Mrwolf1972 Posted January 13 Share Posted January 13 18z GFS stays south but anemicSent from my SM-S916U1 using Tapatalk 1 Link to comment Share on other sites More sharing options...
Jed33 Posted January 13 Share Posted January 13 Very similar to that event we talked about a few weeks ago from 2014 where the mtns got the warm air and cold air was trapped in the valley 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 1 minute ago, TellicoWx said: I wouldn't even call it warmer lol..small Zone of 33-34 temps between the 925-850 layer..dps are really low, so could be end up as virga until it saturates (which the wet bulb is 99.5% below freezing). Valley is like a tub..cold faucet needs turned on for a minute to push the warm out or saturate it long enough to turn cold. Tellico, you really seem like you might have a red tag in your past(met). 2 Link to comment Share on other sites More sharing options...
Jed33 Posted January 13 Share Posted January 13 1 minute ago, Mrwolf1972 said: 18z GFS stays south but anemic Sent from my SM-S916U1 using Tapatalk Looks better than 12z to me. 1 Link to comment Share on other sites More sharing options...
weathertree4u2 Posted January 13 Share Posted January 13 2 minutes ago, Jed33 said: Looks better than 12z to me. Depends where you live 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 Watch nearly any cold front on PWS stations..1st night west of 75 will be colder...as warm advects back in, east will be colder. (As always there are certain exceptions to that rule, but this doesn't seem to be one) 3 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 What Tellico is mentioning is different IMO. I lived in JC for five years as well - love the upslope events! It isn't really a downslope. It is banking warm air up against the Apps as it gets pushed across the valley. Amazing modeling can even model that TBH. But since we are not dealing with sinking air, it would be much easier to overcome with rate driven dynamics IMO. . Link to comment Share on other sites More sharing options...
John1122 Posted January 13 Author Share Posted January 13 The GFS QPF field move N/NW about as much as the RGEM. The same area of N.GA that went from .4 QPF to .1 on the RGEM also did on the GFS. We're talking 25-40 miles. Basically a county width or so. 2 Link to comment Share on other sites More sharing options...
John1122 Posted January 13 Author Share Posted January 13 The GFS starts out the same as the hi-res models but narrows the QPF field way more than they do as the run wears on. Not sure why that is. 1 Link to comment Share on other sites More sharing options...
Silas Lang Posted January 13 Share Posted January 13 12 minutes ago, Carvers Gap said: What Tellico is mentioning is different IMO. I lived in JC for five years as well - love the upslope events! It isn't really a downslope. It is banking warm air up against the Apps as it gets pushed across the valley. Amazing modeling can even model that TBH. 8 minutes ago, PowellVolz said: I can’t remember the date of this storm but (maybe 2017-2019) it feels like this outcome could be a similar situation. It was a snow/rain/snow forecast for the valley, heavy snow on the plateau with mostly rain in the foothills because of downsloping. The warm nose made it to I-40 in Knoxville up against the mountains but did not make it any further NW. I ended up with over 8”. The thought was we had a little CAD up against the eastern slopes of the Plateau that backed up into the valley. John got blasted that event. I remember watching the temps rise as the day went on. Gatlinburg was low 40’s, Knoxville made it to 35° but I stayed below 30. One of those rare times when the cold air won out in the valley. . Not sure if this is the same or different mechanism, but this was the one storm I was thinking about. I remember my parents got blasted in Anderson County, backed up against the plateau and I got nada in JC. lol 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 18z on left and 12z on right. The SE trend on modeling has stopped for the most part. That fits previous winter storm tracking. With 24-36 hours to go, that is pretty much normal. Remember that trends are what are important on deterministic runs as well. It is good to compare the current run to previous ones. Notice the eastern edge of precip has been curtailed. Again, I do suspect the jet is enhancing precip over the eastern valley. Some of the off runs(not 12z or 0z) are beefing up precip amounts. If a storm is gonna be a good one, precip will start to increase as modeling gets closer to the even, because they can't catch up. Time to watch for that trend. 4 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 6 minutes ago, PowellVolz said: But since we are not dealing with sinking air, it would be much easier to overcome with rate driven dynamics IMO. . Unless there is a lee side slp in western NC which has been on some recent runs. Then there would be sinking air. However, sometimes a lee side isn't bad.........We have been known to develop lows over TRI during systems like this, and it enhances precip. So many moving parts at a micro level. I do agree that if the cold air gets over the Plateau, there is very little to stop it from quickly reaching the base of the Apps. I would guess most modeling is struggling with the strength of the cold air and under-doing how far it get into the SE. Tellico had a great explanation. 4 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 Here's the 925 map from the RGEM..you can see from the wind barbs are banking up against the Smokies, and how the 0 line is SW VA is trying to wrap (filling) it's way around the highest points. Hope that helps for a visual. 5 Link to comment Share on other sites More sharing options...
