Holston_River_Rambler Posted February 10, 2021 Share Posted February 10, 2021 NAM may be coming in icier. Last 5 SREF runs of probs of ZR greater than 0.05 in 3hrs: 1 1 Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 I don't remember ever hearing about a warm nose warming the surface in an arctic airmass situation but that's interesting. It's 10c at 850 over Memphis but 20s at the surface during the event so it seems to not affect them. 3 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 10, 2021 Share Posted February 10, 2021 Never tried the "anticipate the NAM" trick with SREF for an icing situation and even for snow, it only works like 75% of the time, at least it seems that way to me. Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 JKL extended their icestorm warning all the way to the Tennessee border. That puts our SE Kentucky guys solidly in the game for ice. Link to comment Share on other sites More sharing options...
Shocker0 Posted February 10, 2021 Share Posted February 10, 2021 44 minutes ago, John1122 said: I feel you. We had 4.5 inches of snow, closed interstates and widespread power outages when a winter storm warning was finally issued at 4am here. I don't think they ever even issued one here and it was obvious by 11pm that night it was gonna snow for several more hours and we already had a couple inches at that point. Ended up being the biggest snow in 5 years here and was a WWA. 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2021 Share Posted February 10, 2021 30 minutes ago, John1122 said: I don't remember ever hearing about a warm nose warming the surface in an arctic airmass situation but that's interesting. It's 10c at 850 over Memphis but 20s at the surface during the event so it seems to not affect them. Latency made add a degree at best...only way I see that helping is if you were borderline 30-31° Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2021 Share Posted February 10, 2021 Example of how the rain droplets transports the warmer 850s to the surface..but it's only going to add a degree or so. Big Rock, TN as the moisture/drizzle moves in (temp rose from 29.8 to 30.4, even tho the winds remained from the north...elev 694' 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2021 Share Posted February 10, 2021 If the NAM 3k is off by a hair..Memphis is in trouble..2" amounts showing up just north of the metro 3 Link to comment Share on other sites More sharing options...
Carvers Gap Posted February 10, 2021 Share Posted February 10, 2021 5 minutes ago, TellicoWx said: If the NAM 3k is off by a hair..Memphis is in trouble..2" amounts showing up just north of the metro Tellico, that looks like a bit of a shift trend southeast on that run. Is that your take? Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2021 Share Posted February 10, 2021 16 minutes ago, Carvers Gap said: Tellico, that looks like a bit of a shift trend southeast on that run. Is that your take? Yeah it dropped the entire line about a county south 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted February 10, 2021 Share Posted February 10, 2021 I don't remember ever hearing about a warm nose warming the surface in an arctic airmass situation but that's interesting. It's 10c at 850 over Memphis but 20s at the surface during the event so it seems to not affect them. It basically defies everything we know about how the atmospheric temps work. I’ve never heard of warm air sinking when there’s cold air underneath it. . 1 Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 0z hi-res modeling suite. Even they can't decide this close to the event where the edge sets up. It has major consequences for many. 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted February 10, 2021 Share Posted February 10, 2021 This is an interesting development..... 2 Link to comment Share on other sites More sharing options...
Matthew70 Posted February 10, 2021 Share Posted February 10, 2021 Very sad to think parts of TN if this happens a disaster area. The landscape will be forever changed. Tornadoes now this. Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 4 minutes ago, PowellVolz said: This is an interesting development.... . Models didn't see it for sure. I suspect it will transition to sleet then freezing rain pretty fast. The moisture races in in front of the 850 warm nose and it snows lightly on the front end. 1 Link to comment Share on other sites More sharing options...
