Holston_River_Rambler

At least it's something

I think I might throw out a thread for Sunday. I think tnweathernut was suggesting that. At the very least we'll have a discreet place to pop some obs if it over performs.

From just a pure model watching standpoint, it seems like we've had a lot of trouble this winter from models struggling with speed and evolution of shortwaves in the NW flow over western ridges. It happened with the storm last week: The timing, press, number, trajectories, and evolution of these shortwaves is just giving NWP fits, even right up to go time. See above. We have a nice STJ but it just gets squished by those stout shortwaves to the north, more times than not. If one of those can drop down and tap into it it'll have a lot of juice, as some recent model runs have shown, but models just cannot seem to resolve those shortwaves at any sort of range. Kind of a weird, twitchy gif here, but just give it a watch: Notice how between 50 and 100 hours the GFS (just chosen for ease of use on TT) does a pretty good job with the longwave features. Big ridges, big troughs are fairly stable. But now look closer at the individual vorts in those ridges and troughs. They are jumping around a lot. Add that weird cutoff mess off the CA coast and you have model problems with finer details. We often talk about better obs and data from the RAOB network and yeah, we 100% have much better satellite data than at any time in the past, but even with better data (and I don't know if there are other non-public satellites at play here) some of the sat. imagery just isn't as...continuous? over the polar region: It's probably hard to have a sat. in geosynchronous orbit there, to be fair, but that can't be helping resolving shortwaves north of the arctic circle, can it? And you can't tell me that is as crisp and clean and detailed as good old GOES 17, 18, 19, or even the Himawari 9: I'm not advocating for a bust or boom next week here, but offering an explanation for some of the model frustration.

We desperately need thunder Friday night.

It gives you point and click meteograms too: https://charts.ecmwf.int/products/medium-simulated-vis?base_time=202501151200&layer_name=sim_image_vis_ch1&projection=opencharts_north_america&valid_time=202501250600

Thanks to the magic of Euro AI we can now live in the make believe world of visible satellite imagery. 12z AIFS, next Tuesday through Saturday:

EPS snow swaths:

Not necessarily related immediately, but I was looking at the upstream over the Pac to try and see some of these features and man, what a split flow:

That would be ideal

CMC pay me now GFS pay me later

6z GFS phase was beautiful. Very mindful. Very Ehh, a little demure. Puts me in the mind of something else, as anyone who knows me a little probably can guess

I think something like 24 out of 50 0z EPS members show a nice stripe of snow either over SE TN or one to two hundred miles south. Approximately (what each person considers a big dog is subjective) 10-15 of those look like big dogs with all the colors we like to see on snow maps.

That was a pretty good miller A on the Euro

GOES 16 Day cloud phase snowfall imagery this PM:

Yeah I was about to add to my above post we might want it 300 miles further SE at this stage.

That was definitely a run of the Euro for the 20 - 22 lol.

Here is a graphic for both up and downsloping. It is a little more dramatic in the graphic than what we see in East TN, but the general idea is there. Here is the local view red = higher elevations, green circle = valley

One thing I also noticed about the whole stomr yesterday was that as the now infamous snow hole was forming east of Nashville the snow was intensifying as clouds where thickening to the north over Ohio and Michigan: Early hours of yesterday morning, just as the storm was approaching east TN: Everything looks like it is a go. Watch what happens later that morning into the early afternoon: It looks to me like the upper low dropping in over Minnesota starts to drop in creates more forcing up that way. The strengthening jet does try to help later, but ultimately there's a dryslot disconnect between the southern moisture and the much more wound up ULL to the north. Euro was emphasizing that ULL feature a lot more than the GFS.

Just saw something interesting in the upslope flow satellite and radar. Some little lee side meso vortices formed as snow bands moved into the eastern valley from the Cumberland plateau and hugher elevations of SW VA: The most pronounced one to me moves from just south of Cumberland Gap toward Greene County:

6z Euro AI is a great example, but pretty much any major global model is showing some variation: Boundary sets up and each wave drags it a bit further south.

I'd say better than average after the 21st, as it stands now. Models have been consistently showing an arctic boundary pressing SE and waves running along it. The only question is timing everything out. Some runs have big hits, some nothing. Big upsides and nothings:

State of the state:

Pretty good rates now for me.