CAD_Wedge_NC Posted December 5, 2013 Share Posted December 5, 2013 I may have to eat some crow if the CMC turns out right. However, it could just as easily trend 1-2 degrees warmer since we have a full 3 days. From the get go I have thought only northern NC counties. It's ok.... we have all had to eat crow at some point. That's why I never write off a CAD potential until I see a clear signal that it's not going to happen. This one is trending colder as we approach verification time and that is not a clear signal that this event can be discounted. It's going to be close, and it is not uncommon for the Canadian model to be leading the way on this one. It can sniff out a CAD in the LR better than most....... By this time tomorrow, the thermal profile/structure will become much clearer and we will likely have a good idea of what we can expect to happen. Link to comment Share on other sites More sharing options...
dsaur Posted December 5, 2013 Author Share Posted December 5, 2013 Models don't deal with snow and ice pack too well, so anything that falls early will impact how cold it gets at ground level later for those further east. Lots on the table still. Cads are like Ull's in that they can be mystery weather sometimes. Never underestimate a classic cad set up, because even in situ, or hybrids surprise all the time. This is a big, sprawling many part system, and relatively weak, which means less heat to dispose of for those on the borderline. And if we get a stalled front next week, and another cold push it's deja vu all over again. I still think nw Ala is in play, and maybe even NeGa, and Lookout, if the cad surprises. Interesting weather for so early in the season. You'd usually expect pocket problems this early, but this could be widespread beyond Ark, and w Tenn. and Va. with a few changes going forward. T Link to comment Share on other sites More sharing options...
DaculaWeather Posted December 5, 2013 Share Posted December 5, 2013 It's ok.... we have all had to eat crow at some point. That's why I never write off a CAD potential until I see a clear signal that it's not going to happen. This one is trending colder as we approach verification time and that is not a clear signal that this event can be discounted. It's going to be close, and it is not uncommon for the Canadian model to be leading the way on this one. It can sniff out a CAD in the LR better than most....... By this time tomorrow, the thermal profile/structure will become much clearer and we will likely have a good idea of what we can expect to happen. After all... it is Canadian so it should know cold! :-) Link to comment Share on other sites More sharing options...
Shawn Posted December 5, 2013 Share Posted December 5, 2013 Models don't deal with snow and ice pack too well, so anything that falls early will impact how cold it gets at ground level later for those further east. Lots on the table still. Cads are like Ull's in that they can be mystery weather sometimes. Never underestimate a classic cad set up, because even in situ, or hybrids surprise all the time. This is a big, sprawling many part system, and relatively weak, which means less heat to dispose of for those on the borderline. And if we get a stalled front next week, and another cold push it's deja vu all over again. I still think nw Ala is in play, and maybe even NeGa, and Lookout, if the cad surprises. Interesting weather for so early in the season. You'd usually expect pocket problems this early, but this could be widespread beyond Ark, and w Tenn. and Va. with a few changes going forward. T Look at this from 12z's GGEM: (if this needs to be moved to the Dec pattern thread please do so; this just seems to go here) Link to comment Share on other sites More sharing options...
CAD_Wedge_NC Posted December 5, 2013 Share Posted December 5, 2013 Don't count on it. You sound so confident......What are you basing that on? Link to comment Share on other sites More sharing options...
dsaur Posted December 5, 2013 Author Share Posted December 5, 2013 Well, by all accounts winter is over in a few weeks, so we need to make some hay now, lol. I'd prefer sleet hay rather than z hay, but hey! Tony Link to comment Share on other sites More sharing options...
calculus1 Posted December 5, 2013 Share Posted December 5, 2013 Brad P with an update around a half-hour ago: Link to comment Share on other sites More sharing options...
triadwx Posted December 5, 2013 Share Posted December 5, 2013 Brad P with an update around a half-hour ago: Still unsure why he only used the GFS in that video. Maybe because he isn't trying to hype anything up in the case that this turns out to be a cold rain for most, but he should at least lay out all of the current model solutions, IMO. Link to comment Share on other sites More sharing options...
Brick Tamland Posted December 5, 2013 Share Posted December 5, 2013 12z Canadian Link to comment Share on other sites More sharing options...
Cold Rain Posted December 5, 2013 Share Posted December 5, 2013 12z Canadian Ok, who hijacked Brick's account? And any word on the Euro yet? Link to comment Share on other sites More sharing options...
tarheelwx Posted December 5, 2013 Share Posted December 5, 2013 Was Brad Panovich the one that scoffed at all the talk about ice a few days ago? It may have been someone else, but they were either from Charlotte or Asheville. TW Link to comment Share on other sites More sharing options...
metalicwx366 Posted December 5, 2013 Share Posted December 5, 2013 Still unsure why he only used the GFS in that video. Maybe because he isn't trying to hype anything up in the case that this turns out to be a cold rain for most, but he should at least lay out all of the current model solutions, IMO.What's the point of using terrible models like the NAM and the GGEM? You guys are only posting them because they show what you would like. Sure it's been consistent, but it also is consistently wrong. It did the same thing during hurricane season. Link to comment Share on other sites More sharing options...
