Daily Archives: December 21, 2017

Time posted: 7:34 pm

Thursday Evening Thoughts

Good evening, everyone. I don’t have a ton of time, but I wanted to drop by and talk about the wild weather for the upcoming Christmas weekend. From heavy rain and possible flooding, to some light snows, it’s a busy one.

The high water threat is  real and we have a Flash Flood Watch for areas of central and south central Kentucky…

That may be expanded later tonight into Friday as we see where the heaviest axis of rain sets up. Here’s my current rainfall forecast…

Watch the creeks and streams, especially Friday night into the first half of Saturday.

Cold air sweeps in, leading to a massive drop in temps from northwest to southeast. Some wet snows will try to mix in across the north and northeast late in the day.

I still likely the light snow maker coming in for Christmas Eve into Christmas morning. Can we get this thing to put some snow on the ground? Yep. Here’s my current “odds” map…

The last two runs of the GFS Ensembles show the spread across our region. You can see that well on the individual members…

12z

18z

Even the NAM is now picking up on the Christmas Eve light snow.

I will have another full update later tonight. Have a good evening and take care.

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Time posted: 12:30 pm

The GFS Comes Around

Good afternoon, folks. The GFS Model has totally caved to a similar solution to what the European Model has been saying for days: Light snow sweeps across the state Christmas Eve into Christmas Morning.

We will get to that in a moment, but we have some wild stuff coming before then.

Heavy rain moves in on Friday and carries us into the first half of Saturday. A general 1″-3″ of rain is likely for most of Kentucky, with locally higher amounts…

That can be enough to cause local high water issues Friday night and early Saturday. Let’s keep a very close eye on that.

As the cold air pushes in on Saturday, it may catch the rain shield, switching it to a period of mix and light snow in the north…

The Christmas Eve system has been on the Canadian and European Models for some time now. The GFS had this several days ago, then lost it entirely.

My earlier post showed the European Model at 500mb and the system digging right on top of us. The GFS is now showing the same thing…

That produces a tremendous amount of lift on the nose of that system, leading to precipitation breaking out. The GFS now looks a lot like the European Model at the surface…

That’s still likely playing catch up, but produces light accumulating snows for many…

Again, that may still get a little juicier over the next few days.

At the least, it appears we have light snow and flurries coming for Christmas Eve and Morning. We also have the chance to put snow on the ground during this same time. Ho Ho Ho!

There may be another disturbance zipping through here on Tuesday, bringing another light snow chance…

The models also continue to take turns offering up something like this by the end of next week…

I will update the Christmas Eve snow threat on WKYT-TV starting at 4. You will also get a fresh update on here later this evening.

Make it a good one and take care.

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Time posted: 2:01 am

It’s A Christmas Weekend Model Fight

Good Thursday, everyone. We are just about to the big Christmas weekend and it’s looking more and more like Mother Nature and Old Man Winter are going to combine to cause travel problems. From a local high water threat to the potential for snow, the big weekend has it all. That includes an epic battle between the GFS and European Models.

In the short-term, temps are going to climb today as a warm front lifts to the north. While the day looks mainly nice, I can’t rule out some late day sprinkles or light showers…

A cold front works into the region on Friday and slows down. That’s when a wave of low pressure develops and works across the state, bringing very heavy rains through early Saturday. The potential is there for a general 1″-3″ rainfall for much of the state, with locally higher amounts.

The NAM is showing the hefty totals…

Cold air crashes in on Saturday, with the potential for a wintry mix of a switch to snow in the west and north. The NAM shows a decent swath over in the north late Saturday…

The European Model doesn’t get quite as cold as the NAM or GFS and keeps it all rain through Saturday. Look at the extensive rain amounts showing up…

Those numbers would be enough to cause high water issues to develop Friday night into Saturday. That’s something we are going to have to follow very closely.

Colder air continues to pour into the region behind the departing rains, setting up an amazing model battle between the European and GFS models for Christmas Eve and Day. The European has been steadfast in showing a swath of accumulating snows across our entire region, while the GFS refuses to show anything.

The European Model is a little more amped up than earlier runs…

Here’s the snow map from that particular run…

To see why the European Model is so much different than the GFS, just look at what’s going on at 500mb. Check out this potent upper level system aimed right into the Ohio Valley…

That’s a lot of lift on the nose of that system. The GFS is much flatter with that, and doesn’t dig it in very much. That’s why you only see a few flurries or a touch of light snow on the GFS…

It’s interesting to note, the individual members of the GFS Ensembles show much better snow chances than the GFS does…

The Canadian Model is more similar to the European Model, but gets the upper level system to dig just a littler farther north and east of us…

That’s a lighter brand of snow than what the European Model has, but the theme is similar.

Moral of the story, the option of Christmas Eve and Christmas morning snows is still very much alive. Let’s see what the models show later today, and if we end this model fight once and for all.

After this headache of a forecast comes later next week. The GFS is all rain and 60, the European Model is light snow with arctic cold keeping the storm track across the deep south, and the Canadian looks like this…

Make it stop!!! 🙂

I will have updates later today, so check back. Have a great first day of winter and take care.

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