Blue_Ridge_Escarpment Posted January 27, 2014 Share Posted January 27, 2014 Well the 12Z NAM was a swing and a miss for most of western North Carolina. But of course it is the NAM, and in my book it is one of the most useless models as of late (like the last 12 months). So I would put very little stock in anything it says outside of 24 hours out. I would really watch the GFS and Euro today. Use a blend of their solutions for a good forecast. More to come later. Stay tuned. Still an improvement from it's previous runs, very sharp cutoff of QPF over the Charlotte Metro area. Would only take a 50-75 mile NW jog for most in the WNC area to be happy. Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 Still an improvement from it's previous runs, very sharp cutoff of QPF over the Charlotte Metro area. Would only take a 50-75 mile NW jog for most in the WNC area to be happy. And that jog is asking a lot from the models, I think. The solutions we are seeing today more closely resemble that which they showed last week - a very suppressed system with most of the Carolina's remaining dry. So far, I have no reason to discount that idea. Link to comment Share on other sites More sharing options...
Hvward Posted January 27, 2014 Share Posted January 27, 2014 What did you see on the gfs that I missed? I saw a qpf of less than a tenth of an inch. Under the .01-.1 qpf for a good 6-8 hrs would result in a couple of inches of snow. Still is a lot to play out with this system, its time to just sit back, watch the 12z gfs, WV, and hope for a miracle. Link to comment Share on other sites More sharing options...
WxBlue Posted January 27, 2014 Share Posted January 27, 2014 Looking at 00z GFS from last night and 12z GFS now, it appears that the heavy QPF shifted east between these two runs. It's still showing around 0.05 for AVL, however. Link to comment Share on other sites More sharing options...
Blue_Ridge_Escarpment Posted January 27, 2014 Share Posted January 27, 2014 Looking at 00z GFS from last night and 12z GFS now, it appears that the heavy QPF shifted east between these two runs. It's still showing around 0.05 for AVL, however. All other models shifting west and the GFS goes east, makes sense I suppose. UKIE was a huge shift west, decent QPF all the way back to the NC/TN line. Link to comment Share on other sites More sharing options...
wncsnow Posted January 27, 2014 Share Posted January 27, 2014 The key here is overrunning. And with this setup, we could be in a decent spot, and like Robert said in the storm thread it is difficult for the models to project it Link to comment Share on other sites More sharing options...
WxBlue Posted January 27, 2014 Share Posted January 27, 2014 The key here is overrunning. And with this setup, we could be in a decent spot, and like Robert said in the storm thread it is difficult for the models to project it Remind me of what Brad Panovich said on Twitter to someone few days ago that we all can't be good at forecasting if we only look at models. Robert made a great point by looking at the bigger picture. Link to comment Share on other sites More sharing options...
K4CF Posted January 27, 2014 Share Posted January 27, 2014 Been away from my PC since 7am...On the 12Z NAM, I'm seeing snow break out on the NC/TN line starting at 7am tomorrow but this is some 300 mi NW of the main moisture plume to the south. What is that deal? Virga? Haven't looked at the qpf maps...Are those only light amounts for us? Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 Been away from my PC since 7am...On the 12Z NAM, I'm seeing snow break out on the NC/TN line starting at 7am tomorrow but this is some 300 mi NW of the main moisture plume to the south. What is that deal? Virga? Haven't looked at the qpf maps...Are those only light amounts for us? In short, it remains a non-event for all mountain areas. While the models do put out that light QPF, it doesn't reach the ground, and by the time it does, the precip is already pulling out to the east. 0.01" of liquid at best for mountain areas. We are getting inside a timeframe that very few additional changes should occur. Don't expect much from this event. Link to comment Share on other sites More sharing options...
wncsnow Posted January 27, 2014 Share Posted January 27, 2014 GSP is slowly increasing their snow totals and now have I-85 corridor at an inch. Link to comment Share on other sites More sharing options...
Hvward Posted January 27, 2014 Share Posted January 27, 2014 In short, it remains a non-event for all mountain areas. While the models do put out that light QPF, it doesn't reach the ground, and by the time it does, the precip is already pulling out to the east. 0.01" of liquid at best for mountain areas. We are getting inside a timeframe that very few additional changes should occur. Don't expect much from this event. I am not ready to throw in the towel yet. This might be our best shot this year so it would be stupid to just give up on it a day before when a lot of dynamics are still unsettled. Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 I am not ready to throw in the towel yet. This might be our best shot this year so it would be stupid to just give up on it a day before when a lot of dynamics are still unsettled. Hey don't get me wrong: I love snow as much as the next person in here. But what I am seeing on the models is not supportive of a drought-breaking event here. I will very happily eat crow if this turns out to be wrong. However, if the 12Z Euro doesn't shift NW, then I am throwing in the towel. Link to comment Share on other sites More sharing options...
