Daily Archives: December 18, 2017

Time posted: 7:28 pm

Updating The Mess Ahead

Good evening, everyone. We continue to see the ugly weather, with a lot more on the way. We have, at least, 3 different systems we will be tracking between now and Christmas Day. These systems take on a full blown winter look as we head into Christmas weekend. I’ll get to that in a moment.

Let’s start with the system rolling in for Wednesday. This is a heavy rain maker for much of the state, with southern Kentucky picking up 1″+ of rainfall. The future radar from the HI-RES NAM shows the possibility for some late day flakes mixing in…

Here’s where that run thinks has the best chance of seeing the flake action…

The new GFS is similar…

I’m not sold on the flakes, but the chance is increasing as we inch closer.

Our strong cold front then arrives on Friday with a wave of low pressure riding along it. This should bring heavy rain across Kentucky, with cold air trying to catch the back edge by Saturday morning. That could mean a switch to a mix of some snow.

That front then slows down over the weekend, with another wave or two of low pressure developing along it. The European Model continues to edge all this a little farther east, as it slowly loses the bias of holding too much energy in the southwest…

Taken verbatim, that run shows rain to ice to snow Christmas Eve into Christmas Day…

Here’s the snow map from that particular run…

The European is doing exactly what we talked about, and is slowly trending colder and farther east with the axis of winter weather.

The new GFS is still much flatter with that setup, as it now shows bitterly cold air crushing the pattern. Still, the model has a swath of light accumulating snows for Christmas Eve and Morning…

Once again, the bias of that model is to be a little too far east and flat with such systems. That said, the above scenario is certainly plausible. I’m more concerned about the cold pushing systems to our east, than any system wrapping up and going to our west.

That same run of the GFS has the polar vortex moving in here by Christmas night. Look at the 850mb temps…

Look at the low temps coming from the GFS for Christmas night…

That basically shows a repeat of Christmas week of 1983.

It’s interesting to note, the European Model has similar lows just a few days later…

The NAVY Model is farther east and wetter. This animation does not show precipitation type…

I want to be clear, these are only models we are looking at and they will all change from run to run. It’s still way too early to give anything specific on what kind of precipitation or how much. All I’m doing is breaking down the models and showing how they are looking a lot like the pattern we’ve been talking about on here.

If you want to see a country going into the Ice box, look at the GFS Ensembles temperature anomalies in Celsius through early January…

I will see you guys back here for another update later tonight. Enjoy the evening and take care.

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Time posted: 12:16 pm

Monday Afternoon Update

Good afternoon, everyone. It’s another dreary day in the bluegrass state, with low clouds and a few showers on the move. The action is about ready to pick up in a big way later this week, with all eyes on the potential winter weather threat for Christmas weekend and Christmas week.

Before we get to the weekend, we have to keep a close eye on the big rain maker impacting parts of the state on Wednesday. This system continues to trend wetter and colder as we get closer, with several models now indicating the potential for a mix or a brief switch to snow late in the day. The HI-RES NAM has this showing up across parts of eastern Kentucky…

The NAM is even printing out the potential for light accumulations in some areas. We shall see, but that’s a system increasing as we get closer. It can also put down an inch or more of rain across southern Kentucky.

The weekend setup continues to slowly evolve on the models. We get the first front to work in here Friday, with a wave of low pressure developing along it. Heavy rains are a good bet with mild temps on Friday. The cold air then presses in Friday night, with the potential for a switch to some snow or mix…

As the front slowly presses to our east, it becomes stationary. Exactly where this happens and exactly where waves of low pressure develop, will be the determining factors on our Christmas Eve and Day weather. All modes of precipitation are still on the table during this time.

The Canadian Model shows a possible healthy winter weather event around here, as it takes a wave of low pressure right up the east slopes of the Appalachian Mountains. Here’s the animation of both systems for the weekend…

The GFS has a similar thought, but is likely too flat with the wave of low pressure…

Knowing a thing or two about the GFS and it’s bias, watch for that system to become stronger, with more precipitation showing up on the cold side.

The current trend on the models continues to bode well for this week old map I made…

I’m going to ride that map until you guys are sick of it… If you aren’t already! 🙂

I will have the latest on WKYT-TV starting at 4pm and will have another update this evening.

Make it a good one and take care.

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Time posted: 2:06 am

A Complicated Christmas Weekend Forecast

Good Monday, everyone. It’s hard to believe we are one week away from Christmas. As we get closer to the big day, the complicated weather pattern should start to become much more clear. As of now, it’s still loaded with a ton of potential and a ton of question marks.

In the run up to Christmas weekend, the pattern is very active. We have lots of clouds out there today, with a scattering of showers a good bet. Temps will be a little higher than what we had on Sunday, but not by much.

Tuesday’s weather may look and feel a lot like what we have out there today. Gloomy is the word of the week, apparently.

Our possible Wednesday rain maker comes from an increasingly strong southern system. It’s a system the models really didn’t start picking up on fully until the past few days. We have been seeing a split with some models bringing good rains into Kentucky, with others keeping the rains to our south.

The new NAM continues to show southern Kentucky getting in on the rain…

The GFS has now given in and joined the party…

There’s the chance we could see a touch of sleet with that setup on Wednesday, especially on the northern edge of the rain.

This brings us to the pattern for Christmas weekend, and it’s one that’s quite potent and energetic. Bitterly cold air will dive into the country, with some semblance of a southeast ridge trying to fight it. This duel is giving the computer forecast models fits, but these fits should be ironed out over the next few days.

The new GFS takes a potent low into the Great Lakes on Friday, dragging a cold front into Kentucky. As this happens, a wave of low pressure develops along the front, bringing rain then snow in here through Saturday morning…

The cold is much deeper and faster on that particular run, with a switch to snow…

Is this the beginning of the models finally grasping the amount of cold coming into the country? Maybe, but you’re still gonna see some wild swings on the models.

As the cold is deeper and stronger, the GFS then tries to figure out how to handle the energy along the stalled front to our south and east for Christmas Eve and Day…

The bias of the GFS is to be too far south and east with such systems. The European Model can sometimes have too much of a west bias in similar situations.

The new version of the European is for a major overrunning event in our region, starting Sunday and going through the middle of next week…

The low-level cold is already pressing on that run, leading to rain and wintry weather. Here’s the snow map from that particular run…

The ice map…

All I can say is we continue to have the potential for all forms of precipitation this weekend into early Christmas week. It’s still too early to tell which type and at which time, but the potential is certainly real.

This map is now one week old, and I haven’t had to make a single change to it..

I’ll try to get more specific with my updates later today.

By the way, after whatever system we get on Christmas, we are likely to track another system just a few days later. The setup through the New Year is absolutely frigid for much of the country. The GFS Ensembles…

Check back for updates. Make it a wonderful Monday and take care.

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