Daily Archives: November 24, 2017

Time posted: 5:01 pm

Friday Evening Update

Good evening, everyone. Nice weather continues for Holiday travelers and all those Black Friday shoppers out there. It looks like the pattern remains calm for the rest of the weekend, even as a cold front drops in from the north. The longer range battle continues between the cold and mild signals.

Saturday is a very windy day with a cold front zipping in from the north. This doesn’t have much moisture with it, so any rain chances are very small.

Colder air comes in behind this for Sunday, with the coldest highs across central and eastern Kentucky. Here’s the NAM…

The models keep a few flurries flying awfully close to eastern and northeastern parts of the state…

Those chilly winds will mild up on Monday, as another southwesterly push of air moves in. Temps will then be mild through the middle of the week, but a bowling ball of a system moves in here by Thursday and Friday…

As you can see, it does tap some colder air into our region as it passes through here. Can that throw  wet flake into the rain at some point? Meh… We shall see.

Temps rebound behind that, but the cold signals I’ve shown you of late continue like they will win the battle as we head into December. It’s rare we get every single set of Ensembles to show the exact same setup, but they are doing that late in the first week of December.

Notice all the blocking over the top, with a deepening trough across the eastern half of the country…

European Ensembles

European Control

GFS

Canadian Ensembles 7 day average centered around the same time…

That’s pretty wild to see every single Ensembles package showing almost the same look across all of North America. This happens as our blocking signals actually grow stronger, while the current mild signals grow weaker and even disappearing. If they go away entirely… Look out.

Have a great evening and take care.

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Time posted: 1:58 am

A Weather Fight Brewing

Good Friday to one and all. We have a heck of a weather fight taking shape amongst the weather indicies I look at from across the globe. It’s a battle between cold and mild signals that will have a huge impact on our weather over the next week or so.

I will get to that in a bit, but let’s talk about the short-term forecast first.

Today is a windy and milder day with temps in the 50s for those holiday shoppers. Gusty winds continue into Saturday as a weak cold front drops in from the northwest. This may touch off a shower or two, with wind gusts hitting 30mph at times.

Blustery winds knock our temps back into the 40s on Sunday, but another big wind change comes back early next week. That’s when we focus on a system rolling in from the plains states. The models show a bowling ball type system, with colder air behind it…

The European is similar, but with more in an interesting look…

I mentioned in my earlier posts about a big weather fight brewing amongst the various indicies I look at. We have some pointing cold, with some pointing mild over the next week and change.

In the cold corner, we have the AO and NAO. Both are forecast to be negative into early December…

 

Usually, that’s a healthy signal for significant cold across the eastern half of the country. But, we find the signals in the Pacific are fighting the blocking signals showing up. Look how positive the forecast is for the Western Pacific Oscillation…

 

The Eastern Pacific Oscillation isn’t as positive, and takes on more of a neutral look by early December. The WPO signal is usually a mild one for the eastern half of the country.

In recent years, I’ve been trying to learn more and more about the Madden-Julian Oscillation (MJO). The MJO is basically an index tracking the tropical precipitation anomalies, generally in the Indian and Pacific Oceans. The placement and intensity of the MJO plays a big role in the overall weather across North America. The current MJO forecast is for it to enter into Phases 3, 4 and 5 over the next 2 weeks…

European

GFS

There isn’t much amplitude on either of those forecasts, and the lower the amplitude, the weaker the impact it has on our weather.

The various phases of the MJO give us different temperature and precipitation outcomes for the country, depending on the month of the year. The temperature composites for this time of year show a milder look for phase 3, with a weakening of that into Phase 4, with a colder look as it enters phase 5…

Again, though, the lower the amplitude of the MJO, the less of an impact it has on our weather and can be overridden by other forces like the NAO or AO.

The GFS keeps showing the cold signals winning the battle as we head into December. Watch the troughs dig in…

I will have updates later today, so check back. Make it a good one and take care.

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