K4CF Posted January 27, 2014 Share Posted January 27, 2014 In short, it remains a non-event for all mountain areas. While the models do put out that light QPF, it doesn't reach the ground, and by the time it does, the precip is already pulling out to the east. 0.01" of liquid at best for mountain areas. We are getting inside a timeframe that very few additional changes should occur. Don't expect much from this event. Thanks Tracker Link to comment Share on other sites More sharing options...
WxBlue Posted January 27, 2014 Share Posted January 27, 2014 Euro gave AVL 0.1 inch of QPF rising up to 0.2 inch in the mountains to northwest. Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 Euro gave AVL 0.1 inch of QPF rising up to 0.2 inch in the mountains to northwest. Yes it did. And it looks to start WAY sooner than any other model (by 7am). In fact, if the Euro were taken at face-value, it would snow lightly all day in the mountains. It seems to be picking up on the best overrunning precipitation early on along the arctic front, which has moved VERY slow today. I believe this will be a factor in the placement of the best precip tomorrow. Euro wants to end the snow-drought. The King has spoken. My towel has been placed back in my pocket for now... Link to comment Share on other sites More sharing options...
Hvward Posted January 27, 2014 Share Posted January 27, 2014 Euro wants to end the snow-drought. The King has spoken. My towel has been placed back in my pocket for now... And the mountain crowd goes wild! Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 And the mountain crowd goes wild! Ha ha. LOL! And I re-read Robert's post in the main disco forum. I think he might be onto something with the models not capturing the overrunning precipitation. I think when he says "surprise", it very well could be over us. I say this only because 1) the Euro hints at it and 2) today's arctic frontal passage was horribly modeled. It is still near 50 at my house, mid-40s downtown, and upper 40s at KAVL at 1pm EST. All models had us dropping into the low 30s by now. Something has changed. Something has slowed down the frontal progression. This may prove a very important detail tomorrow! Link to comment Share on other sites More sharing options...
Hvward Posted January 27, 2014 Share Posted January 27, 2014 Ha ha. LOL! And I re-read Robert's post in the main disco forum. I think he might be onto something with the models not capturing the overrunning precipitation. I think when he says "surprise", it very well could be over us. I say this only because 1) the Euro hints at it and 2) today's arctic frontal passage was horribly modeled. It is still near 50 at my house, mid-40s downtown, and upper 40s at KAVL at 1pm EST. All models had us dropping into the low 30s by now. Something has changed. Something has slowed down the frontal progression. This may prove a very important detail tomorrow! Thanks for your thoughts! I've been a weenie on this storm the whole time as I am sure you guys can tell, but hopefully some of that wishing I did comes to fruition. Link to comment Share on other sites More sharing options...
K4CF Posted January 27, 2014 Share Posted January 27, 2014 Ha ha. LOL! And I re-read Robert's post in the main disco forum. I think he might be onto something with the models not capturing the overrunning precipitation. I think when he says "surprise", it very well could be over us. I say this only because 1) the Euro hints at it and 2) today's arctic frontal passage was horribly modeled. It is still near 50 at my house, mid-40s downtown, and upper 40s at KAVL at 1pm EST. All models had us dropping into the low 30s by now. Something has changed. Something has slowed down the frontal progression. This may prove a very important detail tomorrow! Great post (#1296) over in the main storm thread Tracker...you've made my day! I put this statement here since it will get deleted over on the other main thread Link to comment Share on other sites More sharing options...
K4CF Posted January 27, 2014 Share Posted January 27, 2014 Ha ha. LOL! And I re-read Robert's post in the main disco forum. I think he might be onto something with the models not capturing the overrunning precipitation. I think when he says "surprise", it very well could be over us. I say this only because 1) the Euro hints at it and 2) today's arctic frontal passage was horribly modeled. It is still near 50 at my house, mid-40s downtown, and upper 40s at KAVL at 1pm EST. All models had us dropping into the low 30s by now. Something has changed. Something has slowed down the frontal progression. This may prove a very important detail tomorrow! I'm @ 43o as I'm posting Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 Great post (#1296) over in the main storm thread Tracker...you've made my day! Thanks! Just trying to call it as I see it. I'm not ready to do amounts just yet - would like to see more support for the overrunning idea before I jump on board completely. Link to comment Share on other sites More sharing options...
K4CF Posted January 27, 2014 Share Posted January 27, 2014 Thanks! Just trying to call it as I see it. I'm not ready to do amounts just yet - would like to see more support for the overrunning idea before I jump on board completely. I sure do appreciate it...not many red tags comment in this thread Link to comment Share on other sites More sharing options...
K4CF Posted January 27, 2014 Share Posted January 27, 2014 Thanks! Just trying to call it as I see it. I'm not ready to do amounts just yet - would like to see more support for the overrunning idea before I jump on board completely. If you have a moment to answer this? With respect to overrunning precip, is this like a warm air mass riding over top of the cold already in place? Would this be a heavy, wet snow over a short period of time? Or a less intense, yet steadier, long-lasting event? TIA Link to comment Share on other sites More sharing options...
