Jonathan Hunter @chattwjonathan@qoto.org

Overhead shot of the train derailment in Collegedale - from r/chattanooga

Train derailed in Collegedale, Tennessee this afternoon. 2 injuries reported. Cause under investigation.

https://www.local3news.com/local-news/train-derailed-in-collegedale-nearby-roads-closed/article_1a64ea2e-8094-11ed-a636-7b7a28a38f94.html

One of the funny things about being a meteorologist is that on a day like today, I was buried deep in Artic chill forecast graphics.

But when I step outside, my body is prepared for cold instead of 45 and sunny, a very regular December day in Tennessee

Chattanooga Friday Travel weather in one graph.

#TNwx #chattanooga

My travel plans for Christmas originally included leaving on Friday to drive from Tennessee it Ohio.

However, with the incoming winter storm, I will be changing my plans to Thursday. While I don't expect snow or much of it here on Friday, what I do expect is cold rain and increasing winds here - and a higher liklihood of snow further north.

Change your plans if you need to and check your winter preparedness checklists.

#TNwx #chattanooga

"Hey Google, play Alvin and the Chipmunks!" - 6yo

Update for SE Tennessee and chances of snow before Christmas

Snow chances are down a little bit through Christmas for Chattanooga. Not exactly a surprise for us, as weather models update with better information, and the GFS model has trended towards a different solution. For more on some of these developments, read this post from yesterday written by much a more adept person than I!

https://twitter.com/burgwx/status/1604258544831774722

That's not to say we drop to 0. In fact, we still have the same 3 threats, they've just evolved. Still individual probabilities are probably still around 40% that one of these giving us snow to see, which is again much higher than usual!

1. Monday Afternoon-Midnight

This storm has evolved in to more of a 'Split' storm with a northern and southern component, because the energy isn't quite meeting up properly. Northern Component goes off the Ohio Valley with snow. Southern component is mostly rain, but a chance of some snow on the northern side here. Again low chance of accumulation, but less now.

2. late Thurs/Fri

The GFS has started to become more consistent in making this a storm that digs deep...but ends up with the Low center staying inland and the ECMWF has more agreed with this solution, this this is where I'd lean. Mostly just rain on the front side from what it looks like, but a sweeping cold front would put light snow on the mountain tops, mostly west of the city. Still lots of possibilities.

3. Christmas Day

Energy is still showing up, but it's losing strength by the time it gets to Tennessee. will have everything to do with the prior storm.

#Weather #TNwx #WhiteChristmas #chattanooga

The weather for most of the country has calmed for this weekend, and cold air has settled in to much of the country.

There is a LOT of variability this coming week with what could happen through Christmas, but there are 3 vague potential snow threats for SE Tennessee / Chattanooga showing on the Wx Models!

Don't get to excited yet, because I'm just highlighting the potential. Fair chance that NONE of these materialize, but I'll list out the triple threat that I see, and my current thinking. Individual probabilities are low, but I'd say cumulative chance of seeing any snow in the sky through Christmas day might be as much as 60% right now, which is way higher than usual!

1. Monday afternoon - midnight - ish.

This has shown on most of the weather model runs for the last 2 days. However, it's unlikely to bring accumulation. Cold air being pushed out as we get under a warm front for a quick changeover event.

2. Thursday / Friday - ish

This even has shown on GFS for multiple days - and has been more well signaled than the other. However, the details swing wildly from run to run, showing the high variability. This is the long wave with MUCH higher potential for...well everything. But certainly out there to be a big bust too! Expect...something, but don't bank on snow. This will be a HUGE travel interrupter for the eastern part of the U.S. so be ready.

3. Christmas Day

This has actually shown up on the last few model runs as well, as consistent snow from a shortwave. Don't bank on it - it's way way too far out, but most of the runs dig cold air deeper after the prior storm, and I'd put it in to the plausible category.

#Weather #TNwx #whitechristmas #chattanooga