trends are quite positive with the northern stream. 18Z NAM going berzerk. Link to comment Share on other sites More sharing options...
PoconoD Posted January 17, 2011 Share Posted January 17, 2011 If it stays significantly below freezing after the storm as it seems progged to do (and never gets above freezing during the storm itself), then it will take quite a while for that to happen. Especially in January. It really does need to get above freezing for significant melt on top of the snow. When it stays significantly below freezing the only real melting is near structures sticking out of the snow, along the edges of exposed pavement, etc... in other words, any place that absorbs significantly more heat than the snow itself. That doesn't include pavement buried in snow... I've had no trouble shoveling a driveway quite a few days after a significant snowfall... it actually looked better than the part that had been kept clear more in-time with the actual snow. I just experienced what you are talking about yesterday. I just shoveled from last weeks storm and it was easy. We stayed below freezing the entire time up here. D Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 No. Maybe people have this glacier idea in their head... but glacier ice only freezes into solid ice because of many tons of snow on top. So the pressure of all that snow on top caused it to melt and then refreeze? Does the excessive pressure actually change the freezing point of water? I know this is the case with other fluids. Link to comment Share on other sites More sharing options...
earthlight Posted January 17, 2011 Share Posted January 17, 2011 A Miller B-type snow bomb is likely incoming in the next few frames of the NAM..which we will get a gander at with the DGEX in a few minutes. Those are incredibly dynamic features the NAM is depicting aloft...likely would result in a potentially rapid and deep tropo cyclogenesis. This is the third system this season where I have seen jaw dropping H5 depictions. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 Hey John.... this might be a bit beyond the scope of this discussion, but what do you think is causing bombogenesis so close to the coast so often this season? Is it just the blocking or a combination of other factors? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 17, 2011 Share Posted January 17, 2011 A Miller B-type snow bomb is likely incoming in the next few frames of the NAM..which we will get a gander at with the DGEX in a few minutes. Those are incredibly dynamic features the NAM is depicting aloft...likely would result in a potentially rapid and deep tropo cyclogenesis. This is the third system this season where I have seen jaw dropping H5 depictions. Be careful since the DGEX uses GFS fields to initialize it. It won't be NAM extrapolated verbatim. Link to comment Share on other sites More sharing options...
earthlight Posted January 17, 2011 Share Posted January 17, 2011 Be careful since the DGEX uses GFS fields to initialize it. It won't be NAM extrapolated verbatim. True, but it's usually a fairly accurate depiction of what the NAM would have shown post 84 hours, no? At least within the 90-102 hour time period I have noticed it literally seems to be an extrapolation of the NAM from it's 84 hour frame. Link to comment Share on other sites More sharing options...
Kaner587 Posted January 17, 2011 Share Posted January 17, 2011 A Miller B-type snow bomb is likely incoming in the next few frames of the NAM..which we will get a gander at with the DGEX in a few minutes. Those are incredibly dynamic features the NAM is depicting aloft...likely would result in a potentially rapid and deep tropo cyclogenesis. This is the third system this season where I have seen jaw dropping H5 depictions. it has beautiful overrunning before the dynamics go nuts. Not saying this is going to happen but this has the "look" at the surface and aloft of a major major storm with very high QPF. Would agree with the GGEM and as you said in your discussion the GFS has been trending this way, and if the seasonal trend has told us anything it would be that this storm has the potential to be huge. Lets see how the trends play out over the next couple days... Link to comment Share on other sites More sharing options...
SnowGoose69 Posted January 17, 2011 Share Posted January 17, 2011 The 18Z NAM is going to be a monster beyond 84 hours, unfortunately its the NAM at 18Z and 84 hours...this is a strange setup shown at 500mb by most models, I don't remember seeing this kind of setup before on many systems, it seems generally when you get something close to it the surface low forms well north over NE as many of the GFS runs were showing. Link to comment Share on other sites More sharing options...
jrodd321 Posted January 17, 2011 Share Posted January 17, 2011 I want to cry just looking at the nam sim radar at 84 With the cold air still in place perfectly. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 17, 2011 Share Posted January 17, 2011 True, but it's usually a fairly accurate depiction of what the NAM would have shown post 84 hours, no? At least within the 90-102 hour time period I have noticed it literally seems to be an extrapolation of the NAM from it's 84 hour frame. Not yet--GFS is a lot different with timing/speed of the northern stream. It will not look the same--prolly in between NAM and 12Z GFS. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 17, 2011 Share Posted January 17, 2011 The 18Z NAM is going to be a monster beyond 84 hours, unfortunately its the NAM at 18Z and 84 hours...this is a strange setup shown at 500mb by most models, I don't remember seeing this kind of setup before on many systems, it seems generally when you get something close to it the surface low forms well north over NE as many of the GFS runs were showing. This is one case where SREF/NAM get huge additional credence then I would otherwise bother giving. I think 18Z GFS will be one step closer to if the same trend keeps up. Link to comment Share on other sites More sharing options...