Poimen Posted December 5, 2013 Share Posted December 5, 2013 Ok, who hijacked Brick's account? And any word on the Euro yet? Just eye balling the free maps at PSU E-Wall it looks similar to NAM/GFS...but I obviously can't see the dirty details. Bottom line is that the HP is in the right place and moisture is overrunning NC. Link to comment Share on other sites More sharing options...
tarheelwx Posted December 5, 2013 Share Posted December 5, 2013 What's the point of using terrible models like the NAM and the GGEM? You guys are only posting them because they show what you would like. Sure it's been consistent, but it also is consistently wrong. It did the same thing during hurricane season. Maybe because not only has the GGEM been rock solid consistent, but the GFS is moving closer and closer to its solution. Euro has been pretty good as well. TW Link to comment Share on other sites More sharing options...
Cold Rain Posted December 5, 2013 Share Posted December 5, 2013 What's the point of using terrible models like the NAM and the GGEM? You guys are only posting them because they show what you would like. Sure it's been consistent, but it also is consistently wrong. It did the same thing during hurricane season. False Just eye balling the free maps at PSU E-Wall it looks similar to NAM/GFS...but I obviously can't see the dirty details. Bottom line is that the HP is in the right place and moisture is overrunning NC. Thank you sir! Link to comment Share on other sites More sharing options...
superjames1992 Posted December 5, 2013 Share Posted December 5, 2013 Today's 12z Euro at hr 72 is colder than yesterday's 12z Euro at hr 96 at 850 mb. That's all I can really say with the 24-hour panels. It's not a huge difference, though. Surface temps are probably a bit colder, as well, and every degree counts in this situation. Link to comment Share on other sites More sharing options...
SN_Lover Posted December 5, 2013 Share Posted December 5, 2013 What's the point of using terrible models like the NAM and the GGEM? You guys are only posting them because they show what you would like. Sure it's been consistent, but it also is consistently wrong. It did the same thing during hurricane season. I think knowing each models resolutions and strengths is important and also knowing which model has a lower variation with each run. The NAM is a higher resolution model and therefore captures the CAD better than the lower resolution GFS. No model is perfect, or we would not have people at NCEP trying to make it better. Link to comment Share on other sites More sharing options...
Blue_Ridge_Escarpment Posted December 5, 2013 Share Posted December 5, 2013 Yeah I'm not really sure why all the hugging to the GFS model with a CAD event. CMC and NAM are the two best models for CAD events in this area and have been so for a while now. At any rate, appears that the GFS is caving to the CMC and NAM now anyway. Link to comment Share on other sites More sharing options...
Marion_NC_WX Posted December 5, 2013 Share Posted December 5, 2013 Was Brad Panovich the one that scoffed at all the talk about ice a few days ago? It may have been someone else, but they were either from Charlotte or Asheville. TW Yes...at that time he said there was too much hype for something being 7 days out. I don't think he ever completely ruled out the idea of ice but in general he wasn't as trigger happy as some on social media were. Link to comment Share on other sites More sharing options...
HurricaneTracker Posted December 5, 2013 Share Posted December 5, 2013 What's the point of using terrible models like the NAM and the GGEM? You guys are only posting them because they show what you would like. Sure it's been consistent, but it also is consistently wrong. It did the same thing during hurricane season. This is not a fair point. The NAM has never been good at Hurricanes and everyone in the business knows this. However, when it comes to CAD events, the NAM is slightly preferred because of its higher resolution and ability to properly initialize the terrain across western Carolina and Virginia. Link to comment Share on other sites More sharing options...
WSNC Posted December 5, 2013 Share Posted December 5, 2013 Today's 12z Euro at hr 72 is colder than yesterday's 12z Euro at hr 96 at 850 mb. That's all I can really say with the 24-hour panels. It's not a huge difference, though. Surface temps are probably a bit colder, as well, and every degree counts in this situation. Not a very good run on Euro if your pulling for ice. Temps about the same as 0z run, which were not that impressive for NC CAD area ice, but with less moisture than the 0z run on Sunday. Link to comment Share on other sites More sharing options...
Blue_Ridge_Escarpment Posted December 5, 2013 Share Posted December 5, 2013 I just had the chance to look at the 12z CMC and let me just say that if that verified, many many people will be without power for a long time. Almost a 24 hour frozen event for WNC/CNC Link to comment Share on other sites More sharing options...
Brick Tamland Posted December 5, 2013 Share Posted December 5, 2013 Yeah I'm not really sure why all the hugging to the GFS model with a CAD event. CMC and NAM are the two best models for CAD events in this area and have been so for a while now. At any rate, appears that the GFS is caving to the CMC and NAM now anyway. And the trend for all the models is colder and colder. Link to comment Share on other sites More sharing options...
