Daily Archives: December 17, 2017

Time posted: 8:02 pm

Wrapping Up The Weekend

Good evening, folks. Our half and half weekend is drawing to a close with a lot of ugly out there. As we look ahead to the next week and change, there’s a lot more ugly on the way. This all takes us up to a very complicated forecast for our Christmas weekend.

There are some complications before that, and they may have implications on how all that plays out. Confused? Me too.

Low clouds will spit our a few showers over the next few days, but a much stronger system shows up by Wednesday. The European Model has been all over this for a while, but the other models have been hesitant to bring this wet weather maker into Kentucky.

The European Model shows heavy rains across the southern half of the state on Wednesday…

The NAM has been similar in recent runs…

The GFS wants no part of bringing rain into Kentucky…

The GFS Ensembles don’t even agree with the operational GFS, instead, they look more like the European and NAM for Wednesday…

I’m showing all this because, even in the shorter term, we are finding the models having a tough go at figuring out what to do. If we can’t get them to agree on the Wednesday system, how on earth do we expect them to figure out Christmas weekend and Christmas week? The answer to that is… I don’t.

That’s why you are getting zero forecast flipping and flopping from me, because every single run of every single model looks drastically different from the run before.

For fun, here’s the latest GFS…

That looks exactly ZERO like the run from 6 hours earlier, which looked ZERO like the run 6 hours prior to that.

I like to look at every available piece of model guidance for any forecast, not just in the winter. Sometimes the more obscure models can offer some trends or lend support for other models. One of the models I look at is the JMA. Christmas Day is just now within the window of the model, and it shows a major arctic high invading the country, with a wave of low pressure riding up the eastern slopes of the Appalachian Mountains…

You’re looking at barometric pressure and not temps on that map.

I will keep with my original thoughts that are now a week old: Every mode of precipitation is on the table for Christmas weekend into early Christmas week. Rain, snow, ice or a combo of the three are all possible. Your Christmas may be wet or it may be white, or you may get both. It’s still way too early to tell.

I will have my normal update later tonight so check back. Have a great evening and take care.

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Time posted: 2:21 pm

Sunday Afternoon Update

Good afternoon, everyone. It’s a dreary day across the bluegrass state, with chilly showers dotting our sky. The leading edge of the showers even had a little sleet thrown in for good measure. The active pattern leading up to Christmas is still the top weather headline, but the final headline is a long way from being written.

This afternoon’s showers continue to press through here and are pretty light…

Isolated showers will hang around over the next few days, with our middle of the week system continuing to trend wetter.

The NAM has now joined the European Model in showing a healthy rain event for parts of the region on Wednesday…

Similar to today, the northern edge of that may begin and end as a touch of sleet.

The Christmas weekend systems continue to show up differently with each computer forecast model run. The past two runs of the GFS show this point well. The 6z run trended colder with the initial system Friday into Saturday, then showed our Christmas Eve and Christmas Day system coming together as a snow maker…

Check out that 1064 arctic high showing up behind all that. Wow.

The GFS from 6 hours later looked totally different, even losing the big arctic blast behind it…

The Canadian Model has been lost in the woods with it all, but is, at least, getting the trend right of two systems…

The European Model also continues to bounce back and forth between extremes. The last run had the cold overwhelming the pattern, killing any kind of storm system. The new run holds some energy back, leading to a prolonged period of heavy, overrunning precipitation…

That’s likely keeping the cold too far to the west, but still results in this for Christmas Night and Tuesday…

The low-level cold air is typically shown too far west on forecast models.

Regardless, you’re seeing the back and forth on all the models as they continue to try and figure out exactly what to do.

I’m still riding this almost week old map and think it’s in excellent shape…

Looking farther down te road… The CFS 5 day temperature anomaly maps (In Celsius) show one heck of a push of cold that hangs tough into January.

Here’s the period for Christmas week…

Here’s the 5 days around the New Year…

It stays cold deep into the New Year…

I will have another update this evening. Enjoy this fine Sunday and take care.

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Time posted: 1:58 am

An Action Packed Pattern For Christmas

Good Sunday, folks. Light showers are working across the state today, kicking off a very active setup for the coming few weeks. This action packed pattern is likely to really kick it up a few notches as we head into Christmas Weekend and Christmas week, with winter weather very possible.

Let’s begin with today’s showers, then begin our look ahead. This isn’t a lot of rain working across Kentucky, and it may only dampen the ground for some areas. Still, it’s likely to be a rather gloomy Sunday…

The threat for showers continues for the next few days, with temps at or a little above normal. There’s a stronger system across the south by the middle of the week, and the European Model brings this right into our region…

That looks a little too wound up for my taste, and may be a product of the European being too slow with energy ejecting from the southwest.

The pattern after that will feature a strong cold front rolling into the region on Friday. This will unleash a pattern that can feature waves of low pressure developing and rolling northeastward along a stalled out boundary. Exactly where that boundary sets up is still a mystery.

That scenario can bring rain, snow, ice or a combination of the three from Friday through Christmas Day. I’m going to continue to ride this map I put out last Monday…

I’m hopeful to be able to get a little more specific with that map later today or Monday.

The GFS wobbles from run to run on exactly how everything shakes out, but it continues to bring a significant winter weather threat to our region. The model is settling on two waves of low pressure. The first coming along the front on Friday with rain to some snow. The next wave comes Christmas eve and Day, with the current run showing snow across the east…

Here’s the snow map from that run…

The ice map is significantly lower with this run…

The European Model is similar to the GFS with the Friday system, but can’t seem to find the Christmas Eve and Christmas Day system. The setup on the model appears ripe for much more moisture than it’s currently showing. Just look at the bitter cold coming in, with the mild air across the southeast…

I highlighted the area where the Euro should be showing more precipitation.

Regardless, The European and GFS show the bitter cold taking control of much of the country Christmas week.

The Canadian Model continues to be on its own and has no idea what to do with any of this…

Again, these models will continue to flip and flop with each run for the next few days. One run may show a foot of snow, followed by the next run showing all rain or vice versa. I still cant tell you if your Christmas will be white, wet or both

Updates come your way later today. Have a great Sunday and take care.

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