Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 Models have pretty consistently allowed the system to lose moisture over eastern areas, though some re-intensification is also a consistent component in NE TN east of I-26. @TellicoWxsaid it best a few pages ago, I don't think modeling is handling this well at the surface. This front is FAST moving, intense, and it is thus very difficult for modeling to find the rain/snow line due to that. I do think E TN will have less precip to deal w/ as compared to middle and western areas(north of I-40). I think the cold makes it over the Plateau just fine. I think downsloping is legit for those closest to the eastern slopes of the Plateau. Conversely w/ big coastals, folks in the shadow of the western slopes of the Apps will be the first to tell you that downsloping w/ big storms is legit. How much downsloping is anyone's guess. Buckle up. Gonna be a wild ride. This is a strong, dynamic system which is going to likely hold some surprises. 5 Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 22, 2022 Share Posted December 22, 2022 3 minutes ago, ShawnEastTN said: I think we are going to be stuck in a nowcast situation with this. There have been many things occurring in the plains the last 12 hours that were not modeled correctly even on the hi-res models. Storms of this magnitude don't happen often enough for the models to handle them well. Sent from my SM-F721U using Tapatalk Agree. They've performed pretty bad out that way; cold and snowwise. 1 Link to comment Share on other sites More sharing options...
Knoxtron Posted December 22, 2022 Share Posted December 22, 2022 CANADIAN BNA MEM CKV EURO BNA MEM CKV GFS BNA MEM CKV https://i.ibb.co/MntYnDf/canadian-bna.jpghttps://i.ibb.co/W5Yk4yK/GFS-bna.jpghttps://i.ibb.co/72G0W9s/euro-bna.jpghttps://i.ibb.co/JjXM6RG/euro-mem.jpghttps://i.ibb.co/cQBgRTt/gfs-mem.jpghttps://i.ibb.co/Gt3g3h8/canadian-mem.jpghttps://i.ibb.co/ch7yY5J/canadian-ckv.jpghttps://i.ibb.co/pjFjvty/GFS-ckv.jpghttps://i.ibb.co/Tc0H5rL/euro-ckv.jpg 2 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 And like clockwork, the 12z GFS has this....and no, I hadn't looked at it until after I posted above. I did look at the 3k Nam. The trend is less over E TN w/ the band re-intensifying as it gets east of I-81(sorry, I said I-26 earlier...prob more than once!). We have seen Cuba shred more than one intense hurricane. The Plateau is a formidable obstacle for systems. That said, E TN could bust high. This is one of the setups which could do it. 5 Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 22, 2022 Share Posted December 22, 2022 9 minutes ago, Carvers Gap said: And like clockwork, the 12z GFS has this....and no, I hadn't looked at it until after I posted above. I did look at the 3k Nam. The trend is less over E TN w/ the band re-intensifying as it gets east of I-81(sorry, I said I-26 earlier...prob more than once!). We have seen Cuba shred more than one intense hurricane. The Plateau is a formidable obstacle for systems. That said, E TN could bust high. This is one of the setups which could do it. Yep. The Great Valley killer. The Great Valley does best with weak System's or overrunning Event's. Downsloping from pretty much every direction except SW. Hoosiers and Buckeyes ftw with this ! That's a Blizzard there. May not be feet totals but, criteria will be met. Link to comment Share on other sites More sharing options...
Met1985 Posted December 22, 2022 Share Posted December 22, 2022 20 minutes ago, Carvers Gap said: And like clockwork, the 12z GFS has this....and no, I hadn't looked at it until after I posted above. I did look at the 3k Nam. The trend is less over E TN w/ the band re-intensifying as it gets east of I-81(sorry, I said I-26 earlier...prob more than once!). We have seen Cuba shred more than one intense hurricane. The Plateau is a formidable obstacle for systems. That said, E TN could bust high. This is one of the setups which could do it. I absolutely agree with all the above. We are kind of sitting similar to you but I think this is such a dynamic complex system that just about all the models are having a tough time with this thing. 3 Link to comment Share on other sites More sharing options...
bearman Posted December 22, 2022 Share Posted December 22, 2022 I do think we are in Un-modeled territory in that this is really a historic event. Haveing said that living here all my life I have seen the power of the Plateau to wreck some big storms, 5 Link to comment Share on other sites More sharing options...