MikeGold Posted January 27, 2014 Share Posted January 27, 2014 I'm @ 43o as I'm posting It is in the mid 20's up top and balmy 45 in nearby Waynesville currently..suggesting that there are very steep lapse rates today and the cold air has already arrived. I suspect there isn't much significance to the temps lower down being higher than originally forecast and unfortunately think that this latest coastal gem will be a bust locally once again. (Bust defined as less than 2" like just about every other snowfall this season!) Link to comment Share on other sites More sharing options...
WxBlue Posted January 27, 2014 Share Posted January 27, 2014 Temperature peaked at 48.7 at UNCA station. Already down to 46.5 degrees via my Kestrel 3500. Link to comment Share on other sites More sharing options...
HurricaneTracker Posted January 27, 2014 Share Posted January 27, 2014 If you have a moment to answer this? With respect to overrunning precip, is this like a warm air mass riding over top of the cold already in place? Would this be a heavy, wet snow over a short period of time? Or a less intense, yet steadier, long-lasting event? TIA Good question. Overrunning is commonly used to describe a situation where warm, moist air rises up and over a boundary and then gets "wrung out" over the cold dome. This falling precipitation can take on any number of forms, from snow to sleet to freezing rain. In our case, we will be -10C to -12C at 850mb (about 5000' up), and below 0C at the surface, creating a column that is totally below freezing. Our precipitation type will be all snow. That's the easy part. The hard part are the snow ratios. In a typical setup, a 10:1 ratio is common when the 850mb temperature hovers around 0C. Since we will be so much colder at that level, I expect snow ratios to be higher, say 15:1 or even 20:1 if it is cold enough aloft. This would produce a very light fluffy snow that is also easily picked up and blown by the wind. Accumulations will be harder to do with lighter snow if there is any wind. Euro is suggesting steady winds tomorrow of 5-10 knots, so it won't be terribly windy. The liquid equivalent from the Euro for KAVL was 0.09". At 15:1, this would produce 1.4" of powdery snow, and at 20:1, it would be 1.8" of powdery snow. Hope that helps. EDIT: Overrunning situations also tend to last a bit longer so long as a moisture source is present. Euro suggests snow from 7am to 7pm tomorrow for much of the mountains. But with such low snow totals, you can see that it will take quite a bit of time to accumulate. Link to comment Share on other sites More sharing options...
strongwxnc Posted January 27, 2014 Share Posted January 27, 2014 Thanks for the post Tracker. Ratio at HR 42 http://www.spc.noaa.gov/exper/sref/gifs/2014012709/SREF_snowfall_ratio__f042.gif Good question. Overrunning is commonly used to describe a situation where warm, moist air rises up and over a boundary and then gets "wrung out" over the cold dome. This falling precipitation can take on any number of forms, from snow to sleet to freezing rain. In our case, we will be -10C to -12C at 850mb (about 5000' up), and below 0C at the surface, creating a column that is totally below freezing. Our precipitation type will be all snow. That's the easy part. The hard part are the snow ratios. In a typical setup, a 10:1 ratio is common when the 850mb temperature hovers around 0C. Since we will be so much colder at that level, I expect snow ratios to be higher, say 15:1 or even 20:1 if it is cold enough aloft. This would produce a very light fluffy snow that is also easily picked up and blown by the wind. Accumulations will be harder to do with lighter snow if there is any wind. Euro is suggesting steady winds tomorrow of 5-10 knots, so it won't be terribly windy. The liquid equivalent from the Euro for KAVL was 0.09". At 15:1, this would produce 1.4" of powdery snow, and at 20:1, it would be 1.8" of powdery snow. Hope that helps. EDIT: Overrunning situations also tend to last a bit longer so long as a moisture source is present. Euro suggests snow from 7am to 7pm tomorrow for much of the mountains. But with such low snow totals, you can see that it will take quite a bit of time to accumulate. Link to comment Share on other sites More sharing options...
snowbird1230 Posted January 27, 2014 Share Posted January 27, 2014 New to forum..Hope to help out with observations in the high mountains of Western North Carolina! Link to comment Share on other sites More sharing options...
WxBlue Posted January 27, 2014 Share Posted January 27, 2014 NWS GSP updated their forecast (as you can see in a map above from few hours ago). More snow for mountains west of Asheville. New to forum..Hope to help out with observations in the high mountains of Western North Carolina! Welcome! I joined only few days ago. Link to comment Share on other sites More sharing options...
wncsnow Posted January 27, 2014 Share Posted January 27, 2014 18Z GFS increases QPF once again to the .10-.25 range with ratios could be 2-4 inches of snow for most of WNC, the RAP is also looking to increase the overrunning precip as well... Link to comment Share on other sites More sharing options...
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