Carvers Gap Posted January 13 Share Posted January 13 The NAM looks pretty reasonable through 45, and then almost looks like feedback issues get it at 48. "Reasonable" meaning that it is in line (northwest edge of guidance) of other modeling. Precip pushes further east. It is adjusting (as short range models do) to real time trends. Thus, it moved some eastward. Still not with other modeling, but getting there quickly. Again, I do expect the SE jog to stop at some point and other models(not named NAM) to begin trending NW...maybe that begins later today. 2 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted January 13 Share Posted January 13 1 hour ago, tnweathernut said: Yesterday, I was reading some on another forum covering the Chicago snow (can’t remember where I saw it), but was talking about the NAM being the only one not on board with a major snow). It ended up beating all the other models. I think that might have been a situation where it was modeling the thermals impacted by a relatively warm Lake Michigan, if I remember correctly, so that some of the Chicago suburbs got skunked closer to the Lake. But it still could be on to something else here 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 NBM update....This is almost a slider. 9z to 12z NBM trends are to lift the SW edge(Memphis) by roughly ten miles and drop the NE edge(TRI) by roughly the same. It is flattening it out. 1 Link to comment Share on other sites More sharing options...
Bigbald Posted January 13 Share Posted January 13 RGEM rock solid run over run. Would be east TN best case scenerio. 3 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 The 3k NAM trend to the SE was even more substantial than the 12k NAM. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted January 13 Share Posted January 13 I don't know it didn't look too different to me between 9 and 12z even has a Knoxville dollop 12z on left, 9z on right 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted January 13 Share Posted January 13 That is the NBM, just so there's no confusion with the previous posts 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 12z HRRR...I know voodoo land for it lol Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 7 minutes ago, Holston_River_Rambler said: I don't know it didn't look too different to me between 9 and 12z even has a Knoxville dollop 12z on left, 9z on right There is a slight difference there for sure. Take a look at snow totals in Memphis and precip totals at TRI. If you toggle it back and forth(use the mouse function on wxbell and not side-by-side) you can see it very slightly see-saw. The west side lifts just a hair and the east side drops - talking maybe 10-15 miles. Just means that modeling is ever-so-slighlty still trending flatter. I expect it at some point to rebound a bit. 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 And it should be noted that some of what we see is "noise" or just wobbles as things focus. The NBM can trend very slowly as it should(it is a blend). It takes longer to turn that "aircraft carrier." I don't use it a ton as it tends to wash out too much, but it is a conservative model which means it will be closer to correct for most places but often miss the higher totaling places. 4 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 For TRI, we are likely going to be battling this all the way to "go time." It is plausible that we could end up on the SE side of the snow axis or NW side of the snow axis or right in the middle. Why? The snow axis is more narrow in our part of the state. Any change in trajectory changes things a lot here due to the angle of that axis and the narrowing band. 2 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 Serious question about the DGZ… obviously I know what it is but what is the depth of it? Is it a shallow layer in the atmosphere or does it continue up into the atmosphere? I guess what I’m asking is… the lack of snow in the mountains, is there ever a situation where Mt Leconte could be above the moisture feed?. Link to comment Share on other sites More sharing options...
fountainguy97 Posted January 13 Share Posted January 13 1 minute ago, Carvers Gap said: For TRI, we are likely going to be battling this all the way to "go time." It is plausible that we could end up on the SE side of the snow axis or NW side of the snow axis or right in the middle. Why? The snow axis is more narrow in our part of the state. Any change in trajectory changes things a lot here due to the angle of that axis and the narrowing band. Yep it's a fine line. Not feeling good for me. I'm basically as far east as you can get haha this is one of the times the mountains won't help me. Hope I can at least get an inch just so I'm not a full shutout. Hope you guys and the valley can cash in! Seems like Knoxville and south have been left out a lot in recent winters. 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 For those new to tracking winter storms. Trends from this point forward do matter a lot. So the trends we have seen over the past few days: 1. The snow axis has trended southeast as modeling feels high pressure over the top. 2. Precip amounts have gone down. All of that is normal. Also, the cold is now in western Montana and the energy is being sampled properly as it is over the US mainland. Short range models are amped a bit. Trends will matter on both short range and deterministic. The good thing is that it looks like some areas (maybe many) are going to see wintry precip. How much? I suspect the NBM is going to be close. As for the eastern valley? Lots of uncertainty in my mind. Trends at 6z were good. But sometimes what looks like a good pattern is just a ship passing in the night. 12z and 0z trends are going to be really important. (I may stay up late tonight...)If modeling continues to trend SE, then mountain counties are in business. If modeling(not name the NAM) begins to jog back NW....it may be tougher. Honestly, if I was in western North Carolina, this is a big model suite. They have slowly crept into the game. 4 Link to comment Share on other sites More sharing options...