PowellVolz Posted December 22, 2022 Share Posted December 22, 2022 And like clockwork, the 12z GFS has this....and no, I hadn't looked at it until after I posted above. I did look at the 3k Nam. The trend is less over E TN w/ the band re-intensifying as it gets east of I-81(sorry, I said I-26 earlier...prob more than once!). We have seen Cuba shred more than one intense hurricane. The Plateau is a formidable obstacle for systems. That said, E TN could bust high. This is one of the setups which could do it.It looks like the GFS’s dead zone is 30ish miles east of the other mods. The GFS is the only mod not showing me any snow. All the others have the dry slot west of me. . 3 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 FWIW, snow or no-snow(and I said this yesterday), I am going to stay up and watch this thing blow through. It is not very often that we get to see a front as powerful as this one is modeled. 8 1 Link to comment Share on other sites More sharing options...
EastTNWeatherAdmirer Posted December 22, 2022 Share Posted December 22, 2022 I know most models show very minimal snowfall amounts over the E TN valley and they are probably right because the HRRR has been on top of this system. But, here is the 6z Euro with a very interesting resolution - roughly .3” QPF over the whole forum area with widespread 1.5/2 with up to 3.5/4 in spots in the valley, widespread. I will say the Euro has been the straggler with catching up to the cold temps and it might be in wonderland with this but at least worth mentioning…you can access the 6 and 18z Euro and its kutchera ratio snowfall accumulation on weather.cod.edu btw. 8 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 10 minutes ago, PowellVolz said: It looks like the GFS’s dead zone is 30ish miles east of the other mods. The GFS is the only mod not showing me any snow. All the others have the dry slot west of me. . I think at this point it is just coming down to the resolution of modeling as to where the shadow sets up. The overall message across modeling is dampening out precip once it crosses the Plateau, especially between the Plateau and I-75/81. Where that happens is probably microclimate climatology unique to this event. I would hate to be in MRX's shoes right now in terms of amounts. The system to our west is often over-performing in real time, but modeling is pretty meh in E TN. If MRX puts numbers out which are too high, loads of people will change travel plans. Then, if nothing happens, everyone is gonna be hot. OTH, if they go low and this thing over-performs like it has been....they catch people traveling on the roads. My gut says MBY is gonna see 0.5-1.0." East of I-81 could see 1-2" w/ bands(southwest to northeast) seeing slightly more. If this thing over performs and we get 2-3" of snow in the eastern valley, travel problems are going to be huge on Saturday w/ people traveling for Christmas Eve. I think the real story will be the rapid temperature drop and high winds IMBY. I hope the lights stay on.... 5 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 24 minutes ago, bearman said: I do think we are in Un-modeled territory in that this is really a historic event. Haveing said that living here all my life I have seen the power of the Plateau to wreck some big storms, 26 minutes ago, Met1985 said: I absolutely agree with all the above. We are kind of sitting similar to you but I think this is such a dynamic complex system that just about all the models are having a tough time with this thing. I agree w/ ya'll. If there is ever a system which could over perform, it is this one. 3 Link to comment Share on other sites More sharing options...
Met1985 Posted December 22, 2022 Share Posted December 22, 2022 2 minutes ago, Carvers Gap said: FWIW, snow or no-snow(and I said this yesterday), I am going to stay up and watch this thing blow through. It is not very often that we get to see a front as powerful as this one is modeled. Absolutely! No two ways around this arctic blast being historical. Just look at the NWS map of all the advisors, watches, and warnings across a large portion of the country. 2 Link to comment Share on other sites More sharing options...
John1122 Posted December 22, 2022 Share Posted December 22, 2022 The 15Z HRRR tried to fill in some of the areas in the Valley with snow. It still has a snow hole there but it's much smaller than it was even at 14z. 3 Link to comment Share on other sites More sharing options...
John1122 Posted December 22, 2022 Share Posted December 22, 2022 No modeling caught this. 7 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted December 22, 2022 Share Posted December 22, 2022 Most similar arctic front anafrontal type events I'd just barely follow for the valley, but this being really unprecedented in modern modeling history I think it's game on for this to work out in ways they don't typically. Remember there is not a true analog here, there are similar systems but no true analog for this potent a system. Sent from my SM-F721U using Tapatalk 4 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted December 22, 2022 Share Posted December 22, 2022 No modeling caught this. Great example!!! There have been so many examples of things modeling just couldn't simulate because it's so unprecedented.Sent from my SM-F721U using Tapatalk 2 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted December 22, 2022 Share Posted December 22, 2022 No modeling caught this. Also sorry for quoting you twice, but that makes me wonder about all the trapped low level moisture stuck in the valley that doesn't fully dry from downsloping. I think that could ignight in the same manner and not even be seen on radar.Sent from my SM-F721U using Tapatalk 4 Link to comment Share on other sites More sharing options...