Utvols235 Posted February 10, 2021 Share Posted February 10, 2021 Would like to thank you guys for all the input. I’ve been following for years. This storm definitely has become more concerning for me in Wilson Co. (definitely making a run to the grocery tomorrow) Worried how we are this close to an event and all of the High res models have a different line. This season has brought a lot of unexpected across the region and I don’t think that’s going to change this week. We are in for a wild 24 hours to see what’s going to happen. I wish everyone the best.. 6 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2021 Share Posted February 10, 2021 32 minutes ago, PowellVolz said: It basically defies everything we know about how the atmospheric temps work. I’ve never heard of warm air sinking when there’s cold air underneath it. . Actually it's not...here's the process that happens, it's the reverse of what happens during evaporative cooling. Evaporative cooling is going from a solid (snow) to liquid (rain) as it falls thru the column..to complete the process it needs to absorb the heat from the surrounding air. Freezing rain just reverses that (liquid to solid). When water (in any of the three phrases) moves from a lower to a higher ordered state, the air surrounding the H20 will have energy added to it. This is called a release of latent heat (e.g. when heat is subtracted from liquid water, the individual water molecules will slow down. They eventually slow down to the point at which the hydrogen bonds do not allow the liquid to rotate anymore. Ice now develops. The energy the water molecules once had to rotate has been given up to the surrounding air). The three processes that add heat to the surrounding air are condensation, freezing and deposition (gas to solid). 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted February 10, 2021 Share Posted February 10, 2021 The higher the 850's are, the more heat that is trapped in the water molecules that must be released during the ice formation 1 Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 Big shift on the GFS. 1 Link to comment Share on other sites More sharing options...
Jesse from KY Posted February 10, 2021 Share Posted February 10, 2021 Does anybody expect Bell and Harlan Counties to be added to the Ice Storm Warning? Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 15 minutes ago, Jesse from KY said: Does anybody expect Bell and Harlan Counties to be added to the Ice Storm Warning? It's going to be close that far east but it wouldn't shock me. The hollows there are notorious for draining cold air getting trapped. Harlan has a better shot than Bell if I were guessing. 1 Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 Euro was further south in Western areas with the ice. Got Memphis when it showed rain there at 12z. Warmer in general though. Not a surprise since it has been doing absolutely awful with temps, missing by 5-9 degrees on the high side at the surface the last several days. 2 Link to comment Share on other sites More sharing options...
BuCoVaWx Posted February 10, 2021 Share Posted February 10, 2021 Anyone think Buchanan County, VA will end up with anything frozen? The forecast was 32 degrees and all rain for Thursday night last I checked. Seems like a few of the models show ZR possibly creeping in, but I'm pretty much a noob with a lot of this. Funny thing, and I promise this isn't me whining lol, just very curious. It almost always seems like Buchanan county is the cut off to any kind of frozen precip when temps are borderline. To the east, west, north and sometimes south. Is that anything to do with the formation of the mountains? Maybe the cold has a harder time pushing through? We definitely get our fair share of rain here. One of the only things Grundy is known for are the terrible floods throughout the years. You guys are so awesome with all of your knowledge, maybe someone can fill me in. Sorry this turned into a two part post lol. Link to comment Share on other sites More sharing options...
John1122 Posted February 10, 2021 Share Posted February 10, 2021 34 minutes ago, BuCoVaWx said: Anyone think Buchanan County, VA will end up with anything frozen? The forecast was 32 degrees and all rain for Thursday night last I checked. Seems like a few of the models show ZR possibly creeping in, but I'm pretty much a noob with a lot of this. Funny thing, and I promise this isn't me whining lol, just very curious. It almost always seems like Buchanan county is the cut off to any kind of frozen precip when temps are borderline. To the east, west, north and sometimes south. Is that anything to do with the formation of the mountains? Maybe the cold has a harder time pushing through? We definitely get our fair share of rain here. One of the only things Grundy is known for are the terrible floods throughout the years. You guys are so awesome with all of your knowledge, maybe someone can fill me in. Sorry this turned into a two part post lol. The front will have a better shot the further north you are and you're in a low spot compared to areas around you. If you can get cold air trapped you'll have a good shot. It looks like models are pushing it over the Apps there, so it's likely deeper up that way and should be able to spill over. You are in a tough spot for downsloping when snow hits if you're in Grundy. I believe the elevations are higher to your northwest, west, and southwest, which are all primary directions that snow producing systems have their moisture feed from here. But being down deep in a hollow like that you're much more prone to ice because it is likely tough to scour out of the valley where Grundy is located. Link to comment Share on other sites More sharing options...