RaleighWx Posted December 5, 2013 Share Posted December 5, 2013 For those of you that follow me on twitter @RaleighWx you know I have been concerned about ice potential this Sunday for a while now, despite each model cycle oscillation on the exact thermal structure in place. The reason why was that the models have been unanimous in moving a strong 1035-1040mb high into the northeast US Saturday night and creating a strong classical CAD (cold air damming setup) event. This high pressure is associated with a very cold air mass for this time of year so there was no question that the cold/dry air associated with it could be sufficient for an ice event. The big question was always the timing of the arrival of the cold air and the moisture. Earlier in the week it looked like moisture was going to arrive Saturday night with the cold air associated with the high pressure not filtering in till Saturday night and Sunday not early enough to set up a cold (below freezing) wedge east of the mountains. This scenario would lead to only minor ice or no ice for those south of Virginia as the transport of cold air would not be sufficient and enough. However, recent model trends have shown this cold surface air arriving earlier. And in fact today’s 12z NAM shows it arriving Saturday night with dewpoints in the teens even reaching down into northern NC late Saturday night. This results in strong evaparational cooling Sunday morning and an entrenched strong surface cold air mass east of the mountains. Moisture overruns this early Sunday morning and we get an icy day Sunday with anywhere from 0.25 to 0.75 inches of QPF falling in the form of mostly freezing rain from prone regions in the mountains to around or just north of Charlotte to Sanford to Rocky Mount and north and west of there including the Triangle. In fact the 12z NAM keeps temps near freezing through at least 7pm Sunday. The 12z GFS is very similar in overall features but a bit lighter with precip (0.25 to 0.5 inches) and not quite as cold Sunday although close. It keeps the surface freezing line around or just north of the Triangle along the I-40 corridor. However, it could be that the coarse nature of the GFS model compared to the higher resolution of the NAM means the GFS model isn’t resolving the complicated thermal structure in the lower levels correctly. The 12z GGEM is also colder than previous runs and very similar to the NAM in showing a significant ice event Sunday. The ECMWF trended cooler too but taken literally it does keep the surface freezing line further west and confines ice to the northern foothills. So what is the bottom line? I think that we will receive a moderate to in some places significant ice event on Sunday during the day. Temperatures will fall Sunday night and increasing drier air at the surface will advect into the area from the NE as the CAD wedge establishes itself. Precipitation will likely break out in the wee hours Sunday morning and begin as rain but quickly change over to freezing rain for areas as far south as the NC/SC border in the foothills/southern piedmont. This will continue into much of NC west of I-95 Sunday morning. As winds aloft increase from the SW we will see the warm nose strengthen and slowly the CADS wedge will weaken along the southern/eastern edges with temperatures warming above freezing Sunday morning to lunch time from the southern piedmont (CLT to the NC coastal plain) with perhaps a 0.1 inch of glaze possible. Further north and west including the Triangle, Triad and into the northern foothills the freezing rain will last longer with more significant accumulation. For now I would go with a general 0.25 inch freezing rain glaze for those areas (See map) with likely the usual areas of the Triad to Hickory to getting more than the Triangle. The foothills near the escarpment and the far NW piedmont near the Va border could see damaging ice accrual up to 0.5 inches. Again see the map for my ideas. The general trend of cooler air arriving earlier and ice being a bigger problem is undeniable the last 24 hours. If the 12z Nam scenario is correct these totals could need to be increased. I will update as needed. And as usual these model images are from my site in conjunction with AmericanWx http://www.americanwx.com/models/index.html or click the models tab up top. Feel free to signup lots of cool new images/upgrades since my old site. Link to comment Share on other sites More sharing options...
NCCatawba Posted December 5, 2013 Share Posted December 5, 2013 Looks like a disagreement with moisture. Maybe that will save us from something big. Link to comment Share on other sites More sharing options...
dsaur Posted December 5, 2013 Author Share Posted December 5, 2013 Thank you, Allan. Always good to see you here. T Link to comment Share on other sites More sharing options...
Brick Tamland Posted December 5, 2013 Share Posted December 5, 2013 Great post RaleighWx and explaining why you favor the NAM and Canadian vs the GFS. Link to comment Share on other sites More sharing options...
superjames1992 Posted December 5, 2013 Share Posted December 5, 2013 I just want to say thanks for stopping by, Allan! I've been following your thoughts on Twitter for the last few days. Link to comment Share on other sites More sharing options...
burgertime Posted December 5, 2013 Share Posted December 5, 2013 I agree with everyone, it's always a good day when you stop by Allan and give your thoughts. I'm starting to get a little worried though as we've seen this play out before. We keep getting colder as we move towards the event only for it to be even colder and the wedge stay longer during the event. That is my one worry now. Link to comment Share on other sites More sharing options...
Brick Tamland Posted December 5, 2013 Share Posted December 5, 2013 So at .25 is usually when we start seeing trouble, right? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.