bearman Posted December 22, 2022 Share Posted December 22, 2022 4 minutes ago, ShawnEastTN said: Also sorry for quoting you twice, but that makes me wonder about all the trapped low level moisture stuck in the valley that doesn't fully dry from downsloping. I think that could ignight in the same manner and not even be seen on radar. With extreme cold events some very wild things can happen with “trapped” moisture. I have seen the steam coming off the BowWater paper mill in Charleston TN form low clouds and put down a half inch of snow in the parking lot and front area of the plant. 5 Link to comment Share on other sites More sharing options...
Silas Lang Posted December 22, 2022 Share Posted December 22, 2022 Looks like the front is moving a tick faster on modeling. For example, the HRRR now has Knoxville below freezing at 12 instead of 1. I think that's been the trend everywhere? 3 Link to comment Share on other sites More sharing options...
Scottie16 Posted December 22, 2022 Share Posted December 22, 2022 1 minute ago, Silas Lang said: Looks like the front is moving a tick faster on modeling. For example, the HRRR now has Knoxville below freezing at 12 instead of 1. I think that's been the trend everywhere? I’ve saw anywhere between 10-12 from local media. 1 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted December 22, 2022 Share Posted December 22, 2022 With extreme cold events some very wild things can happen with “trapped” moisture. I have seen the steam coming off the BowWater paper mill in Charleston TN form low clouds and put down a half inch of snow in the parking lot and front area of the plant. I've seen the same from Watts Bar nuclear plant, steam blowing SE in a very cold single digit night with NW winds, back in early 2000s I worked 3rd shift drove under the steam cloud from the plant in an otherwise fair night sky with stars, and flurries were falling right under the steam cloud! Wild stuff, I've told people that over the years who didn't believe me. Awesome someone else with similar experience.Sent from my SM-F721U using Tapatalk Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 28 minutes ago, John1122 said: No modeling caught this. Which means modeling isn't going to see that low level moisture, right? Some reports out west almost implied that a snow was rolling in like a fog when it hit. 4 Link to comment Share on other sites More sharing options...
fountainguy97 Posted December 22, 2022 Share Posted December 22, 2022 2 minutes ago, Carvers Gap said: Which means modeling isn't going to see that low level moisture, right? Some reports out west almost implied that a snow was rolling in like a fog when it hit. Our complaining worked because hrrr is again back to beefing up totals. 5 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted December 22, 2022 Share Posted December 22, 2022 Big concern for the Valley on the low level moisture is the DGZ speed lowering and how dry it is. The residual could be squeezed out in the form of light drizzle/fog creating a nightmare glaze on everything. Won't take very much drizzle to instantly freeze on contact for things to go down hill quickly. 2 1 Link to comment Share on other sites More sharing options...
Tucker1027 Posted December 22, 2022 Share Posted December 22, 2022 4 minutes ago, TellicoWx said: Big concern for the Valley on the low level moisture is the DGZ speed lowering and how dry it is. The residual could be squeezed out in the form of light drizzle/fog creating a nightmare glaze on everything. Won't take very much drizzle to instantly freeze on contact for things to go down hill quickly. It has been drizzling/misting all day in Chattanooga. 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted December 22, 2022 Share Posted December 22, 2022 Sure many of us has seen systems where lift didn't adequately get the moist into the DGZ, and instead of snow we got mist/graupel (while upslope was snow). Imagine that except surface in single digits. 3 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted December 22, 2022 Share Posted December 22, 2022 Sure many of us has seen systems where lift didn't adequately get the moist into the DGZ, and instead of snow we got mist/graupel (while upslope was snow). Imagine that except surface in single digits.Right talk about treacherous!Sent from my SM-F721U using Tapatalk Link to comment Share on other sites More sharing options...
fountainguy97 Posted December 22, 2022 Share Posted December 22, 2022 this is primarily for upslope regions. Rations will be 25:1 a couple hours after frontal passage. That means .04 qpf is an inch of snow. Tiny qpf changes matter a lot here. More than normal. brief blizzard conditions will be possible across most of the area tonight. This is going to be fun! 3 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 22, 2022 Share Posted December 22, 2022 Someone post that recent HRRR w/ Kuchera, please! Euro is rolling. 3 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now