fountainguy97 Posted January 13 Share Posted January 13 8 minutes ago, PowellVolz said: Serious question about the DGZ… obviously I know what it is but what is the depth of it? Is it a shallow layer in the atmosphere or does it continue up into the atmosphere? I guess what I’m asking is… the lack of snow in the mountains, is there ever a situation where Mt Leconte could be above the moisture feed? . Mountain counties are warm nosed. Rain/freezing rain. On rgem atleast. It's not a qpf problem or anything. It's temps. In fact, the rgem warm noses a larger portion of ETN this 12z all the way through Johnson city. 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 The 12z RGEM for sure cuts snow totals almost forum wide. As I thought, it jogged about a county(county and a half) back northwest with totals. The SE trend w/ the RGEM has stopped. Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 Mountain counties are warm nosed. Rain/freezing rain. On rgem atleast In fact, the rgem warm noses a larger portion of ETN this 12z all the way through Johnson city.Is the warm nose from WAA or because the depth of the cold hasn’t spread that far east yet? . Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 The 12z RGEM also continue the trend of flattening-out the NE side of the storm. Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 3 minutes ago, PowellVolz said: Is the warm nose from WAA or because the depth of the cold hasn’t spread that far east yet? . Downscoping IMO. The NAM has a warm nose(RGEM is more downslope), but mountain counties up this way tend to downslope big time w/ a slp to the SE. Winds coming down the mountain compress the air and warm it up. 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 Downsloping near the mountains has a tendency to also reduce precip amounts as it is sinking air. Rising air has to release moisture which is why it is good to have lift. Sinking air does the opposite. The winds in this set-up often are out of the east. 2 Link to comment Share on other sites More sharing options...
tnweathernut Posted January 13 Share Posted January 13 10 minutes ago, fountainguy97 said: Mountain counties are warm nosed. Rain/freezing rain. On rgem atleast. It's not a qpf problem or anything. It's temps. In fact, the rgem warm noses a larger portion of ETN this 12z all the way through Johnson city. I feel attacked here……. lol 1 2 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 2 minutes ago, Carvers Gap said: Downscoping IMO. The NAM has a warm nose(RGEM is more downslope), but mountain counties up this way tend to downslope big time w/ a slp to the SE. Winds coming down the mountain compress the air and warm it up. Add that with rates slightly weaker and end up with drizzle here (freezing drizzle a lot of the time) 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 But we take this 10/10 times. With this falling into cold air, the rates are likely to be very good. Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 The 12z RGEM also continue the trend of flattening-out the NE side of the storm. Looks like Knoxville is still ok with the RGEM. (For now). Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 1 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 The HRW mods… don’t they have a NAM influence to them? They are much further SE than the NAM. More in line with the RGEM. . 1 Link to comment Share on other sites More sharing options...
TellicoWx Posted January 13 Share Posted January 13 12z ICON shift SE..models are consolidating 1 Link to comment Share on other sites More sharing options...
PowellVolz Posted January 13 Share Posted January 13 Update from MRX…. 3 Link to comment Share on other sites More sharing options...
John1122 Posted January 13 Author Share Posted January 13 ICON keeps things pretty steady, it may be wrong but it's remarkably consistent. 2 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted January 13 Share Posted January 13 Kind of an interesting comparison between the RGEM and NAM at 12z. For me, I prefer the RGEM beginning at 0z tonight or 12z tomorrow - meaning it is about in range where I trust it but not quite yet. That said, modeling isn't too far off. You can see possible feedback on the NAM in E KY. However, prior to that in west TN, it looks reasonable. The rest of 12z should clean-up these differences. Link to comment Share on other sites More sharing options...
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