BuCoVaWx Posted February 10, 2021 Share Posted February 10, 2021 Thank you very much. That definitely makes sense. I live in Big Rock, right on the Va/Ky state line. The mountains behind my house and across from my house have had snow on them for what seems like weeks. Down here in the valley, seems it takes a strong push to get the cold to settle in for a good snow. As a snow lover, it can be frustrating to see the snow all around in the higher elevations but not in the lower. I really shouldn't complain though. It is an absolute beautiful sight when the mountain tops are covered in snow. Link to comment Share on other sites More sharing options...
weathertree4u Posted February 10, 2021 Share Posted February 10, 2021 I think OHX is finally recognizing thg he boundary continues shifting south 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted February 10, 2021 Share Posted February 10, 2021 Disco from Memphis this morning....worth the entire read. DISCUSSION... A significant ice storm is expected to impact the Mid South later this afternoon through early Thursday afternoon. We are already seeing some icing and dangerous travel this morning across Arkansas. The Ice Storm Warning continues to be adjusted this morning as the push of colder air made it into the AR/MS delta regions. We have added Lee and Phillips Counties in AR to the warning, and we have also adjusted the Winter Storm Watch to include more areas in west Tennessee and north Mississippi. This will continue to be the case as we go through the event. Portions of the area will be upgraded to Ice Storm Warnings as the event unfolds. The freezing line this morning is draped across the forecast area and we will continue to watch the progress of this line as it will snake across the Mid South and serve as the delineation of ZR and rain. Taking a look at the range of possibilities for ice accumulation across the Mid South, we are generally seeing most of the guidance keep ice accumulations less than an inch of ice for the Mid South. The Worst Case Scenario (90th Percentile) shows a swath of 0.5 to 0.75 inch of ice along and north of I-40...just north of downtown Memphis, and a quarter inch of ice as far south as Clarksdale, MS. The most likely scenario (50th Percentile) has a swath of ice of 0.25-0.40 along and north of I-40 with little to no accumulation south of I-40. The official forecast sticks close to WPC guidance with is more in line with the 50th percentile. We will have to watch for trends in obs and rainfall to adjust the forecast as needed. Either way a significant ice storm will make travel very dangerous...cause power outages...and tree damage. The other thing to be said for this event is that this ice has the potential to be around for a while. Precipitation will move out and end on Thursday, but from Thursday night onward....portions of the forecast area will not get above freezing until late next week. Ice could be around into the weekend. This means the possibility of power outages with bitterly cold temperatures for several days. Wind chill readings Friday and Saturday will be quite cold, approaching single digits in some areas. A fast-moving trough will bring a chance for very light snow to portions of the area Saturday evening, but no impacts are anticipated. A reinforcing cold shot will arrive by Sunday, where wind chill values will fall below zero early next week. Beyond the cold...another system is expected to impact the Mid South Monday night into Tuesday. This could bring another shot of winter precipitation, but let`s get past this ice storm first before we dive into that system. 1 Link to comment Share on other sites More sharing options...
Olhausen Posted February 10, 2021 Share Posted February 10, 2021 For the middle Tennessee area Winter Storm Watch in effect from 6 PM Wednesday through 6 PM on Thursday. Freezing rain with ice accumulations of one tenth to greater than one quarter of an inch possible in the Watch. Power outages and tree damage are possible due to the ice. Tavel could be very dangeergous. Thehazardous conditions could impact the morning and evening commute. Hide Caption 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted February 10, 2021 Share Posted February 10, 2021 12km NAM coming in SE with the ice again. 1 Link to comment Share on other sites More sharing options...
Olhausen Posted February 10, 2021 Share Posted February 10, 2021 59 degrees here and a big bust on high temps for the day. Forecasted to be 45 degrees originally. 14 degrees above what was forecasted is about the biggest bust I can remember. I’m hoping this will help keep surface temps above freezing longer and limit the ZR accumulation later on. 3 Link to comment Share on other sites More sharing options...
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