Bigbald Posted January 13 Share Posted January 13 This little corridor has been showing up a big winner across multiple model runs here and there, and of course on the RGEM over and over again. I hate to even bring it up because I am in it. 5 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 15 minutes ago, Carvers Gap said: Tellico, you really seem like you might have a red tag in your past(met). No, just too many years of watching these models and listening to you guys/ some others who are no longer on the boards. 4 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted January 13 Share Posted January 13 In the past I would watch that sort of slosh of cool and warm blobs either from CAA or Downsloping & WAA depending on the situation on Wunderground PWS map full screen to see as much of the valley as possible at once. Very fun thing to see those pools slosh back and forth before mixing. 3 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 16 minutes ago, weathertree4u2 said: Depends where you live LOL. Truth, man! Truth! NBM is the way to go I think for now. 5 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 Anyone else feel like there’s an opportunity for someone in the valley to over perform? . 6 Link to comment Share on other sites More sharing options...
ShawnEastTN Posted January 13 Share Posted January 13 Anyone else feel like there’s an opportunity for someone in the valley to over perform? .Absolutely! I think there will be a long band that over performs by potentially several inches. 4 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 1 minute ago, PowellVolz said: Anyone else feel like there’s an opportunity for someone in the valley to over perform? . Not quite there yet, but chance (maybe). What's something else that has to get pushed out? The low level moisture that also banks up to the mountains. Sometimes it gets pinched and trapped, especially across NE TN and Central foothills. Lucky to pick that up on modeling 12-24 hrs out. 3 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 Absolutely! I think there will be a long band that over performs by potentially several inches.Yes I agree. I think someone in this area…... 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 23 minutes ago, John1122 said: The GFS starts out the same as the hi-res models but narrows the QPF field way more than they do as the run wears on. Not sure why that is. Resolution issue...Globals have a hard time picking up low level moisture as time goes out...kinda like how the precip shield will typically fill in on the NW side on a LP as the event gets closer. 4 Link to comment Share on other sites More sharing options...
*Flash* Posted January 13 Share Posted January 13 34 minutes ago, Mrwolf1972 said: 18z GFS stays south but anemic Sent from my SM-S916U1 using Tapatalk Theme of the day: It depends, haha. One thing I can appreciate with these threats: For west/middle TN, the microclimatology is relatively less complex compared to east TN. Plenty of secondhand learning with many on here on or east of the plateau. That’s a silver lining when these threads emerge. P.S. The ICON from earlier was only mentioned in passing for having the most coast to coast purple. In Union City traveling today and my car is already white from the salt, lol. 3 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 Not quite there yet, but chance (maybe). What's something else that has to get pushed out? The low level moisture that also banks up to the mountains. Sometimes it gets pinched and trapped, especially across NE TN and Central foothills. Lucky to pick that up on modeling 12-24 hrs out.That’s a great point. The exact flow or stream of moisture (direction) would probably determine which micro climates could come into play. . 1 Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 13 Share Posted January 13 I'm worried about mixing in Sevier County. RGEM, ICON, HRRR, NAM, NAM3K, even the 18z GFS show a possibility of this. Really want a FV3 type of solution with all snow, but am afraid that possibility is beginning to fade. Still a lot of time for change, but after so many disappointing winters/setups, I am greedy for snow. 2 Link to comment Share on other sites More sharing options...
AMZ8990 Posted January 13 Share Posted January 13 winter storm warnings now up in west Tennessee 4 Link to comment Share on other sites More sharing options...
*Flash* Posted January 13 Share Posted January 13 I so want to buy this... 6 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 21z NBM...and likely has the lower 12z (further south) suite. I don't think it will have 18z until maybe 3-6 hours from now(1-2 runs). New is on the left..... 1 4 Link to comment Share on other sites More sharing options...
Silas Lang Posted January 13 Share Posted January 13 21 minutes ago, TellicoWx said: Resolution issue...Globals have a hard time picking up low level moisture as time goes out...kinda like how the precip shield will typically fill in on the NW side on a LP as the event gets closer. Maybe a dumb question, but is low level moisture impacted by ground moisture? I just say this because I remember some time ago reading about it, but forget the exact science behind it. 1 Link to comment Share on other sites More sharing options...
Tucker1027 Posted January 13 Share Posted January 13 What rates are we looking at with this system? . Link to comment Share on other sites More sharing options...
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