Analog96 Posted January 17, 2011 Share Posted January 17, 2011 You bring up a pet peeve of mine... SNOW DOESN'T FREEZE ROCK HARD JUST BECUASE IT IS GONNA GET REALLY COLD. Sorry for yelling But seriously, I've heard the media do this time and again... "better shovel the snow before it gets really cold or you'll never get rid of it!" Uh, yeah, how about no! Snow doesn't just magically freeze solid just because it gets really cold after a storm... if it stays all snow (and given the GEM that IS a question right now), then it'll still be snow the next day. It won't magically change into a brick or get heavier or much denser just because the temperature dropped to 5 degrees. It only freezes rock hard like that if there's some melting first. Link to comment Share on other sites More sharing options...
Kaner587 Posted January 17, 2011 Share Posted January 17, 2011 300mb maps look pretty classic as well if you look from 72-84. Even if it doesn't happen as advertised it seems that every storm has the potential this season to be a biggie. Every storm (including this underwhelming snow to ice to rain) has been fun to track. Link to comment Share on other sites More sharing options...
NortheastPAWx Posted January 17, 2011 Share Posted January 17, 2011 A Miller B-type snow bomb is likely incoming in the next few frames of the NAM..which we will get a gander at with the DGEX in a few minutes. Those are incredibly dynamic features the NAM is depicting aloft...likely would result in a potentially rapid and deep tropo cyclogenesis. This is the third system this season where I have seen jaw dropping H5 depictions. Looks like it could be one for everybody based on that and the SIM radar. Link to comment Share on other sites More sharing options...
famartin Posted January 17, 2011 Share Posted January 17, 2011 So the pressure of all that snow on top caused it to melt and then refreeze? Does the excessive pressure actually change the freezing point of water? I know this is the case with other fluids. I don't think so, I believe (and don't quote me on this) that its just a matter of the pressure compressing the individual ice crystals together into a solid mass. Just think about a glacier which is literally hundreds to even thousands of feet thick... imagine how much weight that is. Now the lowering of the melting point IS how glaciers move... as at the very base there is generally a thin layer of liquid water which the glacier "rides" on. That liquid water is due to the lower melting point causing the ice to melt right at the base. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 The 18Z NAM is going to be a monster beyond 84 hours, unfortunately its the NAM at 18Z and 84 hours...this is a strange setup shown at 500mb by most models, I don't remember seeing this kind of setup before on many systems, it seems generally when you get something close to it the surface low forms well north over NE as many of the GFS runs were showing. This actually sounds like a lot of busted forecasts back in the 80s that we were talking about. Link to comment Share on other sites More sharing options...
Voyager Posted January 17, 2011 Share Posted January 17, 2011 A Miller B-type snow bomb is likely incoming in the next few frames of the NAM..which we will get a gander at with the DGEX in a few minutes. Those are incredibly dynamic features the NAM is depicting aloft...likely would result in a potentially rapid and deep tropo cyclogenesis. This is the third system this season where I have seen jaw dropping H5 depictions. That's good to hear. I just hope it's not the third system this season where I have to deal with being on the short side of tight gradient. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 That's good to hear. I just hope it's not the third system this season where I have to deal with being on the short side of tight gradient. Im wondering if this has the potential to be like one of those Jan 2004-type storms we had in the middle of a very cold pattern. How did you make out in those? I believe there were two of them. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 17, 2011 Share Posted January 17, 2011 That's good to hear. I just hope it's not the third system this season where I have to deal with being on the short side of tight gradient. With this system there is still large potential for a dud--and the far outlier ECM shows just that as it holds the western trough deep into the intermountain W and doesn't phase. It would be a huge bummer if it didn't because this has all sorts of potential across a large area of the US. A lot of this threat will be potentially solved in the next 24 hours quite honestly. Link to comment Share on other sites More sharing options...
famartin Posted January 17, 2011 Share Posted January 17, 2011 That's good to hear. I just hope it's not the third system this season where I have to deal with being on the short side of tight gradient. This might be your storm and NOT I-95's, if I-95 mixes over... Link to comment Share on other sites More sharing options...
famartin Posted January 17, 2011 Share Posted January 17, 2011 With this system there is still large potential for a dud--and the far outlier ECM shows just that as it holds the western trough deep into the intermountain W and doesn't phase. It would be a huge bummer if it didn't because this has all sorts of potential across a large area of the US. A lot of this threat will be potentially solved in the next 24 hours quite honestly. We agree! Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 This might be your storm and NOT I-95's, if I-95 mixes over... There's actually been some storms where Long Island got snow, I-95 got rain and further west in PA it snowed.... I believe it had to do with intensity rates and marginal temps. Link to comment Share on other sites More sharing options...
A-L-E-X Posted January 17, 2011 Share Posted January 17, 2011 We agree! It sounds like the theme of this winter No resolution until within 48 hours of the prospective event. Link to comment Share on other sites More sharing options...
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